title: Oral contraceptives and postmenopausal hormones and risk of contralateral breast cancer among BRCA1 and BRCA2 mutation carriers and noncarriers: the WECARE Study.
abstract: The potential effects of oral contraceptive (OC) and postmenopausal hormone (PMH) use are not well understood among BRCA1 or BRCA2 (BRCA1/2) deleterious mutation carriers with a history of breast cancer. We investigated the association between OC and PMH use and risk of contralateral breast cancer (CBC) in the WECARE (Women's Environment, Cancer, and Radiation Epidemiology) Study. The WECARE Study is a population-based case-control study of 705 women with asynchronous CBC and 1,398 women with unilateral breast cancer, including 181 BRCA1/2 mutation carriers. Risk-factor information was assessed by telephone interview. Mutation status was measured using denaturing high-performance liquid chromatography followed by direct sequencing in all participants. Outcomes, treatment, and tumor characteristics were abstracted from medical records. Ever use of OCs was not associated with risk among noncarriers (RR = 0.87; 95% CI = 0.66-1.15) or BRCA2 carriers (RR = 0.82; 95% CI = 0.21-3.13). BRCA1 carriers who used OCs had a nonsignificant greater risk than nonusers (RR = 2.38; 95% CI = 0.72-7.83). Total duration of OC use and at least 5 years of use before age 30 were associated with a nonsignificant increased risk among mutation carriers but not among noncarriers. Few women had ever used PMH and we found no significant associations between lifetime use and CBC risk among carriers and noncarriers. In conclusion, the association between OC/PMH use and risk of CBC does not differ significantly between carriers and noncarriers; however, because carriers have a higher baseline risk of second primaries, even a potential small increase in risk as a result of OC use may be clinically relevant.
authors: Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Harlyne J Norris Cancer Research Tower, 1450 Biggy Street, Los Angeles, CA, 90033, USA. janefigu@usc.edu
authors: Jane C
authors: JC
authors: Figueiredo
authors: Robert W
authors: RW
authors: Haile
authors: Leslie
authors: L
authors: Bernstein
authors: Kathleen E
authors: KE
authors: Malone
authors: Joan
authors: J
authors: Largent
authors: Bryan
authors: B
authors: Langholz
authors: Charles F
authors: CF
authors: Lynch
authors: Lisbeth
authors: L
authors: Bertelsen
authors: Marinela
authors: M
authors: Capanu
authors: Patrick
authors: P
authors: Concannon
authors: Ake
authors: A
authors: Borg
authors: Anne-Lise
authors: AL
authors: Børresen-Dale
authors: Anh
authors: A
authors: Diep
authors: Sharon
authors: S
authors: Teraoka
authors: Therese
authors: T
authors: Torngren
authors: Shanyan
authors: S
authors: Xue
authors: Jonine L
authors: JL
authors: Bernstein
mesh_terms: D000328:Adult; D001943:Breast Neoplasms / Q000139:chemically induced* / Q000235:genetics*; D016022:Case-Control Studies; D002851:Chromatography, High Pressure Liquid; D003276:Contraceptives, Oral / Q000009:adverse effects*; D015914:Estrogen Replacement Therapy / Q000009:adverse effects*; D005260:Female; D019398:Genes, BRCA1; D024522:Genes, BRCA2; D020022:Genetic Predisposition to Disease; D006579:Heterozygote; D006801:Humans; D008875:Middle Aged; D009154:Mutation; D016609:Neoplasms, Second Primary / Q000139:chemically induced* / Q000235:genetics*; D012307:Risk Factors; D055815:Young Adult
chemical_list: D003276:Contraceptives, Oral