The association between oral contraceptive use and lobular and ductal breast cancer in young women

Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
International Journal of Cancer (Impact Factor: 5.01). 02/2008; 122(4):936-41. DOI: 10.1002/ijc.23163
Source: PubMed

ABSTRACT Recent reports indicate that the incidence of lobular breast cancer is increasing at a faster rate than ductal breast cancer, which may be due to the differential effects of exogenous hormones by histology. To address this issue, we examined whether the relationship between oral contraceptive use and incident breast cancer differs between lobular and ductal subtypes in young women. A population-based sample of in situ and invasive breast cancer cases between ages 20 and 44 were recruited from Atlanta, GA; Seattle-Puget Sound, WA and central New Jersey. Controls were sampled from the same areas by random-digit dialing, and were frequency matched to the expected case age distribution. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated using polytomous logistic regression. Among the 100 lobular cancers, 1,164 ductal cancers, and 1,501 controls, the odds ratios for oral contraceptive ever use were 1.10 (95% CI = 0.68-1.78) for lobular cancers and 1.21 (95% CI = 1.01-1.45) for ductal cancers, adjusted for study site, age at diagnosis, and pap screening history. Our results suggest that the magnitude of the association between ever use of oral contraceptives and breast cancer in young women does not vary strongly by histologic subtype. These results are similar to previous studies that report little difference in the effect of oral contraceptive use on breast cancer by histology.

  • [Show abstract] [Hide abstract]
    ABSTRACT: We examined the relationship between reproductive factors and risk of premenopausal breast cancer among women less than age 40 compared with older premenopausal women. We documented 374 incident cases of breast cancer diagnosed before age 40, and 2,533 cases diagnosed at age 40 and older among premenopausal women in the Nurses' Health Study cohorts. Biennial questionnaires were used to determine age at menarche, age at first birth, parity, breastfeeding, and other reproductive factors. Multivariate relative risks (RR) and 95 % confidence intervals (CI) were calculated using Cox proportional hazards models within age at diagnosis groups. Tumors in younger women were significantly more likely to be higher grade, larger size, and hormone receptor negative than were tumors in older premenopausal women (p < 0.0001). There was no significant heterogeneity according to age in associations between reproductive factors and risk of premenopausal breast cancer. First birth at age 30 or older increased breast cancer risk in both age groups (age <40: RR 1.10, 95 % CI 0.80-1.50; age ≥40: RR 1.16, 95 % CI 1.02-1.32; p-heterogeneity = 0.44). Risk of premenopausal breast cancer decreased with each additional year of age at menarche in both age groups (age <40: RR 0.93, 95 % CI 0.87-0.99; p trend = 0.02; age ≥40: RR 0.94, 95 % CI 0.91-0.97; p trend = <0.0001). Among premenopausal parous women, breastfeeding was protective regardless of age at diagnosis (age <40: RR 0.84, 95 % CI 0.57-1.22; age ≥40: RR 0.85, 95 % CI 0.72-0.99; p-heterogeneity = 0.79). In the largest prospective examination of reproductive risk factors and risk of breast cancer before and after age 40, we found that younger women were more likely to develop tumors with less favorable prognostic characteristics. However, associations between reproductive factors and risk of breast cancer were similar regardless of age at diagnosis of premenopausal breast cancer.
    Breast Cancer Research and Treatment 10/2013; DOI:10.1007/s10549-013-2721-9 · 4.20 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: OBJETIVO: El cáncer de mama en mujeres jóvenes tiene características biológicas y comportamiento clínico al compararlo con el cáncer de mama en mujeres de la tercera edad. MÉTODO: Estudio prospectivo de factores de riesgo para cáncer de mama tomando en cuenta estos dos grupos. 36 pacientes < 40 años y 100 pacientes > 64 años de 515 pacientes evaluados entre abril de 2006 y abril de 2007. Se analizaron: antecedentes familiares de cáncer de mama y ovario, factores de riesgo hormonales (endógenos y exógenos), antecedentes de patología mamaria. RESULTADOS: Antecedentes familiares de cáncer de mama (31 % < 40 años vs. 14 % > 64 años, P= 0,015), antecedentes familiares de cáncer de ovario (25 % < 40 años vs. 15 % > 64 años, P = 0,04), promedio edad primer embarazo a término (21,11 > 64 años vs. 23,0 < 40 años, P = 0,05), promedio número de embarazos a término (5,1 > 64 años vs. 2,2 < 40 años, P= 0,00014), ingestión de anticonceptivos orales (67 % < 40 años vs. 13 % > 64 años, P = 0,0000001). CONCLUSIONES: Antecedentes familiares de cáncer de mama y ovario, edad del primer embarazo a término, número de embarazos a término e ingestión de anticonceptivos orales fueron factores de riesgo más relevantes en mujeres jóvenes con cáncer de mama, siendo la primera vez que se reportan los antecedentes familiares de cáncer de ovario y el número de embarazos a término.
    Revista Venezolana de Oncologia 12/2010; 22(4):216-221.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Oral contraceptives (OC) may influence the risk of certain cancers. As part of the AHRQ Evidence Report, Oral Contraceptive Use for the Primary Prevention of Ovarian Cancer, we conducted a systematic review to estimate associations between OC use and breast, cervical, colorectal, and endometrial cancer incidence. We searched PubMed®, Embase®, and Cochrane Database of Systematic Reviews. Study inclusion criteria were women taking OCs for contraception or ovarian cancer prevention; includes comparison group with no OC use; study reports quantitative associations between OC exposure and relevant cancers; controlled study or pooled patient-level meta-analyses; sample size for nonrandomized studies >100; peer-reviewed, English-language; published from January 1, 2000 forward. Random-effects meta-analyses were performed by estimating pooled odds ratios with 95% confidence intervals. We included 44 breast, 12 cervical, 11 colorectal, and 9 endometrial cancers studies. Breast cancer incidence was slightly but significantly increased in users (OR=1.08, CI 1.00-1.17); results show a higher risk associated with more recent use of OCs. Risk of cervical cancer was increased with duration of OC use in women with human papillomavirus infection; heterogeneity prevented meta-analysis. Colorectal cancer (OR=0.86, CI 0.79-0.95) and endometrial cancer incidences (OR=0.57, CI 0.43-0.77) were significantly reduced by OC use. Compared with never use, ever use of OCs is significantly associated with decreases in colorectal and endometrial cancers and increases in breast cancers. Although elevated breast cancer risk was small, relatively high incidence of breast cancers means that OCs may contribute to a substantial number of cases.
    Cancer Epidemiology Biomarkers & Prevention 09/2013; 22(11). DOI:10.1158/1055-9965.EPI-13-0298 · 4.32 Impact Factor