The objective of this trial is to test whether a low dose of tamoxifen can have a beneficial effect on breast cancer risk biomarkers in women treated with chest radiotherapy for a prior diagnosis of cancer. Such women have a very high risk of developing breast cancer, approximately 55-times that of an average woman. The standard daily dose of 20mg of tamoxifen has been shown to decrease breast cancer risk by 50%. More recent data suggest that a lower dose of 5mg daily has a similar beneficial effect but with lower side effects. The Low Dose Tamoxifen Breast Cancer Risk Reduction Trial is a placebo-controlled randomized controlled trial of tamoxifen delivered at a reduced dose of 5mg daily for two years. The study is also measuring the safety and tolerability of tamoxifen at the lower dose.
This study at City of Hope in Duarte, Calif., is investigating the effect two years of low-dose tamoxifen has on breast density and other biological markers (biomarkers) associated with increased breast cancer risk in women who had been diagnosed and treated with chest or axilla radiation before the age of 40 for a cancer other than breast cancer. The study is also measuring the safety and tolerability of tamoxifen at the lower dose. The researchers wanted to enroll up to 230 volunteers from various cities around the US and reached out to the Army of Women (AOW) to supplement their other recruitment sources. The Call to Action for this study was sent to AOW members on May 2, 2012, and the researchers closed enrollment on March 19, 2015. The AOW provided them with 13 women who were interested in enrolling in the study.