Dale P Sandler

University of Bergen, Bergen, Hordaland, Norway

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Publications (332)1762.53 Total impact

  • Cancer Research 08/2015; 75(15 Supplement):854-854. DOI:10.1158/1538-7445.AM2015-854 · 9.28 Impact Factor
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    ABSTRACT: Classical statistical methods for analyzing exposure data with values below the detection limits are well described in the occupational hygiene literature, but an evaluation of a Bayesian approach for handling such data is currently lacking. Here, we first describe a Bayesian framework for analyzing censored data. We then present the results of a simulation study conducted to compare the β-substitution method with a Bayesian method for exposure datasets drawn from lognormal distributions and mixed lognormal distributions with varying sample sizes, geometric standard deviations (GSDs), and censoring for single and multiple limits of detection. For each set of factors, estimates for the arithmetic mean (AM), geometric mean, GSD, and the 95th percentile (X0.95) of the exposure distribution were obtained. We evaluated the performance of each method using relative bias, the root mean squared error (rMSE), and coverage (the proportion of the computed 95% uncertainty intervals containing the true value). The Bayesian method using non-informative priors and the β-substitution method were generally comparable in bias and rMSE when estimating the AM and GM. For the GSD and the 95th percentile, the Bayesian method with non-informative priors was more biased and had a higher rMSE than the β-substitution method, but use of more informative priors generally improved the Bayesian method's performance, making both the bias and the rMSE more comparable to the β-substitution method. An advantage of the Bayesian method is that it provided estimates of uncertainty for these parameters of interest and good coverage, whereas the β-substitution method only provided estimates of uncertainty for the AM, and coverage was not as consistent. Selection of one or the other method depends on the needs of the practitioner, the availability of prior information, and the distribution characteristics of the measurement data. We suggest the use of Bayesian methods if the practitioner has the computational resources and prior information, as the method would generally provide accurate estimates and also provides the distributions of all of the parameters, which could be useful for making decisions in some applications. © The Author 2015. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.
    Annals of Occupational Hygiene 07/2015; DOI:10.1093/annhyg/mev049 · 2.07 Impact Factor
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    ABSTRACT: Greater body mass index (BMI), a measure of overall adiposity, is associated with a higher risk of postmenopausal breast cancer. The role of central adiposity, often measured by waist circumference, is less well understood, especially among premenopausal women. The objective of the current study was to examine multiple measures of adiposity in relation to breast cancer in a prospective cohort study. A total of 50,884 Sister Study cohort participants aged 35 to 74 years were enrolled from 2003 through 2009. Inclusion criteria for the cohort included having a sister previously diagnosed with breast cancer. Trained study personnel measured height, weight, and waist and hip circumference during a home visit and study participants completed a detailed questionnaire. Using Cox regression analysis, we estimated multivariable hazard ratios (HRs) and 95% confidence intervals (95% CIs) for breast cancer risk associated with adiposity measurements, considering tumor subtype and menopausal status. In total, 2009 breast cancers were diagnosed during follow-up (mean = 5.4 years). Weight, BMI, waist circumference, and waist-to-hip ratio were found to be positively associated with overall breast cancer risk and HRs were greater among postmenopausal women, those with hormonally responsive tumors, and women who were not currently using postmenopausal hormones. In models that adjusted for BMI, waist circumference associations persisted among both postmenopausal women (81-88 cm vs ≤80 cm: HR = 1.16 [95% CI 1.01-1.35] and >88 cm vs ≤80 cm: HR = 1.30 [95% CI 1.10-1.54]) and premenopausal women (81-88 cm vs ≤80 cm: HR = 1.56 [95% CI 1.19-2.04] and >88 cm vs ≤80 cm: HR = 1.30 [95% CI 0.91-1.87]). Findings from this large, prospective study with examiner-measured body size indicate that waist circumference is independently and positively associated with both premenopausal and postmenopausal breast cancer risk. Cancer 2015. © 2015 American Cancer Society. © 2015 American Cancer Society.
    Cancer 07/2015; DOI:10.1002/cncr.29552 · 4.90 Impact Factor
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    ABSTRACT: Experimental studies suggest a relationship between pesticide exposure and renal impairment, but epidemiological evidence is limited. We evaluated the association between exposure to 39 specific pesticides and end-stage renal disease (ESRD) incidence in the Agricultural Health Study, a prospective cohort study of licensed pesticide applicators in Iowa and North Carolina. Via linkage to the US Renal Data System, we identified 320 ESRD cases diagnosed between enrolment (1993-1997) and December 2011 among 55 580 male licensed pesticide applicators. Participants provided information on use of pesticides via self-administered questionnaires. Lifetime pesticide use was defined as the product of duration and frequency of use and then modified by an intensity factor to account for differences in pesticide application practices. Cox proportional hazards models, adjusted for age and state, were used to estimate associations between ESRD and: (1) ordinal categories of intensity-weighted lifetime use of 39 pesticides, (2) poisoning and high-level pesticide exposures and (3) pesticide exposure resulting in a medical visit or hospitalisation. Positive exposure-response trends were observed for the herbicides alachlor, atrazine, metolachlor, paraquat, and pendimethalin, and the insecticide permethrin. More than one medical visit due to pesticide use (HR=2.13; 95% CI 1.17 to 3.89) and hospitalisation due to pesticide use (HR=3.05; 95% CI 1.67 to 5.58) were significantly associated with ESRD. Our findings support an association between ESRD and chronic exposure to specific pesticides, and suggest pesticide exposures resulting in medical visits may increase the risk of ESRD. Clinicaltrials.gov NCT00352924. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
    Occupational and environmental medicine 07/2015; DOI:10.1136/oemed-2014-102615 · 3.23 Impact Factor
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    ABSTRACT: Organophosphates (OPs) are among the most commonly used insecticides. OPs have been linked to cancer risk in some epidemiological studies, which have been largely conducted in predominantly male populations. We evaluated personal use of specific OPs and cancer incidence among female spouses of pesticide applicators in the prospective Agricultural Health Study cohort. At enrolment (1993-1997), spouses provided information about ever use of specific pesticides, including 10 OPs, demographic information, reproductive health history and other potential confounders. We used Poisson regression to estimate relative risks (RRs) and 95% CIs for all cancers diagnosed through 2010 for North Carolina and through 2011 for Iowa. Among 30 003 women, 25.9% reported OP use, and 718 OP-exposed women were diagnosed with cancer during the follow-up period. Any OP use was associated with an elevated risk of breast cancer (RR=1.20, 95% CI 1.01 to 1.43). Malathion, the most commonly reported OP, was associated with increased risk of thyroid cancer (RR=2.04, 95% CI 1.14 to 3.63) and decreased risk of non-Hodgkin lymphoma (RR=0.64, 95% CI 0.41 to 0.99). Diazinon use was associated with ovarian cancer (RR=1.87, 95% CI 1.02 to 3.43). We observed increased risk with OP use for several hormonally-related cancers, including breast, thyroid and ovary, suggesting potential for hormonally-mediated effects. This study represents the first comprehensive analysis of OP use and cancer risk among women, and thus demonstrates a need for further evaluation. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
    Occupational and environmental medicine 07/2015; DOI:10.1136/oemed-2014-102798 · 3.23 Impact Factor
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    ABSTRACT: Associations between anthropometry and head and neck cancer (HNC) risk are inconsistent. We aimed to evaluate these associations while minimizing biases found in previous studies. We pooled data from 1 941 300 participants, including 3760 cases, in 20 cohort studies and used multivariable-adjusted Cox proportional hazard regression models to estimate hazard ratios (HR) and 95% confidence intervals (CI) for the association of anthropometric measures with HNC risk overall and stratified by smoking status. Greater waist circumference (per 5 cm: HR = 1.04, 95% CI 1.03-1.05, P-value for trend = <0.0001) and waist-to-hip ratio (per 0.1 unit: HR = 1.07, 95% CI 1.05-1.09, P-value for trend = <0.0001), adjusted for body mass index (BMI), were associated with higher risk and did not vary by smoking status (P-value for heterogeneity = 0.85 and 0.44, respectively). Associations with BMI (P-value for interaction = <0.0001) varied by smoking status. Larger BMI was associated with higher HNC risk in never smokers (per 5 kg/m(2): HR = 1.15, 95% CI 1.06-1.24, P-value for trend = 0.0006), but not in former smokers (per 5 kg/m(2): HR = 0.99, 95% CI 0.93-1.06, P-value for trend = 0.79) or current smokers (per 5 kg/m(2): HR = 0.76, 95% CI 0.71-0.82, P-value for trend = <0.0001). Larger hip circumference was not associated with a higher HNC risk. Greater height (per 5 cm) was associated with higher risk of HNC in never and former smokers, but not in current smokers. Waist circumference and waist-to-hip ratio were associated positively with HNC risk regardless of smoking status, whereas a positive association with BMI was only found in never smokers. © The Author 2015; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association.
    International Journal of Epidemiology 06/2015; 44(2). DOI:10.1093/ije/dyv059 · 9.20 Impact Factor
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    ABSTRACT: This study describes associations of ozone and fine particulate matter with Parkinson's disease observed among farmers in North Carolina and Iowa. We used logistic regression to determine the associations of these pollutants with self-reported, doctor-diagnosed Parkinson's disease. Daily predicted pollutant concentrations were used to derive surrogates of long-term exposure and link them to study participants' geocoded addresses. We observed positive associations of Parkinson's disease with ozone (odds ratio = 1.39; 95% CI: 0.98 to 1.98) and fine particulate matter (odds ratio = 1.34; 95% CI: 0.93 to 1.93) in North Carolina but not in Iowa. The plausibility of an effect of ambient concentrations of these pollutants on Parkinson's disease risk is supported by experimental data demonstrating damage to dopaminergic neurons at relevant concentrations. Additional studies are needed to address uncertainties related to confounding and to examine temporal aspects of the associations we observed.
    Journal of occupational and environmental medicine / American College of Occupational and Environmental Medicine 05/2015; 57(5):509-17. DOI:10.1097/JOM.0000000000000451 · 1.80 Impact Factor
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    ABSTRACT: Metolachlor, a widely used herbicide, is classified as a Group C carcinogen by the U.S. Environmental Protection Agency based on increased liver neoplasms in female rats. Epidemiologic studies of the health effects of metolachlor have been limited. The Agricultural Health Study (AHS) is a prospective cohort study including licensed private and commercial pesticide applicators in Iowa and North Carolina enrolled 1993-7. We evaluated cancer incidence through 2010/2011 (NC/IA) for 49,616 applicators, 53% of whom reported ever using metolachlor. We used Poisson regression to evaluate relations between two metrics of metolachlor use (lifetime days, intensity-weighted lifetime days) and cancer incidence. We saw no association between metolachlor use and incidence of all cancers combined (n=5701 with a 5-year lag) or most site-specific cancers. For liver cancer, in analyses restricted to exposed workers, elevations observed at higher categories of use were not statistically significant. However, trends for both lifetime and intensity-weighted lifetime days of metolachor use were positive and statistically significant with an unexposed reference group. A similar pattern was observed for follicular-cell lymphoma, but no other lymphoma subtypes. An earlier suggestion of increased lung cancer risk at high levels of metolachlor use in this cohort was not confirmed in this update. This suggestion of an association between metolachlor and liver cancer among pesticide applicators is a novel finding and echoes observation of increased liver neoplasms in some animal studies. However, our findings for both liver cancer and follicular-cell lymphoma warrant follow-up to better differentiate effects of metolachlor use from other factors. This article is protected by copyright. All rights reserved. © 2015 UICC.
    International Journal of Cancer 05/2015; DOI:10.1002/ijc.29621 · 5.01 Impact Factor
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    ABSTRACT: High rates of mental health (MH) problems have been documented among disaster relief workers. However, few workers utilize MH services, and predictors of service use among this group remain unexplored. The purpose of this study was to explore associations between predisposing, illness-related, and enabling factors from Andersen's behavioral model of treatment-seeking and patterns of service use among participants who completed at least one full day of cleanup work after the Deepwater Horizon oil spill and participated in home visits for the NIEHS GuLF STUDY (N = 8931). Workers reported on MH symptoms and whether they had used counseling or medication for MH problems since the oil spill. Hierarchical logistic regression models explored associations between predictors and counseling and medication use in the full sample, and type of use (counseling only, medication only, both) among participants who used either service. Analyses were replicated for subsamples of participants with and without symptom inventory scores suggestive of probable post-disaster mental illness. Having a pre-spill MH diagnosis, pre-spill service use, more severe post-spill MH symptoms, and healthcare coverage were positively associated with counseling and medication use in the full sample. Among participants who used either service, non-Hispanic Black race, pre-spill counseling, lower depression, and not identifying a personal doctor or healthcare provider were predictive of counseling only, whereas older age, female gender and pre-spill medication were predictive of medication only. The results were generally consistent among participants with and without probable post-disaster mental illness. The results suggest variability in which factors within Andersen's behavioral model are predictive of different patterns of service use among disaster relief workers. Copyright © 2015 Elsevier Ltd. All rights reserved.
    Social Science & Medicine 04/2015; 130. DOI:10.1016/j.socscimed.2015.02.009 · 2.56 Impact Factor
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    ABSTRACT: Laboratory models support an inverse association between anti-Müllerian hormone (AMH) and breast tumor development. Human studies are lacking; one study (N=105 cases, 204 controls) with prospectively-collected serum reported the opposite-an approximate 10-fold increase in breast cancer risk comparing 4th to 1st quartile AMH levels. We investigated the relation between serum AMH levels and breast cancer risk in a case-control (N=452 cases, 902 controls) study nested within the prospective Sister Study cohort of 50,884 women. At enrollment, participants were ages 35-54, premenopausal, and completed questionnaires on medical and family history, lifestyle factors, and demographics. AMH (ng/ml) was measured by ultrasensitive ELISA in serum collected at enrollment and log-transformed for analysis. Multivariate conditional logistic regression was used to calculate odds ratios (OR) and 95% confidence intervals (CI) to account for matching on age and enrollment year. Mean age at enrollment was 46.8 years with an average 2.9 years from blood draw to breast cancer diagnosis (SD=1.9). AMH concentrations were below the limit of detection (0.003 ng/ml) for ~25% of samples. Compared with samples below the LOD, women with AMH >2.84 ng/ml (90th percentile among controls) had a two-fold increase in breast cancer odds (OR=2.25; 95% CI: 1.26-4.02). For each 1-unit increase in lnAMH, overall breast cancer odds increased by 8% (OR=1.08; 95% CI: 1.02-1.15) and odds of ER-positive, invasive disease increased by 15% (OR=1.15; 95% CI: 1.05-1.25). Our findings demonstrate an overall positive relation between AMH and breast cancer. Copyright © 2015, American Association for Cancer Research.
    Cancer Prevention Research 04/2015; 8(6). DOI:10.1158/1940-6207.CAPR-14-0377 · 5.27 Impact Factor
  • Christine C. Ekenga · Christine G. Parks · Dale P. Sandler
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    ABSTRACT: We investigated the relationship between workplace chemical exposures and breast cancer risk among women enrolled in the Sister Study, a prospective cohort study of US and Puerto Rican women. A total of 47,640 participants reported work outside of the home. Workplace exposure to eleven agents (acids, dyes or inks, gasoline or other petroleum products, glues or adhesives, lubricating oils, metals, paints, pesticides, soldering materials, solvents, and stains or varnishes) was characterized based on self-reports of frequency and duration of use. Approximately 14% of the study population reported exposure to only one agent, and 11% reported working with two or more of the eleven agents in their lifetime. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated for each agent, adjusting for established breast cancer risk factors. During follow-up, 1,966 cases of breast cancer were reported. Although there were no significant associations between ever-use of the eleven agents evaluated and breast cancer risk, women with cumulative exposure to gasoline or petroleum products at or above the highest quartile cutoff had an elevated risk of total (HR: 2.3, 95%CI: 1.1-4.9) and invasive (HR: 2.5, 95%CI: 1.1-5.9) breast cancer compared to women in the lowest quartile group (ptrend = 0.03). Workplace exposure to soldering materials was associated with an increased risk of premenopausal breast cancer (HR=1.8, 95% CI = 1.1-3.0). Findings support the need for further studies to elucidate the role of occupational chemicals in breast cancer etiology. This article is protected by copyright. All rights reserved. © 2015 UICC.
    International Journal of Cancer 04/2015; DOI:10.1002/ijc.29545 · 5.01 Impact Factor
  • Sangmi Kim · Joseph Rimando · Dale P Sandler
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    ABSTRACT: Prostaglandin E2 (PGE2) is an inflammatory mediator that plays key roles in promoting tumor development and progression. Urinary concentration of a major PGE2 metabolite (PGE-M) has been recently proposed as a promising cancer biomarker. Using dietary intake data from 600 postmenopausal women aged 50-74 years, we examined cross-sectional relationships between fruit and vegetable intake and urinary levels of PGE-M, determined using liquid chromatography/tandem mass spectrometry. After multivariable adjustment, increasing consumption of fruits, but not vegetables, was associated with reduced levels of urinary PGE-M (P for linear trend = 0.02), with geometric means of 5.8 [95% confidence interval (CI): 5.2-6.6] in the lowest quintile versus 4.8 (95% CI: 4.3-5.4) in the highest quintile (Q5) of fruit consumption. A better quality diet, indicated by higher scores on the Healthy Eating Index, was also associated with decreased PGE-M (P for linear trend <0.01). The lack of association with vegetable intake may be related to variation in antioxidant capacities of the major dietary sources of fruits and vegetables for the study participants. Our findings suggest that urinary PGE-M may be modifiable by a healthy diet that follows current national dietary guideline. Further studies are warranted to assess potential utility of urinary PGE-M in assessing cancer prevention efficacy.
    Nutrition and Cancer 03/2015; 67(4):1-7. DOI:10.1080/01635581.2015.1011787 · 2.47 Impact Factor
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    ABSTRACT: To examine the association between occupational physical activity and leisure-time physical activity among US women in the Sister Study. We conducted a cross-sectional study of 26,334 women who had been employed in their current job for at least 1 year at baseline (2004-2009). Occupational physical activity was self-reported and leisure-time physical activity was estimated in metabolic equivalent hours per week. Log multinomial regression was used to evaluate associations between occupational (sitting, standing, manually active) and leisure-time (insufficient, moderate, high) activity. Models were adjusted for age, race/ethnicity, education, income, geographic region, and body mass index. Only 54% of women met or exceeded minimum recommended levels of leisure-time physical activity (moderate 32% and high 22%). Women who reported sitting (PR = 0.82, 95% CI: 0.74-0.92) or standing (PR = 0.84, 95% CI: 0.75-0.94) most of the time at work were less likely to meet the requirements for high leisure-time physical activity than manually active workers. Associations were strongest among women living in the Northeast and the South. In this nationwide study, low occupational activity was associated with lower leisure-time physical activity. Women who are not active in the workplace may benefit from strategies to promote leisure-time physical activity. Copyright © 2015. Published by Elsevier Inc.
    Preventive Medicine 03/2015; 74. DOI:10.1016/j.ypmed.2015.03.003 · 2.93 Impact Factor
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    ABSTRACT: In utero exposure to diethylstilbestrol (DES) has been associated with increased risk of adverse health outcomes such as fertility problems and vaginal as well as breast cancer. Animal studies have linked prenatal DES exposure to lasting DNA methylation changes. We investigated genome-wide DNA methylation and in utero DES exposure in a sample of non-Hispanic white women aged 40-59 years from the Sister Study, a large United States cohort study of women with a family history of breast cancer. Using questionnaire information from women and their mothers, we selected 100 women whose mothers reported taking DES while pregnant and 100 control women whose mothers had not taken DES. DNA methylation in blood was measured at 485,577 CpG sites using the Illumina HumanMethylation450 BeadChip. Associations between CpG methylation and DES exposure status were analyzed using robust linear regression with adjustment for blood cell composition and multiple comparisons. Although four CpGs had p<105, after accounting for multiple comparisons using the false discovery rate (FDR), none reached genome-wide significance. In conclusion, adult women exposed to DES in utero had no evidence of large persistent changes in blood DNA methylation.
    PLoS ONE 03/2015; 10(3):e0118757. DOI:10.1371/journal.pone.0118757 · 3.23 Impact Factor
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    ABSTRACT: Exposure to air pollution has been consistently associated with cardiovascular morbidity and mortality but mechanisms remain uncertain. Associations with blood pressure (BP) may help to explain the cardiovascular effects of air pollution. We examined the cross-sectional relationship between long-term (annual average) residential air pollution exposure and BP in the National Institute of Environmental Health Sciences' Sister Study, a large U.S. cohort study investigating risk factors for breast cancer and other outcomes. This analysis included 43,629 women aged 35-76, enrolled 2003 to 2009, who had a sister with breast cancer. Geographic information systems contributed to satellite-based nitrogen dioxide (NO2) and fine particulate matter (PM2.5) predictions at participant residences at study entry. Generalized additive models were used to examine the relationship between pollutants and measured BP at study entry, adjusting for cardiovascular disease risk factors, and including thin plate splines for potential spatial confounding. A 10 μg/m(3) increase in PM2.5 was associated with 1.4 mmHg higher systolic BP (95% CI: 0.6, 2.3; p<0.001), 1.0 mmHg higher pulse pressure (95% CI: 0.4, 1.7; p=0.001), 0.8 mmHg higher mean arterial pressure (95% CI: 0.2, 1.4; p=0.01), and no significant association with diastolic BP. A 10 ppb increase in NO2 was associated with a 0.4 mmHg (95% CI: 0.2, 0.6; p<0.001) higher pulse pressure. Long-term PM2.5 and NO2 exposures were associated with higher blood pressure. On a population scale, such air pollution-related increases in blood pressure could, in part, account for the increases in cardiovascular disease morbidity and mortality seen in prior studies.
    Environmental Health Perspectives 03/2015; DOI:10.1289/ehp.1408125 · 7.98 Impact Factor
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    ABSTRACT: Recently the International Agency for Research on Cancer (IARC) Programme for the Evaluation of Carcinogenic Risks to Humans has been criticized for several of its evaluations, and also the approach used to perform these evaluations. Some critics have claimed that IARC Working Groups' failures to recognize study weaknesses and biases of Working Group members have led to inappropriate classification of a number of agents as carcinogenic to humans. The authors of this paper are scientists from various disciplines relevant to the identification and hazard evaluation of human carcinogens. We have examined here criticisms of the IARC classification process to determine the validity of these concerns. We review the history of IARC evaluations and describe how the IARC evaluations are performed. We conclude that these recent criticisms are unconvincing. The procedures employed by IARC to assemble Working Groups of scientists from the various discipline and the techniques followed to review the literature and perform hazard assessment of various agents provide a balanced evaluation and an appropriate indication of the weight of the evidence. Some disagreement by individual scientists to some evaluations is not evidence of process failure. The review process has been modified over time and will undoubtedly be altered in the future to improve the process. Any process can in theory be improved, and we would support continued review and improvement of the IARC processes. This does not mean, however, that the current procedures are flawed. The IARC Monographs have made, and continue to make, major contributions to the scientific underpinning for societal actions to improve the public's health.
    Environmental Health Perspectives 02/2015; DOI:10.1289/ehp.1409149 · 7.98 Impact Factor
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    ABSTRACT: Estrogen plus progestin hormone therapy (HT) is associated with an increased risk of postmenopausal breast cancer, but few studies have examined the impact of HT use on the risk of breast cancer in younger women. We assessed the association between estrogen plus progestin HT or unopposed estrogen HT and young-onset breast cancer using data from the Two Sister Study (2008-2010), a sister-matched study of 1,419 cases diagnosed with breast cancer before the age of 50 years and 1,665 controls. We assessed exposures up to a family-specific index age to ensure comparable opportunities for exposures and used propensity scores to control for birth cohort effects on HT use. Ever HT use was uncommon (7% and 11% in cases and controls, respectively). Use of estrogen plus progestin was not associated with an increased risk of young-onset breast cancer (odds ratio = 0.80, 95% confidence interval: 0.41, 1.59). Unopposed estrogen use was inversely associated with the risk of young-onset breast cancer (odds ratio = 0.58, 95% confidence interval: 0.34, 0.99). Duration of use, age at first use, and recency of use did not modify these associations. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health 2015. This work is written by (a) US Government employee(s) and is in the public domain in the US.
    American Journal of Epidemiology 02/2015; 181(10). DOI:10.1093/aje/kwu347 · 4.98 Impact Factor
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    ABSTRACT: Prospective cohorts have played a major role in understanding the contribution of diet, physical activity, medical conditions, and genes to the development of many diseases, but have not been widely used for occupational exposures. Studies in agriculture are an exception. We draw upon our experience using this design to study agricultural workers to identify conditions that might foster use of prospective cohorts to study other occupational settings. Prospective cohort studies are perceived by many as the strongest epidemiologic design. It allows updating of information on exposure and other factors, collection of biologic samples before disease diagnosis for biomarker studies, assessment of effect modification by genes, lifestyle, and other occupational exposures, and evaluation of a wide range of health outcomes. Increased use of prospective cohorts would be beneficial in identifying hazardous exposures in the workplace. Occupational epidemiologists should seek opportunities to initiate prospective cohorts to investigate high priority, occupational exposures. Am. J. Ind. Med. 58:113–122, 2015.
    American Journal of Industrial Medicine 02/2015; 58(2):113-122. DOI:10.1002/ajim.22403 · 1.59 Impact Factor
  • Hazel B Nichols · Lisa A DeRoo · Daniel R Scharf · Dale P Sandler
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    ABSTRACT: Tamoxifen has been US Food and Drug Administration-approved for primary prevention of breast cancer since 1998 but has not been widely adopted, in part because of increased risk of serious side effects. Little is known about the risk-benefit profiles of women who use chemoprevention outside of a clinical trial. We examined characteristics associated with initiation and discontinuation of tamoxifen for primary prevention of breast cancer within a large cohort of women with a first-degree family history of breast cancer. This research was conducted within The Sister Study, a cohort of 50884 US and Puerto Rican women age 35 to 74 years enrolled from 2003 to 2009. Eligible women were breast cancer-free at enrollment and had a sister who had been diagnosed with breast cancer. Participants reported tamoxifen use, ages started and stopped taking tamoxifen, and total duration of use at enrollment. We identified 788 tamoxifen users and 3131 nonusers matched on age and year of enrollment who had no history of contraindicating factors (stroke, transient ischemic attack, cataract, endometrial or uterine cancer). Characteristics associated with tamoxifen initiation were evaluated with multivariable conditional logistic regression. All statistical tests were two-sided. Based on published risk-benefit indices, 20% of women who used tamoxifen had insufficient evidence that the benefits of tamoxifen outweigh the risk of serious side effects. After 4.5 years, 46% of women had discontinued tamoxifen. While the majority of women who used tamoxifen for primary prevention of breast cancer were likely to benefit, substantial discontinuation of tamoxifen before five years and use by women at risk of serious side effects may attenuate benefits for breast cancer prevention. Published by Oxford University Press 2014.
    JNCI Journal of the National Cancer Institute 01/2015; 107(1). DOI:10.1093/jnci/dju354 · 15.16 Impact Factor
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    ABSTRACT: Pesticides have been associated with Parkinson's disease (PD), and protective gloves and workplace hygiene can reduce pesticide exposure. We assessed whether use of gloves and workplace hygiene modified associations between pesticides and PD. The Farming and Movement Evaluation (FAME) study is a nested case–control study within the Agricultural Health Study. Use of protective gloves, other PPE, and hygiene practices were determined by questionnaire (69 cases and 237 controls were included). We considered interactions of gloves and hygiene with ever-use of pesticides for all pesticides with ≥ 5 exposed and unexposed cases and controls in each glove-use stratum (paraquat, permethrin, rotenone, and trifluralin). 61% of respondents consistently used protective gloves and 87% consistently used ≥ 2 hygiene practices. Protective glove use modified the associations of paraquat and permethrin with PD: neither pesticide was associated with PD among protective glove users, while both pesticides were associated with PD among non-users (paraquat OR 3.9 [95% CI 1.3, 11.7], interaction p = 0.15; permethrin OR 4.3 [95% CI 1.2, 15.6] interaction p = 0.05). Rotenone was associated with PD regardless of glove use. Trifluralin was associated with PD among participants who used < 2 hygiene practices (OR 5.5 [95% CI 1.1, 27.1]) but was not associated with PD among participants who used 2 or more practices (interaction p = 0.02). Although sample size was limited in the FAME study, protective glove use and hygiene practices appeared to be important modifiers of the association between pesticides and PD and may reduce risk of PD associated with certain pesticides.
    Environment International 11/2014; 75. DOI:10.1016/j.envint.2014.11.002 · 5.66 Impact Factor

Publication Stats

9k Citations
1,762.53 Total Impact Points


  • 2014–2015
    • University of Bergen
      • Department of Public Health and Primary Health Care
      Bergen, Hordaland, Norway
  • 2003–2015
    • National Institutes of Health
      • • Branch of Epidemiology (EPI)
      • • Division of Cancer Epidemiology and Genetics
      베서스다, Maryland, United States
    • Harvard University
      Cambridge, Massachusetts, United States
  • 1983–2015
    • National Institute of Environmental Health Sciences
      • • Epidemiology Branch
      • • Biostatistics Branch
      Durham, North Carolina, United States
  • 1988–2014
    • University of North Carolina at Chapel Hill
      • • Department of Epidemiology
      • • Department of Obstetrics and Gynecology
      • • Department of Pediatrics
      • • Department of Psychiatry
      North Carolina, United States
  • 2008–2013
    • Karolinska Institutet
      • Institutionen för medicinsk epidemiologi och biostatistik
      Solna, Stockholm, Sweden
  • 1996–2012
    • National Cancer Institute (USA)
      • • Division of Cancer Epidemiology and Genetics
      • • Occupational and Environmental Epidemiology
      • • Epidemiology and Biostatistics
      베서스다, Maryland, United States
  • 2010
    • The Nebraska Medical Center
      Omaha, Nebraska, United States
  • 2004–2010
    • University of Washington Seattle
      • Department of Pediatrics
      Seattle, WA, United States
    • Memorial Sloan-Kettering Cancer Center
      New York, New York, United States
  • 2007
    • Northern Inyo Hospital
      BIH, California, United States
    • University of New Mexico
      Albuquerque, New Mexico, United States
    • Battelle Memorial Institute
      Columbus, Ohio, United States
  • 2006
    • University of Iowa
      Iowa City, Iowa, United States
  • 2005
    • University of Ottawa
      Ottawa, Ontario, Canada
    • Woolcock Institute of Medical Research
      Sydney, New South Wales, Australia
    • Harvard Medical School
      Boston, Massachusetts, United States
    • University of Illinois at Chicago
      • Division of Epidemiology and Biostatistics
      Chicago, IL, United States
  • 2003–2004
    • NCI-Frederick
      Фредерик, Maryland, United States
  • 2002
    • Temple University
      • Institute for Survey Research
      Filadelfia, Pennsylvania, United States
  • 1994
    • Cornell University
      Итак, New York, United States