Time to Mammographic Density Decrease After Exposure to Tamoxifen.

Mammographic density change has proven to be a reliable proxy for tamoxifen therapy response. The primary aim of this study was to identify time to tamoxifen-induced mammographic density change. We also analyzed side effects and adherence to therapy. In all, 42 women were randomized to 10 or 20 mg of daily oral tamoxifen. Mammograms were taken at baseline, 3, 6, and 9 months. Mammographic density change was measured using the automated STRATUS tool. Adverse events were monitored through a web-based questionnaire based on the FACT-ES tool. Nine out of the 42 (21%) participants discontinued therapy due to adverse events leaving 33 women in the study. A significant decrease in density was seen after 3 months of therapy. Dose did not seem to affect density change, side effects or adherence. Given the size of the study, additional studies are needed to confirm our data.