KARISMA trial results: chemoprevention for breast cancer

We completed the KARISMA trial (PI Per Hall) and show for the first time in a 6-armed controlled randomized trial (n=1440) that low-dose Tamoxifen induces noninferior magnitude of breast density decrease at a 2.5 mg dose, but fewer side effects compared with the standard dose of 20 mg [4]. These results may impact uptake of breast cancer chemoprevention; future studies should test whether 2.5 mg of tamoxifen reduces the risk of primary breast cancer.