Article

Hair dye and chemical straightener use and breast cancer risk in a large US population of black and white women

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Abstract

Many hair products contain endocrine-disrupting compounds and carcinogens potentially relevant to breast cancer. Products used predominately by black women may contain more hormonally-active compounds. In a national prospective cohort study, we examined the association between hair dye and chemical relaxer/straightener use and breast cancer risk by ethnicity. Sister Study participants (n = 46,709), women ages 35-74, were enrolled between 2003 and 2009, and had a sister with breast cancer but were breast cancer-free themselves. Enrollment questionnaires included past 12-month hair product use. Cox proportional hazards models estimated adjusted hazard ratios (HRs) and 95% confidence intervals (95% CIs) for the association between hair products and breast cancer; effect measure modification by ethnicity was evaluated. During follow-up (mean = 8.3 years), 2,794 breast cancers were identified. Fifty-five percent of participants reported using permanent dye at enrollment. Permanent dye use was associated with 45% higher breast cancer risk in black women (HR = 1.45, 95% CI: 1.10-1.90), and 7% higher risk in white women (HR = 1.07, 95% CI: 0.99-1.16; heterogeneity p = 0.04). Among all participants, personal straightener use was associated with breast cancer risk (HR = 1.18, 95% CI 0.99-1.41); with higher risk associated with increased frequency (p for trend = 0.02). Nonprofessional application of semipermanent dye (HR = 1.28, 95% CI 1.05-1.56) and straighteners (HR = 1.27, 95% CI 0.99-1.62) to others was associated with breast cancer risk. We observed a higher breast cancer risk associated with any straightener use and personal use of permanent dye, especially among black women. These results suggest that chemicals in hair products may play a role in breast carcinogenesis.

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... [21][22][23][24][25][26] In the Sister Study, we previously reported positive associations of permanent hair dye and straighteners with overall breast cancer risk focusing on use in the year prior to enrollment; associations for permanent dye were notably stronger in black women. 27 In this study, we have expanded on our previous study focused on adult hair product use by investigating the association between adolescent use of various types of hair products and incident breast cancer risk in a large, prospective cohort of women. We hypothesized that breast cancer risk would be highest for women who frequently used these hair products during adolescence and that associations would vary by timing of breast cancer (eg, premenopausal vs postmenopausal breast cancer) and by race/ethnicity. ...
... Other breast cancer risk factors, in particular obesity, have been shown to differ based on menopausal status at diagnosis. 37,38 In our study of adult hair product use and breast cancer, associations did not vary by menopausal status, 27 which supports that the finding observed here is not simply a reflection of continued use of these products in adulthood. It is plausible that adolescence may be a more relevant exposure window for premenopausal breast cancer risk than for breast cancer occurring after menopause. ...
... We previously observed that use of straighteners in the year prior to baseline was associated with an 18% higher risk of breast cancer overall and this association was stronger with increasing frequency of use. 27 Other studies considering the risk associated with hair straighteners have been able to evaluate the risk associated with exposure during childhood or adolescence in addition to adult use. In the Women's Circle of Health Study (WCHS), a case-control study of women in New York, use of relaxers before age 12 and between the ages of 13-19 years was positively, but imprecisely, associated with ER− breast cancer among African-American women 24 ; which is consistent with our finding of a suggestive higher risk for ER− tumors. ...
Article
Hair products can contain hormonally active and carcinogenic compounds. Adolescence may be a period of enhanced susceptibility of the breast tissue to exposure to chemicals. We therefore evaluated associations between adolescent hair product use and breast cancer risk. Sister Study participants (ages 35‐74 years) who had completed enrollment questionnaires (2003‐2009) on use of hair dyes, straighteners/relaxers, and perms at ages 10‐13 years (N = 47 522) were included. Cox proportional hazards regression was used to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (95% CIs) for associations between hair products and incident breast cancer (invasive cancer or ductal carcinoma in situ), with consideration of heterogeneity by menopausal status and race/ethnicity. Over an average of 10 years of follow‐up, 3380 cases were diagnosed. Frequent use of straighteners and perms was associated with a higher risk of premenopausal (HR = 2.11, 95% CI 1.26‐3.55 and HR = 1.55, 95%CI: 0.96‐2.53, respectively) but not postmenopausal breast cancer (HR = 0.99, 95% CI: 0.76‐1.30 and HR = 1.09, 95% CI: 0.89‐1.35, respectively). Permanent hair dye use during adolescence was uncommon (<3%) and not associated with breast cancer overall (HR = 0.97, 95% CI: 0.78‐1.20), though any permanent dye use was associated with a higher risk among Black women (HR = 1.77, 95% CI: 1.01‐3.11). Although frequency of use of perms (37% non‐Hispanic white vs 9% Black) and straighteners (3% non‐Hispanic white vs 75% Black) varied by race/ethnicity, associations with breast cancer did not. Use of hair products, specifically perms and straighteners, during adolescence may be associated with a higher risk of premenopausal breast cancer. This article is protected by copyright. All rights reserved.
... Further, the triple-negative (TN) subtype-associated with the worst prognosis-has the highest incidence among Black women compared to women of other races/ethnicities (DeSantis et al., 2016). Of interest, use of hair dyes and relaxers is a suspected risk factor for breast cancer (Brinton et al., 2018;Cook et al., 1999;Donovan et al., 2007;Eberle et al., 2020;Green et al., 1987;Heikkinen et al., 2015;Hennekens et al., 1979;Kinlen et al., 1977;Koenig et al., 1991;La Vecchia and Tavani, 1995;Llanos et al., 2017;Mendelsohn et al., 2009;Nasca et al., 1980Nasca et al., , 1992Rosenberg et al., 2007;Shore et al., 1979;Stavraky et al., 1979;Stiel et al., 2016;Takkouche et al., 2005;Thun et al., 1994;Wynder and Goodman, 1983;Zhang et al., 2012;Zheng et al., 2002;White et al., 2021), though a causal relationship between this exposure and breast cancer risk has not been established. Most recently, it has been hypothesized to be associated with disparities in breast cancer phenotype (Eberle et al., 2020;Llanos et al., 2017). ...
... Of interest, use of hair dyes and relaxers is a suspected risk factor for breast cancer (Brinton et al., 2018;Cook et al., 1999;Donovan et al., 2007;Eberle et al., 2020;Green et al., 1987;Heikkinen et al., 2015;Hennekens et al., 1979;Kinlen et al., 1977;Koenig et al., 1991;La Vecchia and Tavani, 1995;Llanos et al., 2017;Mendelsohn et al., 2009;Nasca et al., 1980Nasca et al., , 1992Rosenberg et al., 2007;Shore et al., 1979;Stavraky et al., 1979;Stiel et al., 2016;Takkouche et al., 2005;Thun et al., 1994;Wynder and Goodman, 1983;Zhang et al., 2012;Zheng et al., 2002;White et al., 2021), though a causal relationship between this exposure and breast cancer risk has not been established. Most recently, it has been hypothesized to be associated with disparities in breast cancer phenotype (Eberle et al., 2020;Llanos et al., 2017). ...
... Therefore, not only does early exposure to EDC-containing hair products increase cumulative lifetime exposure to potentially harmful compounds, but these products are also implicated as a contributor to earlier pubertal timing (Berger et al., 2018;Wolff et al., 2010;McDonald et al., 2018), which is in an important risk factor for breast cancer. In addition, while findings from several epidemiologic studies have historically suggested that hair dye use is associated with increased risk of hematopoietic neoplasms (Mendelsohn et al., 2009;Thun et al., 1994;de Sanjose et al., 2006;Zhang et al., 2008;Rauscher et al., 2004) and bladder cancer (Zhang et al., 2012;Gago-Dominguez et al., 2001, 2003Koutros et al., 2011), emerging data have suggested a positive association with breast cancer as well (Eberle et al., 2020;Heikkinen et al., 2015;Llanos et al., 2017;Zhang et al., 2020). A meta-analysis examining the association between hair dye use and breast cancer risk in eight studies (N = 38,037) suggested a significant dose-dependent relationship (Gera et al., 2018). ...
... A prospective cohort study suggested that hair dyes and straighteners containing endocrine-disrupting chemicals and other carcinogenic compounds might increase the risk of breast cancer, specifically in black women using permanent hair colorants [15]. Breast cancer is still the most common cause of cancer-related death in women, although its overall mortality is gradually decreasing in developed and developing countries [16]. ...
... Therefore, 34 studies were left for full-text scrutiny, and 20 of them were deleted because they lacked useful data (n = 10), were reviews (n = 6) or were letters (n = 4)). Ultimately, 14 eligible publications [4,15,[18][19][20][21][22][23][24][30][31][32][33][34] with 210319 unique subjects met the inclusion criteria. The PRISMA flow diagram of the inclusion process is shown in Fig 1. ...
... The most common interview method was a questionnaire survey alone (35.7%) ( Table 1). As outlined in Table 2, seven studies [4,15,18,19,23,31,33] examined semipermanent or permanent hair dyes and rinses, and two [15,24] examined straighteners, while the Green et al. article [20] only examined permanent hair coloring. Several studies specifically considered the impact of race (n = 5), hair dye color (n = 4) and usage duration (n = 8) on the association between hair products and breast cancer risk. ...
Article
Full-text available
Background The association between personal hair dye use and breast cancer risk is currently debated. The aim of this work is to investigate the association between the use of hair care products and breast cancer risk in women. Methods Based on the PRISMA-IPD statement, the PubMed, Embase, Cochrane Library, Web of Science, OVID and Scopus databases were used to identify eligible studies published from inception to 22 April 2020. A pooled odds ratio (OR) with a 95% confidential interval (CI) was calculated to assess this correlation via fixed- or random-effect Mantel-Haenszel models using a heterogeneity Chi ² test with a significance level of p<0.1. All statistical tests were performed using StataSE software (version 12.0). Results The analyzed data comprised 14 eligible studies with 210319 unique subjects. The pooled results suggested that there was a significant association between the use of hair dyes and breast cancer occurrence (pooled OR = 1.07; 95% CI, 1.01–1.13). Regarding the individual analysis regarding the different types of hair chemicals, permanent hair dye users (pooled OR = 1.08; 95% CI, 1.03–1.14) and rinse users (pooled OR = 1.17; 95% CI, 1.02–1.35) were both found to have a significantly elevated breast cancer risk compared to natural hair subjects, whereas there was an insignificant relationship between the use of semipermanent hair dyes (pooled OR = 1.09; 95% CI, 0.92–1.28) and straighteners (pooled OR = 1.04; 95% CI, 0.96–1.14) and breast cancer risk. No impact on the overall correlation between hair dyes and breast cancer risk due to race (White vs non-White) (pooled OR = 1.05; 95% CI, 0.86–1.29), timing of use (<10 years vs ≥10 years) (pooled OR = 0.96; 95% CI, 0.85–1.08) or dye color (Darker than natural hair vs Lighter than natural hair) (pooled OR = 0.91; 95% CI, 0.62–1.32) was found. Conclusions Chemicals in hair dyes may play a role in breast carcinogenesis and increase breast cancer risk.
... Previous studies on the association between hair product use and breast cancer have shown inconsistent results; however, a large national prospective cohort study recently yielded significant results. 1,3,4 The study enrolled 50,888 participants with no history of breast cancer but had a sister with breast cancer. 4 The association between hair dye and chemical relaxer/straightener use and breast cancer risk was examined by ethnicity. ...
... 1,3,4 The study enrolled 50,888 participants with no history of breast cancer but had a sister with breast cancer. 4 The association between hair dye and chemical relaxer/straightener use and breast cancer risk was examined by ethnicity. 4 Permanent hair dye use was associated with a 45% higher breast cancer risk in black women and a 7% higher risk in white women. ...
... 4 The association between hair dye and chemical relaxer/straightener use and breast cancer risk was examined by ethnicity. 4 Permanent hair dye use was associated with a 45% higher breast cancer risk in black women and a 7% higher risk in white women. 4 Hair straightener use was associated with breast cancer, with higher risk associated with increased frequency. ...
... Further, the triple-negative (TN) subtype-associated with the worst prognosis-has the highest incidence among Black women compared to women of other races/ethnicities (DeSantis et al., 2016). Of interest, use of hair dyes and relaxers is a suspected risk factor for breast cancer (Brinton et al., 2018;Cook et al., 1999;Donovan et al., 2007;Eberle et al., 2020;Green et al., 1987;Heikkinen et al., 2015;Hennekens et al., 1979;Kinlen et al., 1977;Koenig et al., 1991;La Vecchia and Tavani, 1995;Llanos et al., 2017;Mendelsohn et al., 2009;Nasca et al., 1980Nasca et al., , 1992Rosenberg et al., 2007;Shore et al., 1979;Stavraky et al., 1979;Stiel et al., 2016;Takkouche et al., 2005;Thun et al., 1994;Wynder and Goodman, 1983;Zhang et al., 2012;Zheng et al., 2002;White et al., 2021), though a causal relationship between this exposure and breast cancer risk has not been established. Most recently, it has been hypothesized to be associated with disparities in breast cancer phenotype (Eberle et al., 2020;Llanos et al., 2017). ...
... Of interest, use of hair dyes and relaxers is a suspected risk factor for breast cancer (Brinton et al., 2018;Cook et al., 1999;Donovan et al., 2007;Eberle et al., 2020;Green et al., 1987;Heikkinen et al., 2015;Hennekens et al., 1979;Kinlen et al., 1977;Koenig et al., 1991;La Vecchia and Tavani, 1995;Llanos et al., 2017;Mendelsohn et al., 2009;Nasca et al., 1980Nasca et al., , 1992Rosenberg et al., 2007;Shore et al., 1979;Stavraky et al., 1979;Stiel et al., 2016;Takkouche et al., 2005;Thun et al., 1994;Wynder and Goodman, 1983;Zhang et al., 2012;Zheng et al., 2002;White et al., 2021), though a causal relationship between this exposure and breast cancer risk has not been established. Most recently, it has been hypothesized to be associated with disparities in breast cancer phenotype (Eberle et al., 2020;Llanos et al., 2017). ...
... Therefore, not only does early exposure to EDC-containing hair products increase cumulative lifetime exposure to potentially harmful compounds, but these products are also implicated as a contributor to earlier pubertal timing (Berger et al., 2018;Wolff et al., 2010;McDonald et al., 2018), which is in an important risk factor for breast cancer. In addition, while findings from several epidemiologic studies have historically suggested that hair dye use is associated with increased risk of hematopoietic neoplasms (Mendelsohn et al., 2009;Thun et al., 1994;de Sanjose et al., 2006;Zhang et al., 2008;Rauscher et al., 2004) and bladder cancer (Zhang et al., 2012;Gago-Dominguez et al., 2001, 2003Koutros et al., 2011), emerging data have suggested a positive association with breast cancer as well (Eberle et al., 2020;Heikkinen et al., 2015;Llanos et al., 2017;Zhang et al., 2020). A meta-analysis examining the association between hair dye use and breast cancer risk in eight studies (N = 38,037) suggested a significant dose-dependent relationship (Gera et al., 2018). ...
Article
Background Building upon our earlier findings of significant associations between hair dye and relaxer use with increased breast cancer risk, we evaluated associations of select characteristics of use with breast tumor clinicopathology. Methods Using multivariable-adjusted models we examined the associations of interest in a case-only study of 2998 women with breast cancer, overall and stratified by race and estrogen receptor (ER) status, addressing multiple comparisons using Bonferroni correction. Results Compared to salon application of permanent hair dye, home kit and combination application (both salon and home kit application) were associated with increased odds of poorly differentiated tumors in the overall sample. This association was consistent among Black (home kit: OR 2.22, 95 % CI: 1.21–5.00; combination: OR 2.46, 95 % CI: 1.21–5.00), but not White women, and among ER+ (home kit: OR 1.47, 95 % CI: 0.82–2.63; combination: OR 2.98, 95 % CI: 1.62–5.49) but not ER-cases. Combination application of relaxers was associated with increased odds of tumors >2.0 cm vs. <1.0 cm (OR = 1.82, 95 % CI: 1.23–2.69). Longer duration and earlier use of relaxers and combination application of permanent hair dyes and relaxers were associated with breast tumor features including higher tumor grade and larger tumor size, which often denote more aggressive phenotypes, although the findings did not maintain significance with Bonferroni correction. Conclusions These novel data support reported associations between hair dye and relaxer use with breast cancer, showing for the first time, associations with breast tumor clinicopathologic features. Improved hair product exposure measurement is essential for fully understanding the impact of these environmental exposure with breast cancer and to guide risk reduction strategies in the future.
... Multivariable analyses showed no significant association between status, duration, frequency, or cumulative dose and cancer related death, and stratified by natural hair color. The spline analysis showed no statistically significant nonlinear relation between cumulative dose and cancer related death (supplementary table 29 personal use of permanent hair dyes and cancer risk and mortality (sensitivity analyses) Assumptions of various latencies did not materially change the main findings for the aggregated and site specific cancer endpoints, except for a possible increased ovarian cancer risk with longer latency among women with naturally light hair (supplementary tables [30][31][32][33][34][35][36][37]. Similarly, we did not observe any major variation in the associations when follow-up was restricted to the first 10 and 20 years after exposure assessments stopped. ...
... In particular, this recent study detected potential differences by estrogen receptor status; the risk associated with permanent hair dye appeared to be specifically increased for estrogen receptor negative breast cancer compared with estrogen receptor positive breast cancer. 37 Our study, which was based on a larger number of women with breast cancer and more refined confounding control, 39 observed similar findings for estrogen receptor negative breast cancers. Additionally, our study performed stratification analyses according to progesterone receptor status, and risk was similarly increased for progesterone receptor negative and hormone receptor negative breast cancer. ...
Article
Full-text available
Objective: To evaluate the associations between personal use of permanent hair dyes and cancer risk and mortality. Design: Prospective cohort study. Setting and participants: 117 200 women enrolled in the Nurses' Health Study, an ongoing prospective cohort study of female nurses in the United States. The women were free of cancer at baseline, reported information on personal use of permanent hair dyes, and were followed for 36 years. Exposure: Status, duration, frequency, and integral use (cumulative dose calculated from duration and frequency) of permanent hair dyes. Age at first use and time since first use of permanent hair dyes. Main outcome measures: Associations of personal use of permanent hair dyes with risk of overall cancer and specific cancers, and cancer related death. Age and multivariable adjusted hazard ratios and 95% confidence intervals were estimated by using Cox proportional hazard models. Results: Ever users of permanent hair dyes had no significant increases in risk of solid cancers (n=20 805, excluding non-melanoma skin cancers; hazard ratio 0.98, 95% confidence interval 0.96 to 1.01) or hematopoietic cancers overall (n=1807; 1.00, 0.91 to 1.10) compared with non-users. Additionally, ever users did not have an increased risk of most specific cancers (cutaneous squamous cell carcinoma, bladder cancer, melanoma, estrogen receptor positive breast cancer, progesterone receptor positive breast cancer, hormone receptor positive breast cancer, brain cancer, colorectal cancer, kidney cancer, lung cancer, and most of the major subclasses and histological subtypes of hematopoietic cancer) or cancer related death (n=4860; 0.96, 0.91 to 1.02). Basal cell carcinoma risk was slightly increased for ever users (n=22 560; 1.05, 1.02 to 1.08). Cumulative dose was positively associated with risk of estrogen receptor negative breast cancer, progesterone receptor negative breast cancer, hormone receptor negative breast cancer, and ovarian cancer. An increased risk of Hodgkin lymphoma was observed only for women with naturally dark hair (based on 70 women, 24 with dark hair), and a higher risk of basal cell carcinoma was observed for women with naturally light hair. Conclusion: No positive association was found between personal use of permanent hair dye and risk of most cancers and cancer related mortality. The increased risk of basal cell carcinoma, breast cancer (estrogen receptor negative, progesterone receptor negative, hormone receptor negative) and ovarian cancer, and the mixed findings in analyses stratified by natural hair color warrant further investigation.
... Other studies evaluating the risk of ovarian cancer associated with hair products have been limited (7,8) and have focused on hair dye exposure without consideration of other commonly used hair products such as straighteners/relaxers that are predominately used by African American women. In the Sister Study, we previously observed that both adolescent and adult use of hair products, in particular straighteners/relaxers or pressing products, was associated with a higher risk of developing breast cancer (9,10). In addition to containing endocrine disrupting compounds, (4,11) certain formulations of straighteners release the carcinogen formaldehyde when heated (12). ...
... This association was more pronounced for non-serous ovarian cancer, a heterogeneous group of histologic subtypes. Frequent use of straighteners has been previously associated with breast cancer risk, in both this study population as well as in others (9,10,19,20). To the best of our knowledge, there have been no previous studies considering how straighteners are associated with the incidence of ovarian cancer or any other cancer types aside from breast cancer. ...
Article
We evaluated whether hair products, which may contain carcinogens and endocrine disruptors that can be absorbed into the bloodstream, are related to ovarian cancer incidence in a prospective cohort. After excluding women with a history of ovarian cancer or bilateral oophorectomy, 40,559 Sister Study participants ages 35-74 at enrollment (2003-2009) were included. Participants completed questionnaires on hair product use, including hair dyes, straighteners/relaxers and permanents/body waves, in the past 12 months. Cox regression was used to estimate adjusted hazard ratios (HRs) and 95% Confidence Intervals (CIs) for the association between hair products and incident ovarian cancer. We assessed associations stratified by tumor type (serous, non-serous). Over a mean follow-up of 10 years, 241 women were diagnosed with ovarian cancer. Ever use of any of the examined hair products during the past year was not associated with ovarian cancer risk. However, frequent use (>4 times/year) of straighteners/relaxers or pressing products in the past year was associated with an increased risk of ovarian cancer (HR=2.19, 95% CI: 1.12-4.27). Ever use of permanent hair dye was positively associated with non-serous (HR=1.94, 95% CI 1.12-3.37), but inversely associated with serous (HR=0.65, 95% CI: 0.43-0.99) tumors (p-for-heterogeneity=0.002). Our novel findings suggest that frequent use of hair straighteners/relaxers or pressing products, which are primarily used by African American/Black women, and possibly permanent hair dye, may be associated with the occurrence of ovarian cancers.
... A recent study from the U.S. National Institutes of Health found increased breast cancer risks associated with use of permanent hair dye, with black women facing higher risks compared to white women [1]. This study raises questions about the safety of hair dye chemicals, and unfortunately these questions apply widely to chemicals in every day products, but not only for the product user. ...
Article
Full-text available
Evidence shows, that over their life cycle, chemicals used in everyday products contribute to raising cancer risks, especially for vulnerable populations such as children and communities of color. This article outlines how US policies have not yet incorporated current science in relation to environmental carcinogenesis and recommends improvements to protect public health.
... To the Editor: A recent widely publicized study suggested that permanent hair dye use was associated with a 45% increased risk of breast cancer in black women. 1 In white women, permanent dye use only increased the risk of breast cancer by 7%. In addition, it was reported that the use of straighteners, defined as chemical treatments used to permanently or semipermanently straighten or relax hair, was also associated with increased breast cancer risk. ...
... The International Agency for Research on Cancer (IARC) has declared hair dye exposure to be "not classifiable to its carcinogenicity to humans" (Group 3) for individuals [7]. However, concerns regarding the genotoxic potential of the dyes have resurfaced from a recent study reporting a 45% higher breast cancer risk among certain women who utilize permanent hair dyes [8]. It is known that some permanent hair dye precursors are moderate to strong/extreme sensitizers (or allergens). ...
Article
As a new approach to permanent/oxidative hair dyes, we demonstrated that certain monoazo dyes containing substituents that enable diffusion into hair fibers and subsequent chelation/complexation using benign metal ions (Al³⁺ and Fe³⁺), rather than a harsh oxidant and strong alkali, merit consideration in this application area. This is important, because billions of individuals worldwide color their hair using permanent hair dye products that can contain aromatic amines and phenols that display genotoxicity and/or skin sensitization (e.g., para-phenylenediamine, PPD). Herein, our work is extended to an examination of the toxicological properties and durability of metallizable monoazo dyes, in comparison to a commercially used permanent hair dye product. Results from the Salmonella/microsome mutagenicity assay and from acute toxicity tests using aquatic test organisms (Daphnia similis, 48-h and Parhyale hawaiensis, 96-h) indicated that the proposed dyes were significantly less toxic than the top-eight permanent hair dye precursors utilized annually. Regarding durability, monoazo dye chelation in situ led to a higher degree of resistance to removal by washing than a commercial permanent hair dye. Taken together, these results further demonstrate the potential of the dyes as sustainable alternatives to conventional permanent hair dyes.
... 6 Other determinants unique to women of African origin have been suggested, such as the use of skin lighteners and increased exposures to hormone modulators in skincare and hair products, as often used by women of African descent. [7][8][9] Although this changing risk is common across populations, the incidence of breast cancer in sub-Saharan Africa varies across countries and regions. GLOBOCAN 2018 10 estimated the age standardised breast cancer incidence at 29.9 per 10 5 person-years in Eastern Africa, 27 6 Thus, little is published on long-term cancer trends from other SSA countries. ...
Article
Full-text available
Breast cancer (BC) is the leading cause of cancer in sub‐Saharan Africa (SSA) with rapidly increasing incidence rates reported in Uganda and Zimbabwe. However, the magnitude of these rising trends in pre‐ and post‐menopausal women is unknown in most African countries. We used data from the African Cancer Registry Network on incident breast cancers in women from 11 population‐based cancer registries in 10 countries representing each of the four SSA regions. We explored incidence changes among women before and after age 50 by calendar period and, where possible, generational effects in this unique sub‐Saharan African cohort. Temporal trends revealed increasing incidence rates in all registries during the study period, except in Nairobi where rates stabilized during 2010‐2014 after rapidly increasing from 2003‐2010 (APC = 8.5 95%, CI:3.0‐14.2). The cumulative risk varied between and within regions, with the highest risks observed in Nairobi‐Kenya, Mauritius and the Seychelles. There were similar or more rapidly increasing incidence rates in women aged 50+ compared to women <50 years in all registries except The Gambia. Birth cohort analyses revealed increases in the incidence rates in successive generations of women aged 45 and over in Harare‐Zimbabwe and Kampala‐Uganda. In conclusion, the incidence of BC is increasing rapidly in many parts of Africa; however, the magnitude of these changes differs. These results highlight the need for urgent actions across the cancer continuum from in‐depth risk factor studies to provision of adequate therapy as well as the necessity of supporting the maintenance of good quality population‐based cancer registration in Africa. This article is protected by copyright. All rights reserved.
... In particular, hair products marketed towards and more commonly used by non-Hispanic Black women have been shown to contain multiple EDCs, including parabens, phthalates, and phenols [15,16], and recent evidence suggests that these products may be hormonally active [17,18]. Furthermore, the use of certain hair products has been associated with multiple hormonally-mediated health outcomes, such as earlier age at menarche, breast cancer, and uterine leiomyomata [19][20][21][22][23][24][25][26][27], indicating that differences in hair product use patterns could potentially contribute to the observed disparities in EDC exposure and women's reproductive health outcomes [13,28]. However, research on the use of EDC-associated hair products during pregnancy and risk of preterm birth or earlier gestational age at delivery is lacking. ...
Article
Full-text available
Background Prenatal endocrine disrupting chemical (EDC) exposure has been associated with increased risk of preterm birth. Non-Hispanic Black women have higher incidence of preterm birth compared to other racial/ethnic groups and may be disproportionately exposed to EDCs through EDC-containing hair products. However, research on the use of EDC-associated hair products during pregnancy and risk of preterm birth is lacking. Therefore, the objective of this pilot study was to estimate associations of prenatal hair product use with gestational age at delivery in a Boston, Massachusetts area pregnancy cohort. Methods The study population consisted of a subset of participants enrolled in the Environmental Reproductive and Glucose Outcomes (ERGO) Study between 2018 and 2020. We collected self-reported data on demographics and hair product use using a previously validated questionnaire at four prenatal visits (median: 12, 19, 26, 36 weeks’ gestation) and abstracted gestational age at delivery from medical records. We compared gestational age and hair product use by race/ethnicity and used linear regression to estimate covariate-adjusted associations of product use and frequency of use at each study visit with gestational age at delivery. Primary models were adjusted for maternal age at enrollment and delivery method. Results Of the 154 study participants, 7% delivered preterm. Non-Hispanic Black participants had lower mean gestational age at delivery compared to non-Hispanic White participants (38.2 vs. 39.2 weeks) and were more likely to report ever and more frequent use of hair products. In regression models, participants reporting daily use of hair oils at visit 4 had lower mean gestational age at delivery compared to non-users (β: -8.3 days; 95% confidence interval: -14.9, -1.6). We did not find evidence of associations at earlier visits or with other products. Conclusions Frequent use of hair oils during late pregnancy may be associated with shorter gestational duration. As hair oils are more commonly used by non-Hispanic Black women and represent potentially modifiable EDC exposure sources, this may have important implications for the known racial disparity in preterm birth.
... Emerging evidence suggests the use of hair and other personal care products may contribute to breast cancer development (Breast Cancer Prevention Partners, 2018;Eberle et al., 2019;Helm et al., 2018;Llanos et al., 2017;Stiel et al., 2016). Personal care products may contain endocrine disrupting chemicals (EDCs)-chemicals that may interfere with the body's endocrine system and produce negative developmental, reproductive, neurological, and immune effects in both humans and animals (National Institute of Environmental Health Sciences, 2020). ...
Article
Full-text available
Racial disparities in breast cancer are well-documented, and Black women assume a disproportionate burden of breast cancer mortality. Black women also commonly use hair products containing endocrine disrupting chemicals (EDCs) more often at an increased rate, as compared to other racial/ethnic groups. Emerging findings have reported the use of hair and other personal care products containing EDCs may contribute to breast cancer risk. While some sociocultural perspectives about hair and identity have been explored, the role of beauty expectations upheld by males has not been studied. Through a community-based participatory methodology, we explored perceptions and beliefs held by Black men regarding Black women’s hair, chemical exposures in hair products, and breast cancer risk. Focus groups and key informant interviews—among men with and without partners with a history of breast cancer—were used to examine the male perspective regarding the attractiveness of Black hairstyles, opinions of beauty norms, and knowledge of breast cancer risk factors. Interviews were audio-recorded, transcribed, and analyzed guided by grounded theory methods. From the 66 participants interviewed, there was general support for natural hairstyles, which were associated with confidence and self-esteem in women. Men agreed that beauty standards and societal pressures play notable roles in the women’s personal behaviors though they mostly lacked knowledge of women’s breast cancer risk related to EDCs found in personal care products. Participants suggested a multipronged strategy centered on community education involving social and traditional media campaigns, and the engagement of policy makers in intervention efforts.
... 94 Subsequent meta-analyses on this 95,96 and other cancer types, 97,98 as well as toxicological data published in Opinions, are consistent with a view that actives listed in Annex III present no significant oncological risk for professional or personal users under prescribed conditions. 12,99 (More broadly, contention continues, as illustrated by recent USA-based studies, for example [100], which discovered that ethnicity may contribute to susceptibility in users of permanent hair colorants on the US market.) The conclusions of numerous Opinions relating to EU-approved actives are couched in terms of "…does not pose a risk to the consumer, apart from its [ie, the active's] sensitizing potential". ...
Article
This paper reviews developments in industrial colorants as active ingredients of commercial products that rely on oxidative chemistry for the coloration of human hair. After outlining the regulatory challenges faced by the industry, which are shaping the landscape of colorant usage, the most commercially important actives utilised in oxidative hair colorant formulations are surveyed from the perspective of their chemistry and economics. Some developments in the form of recently introduced actives are also described.
... luded relaxers, Two studies attempt to quantify hair product usage and breast cancer risk. Llanos and colleagues (2017) compared hair product usage and their associations with breast cancer risk in Black and White women. While relaxer and deep conditioner use were more common in Black women, only dark hair dye use was related to breast cancer risk.Eberle et al. (2020) builds on this by looking at 50,884 White and Black women about their hair product use frequency and breast cancer incidence over the course of 8 years. Hazard ratios were calculated looking at hair product use in those who developed breast cancer and those who did not. All women who used permanent dyes or straighteners within the past ...
Thesis
Black women and girls in the United States disproportionately experience adverse health outcomes. While racism has been widely discussed as a determinant of health, we need to consider the intersectional experiences of Black women and girls and how health inequities perpetuate. Although the denigration of afro-textured hair has received some legal attention, it has been overlooked as a public health and equity concern. This critical literature synthesis presents the impact of Black hair politics on the well-being of Black women and girls through three specific factors: physiological, psychosocial, and socioeconomic. These influences exist at different levels of the social-ecological model, highlighting its public health significance and need for multilevel interventions. Legislation like the CROWN Act sets a legal precedent to change the conditions in which Black women and girls live, learn, and grow. In addition, an intervention for educational and medical institutions is suggested. It includes the integration of Black hair education, empowerment, inclusion, and accountability into curricula and practice to mitigate health inequities.
... The International Agency for Research on Cancer (IARC) has declared hair dye exposure to be "not classifiable to its carcinogenicity to humans" (Group 3) for individuals [7]. However, concerns regarding the genotoxic potential of the dyes have resurfaced from a recent study reporting a 45% higher breast cancer risk among certain women who utilize permanent hair dyes [8]. It is known that some permanent hair dye precursors are moderate to strong/extreme sensitizers (or allergens). ...
... Particularly relevant to our findings of the greatest methyl and ethyl paraben disparities in the youngest non-Hispanic Black women was the finding that early life paraben exposures can alter developing mammary gland morphology and induce gene expression that resembles an early cancerlike state (Gopalakrishnan et al., 2017). Use of hair products has been identified as a potential risk factor for breast cancer in non-Hispanic Black women (Stiel et al., 2016;Eberle et al., 2019). When we adjusted for breastfeeding in the regression models, parabens levels are higher in Non-Hispanic White women compared to Mexican American, Other Hispanics, and Other Race/Multi-Racial women. ...
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Background Stark racial disparities in disease incidence among American women remain a persistent public health challenge. These disparities likely result from complex interactions between genetic, social, lifestyle, and environmental risk factors. The influence of environmental risk factors, such as chemical exposure, however, may be substantial and is poorly understood. Objectives We quantitatively evaluated chemical-exposure disparities by race/ethnicity, life stage, and time in United States (US) women (n = 38,080) by using biomarker data for 143 chemicals from the National Health and Nutrition Examination Survey (NHANES) 1999–2014. Methods We applied a series of survey-weighted, generalized linear models using data from the entire NHANES women population along with cycle and age-group stratified subpopulations. The outcome was chemical biomarker concentration, and the main predictor was race/ethnicity with adjustment for age, socioeconomic status, smoking habits, and NHANES cycle. Results Compared to non-Hispanic White women, the highest disparities were observed for non-Hispanic Black, Mexican American, Other Hispanic, and Other Race/Multi-Racial women with higher levels of pesticides and their metabolites, including 2,5-dichlorophenol, o,p’-DDE, beta-hexachlorocyclohexane, and 2,4-dichlorophenol, along with personal care and consumer product compounds, including parabens and monoethyl phthalate, as well as several metals, such as mercury and arsenic. Moreover, for Mexican American, Other Hispanic, and non-Hispanic black women, there were several exposure disparities that persisted across age groups, such as higher 2,4- and 2,5-dichlorophenol concentrations. Exposure levels for methyl and propyl parabens, however, were the highest in non-Hispanic black compared to non-Hispanic white children with average differences exceeding 4-fold. Exposure disparities for methyl and propyl parabens are increasing over time in Other Race/Multi-Racial women while fluctuating for non-Hispanic Black, Mexican American, and Other Hispanic. Cotinine levels are among the highest in Non-Hispanic White women compared to Mexican American and Other Hispanic women with disparities plateauing and increasing, respectively. Discussion We systematically evaluated differences in chemical exposures across women of various race/ethnic groups and across age groups and time. Our findings could help inform chemical prioritization in designing epidemiological and toxicological studies. In addition, they could help guide public health interventions to reduce environmental and health disparities across populations.
... Black girls reach menarche earlier [8] and Black women have higher mortality due to breast cancer, often due to a higher incidence of a subtype of the disease that is less responsive to hormone therapy treatment [54]. Considering data evaluating hair products and these conditions, two studies found associations between hair products (e.g., hair dyes and relaxers) with an increased breast cancer risk [55,56]. In the present study, it is worth noting that while three of the products showed estrogen agonist properties, one of these three along with two others showed estrogen antagonist properties. ...
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Background Certain types of hair products are more commonly used by Black women. Studies show hair products contain several endocrine-disrupting chemicals that are associated with adverse health outcomes. As chemical mixtures of endocrine disruptors, hair products may be hormonally active, but this remains unclear. Objective To assess the hormonal activity of commonly used Black hair products. Methods We identified six commonly used hair products (used by >10% of the population) from the Greater New York Hair Products Study. We used reporter gene assays (RGAs) incorporating natural steroid receptors to evaluate estrogenic, androgenic, progestogenic, and glucocorticoid hormonal bioactivity employing an extraction method using bond elution prior to RGA assessment at dilutions from 50 to 500. Results All products displayed hormonal activity, varying in the amount and effect. Three samples showed estrogen agonist properties at levels from 12.5 to 20 ng/g estradiol equivalent concentrations All but one sample showed androgen antagonist properties at levels from 20 to 25 ng/g androgen equivalent concentrations. Four samples showed antagonistic and agonistic properties to progesterone and glucocorticoid. Significance Hair products commonly used by Black women showed hormonal activity. Given their frequent use, exposure to hormonally active products could have implications for health outcomes and contribute to reproductive and metabolic health disparities.
Article
Human hair is naturally colored by melanin pigments, which afford myriad colors from black, to brown, to red depending on the chemical structures and specific blends. In recent decades, synthetic efforts have centered on dopamine oxidation to polydopamine, an effective eumelanin similar to the one found in humans. To date, only a few attempts at polydopamine deposition on human hair have been reported, and their translation to widespread usage and potential commercialization is still hampered by the harsh conditions employed. We reasoned that novel, mild, biocompatible approaches could be developed to establish a metal-free route to tunable, nature-inspired, long-lasting coloration of human hair. Herein, we describe synthetic and formulation routes to achieving this goal and show efficacy on a variety of human hair samples via multiple spectroscopic and imaging techniques. Owing to the mild and inexpensive conditions employed, this novel approach has the potential to replace classical harsh hair dyeing conditions that have raised concerns for several decades due to their potential toxicity.
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Recent reports suggest that next-generation hair dyes might take inspiration from the natural pigment melanin. In humans, melanin imparts color to hair and skin and acts as a natural sunscreen and radical scavenger, thereby protecting lipids and proteins from damage. The most commonly employed synthetic mimic of melanin is polydopamine, and its successful deposition on human hair was recently reported. Herein, we describe an enzymatic approach to synthetic melanin for dyeing human hair in a process that closely mimics part of natural melanogenesis. This chemoenzymatic method avoids the addition of a base and enables the implementation of several monomers beyond dopamine, including tyrosine, tyramine, and their derivatives. Critically, the enzyme provides a milder process for producing coated hair fibers than conventional chemical hair dyeing methods. In addition to providing natural coloration, these coatings have the potential to act as protective sunscreens that prevent photodamage of the inner hair fibers during exposure to sunlight. The protocols developed herein represent a mild and efficient route to nature-inspired multifunctional coatings. Such materials are promising candidates for artificial hair pigmentation and, more generally, could find extensive application as functional fiber coatings.
Article
Given the worldwide popularity of hair dyeing, there is an urgent need to understand the toxicities and risks associated with exposure to chemicals found in hair dye formulations. Hair dyes are categorized as oxidative and nonoxidative in terms of their chemical composition and ingredients. For several decades, the expert panel's Cosmetic Ingredient Review (CIR) has assessed the safety of many of the chemicals used in hair dyes; however, a comprehensive review of hair dye ingredients and the risk of exposure to hair dyeing has not been documented. Herein, we review the safety of the various chemicals in oxidative and nonoxidative hair dyes, toxicities associated with hair dyeing, and the carcinogenic risks related to hair dyeing. While many compounds are considered safe for users at the concentrations in hair dyes, there are conflicting data about a large number of hair dye formulations. The CIR expert panel has ratified a number of coloring ingredients for hair dyes and banned a series of chemicals as carcinogenic to animals and unsafe for this application. The use of these chemicals as raw materials for producing hair dyes may result in the synthesis of other contaminants with potential toxicities and increased risk of carcinogenesis. It is an open question whether personal or occupational hair dyeing increases the risk of cancer; however, in specific subpopulations, a positive association between hair dye use and cancer occurrence has been reported. To address this question, a better understanding of the chemical and mechanistic basis of the reported toxicities of hair dye mixtures and individual hair dye ingredients is needed. It is anticipated that in-depth chemical and systems toxicology studies harnessing modern and emerging techniques can shed light on this public health concern in the future.
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Background Personal care product use may contribute to elevated body burdens of consumer product chemicals among women of color; however, racial/ethnic differences in product use has been understudied. Community-engaged research can support the recruitment of diverse participants. Objective To document personal care product use among a diverse group of women (aged 18–34 years) living in California. Methods Through a community-academic partnership, we surveyed 357 women in California about product use information for 54 cosmetic, hair, menstrual/intimate care, and leave-on and rinse-off personal care products. We compared type and frequency of product use among Black, Hispanic/Latinx, Asian, and White women. We also summarized use of scented products and reasons women select products. Results Women reported using a median of 8 products daily, with some women reporting up to 30 products daily. Hispanic/Latinx and Asian women used more cosmetics, and Black women used more hair and menstrual/intimate products than other women. Of the 54 products compared, there were significant differences in use by race/ethnicity for 28 products, with the largest number of significant differences between Black and White women. Significance There is growing information on chemical exposures from personal care products and consequent adverse health effects, with implications for health disparities. Yet, there remains limited information on the range and types of products used by diverse racial/ethnic communities. This study helps close an important gap on product use inventories that can enable more informed public health interventions to limit exposures from personal care products.
Article
Hair relaxers and leave-in conditioners and oils, commonly used by Black/African American women, may contain estrogens or estrogen-disrupting compounds. Thus, their use may contribute to breast cancer risk. Results of the few previous studies on this topic are inconsistent. We assessed the relation of hair relaxer and leave-in conditioner use to breast cancer incidence in the Black Women's Health Study, a nationwide prospective study of Black women. Among 50,543 women followed from 1997 to 2017, 2,311 incident breast cancers occurred. Multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using Cox proportional hazards regression for breast cancer overall and by estrogen receptor (ER) status. For heavy use (≥15 years of use for ≥7 times/ year) of hair relaxers relative to never/light use (<4 years, no more than 1-2 times/year), the multivariable HR for breast cancer overall was 1.13 (95%CI: 0.96-1.33). Duration, frequency, age at first use and number of scalp burns were not associated with overall breast cancer risk. For heavy use of hair relaxers containing lye, the corresponding HR for ER+ breast cancer was 1.32 (95% CI: 0.97, 1.80); there was no association for non-lye products. There was no association of conditioner use and breast cancer. Results of this study were largely null, but there was some evidence that heavy use of lye-containing hair relaxers may be associated with increased risk of ER+ breast cancer. Consistent results from several studies are needed before it can be concluded that use of certain hair relaxers impacts breast cancer development.
Article
The deleterious impact of toxic constituents of hair dyes over the human health has gained immense attention in the recent past. Their oncogenicity, mutagenicity, role in protein modification, impact on cellular metabolism has been documented. There is little information on the mechanism of reactivity of hair dye components with the nucleic acids and its implications. This work, therefore, uses computational, biophysical/biochemical, microscopic and cell-based study to analyze the interaction of monocyclic aromatic amine and a hair dye component, 4-chloro-orthophenylenediamine (4-Cl-OPD) with the DNA, its impact on DNA structure and cell survival. The results suggest that 4-Cl-OPD binds with the DNA in minor groove of the duplex involving three base pairs preferentially the G-C residues, induces strand breaks and makes DNA thermally labile through loss of hydrogen bonding/base unstacking. 4-Cl-OPD causes fragmentation of DNA, reduction in size of the molecule, alters B-DNA conformation and disrupts its secondary structure. The modified DNA gives fragmented appearance, shows broken strands and aggregation in ultra-structural analysis. 4-Cl-OPD induces ROS generation in lymphocytes, increases the comet’s average tail length and reduces the viability of lymphocytes. This study forms a base for establishing the direct toxicity of 4-Cl-OPD at the molecular and cellular level through direct production of superoxide radical Communicated by Ramaswamy H. Sarma
Article
Personal care products (PCPs) refer to a wide variety of items commonly characterized as health or beauty products. PCPs contain a number of ingredients, often including a wide range of endocrine disrupting chemicals such as phthalates and parabens. The present study examines the association between self-reported PCP use and prenatal sex-steroids and thyroid hormones levels in women from Puerto Rico. We recruited pregnant women (n = 1070) through the Puerto Rico PROTECT Cohort and collected blood, demographic and pregnancy-related data at recruitment and subsequent visits. PCP use in the 48-h preceding the blood sample was collected through self-reported questionnaires. Nine hormones (corticotropin-releasing hormone [CRH], sex-hormone binding globulin [SHBG], estriol [E3], progesterone, testosterone, thyroid-stimulating hormone [TSH], total triiodothyronine [T3], total thyroxine [T4], and free thyroxine [fT4]) were measured in maternal serum samples at two points during pregnancy. Linear mixed models with random intercepts were used to examine associations between PCP use and serum hormone levels. Use of cosmetics significantly increased with age, household income and education level (p < 0.01). Use of hair products, such as hair dyes and bleach, relaxers, and mousse, was associated with lower levels of all sex steroid hormones compared to non-use: SHBG (%Δ = −7.1, 95%CI: −12.4,-1.8), E3 (%Δ = −23.2, 95%CI: −32.2,-13.0), progesterone (%Δ = −21.5, 95%CI: −29.4,-12.9) and testosterone (%Δ = −21.5, 95%CI: −33.1,-7.8) adjusted for maternal age, education and pre-pregnancy body mass index. Our findings suggest that household income and education level influence PCP use among pregnant women in this study. Use of certain hair products was associated with lower concentrations of sex steroid hormones. Although there are limitations to questionnaire data, characterizing PCP use is inexpensive and may represent exposure from multiple classes of chemicals, including chemicals that may not specifically appear on product labels and/or have not been tested for endocrine disrupting potential, making it a useful complement to chemical biomarker data.
Article
Background: According to the International Agency for Research on Cancer, some hair dye chemicals are considered mutagenic and carcinogenic in humans. One hospital-based study reported a positive association between hair dye use and prostate cancer risk, but no prospective analyses have been conducted. Methods: This study investigated the association between hair dye use and prostate cancer risk in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study cohort, a large, well-characterized cohort of 29,133 male Finnish smokers. Participants completed questionnaires regarding lifestyle, medical, and risk factor information, including the use of hair dye, which was available for 98.8% of the cohort (28,795 men). Prostate cancer cases were identified through linkage with the Finnish Cancer Registry and the Finnish Mortality Register. Hazard ratios (HRs) and confidence intervals (CIs) were estimated via multivariable Cox proportional hazards regression. Results: During a 28-year period of observation, 2703 incident prostate cancer cases were diagnosed. As reported at the baseline, 75 men used hair dye, and 13 of these men were subsequently diagnosed with prostate cancer. After adjustments for potential confounders, men who used hair dyes experienced substantially higher prostate cancer risk than men who did not (HR, 1.77; 95% CI, 1.03-3.05). Conclusions: This first prospective investigation of hair dye use and prostate cancer suggests that personal hair dye use may be related to increased risk. The findings warrant re-examination in other prospective cohorts along with studies evaluating specific hair dyes and possible underlying biological mechanisms.
Article
Contamination of agricultural land and surface water by personal care products and pharmaceutical constituents is a potential environmental threat. The active ingredients of personal care products are life-threatening for users. Present work highlighted the efficacy of the different components of two commercially available hair dyes (synthetic and herbal) on germination, morpho-physiological, biochemical parameters of Cicer arietinum, and cytotoxicity study by Allium cepa root tip. Different treatments such as T1 (control), T2 (cream colour rich), T3 (developer) (The ingredients T2 and T3 are from the same hair dye), T4 (an equal mixture of T2 and T3), and T5 (herbal dye) were considered to run this experiment. The results revealed that all the treatments improve germination with respect to control. Moreover, GSI data suggests that T2 showed the highest germination speed and T3 showed the lowest with respect to other treatments. But root lengths are severely affected by the treatments T3 (100% developer of synthetic hair dye), T4 (an equal mixture of T2 (100% cream colour rich) and T3), and T5 (100% herbal hair dye) with respect to control.T2 also showed the highest root tolerance of all treatments other than control. Similarly, one-way ANOVA results revealed that both fresh weight of roots (p ≤ 0.03) and shoots (p ≤ 0.03) are statistically significant among the different treatments. Moreover, both proline and root ion leakage are higher in the treatment T4 and T5 with respect to control, respectively. On the other hand, the cytotoxicity study highlighted that treatments T3 and T4 showed a higher level of aberration and significantly lower mitotic index compared to treatment T5. Therefore, finally, it may be concluded that both individual and combined forms of ingredients of hair dyes are toxic with respect to cell division and overall plant growth and development.
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Background: Breast cancer (BC) is one of the leading causes of death among women around the world. Circular RNAs (circRNAs) are a newly discovered group of non-coding RNAs that their roles are being investigated in BC and other cancer types. In this study, we evaluated the association of hsa_circ_0005986 and hsa_circ_000839 in tumor and adjacent normal tissues of BC patients with their clinicopathological characteristics. Materials and methods: Total RNA was extracted from tumors and adjacent non-tumor tissues by the Trizol isolation reagent, and cDNA was synthesized using First Strand cDNA Synthesis Kit (Thermo Scientific). The expression level of hsa_circ_0005986 and hsa_circ_000839 was quantified using RT-qPCR. Online in silico tools were used for identifying potentially important competing endogenous RNA (ceRNA) networks of these two circRNAs. Results: The expression level of hsa_circ_0005986 and hsa_circ_000839 was lower in the tumor as compared to adjacent tissues. The expression level of hsa_circ_0005986 in the patients who had used hair dye in the last 5 years was significantly lower. Moreover, a statistically significant negative correlation between body mass index (BMI) and hsa_circ_000839 expression was observed. In silico analysis of the ceRNA network of these circRNAs revealed mRNAs and miRNAs with crucial roles in BC. Conclusion: Downregulation of hsa_circ_000839 and hsa_circ_0005986 in BC tumors suggests a tumor-suppressive role for these circRNAs in BC, meriting the need for more experimentations to delineate the exact mechanism of their involvement in BC pathogenesis.
Article
Article tries to visualize the potential for carcinogenic trigger in humans with a preference for oxidative synthetic of hair dyeing formulations, especially which belong to the category of permanent colours. According to the International Agency for Cancer, hair dyes for personal use are not strictly classified as carcinogen to humans. However, some controversy exists that requires clarification. Some epidemiological studies support the association between the risk of cancer development and personal use of hair dyes (pooled relative risk RR = 1.50. 95% CI: 1.30–1.98). The world-wide sale of hair dyeing cosmetics have exceeded 15 billion dollars by the year 2012 and has maintained an annual growth rate of 8–10%. This raises concerns and need to be addressed. The review article briefly discusses about the different hair dye components based on their chemical nature, permanence, interaction of dye components with different parts of the hair shaft, action mechanisms, health risk assessment, associated challenges and possible alternatives. There appears variability towards the pathological changes incurred in the human system upon the use of synthetic hair formulations. This probably appears due to the presence of interindividual genetic variation of enzymes handling these xenobiotics. The redox mechanism of major hair dye components appears to be involved in the carcinogenic trigger. Most of the hair dye constituents pose serious health issues. However, we do have few better alternatives to prevent the toxicity associated with hair dye constituents without compromising the need of today’s fashion statement and expectations of the youth.
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Background: Personal care products are a source of exposure to endocrine disrupting and asthma-associated chemicals. Because use of hair products differs by race/ethnicity, these products may contribute to exposure and disease disparities. Objective: This preliminary study investigates the endocrine disrupting and asthma-associated chemical content of hair products used by U.S. Black women. Methods: We used gas chromatography/mass spectrometry (GC/MS) to test 18 hair products in 6 categories used by Black women: hot oil treatment, anti-frizz/polish, leave-in conditioner, root stimulator, hair lotion, and relaxer. We tested for 66 chemicals belonging to 10 chemical classes: ultraviolet (UV) filters, cyclosiloxanes, glycol ethers, fragrances, alkylphenols, ethanolamines, antimicrobials, bisphenol A, phthalates, and parabens. Results: The hair products tested contained 45 endocrine disrupting or asthma-associated chemicals, including every targeted chemical class. We found cyclosiloxanes, parabens, and the fragrance marker diethyl phthalate (DEP) at the highest levels, and DEP most frequently. Root stimulators, hair lotions, and relaxers frequently contained nonylphenols, parabens, and fragrances; anti-frizz products contained cyclosiloxanes. Hair relaxers for children contained five chemicals regulated by California's Proposition 65 or prohibited by EU cosmetics regulation. Targeted chemicals were generally not listed on the product label. Conclusions: Hair products used by Black women and children contained multiple chemicals associated with endocrine disruption and asthma. The prevalence of parabens and DEP is consistent with higher levels of these compounds in biomonitoring samples from Black women compared with White women. These results indicate the need for more information about the contribution of consumer products to exposure disparities. A precautionary approach would reduce the use of endocrine disrupting chemicals in personal care products and improve labeling so women can select products consistent with their values.
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Skin lighteners and hair relaxers, both common among women of African descent, have been suggested as possibly affecting breast cancer risk. In Accra and Kumasi, Ghana, we collected detailed information on usage patterns of both exposures among 1,131 invasive breast cancer cases and 2,106 population-controls. Multivariate analyses estimated odds ratios (OR) and 95% confidence intervals (CIs) after adjustment for breast cancer risk factors. Control usage was 25.8% for ever use of skin lighteners and 90.0% for use of hair relaxers for >1 year. The OR for skin lighteners was 1.10 (95% CI 0.93-1.32), with higher risks for former (1.21, 0.98-1.50) than current (0.96, 0.74-1.24) users. No significant dose-response relations were seen by duration, age at first or frequency of use. In contrast, an OR of 1.58 (95% CI 1.15-2.18) was associated with hair relaxers, with higher risks for former (2.22, 1.56-3.16) than current (1.39, 1.00-1.93) users. Although numbers of burns were inconsistently related to risk, associations increased with duration of use, restricted to women who predominately used non-lye products (p for trend<0.01). This was most pronounced among women with few children and those with smaller tumors, suggesting a possible role for other unmeasured lifestyle factors. This study does not implicate a substantial role for skin lighteners as breast cancer risk factors, but the findings regarding hair relaxers were less reassuring. The effects of skin lighteners and hair relaxers on breast cancer should continue to be monitored, especially given some biologic plausibility for their affecting risk.
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Background Women may have incomplete understanding of a breast cancer diagnosis, leading to inaccurate reporting in epidemiological studies. However, it is not feasible to obtain consent for medical records from all women participating in a study. Therefore, it is important to determine how well self-reported breast cancer characteristics correspond with what is found in medical records, but few studies have evaluated agreement of self-reported breast cancer characteristics with abstracted medical records. Methods We calculated the positive predictive value (PPV) of self-reports compared to medical records and explored whether participant characteristics may have influenced reporting accuracy. We analyzed data from 2518 reported breast cancer cases from the Sister Study, a large nationwide cohort of women with a family history of breast cancer. Results Medical records or pathology reports were obtained for 2066 of 2518 (82%) women who reported incident breast cancer. Breast cancer was confirmed for over 99% (n = 2054) of women with medical records. Confirmation rates were high for invasive, ductal, hormone receptor positive, and HER2 negative breast cancers, with little variation by race/ethnicity or age. Self-reported in situ breast cancer had a lower PPV (64.2%), with medical records showing invasive breast cancer instead, especially for older and Hispanic women. Hormone receptor (ER and PR) negative and HER2 positive self-reports had lower PPVs (83.0%, 71.6%, and 66.1% respectively). Hispanic women and women ages 65 or older at diagnosis were less able to accurately report breast cancer stage, excluding stage I. Conclusions Accuracy of reporting overall breast cancer and common subtypes is high. Despite having a family history of breast cancer and voluntarily enrolling in a study evaluating breast cancer risk factors, participants may have greater difficulty distinguishing between in situ and invasive breast cancer and may less accurately report other less common subtypes. Discrepancies may reflect women’s poor understanding of information conveyed by health care providers or lack of consistent terminology used to describe subtypes.
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The obstetrics-gynecology community has issued a call to action to prevent toxic environmental chemical exposures and their threats to healthy human reproduction. Recent committee opinions recognize that vulnerable and underserved women may be impacted disproportionately by environmental chemical exposures and recommend that reproductive health professionals champion policies that secure environmental justice. Beauty product use is an understudied source of environmental chemical exposures. Beauty products can include reproductive and developmental toxicants such as phthalates and heavy metals; however, disclosure requirements are limited and inconsistent. Compared with white women, women of color have higher levels of beauty product–related environmental chemicals in their bodies, independent of socioeconomic status. Even small exposures to toxic chemicals during critical periods of development (such as pregnancy) can trigger adverse health consequences (such as impacts on fertility and pregnancy, neurodevelopment, and cancer). In this commentary, we seek to highlight the connections between environmental justice and beauty product–related chemical exposures. We describe racial/ethnic differences in beauty product use (such as skin lighteners, hair straighteners, and feminine hygiene products) and the potential chemical exposures and health risks that are associated with these products. We also discuss how targeted advertising can take advantage of mainstream beauty norms to influence the use of these products. Reproductive health professionals can use this information to advance environmental justice by being prepared to counsel patients who have questions about toxic environmental exposures from beauty care products and other sources. Researchers and healthcare providers can also promote health-protective policies such as improved ingredient testing and disclosure for the beauty product industry. Future clinical and public health research should consider beauty product use as a factor that may shape health inequities in women's reproductive health across the life course.
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The incidence rate of breast cancer for African American women has recently converged with that of non-Hispanic White women in the United States, although African Americans have a higher mortality rate due to this disease. Although most research exploring health disparities associated with this phenomenon has focused on differences between women based on biology and behavior, both the academic and lay communities have begun to explore the potential role of environmental exposure to estrogen and endocrine disrupting chemicals (EDCs). This study reviews the current state of the science associating one such means of exposure, hair products containing EDCs, with breast cancer risk in African American women. We found a growing body of evidence linking: (1) environmental estrogen and EDC exposures to breast cancer risk, (2) the presence of such chemicals in personal care products, including hair products, and (3) the use of certain hair products with potential breast cancer risk in African Americans. At the same time, there is also increasing concern in the lay community about this risk. These results indicate the need for additional research, and the opportunity to benefit from strategic partnerships in community-collaborative approaches in order to better understand the potential "cost of beauty."
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Introduction: Role of hair dyes in the etiology of breast cancer has occasionally raised concern but previous research has concluded with mixed results. Remnants of prohibited aromatic amines have been found in many hair dye products, and elevated levels of DNA-adducts of these amines have been detected from breast epithelial cells of hair dye users. However, the IARC working group has concluded that there is inadequate evidence for carcinogenicity of personal hair dye use and limited evidence in experimental animals for carcinogenicity of hair colorants. Material and methods: We investigated whether the use of hair dyes is associated with breast cancer risk in women. The study design was a retrospective population-based case-control study in Finland, with a self-administered questionnaire from 6,567 breast cancer patients, aged 22-60 years and diagnosed in 2000-2007, and their 21,598 matched controls. We report odds ratios (OR) with 95% confidence interval (95% CI) from a conditional logistic regression model applied to the frequency matched sets of cases and controls. Bias-adjusted odds ratios from the sensitivity analysis are also presented. Results: After adjusting for potential confounders, the odds of breast cancer increased by 23% (OR: 1.23, 95% CI: 1.11-1.36) among women who used hair dyes compared to those who did not. In women born before 1950 an increase of 28% was noted (OR: 1.28, 95% CI: 1.10-1.48). We also observed a significant trend between the OR and cumulative use of hair dyes (P: 0.005). Bias-adjusted odds ratios varied between 1.04 and 2.50. Conclusions: Our results suggest that use of hair dyes is associated with breast cancer incidence. The impact on public health may be substantial due to vast popularity of hair coloring in modern societies. It should be noted that regardless of all efforts, a possibility of bias cannot definitively be ruled out and use of a prospective design is warranted. Based on the present results, it may be concluded however that safety of hair dyes in relation to breast cancer cannot yet be fully acknowledged and lack of external safety assessment within the cosmetics industry is of major concern.
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In 2010, Surveillance, Epidemiology, and End Results (SEER) registries began collecting human epidermal growth factor 2 (HER2) receptor status for breast cancer cases. Breast cancer subtypes defined by joint hormone receptor (HR; estrogen receptor [ER] and progesterone receptor [PR]) and HER2 status were assessed across the 28% of the US population that is covered by SEER registries. Age-specific incidence rates by subtype were calculated for non-Hispanic (NH) white, NH black, NH Asian Pacific Islander (API), and Hispanic women. Joint HR/HER2 status distributions by age, race/ethnicity, county-level poverty, registry, stage, Bloom-Richardson grade, tumor size, and nodal status were evaluated using multivariable adjusted polytomous logistic regression. All statistical tests were two-sided. Among case patients with known HR/HER2 status, 36810 (72.7%) were found to be HR(+)/HER2(-), 6193 (12.2%) were triple-negative (HR(-)/HER2(-)), 5240 (10.3%) were HR(+)/HER2(+), and 2328 (4.6%) were HR(-)/HER2(+); 6912 (12%) had unknown HR/HER2 status. NH white women had the highest incidence rate of the HR(+)/HER2(-) subtype, and NH black women had the highest rate of the triple-negative subtype. Compared with women with the HR(+)/HER2(-) subtype, triple-negative patients were more likely to be NH black and Hispanic; HR(+)/HER2(+) patients were more likely to be NH API; and HR(-)/HER2(+) patients were more likely to be NH black, NH API, and Hispanic. Patients with triple-negative, HR(+)/HER2(+), and HR(-)/HER2(+) breast cancer were 10% to 30% less likely to be diagnosed at older ages compared with HR(+)/HER2(-) patients and 6.4-fold to 20.0-fold more likely to present with high-grade disease. In the future, SEER data can be used to monitor clinical outcomes in women diagnosed with different molecular subtypes of breast cancer for a large portion (approximately 28%) of the US population.
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Previous studies suggest that hair products containing endocrine disrupting chemicals could alter puberty. We evaluated the association between childhood hair product use and age at menarche in a racially diverse study population. We recruited 300 African-American, African-Caribbean, Hispanic, and white women from the New York City metropolitan area who were between 18-77 years of age. Data were collected retrospectively on hair oil, lotion, leave-in conditioner, perm, and other types of hair products used before age 13. Recalled age at menarche ranged from 8 to 19 years. We used multivariable binomial regression to evaluate the association between hair product use and age at menarche (<12 vs. ≥12), adjusting for potential confounders. African-Americans were more likely to use hair products and reached menarche earlier than other racial/ethnic groups. Women reporting childhood hair oil use had a risk ratio of 1.4 (95% confidence interval [CI]: 1.1-1.9) for earlier menarche, adjusting for race/ethnicity and year of birth. Hair perm users had an increased risk for earlier menarche (adjusted risk ratio = 1.4, 95% CI: 1.1-1.8). Other types of hair products assessed in this study were not associated with earlier menarche. Childhood hair oil and perm use were associated with earlier menarche. If replicated, these results suggest that hair product use may be important to measure in evaluating earlier age at menarche.
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Although widely studied over the past 40 years, personal use of hair dye generally has not been associated with overall cancer risk. The association between hair dye use and risk of bladder and hematopoietic cancers has been less conclusive. Most hair dye studies have been case-control studies conducted in Caucasian populations. We examined the relationship between personal hair dye use and cancer risk in a prospective cohort of 70,366 Chinese women. After an average of 7 years of follow up, 2437 women were newly diagnosed with cancer by 31 December 2005. Cox proportional hazard models were used to estimate relative risks (RR) and 95% confidence intervals (CI) of cancer risk associated with hair dye use, adjusting for potential confounding factors. Compared with women who reported no hair dye use, ever users had an overall cancer risk of 0.89 (95% CI 0.82, 0.97). No significant association was observed for several common cancers, including cancers of the breast (RR 0.93, 95% CI 0.78, 1.09), lung (RR 0.81, 95% CI 0.62, 1.09), stomach (RR 0.90, 95% CI 0.66, 1.21), and colorectum (RR 1.04, 95% CI 0.84, 1.28). We also found no significant association with most other cancers, including bladder cancer (RR 1.14, 95% CI 0.56, 2.35) and hematopoietic cancers overall (RR 0.89, 95% CI 0.59, 1.35) or their subtypes, including non-Hodgkin lymphoma, multiple myeloma, and leukemia. We generally found no evidence of an association between personal use of hair dye and cancer risk, although our study is limited by small numbers for certain cancer types.
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We measured the urinary monoester metabolites of seven commonly used phthalates in approximately 2,540 samples collected from participants of the National Health and Nutrition Examination Survey (NHANES), 1999-2000, who were greater than or equal to 6 years of age. We found detectable levels of metabolites monoethyl phthalate (MEP), monobutyl phthalate (MBP), monobenzyl phthalate (MBzP), and mono-(2-ethylhexyl) phthalate (MEHP) in > 75% of the samples, suggesting widespread exposure in the United States to diethyl phthalate, dibutyl phthalate or diisobutylphthalate, benzylbutyl phthalate, and di-(2-ethylhexyl) phthalate, respectively. We infrequently detected monoisononyl phthalate, mono-cyclohexyl phthalate, and mono-n-octyl phthalate, suggesting that human exposures to di-isononyl phthalate, dioctylphthalate, and dicyclohexyl phthalate, respectively, are lower than those listed above, or the pathways, routes of exposure, or pharmacokinetic factors such as absorption, distribution, metabolism, and elimination are different. Non-Hispanic blacks had significantly higher concentrations of MEP than did Mexican Americans and non-Hispanic whites. Compared with adolescents and adults, children had significantly higher levels of MBP, MBzP, and MEHP but had significantly lower concentrations of MEP. Females had significantly higher concentrations of MEP and MBzP than did males, but similar MEHP levels. Of particular interest, females of all ages had significantly higher concentrations of the reproductive toxicant MBP than did males of all ages; however, women of reproductive age (i.e., 20-39 years of age) had concentrations similar to adolescent girls and women 40 years of age. These population data on exposure to phthalates will serve an important role in public health by helping to set research priorities and by establishing a nationally representative baseline of exposure with which population levels can be compared.
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Hair dyes have been evaluated as possibly being mutagenic and carcinogenic in animals. Studies of the association between human cancer risk and use of hair dyes have yielded inconsistent results. The authors evaluated the risk of lymphoid malignancies associated with personal use of hair dyes. The analysis included 2,302 incident cases of lymphoid neoplasms and 2,417 hospital- or population-based controls from the Czech Republic, France, Germany, Ireland, Italy, and Spain (1998-2003). Use of hair dyes was reported by 74% of women and 7% of men. Lymphoma risk among dye users was significantly increased by 19% in comparison with never use (odds ratio (OR) = 1.19, 95% confidence interval (CI): 1.00, 1.41) and by 26% among persons who used hair dyes 12 or more times per year (OR = 1.26, 95% CI: 1.00, 1.60; p for linear trend = 0.414). Lymphoma risk was significantly higher among persons who had started coloring their hair before 1980 (OR = 1.37, 95% CI: 1.09, 1.72) and persons who had used hair dyes only before 1980 (OR = 1.62, 95% CI: 1.10, 2.40). Personal use of hair dyes is associated with a moderate increase in lymphoma risk, particularly among women and persons who used dyes before 1980. Specific compounds associated with this risk remain to be elucidated.
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Background: The Sister Study was designed to address gaps in the study of environment and breast cancer by taking advantage of more frequent breast cancer diagnoses among women with a sister history of breast cancer and the presumed enrichment of shared environmental and genetic exposures. Objective: The Sister Study sought a large cohort of women never diagnosed with breast cancer but who had a sister (full or half) diagnosed with breast cancer. Methods: A multifaceted national effort employed novel strategies to recruit a diverse cohort, and collected biological and environmental samples and extensive data on potential breast cancer risk factors. Results: The Sister Study enrolled 50,884 U.S. and Puerto Rican women 35-74y of age (median 56 y). Although the majority were non-Hispanic white, well educated, and economically well off, substantial numbers of harder-to-recruit women also enrolled (race/ethnicity other than non-Hispanic white: 16%; no college degree: 35%; household income <$50,000: 26%). Although all had a biologic sister with breast cancer, 16.5% had average or lower risk of breast cancer according to the Breast Cancer Risk Assessment Tool (Gail score). Most were postmenopausal (66%), parous with a first full-term pregnancy <30y of age (79%), never-smokers (56%) with body mass indexes (BMIs) of <29.9 kg/m2 (70%). Few (5%) reported any cancer prior to enrollment. Conclusions: The Sister Study is a unique cohort designed to efficiently study environmental and genetic risk factors for breast cancer. Extensive exposure data over the life-course and baseline specimens provide important opportunities for studying breast cancer and other health outcomes in women. Collaborations are welcome. https://doi.org/10.1289/EHP1923.
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Each year, the American Cancer Society estimates the numbers of new cancer cases and deaths that will occur in the United States and compiles the most recent data on cancer incidence, mortality, and survival. Incidence data, available through 2014, were collected by the Surveillance, Epidemiology, and End Results Program; the National Program of Cancer Registries; and the North American Association of Central Cancer Registries. Mortality data, available through 2015, were collected by the National Center for Health Statistics. In 2018, 1,735,350 new cancer cases and 609,640 cancer deaths are projected to occur in the United States. Over the past decade of data, the cancer incidence rate (2005-2014) was stable in women and declined by approximately 2% annually in men, while the cancer death rate (2006-2015) declined by about 1.5% annually in both men and women. The combined cancer death rate dropped continuously from 1991 to 2015 by a total of 26%, translating to approximately 2,378,600 fewer cancer deaths than would have been expected if death rates had remained at their peak. Of the 10 leading causes of death, only cancer declined from 2014 to 2015. In 2015, the cancer death rate was 14% higher in non-Hispanic blacks (NHBs) than non-Hispanic whites (NHWs) overall (death rate ratio [DRR], 1.14; 95% confidence interval [95% CI], 1.13-1.15), but the racial disparity was much larger for individuals aged <65 years (DRR, 1.31; 95% CI, 1.29-1.32) compared with those aged ≥65 years (DRR, 1.07; 95% CI, 1.06-1.09) and varied substantially by state. For example, the cancer death rate was lower in NHBs than NHWs in Massachusetts for all ages and in New York for individuals aged ≥65 years, whereas for those aged <65 years, it was 3 times higher in NHBs in the District of Columbia (DRR, 2.89; 95% CI, 2.16-3.91) and about 50% higher in Wisconsin (DRR, 1.78; 95% CI, 1.56-2.02), Kansas (DRR, 1.51; 95% CI, 1.25-1.81), Louisiana (DRR, 1.49; 95% CI, 1.38-1.60), Illinois (DRR, 1.48; 95% CI, 1.39-1.57), and California (DRR, 1.45; 95% CI, 1.38-1.54). Larger racial inequalities in young and middle-aged adults probably partly reflect less access to high-quality health care. CA Cancer J Clin 2018.
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Exposures to carcinogens in hair products have been explored as breast cancer risk factors, yielding equivocal findings. We examined hair product use (hair dyes, chemical relaxers and cholesterol or placenta-containing conditioners) among African American (AA) and White women, and explored associations with breast cancer. Multivariable-adjusted models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) to describe the associations of interest among 2,280 cases (1,508 AA and 772 White) and 2,005 controls (1,290 AA and 715 White). Among controls, hair dye use was more common among Whites than AAs (58% vs. 30%), while relaxer (88% vs. 5%) and deep conditioner use (59% vs. 6%) was more common among AAs. Among AAs, use of dark hair dye shades was associated with increased breast cancer risk (OR=1.51, 95% CI: 1.20-1.90) and use of dark shades (OR=1.72, 95% CI: 1.30-2.26) and higher frequency of use (OR=1.36, 95% CI: 1.01-1.84) were associated with ER+ disease. Among Whites, relaxer use (OR=1.74, 95% CI: 1.11- 2.74) and dual use of relaxers and hair dyes (OR=2.40, 95% CI: 1.35-4.27) was associated with breast cancer; use of dark hair dyes was associated with increased ER+ disease (OR=1.54, 95% CI: 1.01-2.33), and relaxer use was associated with increased ER- disease (OR=2.56, 95% CI: 1.06-6.16). These novel findings provide support a relationship between the use of some hair products and breast cancer. Further examinations of hair products as important exposures contributing to breast cancer carcinogenesis are necessary.
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It is hypothesized that certain chemicals in personal care products may alter the risk of adverse health outcomes. The primary aim of this study was to use a data-centered approach to classify complex patterns of exposure to personal care products and to understand how these patterns vary according to use of exogenous hormone exposures, oral contraceptives (OCs) and post-menopausal hormone therapy (HT). The NIEHS Sister Study is a prospective cohort study of 50,884 US women. Limiting the sample to non-Hispanic blacks and whites (N=47,019), latent class analysis (LCA) was used to identify groups of individuals with similar patterns of personal care product use based on responses to 48 survey questions. Personal care products were categorized into three product types (beauty, hair, and skincare products) and separate latent classes were constructed for each type. Adjusted prevalence differences (PD) were calculated to estimate the association between exogenous hormone use, as measured by ever/never OC or HT use, and patterns of personal care product use. LCA reduced data dimensionality by grouping of individuals with similar patterns of personal care product use into mutually exclusive latent classes (three latent classes for beauty product use, three for hair, and four for skin care. There were strong differences in personal care usage by race, particularly for haircare products. For both blacks and whites, exogenous hormone exposures were associated with higher levels of product use, especially beauty and skincare products. Relative to individual product use questions, latent class variables capture complex patterns of personal care product usage. These patterns differed by race and were associated with ever OC and HT use. Future studies should consider personal care product exposures with other exogenous exposures when modeling health risks.
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Disparities in women’s reproductive health outcomes across the life course have been well-documented. Endocrine disrupting chemicals may be one factor driving disparities, as studies suggest exposure to certain environmental endocrine disrupting chemicals, such as certain phthalates, bisphenol A, parabens, and polybrominated diphenyl ethers, is higher in non-Whites. Yet, a limited amount of research has focused on these chemical exposures as a potential mediator of racial/ethnic differences in women’s reproductive health outcomes, such as pubertal development, fibroids, infertility, and pregnancy complications. Given that race/ethnicity is a social construct, the purpose of this review was to present the current state of the literature on racial/ethnic disparities in both environmental endocrine disrupting chemicals, as well as associations between these chemicals and selected women’s reproductive health outcomes. Our goal was to evaluate literature from populations based in the USA to (1) characterize racial/ethnic differences in environmental endocrine disrupting chemicals and (2) systematically review literature on environmental endocrine disrupting chemicals and selected women’s health outcomes in populations containing more than one racial/ethnic group. This review highlights the need for future work in determining whether higher exposures to some environmental endocrine disrupting chemicals might partly explain differences in women’s reproductive health outcomes in these higher-exposure and high-risk groups.
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In this article, the American Cancer Society provides an overview of female breast cancer statistics in the United States, including data on incidence, mortality, survival, and screening. Approximately 231,840 new cases of invasive breast cancer and 40,290 breast cancer deaths are expected to occur among US women in 2015. Breast cancer incidence rates increased among non-Hispanic black (black) and Asian/Pacific Islander women and were stable among non-Hispanic white (white), Hispanic, and American Indian/Alaska Native women from 2008 to 2012. Although white women have historically had higher incidence rates than black women, in 2012, the rates converged. Notably, during 2008 through 2012, incidence rates were significantly higher in black women compared with white women in 7 states, primarily located in the South. From 1989 to 2012, breast cancer death rates decreased by 36%, which translates to 249,000 breast cancer deaths averted in the United States over this period. This decrease in death rates was evident in all racial/ethnic groups except American Indians/Alaska Natives. However, the mortality disparity between black and white women nationwide has continued to widen; and, by 2012, death rates were 42% higher in black women than in white women. During 2003 through 2012, breast cancer death rates declined for white women in all 50 states; but, for black women, declines occurred in 27 of 30 states that had sufficient data to analyze trends. In 3 states (Mississippi, Oklahoma, and Wisconsin), breast cancer death rates in black women were stable during 2003 through 2012. Widening racial disparities in breast cancer mortality are likely to continue, at least in the short term, in view of the increasing trends in breast cancer incidence rates in black women. CA Cancer J Clin 2015. © 2015 American Cancer Society.
Article
To evaluate the relationship between race/ethnicity and breast cancer-specific survival according to subtype and explore mediating factors. Participants were women presenting with stage I to III breast cancer between January 2000 and December 2007 at National Comprehensive Cancer Network centers with survival follow-up through December 2009. Cox proportional hazards regression was used to compare breast cancer-specific survival among Asians (n = 533), Hispanics (n = 1,122), and blacks (n = 1,345) with that among whites (n = 14,268), overall and stratified by subtype (luminal A like, luminal B like, human epidermal growth factor receptor 2 type, and triple negative). Model estimates were used to derive mediation proportion and 95% CI for selected risk factors. In multivariable adjusted models, overall, blacks had 21% higher risk of breast cancer-specific death (hazard ratio [HR], 1.21; 95% CI, 1.00 to 1.45). For estrogen receptor-positive tumors, black and white survival differences were greatest within 2 years of diagnosis (years 0 to 2: HR, 2.65; 95% CI, 1.34 to 5.24; year 2 to end of follow-up: HR, 1.50; 95% CI, 1.12 to 2.00). Blacks were 76% and 56% more likely to die as a result of luminal A-like and luminal B-like tumors, respectively. No disparities were observed for triple-negative or human epidermal growth factor receptor 2-type tumors. Asians and Hispanics were less likely to die as a result of breast cancer compared with whites (Asians: HR, 0.56; 95% CI, 0.37 to 0.85; Hispanics: HR, 0.74; 95% CI, 0.58 to 0.95). For blacks, tumor characteristics and stage at diagnosis were significant disparity mediators. Body mass index was an important mediator for blacks and Asians. Racial disparities in breast cancer survival vary by tumor subtype. Interventions are needed to reduce disparities, particularly in the first 2 years after diagnosis among black women with estrogen receptor-positive tumors. © 2015 by American Society of Clinical Oncology.
Article
Brazilian keratin treatments are widely available products that are used by women all over the world to straighten hair. Marketers of these products claim that the keratin treatments render naturally curly hair more manageable and frizz-free while enhancing color and shine, giving the hair a healthier appearance. Although widely used, there have been virtually no reports of adverse side effects. Unfortunately, many of the products that are applied by salon professionals contain formaldehyde or its derivatives and are being marketed as safe.
Article
Purpose: The incidence of estrogen receptor positive (ER+) breast cancer is higher among white women relative to black women. In two large prospective cohorts, the Black Women's Health Study (BWHS) and the Nurses' Health Study II (NHSII), we investigated whether reproductive factors explain the difference. Methods: During 1,582,083 person-years of follow-up of 140,914 women observed from 1995 to 2007, 327 ER+ breast cancers were identified among black women in BWHS and NHSII and 1,179 among white women in NHSII. Cox proportional hazards regression models, stratified by race and pooled, were used to estimate hazard ratios (HR) and 95 % confidence intervals (CI) for the association of race, parity, age at first birth, and lactation in relation to risk of ER+ cancer with adjustment for age and other breast cancer risk factors. Results: Age at first birth differed markedly in the two groups, with 66 % of parous black women having their first child before age 25 as compared with 36 % of white women. Each additional year of age at first birth was associated with a 4 % increased risk of ER+ breast cancer among both racial groups. Relative to nulliparous women, parous women were at decreased risk of ER+ breast cancer (HR 0.59, 95 % CI 0.20, 1.77), in black women and (HR 0.63, 95 % CI 0.45, 0.87) in white women. The HR for the association of black race with ER+ cancer was 0.67 (95 % CI 0.53, 0.84) in a model that adjusted for age only, 0.77 (95 % CI 0.61, 0.99) in a model that controlled for parity, age at first birth, and other reproductive/hormonal factors, and 0.83 (95 % CI 0.70, 0.98) in a model that additionally controlled for other breast cancer risk factors such as alcohol consumption and use of hormone supplements. Similar associations were seen among premenopausal women and in an analysis restricted to ER+PR+ tumors. Conclusions: Reproductive factors explained some of the higher incidence of ER+ tumors among white women as compared to black women.
Article
Aromatic amine components in hair dyes and polymorphisms in genes that encode enzymes responsible for hair dye metabolism may be related to bladder cancer risk. We evaluated the association between hair dye use and bladder cancer risk and effect modification by N-acetyltransferase-1 (NAT1), NAT2, glutathione S-transferase Mu-1 (GSTM1) and glutathione S-transferase theta-1 (GSTT1) genotypes in a population-based case-control study of 1193 incident cases and 1418 controls from Maine, Vermont and New Hampshire enrolled between 2001 and 2004. Individuals were interviewed in person using a computer-assisted personal interview to assess hair dye use and information on potential confounders and effect modifiers. No overall association between age at first use, year of first use, type of product, color, duration or number of applications of hair dyes and bladder cancer among women or men was apparent, but increased risks were observed in certain subgroups. Women who used permanent dyes and had a college degree, a marker of socioeconomic status, had an increased risk of bladder cancer [odds ratio (OR) = 3.3, 95% confidence interval (CI): 1.2-8.9]. Among these women, we found an increased risk of bladder cancer among exclusive users of permanent hair dyes who had NAT2 slow acetylation phenotype (OR = 7.3, 95% CI: 1.6-32.6) compared to never users of dye with NAT2 rapid/intermediate acetylation phenotype. Although we found no relation between hair dye use and bladder cancer risk in women overall, we detected evidence of associations and gene-environment interaction with permanent hair dye use; however, this was limited to educated women. These results need confirmation with larger numbers, requiring pooling data from multiple studies.
Article
A survey of 120 557 married, female, registered U.S. nurses, aged 30 to 55 years, carried out in 1976, showed that 38 459 (31·9%) had at some time used hair dyes, and 3548 (2·9%) had had cancer. For all cancers combined, the risk ratio (R.R.) for the development of cancer among women who had used hair dyes at any time, compared with those who had never used them, was 1·10 (P=0·02). When cancers were subdivided by anatomical site into 16 main groups, only those of the cervix uteri (R.R.=1·44, P<0·001) and those of the vagina and vulva (R.R.=2·58, P=0·02) showed statistically significant associations with use of permanent hair dyes. Both these associations were reduced but remained significant after standardisation for cigarette smoking, and neither showed increases in risk of cancer with increasing years since first use of hair dyes. Women who had used permanent dyes for 21 years or more before the onset of cancer had a significant increase in risk for all sites combined (R.R.=1·38, P=0·02), compared with "never users". This increase was primarily due to an excess number of observed to expected cases of breast cancer (24 versus 16·3). However, among those who had first used dye 16 to 20 years before diagnosis of breast cancer, there was an almost equal deficit in numbers of cancers at this site (16 observed versus 25·1 expected). The present evidence does not indicate that any material risk of cancer is likely to have occurred during the initial 20 years following first use of permanent hair dyes.
Article
A case-control study was undertaken of use of permanent and semipermanent hair dyes by women with cancers of several sites, including breast and endometrium. In London, Ontario, 50 cases of of breast cancer and in Toronto 35 cases of breast cancer and 36 cases of endometrial cancer were identified in cancer treatment centers. In London, controls were selected from hospitalized women with diseases other than cancer; in Toronto, controls were selected from women living in the same neighborhood as the patients with cancer. The results did not suggest an increased risk of either breast or endometrial cancer in users of permanent or permanent and semipermanent dyes combined. Although the numbers of cases and controls were small, the consistency of the results for both sites, in both study centers, and the absence of any clear positive relationship between various measures of intensity of use and risk of cancer provided evidence that a large increase in risk was not missed.
Article
The recent finding that many permanent and semipermanent hair dyes are strongly mutagenic in a laboratory test, together with the fact that single female hair-dressers had higher than expected death rates from breast-cancer in 1959-63, prompted a study into the use of hair dyes by patients with breast cancer and by matched controls. There was no difference between the patients and their controls in their use of hair dyes. There were also no significant differences between the two groups when the analysis was confinedto women who had used dyes over four years and over nine years before diagnosis. The only significant findings were a higher proportion of past or present smokers among women aged over 50 who used hair dyes and an association between hair dyes use and age at first pregnancy. Further epidemiological studies are clearly needed in view of the mutagenicity found in the Ames test, and the fact th & several human carcinogens are also mutagenic according to this test.
Article
An epidemiologic case-control study of 1617 patients with a primary breast cancer and 1617 control subjects was conducted to test the hypothesis that use of hair dyes is related to breast cancer. No overall association was observed between breast cancer risk and "ever use" of hair dyes (odds ratio, 1.04; 95% confidence interval, 0.90 to 1.21), age when hair dye use started and age when it stopped, duration of hair dye use (years), types of hair dyes used, and estimated lifetime number of individual applications. The current data set also failed to show an increased risk for breast cancer in women who had been diagnosed with benign breast disease and were exposed to hair dyes.
Article
To investigate whether hair dye use increases the risk of breast cancer, a case-control study was conducted among patients attending a screening center in New York City. The study group consisted of 398 breast cancer cases identified at the screening center between 1977 and 1981, and 790 randomly selected controls screened during the same period. Subjects were interviewed by telephone to obtain information on known risk factors for breast cancer, along with a complete history of hair dye use detailing type of dye, color, duration, frequency, and temporal periods of use. Most subjects (77%) had used hair dye at least once, 38% of the subjects at least 100 times. However, little increased risk of breast cancer was found among hair dye users. The adjusted odds ratio for ever having used hair dye was 0.8 (95% confidence interval 0.6-1.1), and there was no evidence of a trend in risk with increasing number of hair dye uses. The results were the same whether all past exposures were considered or only exposures more than 10 years before disease. Breast cancer risk did not increase with increasing intensity of exposure, as measured by frequency of use or darkness of color. No effect was seen for different types or colors of dye, or for use during different periods of reproductive life. Although personal hair dye use was unrelated to breast cancer risk, there was an adjusted odds ratio of 3.0 (95% confidence interval 1.1-7.8) for 5 or more years of work as a beautician. Overall, the results of this study, taken in conjunction with the findings of other epidemiologic studies, do not implicate hair dye use as an important cause of human breast cancer.
Article
Aromatic amines contained in permanent hair dyes can be absorbed percutaneously and are mutagenic and carcinogenic in some laboratory studies. Concern has been raised that use of these dyes may increase the risk of human cancers. Therefore, the present study examined the relationship between permanent hair dye use and incidence of breast cancer among 118,404 U.S. women aged 30-55 years who were followed prospectively for 6 years. Among women who had ever used permanent hair dyes, 353 developed breast cancer during 246,848 person-years of follow-up, while 505 cases occurred during 397,460 person-years among never users (age-adjusted rate ratio = 1.1; 95% confidence interval = 0.9-1.2). Identical rate ratios were observed when women who had ever used hair dyes were subdivided into current and past users. Adjustment for known determinants of breast cancer in multivariate models did not alter these relationships. The risk of breast cancer did not increase with more frequent use, longer duration of use, or interval since first use. On the basis of these data and previous findings, it appears unlikely that the use of permanent hair dyes causes any important increase in risk of breast cancer.
Article
para-Phenylenediamine (p-PD), a widely used aromatic amine in the preparation of commercial oxidative-type hair dyes, has been previously demonstrated to have neither mutagenic activity to Salmonella typhimurium nor carcinogenic activity in rats and mice. In this study, the mutagenicity of p-PD after an oxidation by hydrogen peroxide towards S. typhimurium TA98 and its carcinogenkity in Wistar rats were examined both by topical application to the shaved skin and by s.c. injection. Hie oxidation product was found to be strongly muta-genic to the bacterial tester strain in the presence of rat liver S-9 fraction. Interestingly, in female rats, both topical application and s.c. injection for 18 months of oxidized p-PD could induce a statistically significant incidence of mammary gland tumors (>50%, P < 0.05). In addition, uterine tumors and soft tissue tumors of both malignant and benign types were also significantly induced (43% and 57%, P < 0.05) hi the s.c. injection group. On the other hand, tumors of mammary gland and soft tissue were not observed in male rats under similar experimental conditions. However, tumors of other organs including liver, kidney, adrenal gland, thyroid gland, urinary bladder and lung were occasionally observed in male rats of both groups and might be related to the p-PD treatment.
Article
In a case-control study of 401 breast cancer cases and 625 age-matched controls, the possible etiologic role of hair dye usage was investigated. No association was found between hair dye use and breast cancer (odds ratio = 1.02; 95% confidence interval = 0.77-1.32) or any factors affecting dosage, frequency, duration, type, or color of hair dye. Important confounders of hair dye use included religion and smoking status. When stratified by 10-year age groups, there was no appreciable trend in risk status between case and referent populations. No dose-response relationship (frequency X duration X shade X type of dye used) was found, even after controlling for factors affecting hair dye use. A multiple logistic regression analysis supported the absence of this relationship.
Article
F344 female rats were fed 2,4-diaminoanisole sulfate (2,4-DAA) (a hair dye component) at three concentration levels up to 86 weeks. The administration of hair dye was interrupted after 10 weeks' feeding for 15 animals at the highest concentration level. Both the early effect of 2,4-DAA on the thyroid gland and the late effect on thyroid, mammary, clitoral, and pituitary glands were studied. In a few weeks, 2,4-DAA showed goitrogenic effects on the thyroid gland. However, the nodular phase of the goiter did not develop. Cystic colloid-filled follicles became lined with basophilic flattened epithelium that continued to proliferate and to form adenomatous or papillary neoplasms. Only 10 weeks of feeding at the high level of 2,4-DAA produced a 42% tumor incidence, and one-fourth of the animals had thyroid tumors. Dark pigment in the thyroid epithelium was still present 70 weeks after the feeding of 2,4-DAA had been interrupted. Feeding of high levels of 2,4-DAA for 82 weeks produced a 78% thyroid tumor incidence. Mammary tumor incidence was nearly five times higher at the 0.24% 2,4-DAA feeding level than among controls. At this same feeding level, 45% of the rats had clitoral tumors. Lesions of the pituitary gland were present in all groups, but tumors were encountered only among the 2,4-DAA-fed animals.
Article
Permanent hair dyes are used by about one third of adult American women. Several epidemiologic studies associate hair dye use with increased risk of non-Hodgkin's lymphoma and multiple myeloma. In one study, risk increased with more prolonged exposure to darker, more concentrated, permanent dyes. The purpose of our study was to examine the relationship between hair dye use and development of certain cancers associated with hair dye use in previous studies. We examined prospectively the relationship between the use of permanent hair dyes and selected fatal cancers in 573,369 women. The participants provided information in 1982 on the frequency and duration of hair dye use and the color of hair dye used. Death rates were measured through 1989. Relative risks (RRs) were computed with subjects who had not used hair dyes serving as the referent group, and 95% confidence intervals (CIs) were calculated on the basis of approximate-variance formulas. Women who had ever used permanent hair dyes showed decreased risk of all fatal cancers combined (RR = 0.93; 95% CI = 0.89-0.98) and of urinary system cancers (RR = 0.65; 95% CI = 0.49-0.87) and no increase in risk of any type of hematopoietic cancer. Women who had used black hair dyes for 20 years (0.6% of women hair dyers) or more had increased risk of fatal non-Hodgkin's lymphoma (RR = 4.37; 95% CI = 1.3-15.2) and multiple myeloma (RR = 4.39; 95% CI = 1.1-18.3). These positive findings are based on three cases of non-Hodgkin's lymphoma and two cases of multiple myeloma. We found no relationship between use of permanent hair dyes and fatal cancers of the mouth, breast, lung, bladder, or cervix, areas that were of interest as the result of earlier studies. Women using permanent hair dyes are not generally at increased risk of fatal cancer. Women with prolonged use of dark, particularly black, hair dyes may have increased risk of fatal non-Hodgkin's lymphoma and multiple myeloma, but these women are a small fraction of hair dye users. Nonetheless, the removal of carcinogens from hair dyes and appropriate labeling of hair-coloring products would help reduce this potential risk.
Article
Four African-American girls aged 14 months to 93 months developed breast or pubic hair 2 to 24 months after starting the use of estrogen or placenta-containing hair products. Discontinuing the use of the hair products resulted in regression of the breast or pubic hair. Serum gonadotropins and estradiol levels were variable. No other cause for early sexual development was noted in these girls.
Article
Causal diagrams have a long history of informal use and, more recently, have undergone formal development for applications in expert systems and robotics. We provide an introduction to these developments and their use in epidemiologic research. Causal diagrams can provide a starting point for identifying variables that must be measured and controlled to obtain unconfounded effect estimates. They also provide a method for critical evaluation of traditional epidemiologic criteria for confounding. In particular, they reveal certain heretofore unnoticed shortcomings of those criteria when used in considering multiple potential confounders. We show how to modify the traditional criteria to correct those shortcomings.
Article
A recent epidemiological study suggested that aromatic amines present in hair dyes may contribute to an increased risk of bladder cancer (Gago-Dominguez, et al. (2003) Carcinogenesis 24, 483-489). Moreover, a preliminary study linked frequent hair dye usage with elevated levels of DNA adducts of 4-aminobiphenyl (4-ABP) in human epithelial breast cells (Gorlewska, et al. Proc. Am. Assoc. Cancer Res. 43, 1018-1019). Therefore, we sought to determine if 4-ABP, a recognized human urinary bladder carcinogen, is present in commercial hair dyes. 4-ABP was isolated from dyes by solvent extraction with hexane, followed by silica gel chromatography, either with or without chemical treatment of the extract with Zinc/HCl, and a final purification with a mixed cation exchange reversed-phase resin. The identity of 4-ABP was confirmed by both HPLC with electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS) and gas chromatography with negative ion chemical ionization mass spectrometry (GC-NICI-MS) following chemical derivatization with pentafluoropropionic anhydride (PFPA). The levels of 4-ABP ranged from not detectable (<0.29 parts per billion (ppb)) up to 12.8 ppb. The noncarcinogenic isomer 2-aminobiphenyl (2-ABP) was also found at quantities up to 310 ppb. 4-ABP was detected in eight of the 11 hair dyes and found in black, red, and blonde hair dyes but not in brown hair dyes. 1,4-Phenylenediamine (PPD) is a key constituent for color development of many permanent hair dyes. Some batches of chemical research grade PPD were contaminated with 4-ABP (up to 500 ppb) and 2-ABP (up to 70 parts per million) and may be a source of ABP contamination in hair dyes. These analytical data demonstrate that 4-ABP is present in some hair dyes. Studies on dermal absorption and bioavailability of 4-ABP from hair dyes are required to determine if this aromatic amine contributes to the increased risk of bladder cancer reported in frequent users of hair dyes.
Article
We surveyed 2,097 subjects stationed at a US Army School to study the use of commercial hair products whose labeled ingredients included hormone or placenta. Use of some of these products is associated with premature sexual development. Use by demographics is: All = 14.8%, whites = 6.3%, non-whites = 27.0%; males = 8.7%, females = 24.6%; officers = 7.3%, enlisted = 18.7%. Frequency of use was highest among non-white female enlisted personnel (43 +/- 6.4%) and lowest among white male commissioned officers (2.0 +/- 1.7%). Regardless of ethnicity, 13.4% of respondents' children used the hair product. Use is about four times higher for non-whites than for whites. Females and enlisted personnel are more likely to use the hair product than males or officers. The use of hormonal hair products among children parallels use by their parents. In spite of federal regulation, the use of these hair products is still common.
Article
Established models of breast cancer risk, such as the Gail model, do not account for patterns of the disease in women under the age of 35, especially in African Americans. With the possible exceptions of ionizing radiation or inheriting a known genetic mutation, most of the known risk factors for breast cancer are related to cumulative lifetime exposure to estrogens. Increased risk of breast cancer has been associated with earlier onset of menses or later age at menopause, nulliparity or late first parity, use of hormonal contraceptives or hormone replacement therapy, shorter lactation history, exposure to light at night, obesity, and regular ingestion of alcohol, all of which increase circulating levels of unbound estradiol. Among African Americans at all ages, use of hormone-containing personal care products (PCPs) is more common than among whites, as is premature appearance of secondary sexual characteristics among infants and toddlers. We hypothesize that the use of estrogen and other hormone-containing PCPs in young African American women accounts, in part, for their increased risk of breast cancer prior to menopause, by subjecting breast buds to elevated estrogen exposure during critical windows of vulnerability in utero and in early life. These early life and continuing exposures to estrogenic and xenoestrogenic agents may also contribute to the increased lethality of breast cancer in young women in general and in African American women of all ages. Public disclosure by manufacturers of proprietary hormonally active ingredients is required for this research to move forward.
Article
Hair relaxers (straighteners) have been used by millions of African American women, often for many years. Relaxer ingredients can enter the body through scalp lesions and burns. Because manufacturers are not required to list all ingredients, these products may contain unknown harmful substances. We assessed hair relaxer use in relation to breast cancer incidence in the Black Women's Health Study, a nationwide follow-up study of African American women. Information on hair relaxer use was collected in 1997; 48,167 women were followed subsequently through 2003 for incident breast cancer. Incidence rate ratios of breast cancer were estimated with Cox regression. During 266,298 person-years of follow-up, 574 incident cases of breast cancer were ascertained. There were no increases in breast cancer risk associated with any categories of duration of hair relaxer use, frequency of use, age at first use, number of burns experienced during use, or type of relaxer used. The incidence rate ratio for use at least seven times a year for 20 or more years relative to use for less than a year was 0.98 (95% confidence interval, 0.78-1.39). These results suggest that hair relaxer use does not increase the incidence of breast cancer in African American women.
Article
Diet and environmental exposures to aromatic and heterocyclic amines, and polycyclic aromatic hydrocarbons, are thought to be etiologic factors for breast cancer risk. In this study, we chose to quantify the major DNA adduct derived from one member of each of these classes of carcinogens in epithelial cell DNA isolated from human breast milk. Appreciable adducts were detected for each class, namely 2-amino-6-phenylimidazo[4,5-b]pyridine (PhIP), 4-aminobiphenyl (ABP) and benzo[a]pyrene. The effect of several metabolic genotypes on adduct levels were also investigated and higher PhIP and ABP adducts were associated with the rapid NAT2 and/or rapid NAT1 genotypes. The presence of ABP adducts was also significantly associated with the use of hair coloring products (OR=11.2, 95% CI=1.1-109.2) but not tobacco usage. These data indicate that women are exposed to several classes of dietary and environmental carcinogens and that metabolic genotype can be a susceptibility factor.