Topical Endoxifen for Mammographic Density Reduction-A Randomized Controlled Trial.

ABSTRACT: Although breast cancer incidence is increasing, there are few primary preventive initiatives. Tamoxifen can reduce breast cancer incidence but is rarely used for primary prevention due to adverse events and tolerance issues. We tested if endoxifen, a tamoxifen metabolite, applied directly to the skin of the breast, could reduce mammographic density, a proxy for therapy response. Ninety women were randomized to placebo, 10 and 20 mg of topical Z-endoxifen for 6 months. Mammographic density and symptoms were measured at baseline and study exit. Despite a high discontinuation rate, driven by skin rashes, we found a significant mammographic density decrease, a dose-dependent increase in the concentration of plasma Z-endoxifen but no systemic side effects. Topical application of tamoxifen metab

SUBMITTER: Backlund M 

PROVIDER: S-EPMC9256025 | biostudies-literature | 2022 Jul

REPOSITORIES: biostudies-literature