BRCA1 and BRCA2 mutation carriers, oral contraceptive use, and breast cancer before age 50
Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology, 15(10), 1863-1870
Abstract
Background
Understanding the effect of oral contraceptives on risk of breast cancer in BRCA1 or BRCA2 mutation carriers is important because oral contraceptive use is a common, modifiable practice.
Methods
We studied 497 BRCA1 and 307 BRCA2 mutation carriers, of whom 195 and 128, respectively, had been diagnosed with breast cancer. Case-control analyses were conducted using unconditional logistic regression with adjustments for family history and familial relationships and were restricted to subjects with a reference age under 50 years.
Results
For BRCA1 mutation carriers, there was no significant association between risk of breast cancer and use of oral contraceptives for at least 1 year [odds ratio (OR), 0.77; 95% confidence interval (95% CI), 0.53-1.12] or duration of oral contraceptive use (P(trend) = 0.62). For BRCA2 mutation carriers, there was no association with use of oral contraceptives for at least 1 year (OR, 1.62; 95% CI, 0.90-2.92); however, there was an association of elevated risk with oral contraceptive use for at least 5 years (OR, 2.06; 95% CI, 1.08-3.94) and with duration of use (OR(trend) per year of use, 1.08; P = 0.008). Similar results were obtained when we considered only use of oral contraceptives that first started in 1975 or later.
Conclusions
We found no evidence overall that use of oral contraceptives for at least 1 year is associated with breast cancer risk for BRCA1 and BRCA2 mutation carriers before age 50. For BRCA2 mutation carriers, use of oral contraceptives may be associated with an increased risk of breast cancer among women who use them for at least 5 years. Further studies reporting results separately for BRCA1 and BRCA2 mutation carriers are needed to resolve this important issue.
Topics
Cite this article
Haile, R. W., Thomas, D. C., McGuire, V., Felberg, A., John, E. M., Milne, R. L., Hopper, J. L., Jenkins, M. A., Levine, A. J., Daly, M. M., Buys, S. S., Senie, R. T., Andrulis, I. L., Knight, J. A., Godwin, A. K., Southey, M., McCredie, M. R., Giles, G. G., Andrews, L., . . . Whittemore, A. S. (2006). BRCA1 and BRCA2 mutation carriers, oral contraceptive use, and breast cancer before age 50. *Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology*, *15*(10), 1863-1870. https://doi.org/10.1158/1055-9965.EPI-06-0258
Haile RW, Thomas DC, McGuire V, Felberg A, John EM, Milne RL, et al. BRCA1 and BRCA2 mutation carriers, oral contraceptive use, and breast cancer before age 50. Cancer Epidemiol Biomarkers Prev. 2006;15(10):1863-1870. doi:10.1158/1055-9965.EPI-06-0258
Haile, R. W., et al. "BRCA1 and BRCA2 mutation carriers, oral contraceptive use, and breast cancer before age 50." *Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology*, vol. 15, no. 10, 2006, pp. 1863-1870.
Keywords
Adult, Australia, Breast Neoplasms, Canada, Carcinoma in Situ, Carcinoma, Ductal, Breast, Case-Control Studies, Contraceptives, Oral, Female, Genes, BRCA1, BRCA2, Genetic Predisposition to Disease, Heterozygote, Humans, Logistic Models, Middle Aged, Mutation, Receptors, Estrogen, Progesterone, Risk Factors, Surveys and Questionnaires, Time Factors, United States