Oral contraceptives and postmenopausal hormones and risk of contralateral breast cancer among BRCA1 and BRCA2 mutation carriers and noncarriers: the WECARE Study.
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.
Figueiredo
Jane C
JC
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
Haile
Robert W
RW
Bernstein
Leslie
L
Malone
Kathleen E
KE
Largent
Joan
J
Langholz
Bryan
B
Lynch
Charles F
CF
Bertelsen
Lisbeth
L
Capanu
Marinela
M
Concannon
Patrick
P
Borg
Ake
A
Børresen-Dale
Anne-Lise
AL
Diep
Anh
A
Teraoka
Sharon
S
Torngren
Therese
T
Xue
Shanyan
S
Bernstein
Jonine L
JL
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
D003276:Contraceptives, Oral