POWERPIINC (PreOperative Window of Endocrine TheRapy Provides Information to Increase Compliance) trial: Changes in tumor proliferation index and quality of life with 7 days of preoperative tamoxifen
Seven days of tamoxifen produces Ki67 decreases similar to longer courses. Ki67 decreases by an average of 40% after 7 days of tamoxifen. 73% of women had decreased Ki67 after 7 days of tamoxifen. Seven days of preoperative tamoxifen is safe and tolerable.