Bottom Line: Women with BRCA1 or BRCA2 mutations who underwent adjuvant tamoxifen for breast cancer have a reduced risk of contralateral (other side) breast cancer.
The Study: Investigators used the International BRCA1 and BRCA2 Carrier Cohort Study, the Kathleen Cunningham Foundation Consortium for Research into Familial Breast Cancer, and the Breast Cancer Family Registry to identify women with primary breast cancer. Of the BRCA1 carriers, 24% received the anti-estrogen agent tamoxifen. Of the BRCA2 carriers, 52% got the drug.
Among women treated with tamoxifen after first breast cancer diagnosis, adjusted hazard ratios were 0.38 for BRCA1 mutation carriers and 0.33 for BRCA2 carriers; in other words, women on tamoxifen had a nearly 2/3 reduction in the risk of getting a cancer in the other breast. Still, among BRCA1 mutation carriers that were premenopausal. the risk reduction associated with tamoxifen appeared less apparent for those who had had their ovaries removed (HR 0.70 vs 0.26).
My Take: If you have a BRCA mutation, you should review your cancer risk management with a specialist, including whether you should consider taking tamoxifen as a risk-reducing agent. For those who take tamoxifen as a part of treatment for breast cancer, we now know that you reduce the risk of cancer developing in the other breast, even if you carry a BRCA mutation.
The small print: The material presented herein is informational only, and is not designed to provide specific guidance for an individual. Please check with a valued health care provider with any questions or concerns. As for me, I am a Harvard- , Yale- and UPenn-educated radiation oncologist, and I practice in the Seattle, WA (USA) area. I feel genuinely privileged to be able to share with you. If you enjoyed today’s offering, please consider clicking the follow button at the bottom of this page.
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Reference: Phillips KA. J Clin Oncol 2013;doi:10/1200/JCO/2012.47.8313.