Hormonal Contraception and Breast Cancer Risk for Carriers of Germline Mutations in <i>BRCA1</i> and <i>BRCA2</i>
Authors: Kelly-Anne Phillips, Joanne Kotsopoulos, Susan M. Domchek, Mary Beth Terry, James A. Chamberlain, Julie K. Bassett, Amber M. Aeilts, Irene L. Andrulis, Saundra S. Buys, Wanda Cui, Mary B. Daly, Andrea F. Eisen, William D. Foulkes, Michael L. Friedlander, Jacek Gronwald, John L. Hopper, Esther M. John, Beth Y. Karlan, Raymond H. Kim, Allison W. Kurian, Jan Lubinski, Kelly Metcalfe, Katherine L. Nathanson, Christian F. Singer, Melissa C. Southey, Heather Symecko, Nadine Tung, Steven A. Narod, Roger L. Milne, David Amor, Lesley Andrews, Yoland Antill, Rosemary Balleine, Jonathan Beesley, Ian Bennett, Michael Bogwitz, Simon Bodek, Leon Botes, Meagan Brennan, Melissa Brown, Michael Buckley, Jo Burke, Phyllis Butow, Liz Caldon, Ian Campbell, Michelle Cao, Anannya Chakrabarti, Deepa Chauhan, Manisha Chauhan, Georgia Chenevix-Trench, Alice Christian, Paul Cohen, Alison Colley, Ashley Crook, James Cui, Eliza Courtney, Margaret Cummings, Sarah-Jane Dawson, Anna DeFazio, Martin Delatycki, Rebecca Dickson, Joanne Dixon, Stacey Edwards, Gelareh Farshid, Andrew Fellows, Georgina Fenton, Michael Field, James Flanagan, Peter Fong, Laura Forrest, Stephen Fox, Juliet French, Michael Friedlander, Clara Gaff, Mike Gattas, Peter George, Sian Greening, Marion Harris, Stewart Hart, Philip Harraka, Nick Hayward, John Hopper, Cass Hoskins, Clare Hunt, Paul James, Mark Jenkins, Alexa Kidd, Judy Kirk, Jessica Koehler, James Kollias, Sunil Lakhani, Mitchell Lawrence, Jason Lee, Shuai Li, Geoff Lindeman, Jocelyn Lippey, Lara Lipton, Liz Lobb, Sherene Loi, Graham Mann, Deborah Marsh, Sue Anne McLachlan, Bettina Meiser, Roger Milne, Sophie Nightingale, Shona O'Connell, Sarah O'Sullivan, David Gallego Ortega, Nick Pachter, Jia-Min Pang, Gargi Pathak, Briony Patterson, Amy Pearn, Kelly Phillips, Ellen Pieper, Susan Ramus, Edwina Rickard, Abi Ragunathan, Bridget Robinson, Mona Saleh, Anita Skandarajah, Elizabeth Salisbury, Christobel Saunders, Jodi Saunus, Peter Savas, Rodney Scott, Clare Scott, Adrienne Sexton, Joanne Shaw, Andrew Shelling, Shweta Srinivasa, Peter Simpson, Melissa Southey, Amanda Spurdle, Jessica Taylor, Renea Taylor, Heather Thorne, Alison Trainer, Kathy Tucker, Jane Visvader, Logan Walker, Rachael Williams, Ingrid Winship, Mary Ann Young, Milita Zaheed
Journal: Journal of Clinical Oncology (2024)

PURPOSE It is uncertain whether, and to what extent, hormonal contraceptives increase breast cancer (BC) risk for germline BRCA1 or BRCA2 mutation carriers. METHODS Using pooled observational data from four prospective cohort studies, associations between hormonal contraceptive use and BC risk for unaffected female BRCA1 and BRCA2 mutation carriers were assessed using Cox regression. RESULTS Of 3,882 BRCA1 and 1,509 BRCA2 mutation carriers, 53% and 71%, respectively, had ever used hormonal contraceptives for at least 1 year (median cumulative duration of use, 4.8 and 5.7 years, respectively). Overall, 488 BRCA1 and 191 BRCA2 mutation carriers developed BC during median follow-up of 5.9 and 5.6 years, respectively. Although for BRCA1 mutation carriers, neither current nor past use of hormonal contraceptives for at least 1 year was statistically significantly associated with BC risk (hazard ratio [HR], 1.40 [95% CI, 0.94 to 2.08], P = .10 for current use; 1.16 [0.80 to 1.69], P = .4, 1.40 [0.99 to 1.97], P = .05, and 1.27 [0.98 to 1.63], P = .07 for past use 1-5, 6-10, and &gt;10 years before, respectively), ever use was associated with increased risk (HR, 1.29 [95% CI, 1.04 to 1.60], P = .02). Furthermore, BC risk increased with longer cumulative duration of use, with an estimated proportional increase in risk of 3% (1%-5%, P = .002) for each additional year of use. For BRCA2 mutation carriers, there was no evidence that current or ever use was associated with increased BC risk (HR, 0.70 [95% CI, 0.33 to 1.47], P = .3 and 1.07 [0.73 to 1.57], P = .7, respectively). CONCLUSION Hormonal contraceptives were associated with increased BC risk for BRCA1 mutation carriers, especially if used for longer durations. Decisions about their use in women with BRCA1 mutations should carefully weigh the risks and benefits for each individual.