The Recommendation: We're talking of course about the selective estrogen receptor modulator (SERM)s tamoxifen and raloxifene that have been formally recommended for use as breast cancer prophylaxis in selected populations for years, having consistently proven relative reductions in primary breast cancer surpassing 50%—not to mention the added bonus of lowering fracture risk. But despite what's been on paper since at least 2013, less than 10% of women eligible for such "chemoprevention" in the US have signed up for a daily pill. Now we have a splashy updated rec from the US Preventive Services Task Force (USPSTF) that not only tacks on the myriad aromatase inhibitor (AI)s we've all grown to know and love but also delves into the real issue at hand: the tricky absolute risk versus benefit discussions surrounding prescribing meds for otherwise healthy young women. And by "delve" we mean land on a rec that it's probably worth it (aka a B rec) for women with a history of atypical hyperplasia or lobular carcinoma in situ or with at least a 3% chance of developing breast cancer within 5 years per an established risk calculator. Note: 3% is almost double the risk required for enrollment in most supporting trials, and there's virtually no data supporting this strategy in women with BRCA-mutations or prior chest radiation. And as an excellent accompanying editorial points out re: the risk-half of the equation, don't forget that low-dose chemoprevention is a thing.
TBL: The USPSTF now recommends offering primary chemoprevention via SERM or AI to women with a "high-risk" of developing breast cancer and without medical contraindications. | USPSTF, JAMA Oncol 2019 and Pace & Keating, JAMA Oncol 2019