Chemoprevention of Breast Cancer: Communicating the Benefits and Risk

The National Surgical Breast and Bowel Project (NSABP) has randomized over 34,000 women who were at high risk for the development of breast cancer into two sequentially conducted clinical trials to evaluate agents for the chemoprevention of breast cancer.  The chemicals evaluated were hormones in the class referred to as selective estrogen receptor modulators (SERMs).  The first trial, the Breast Cancer Prevention Trial (BCPT), demonstrated that compared to placebo, tamoxifen treatment resulted in an almost fifty percent reduction in the incidence of invasive breast cancer.  The second trial, the Study of Tamoxifen and Raloxifene (STAR), demonstrated that raloxifene treatment provided similar effects as tamoxifen in terms of reduction in invasive breast cancer risks and that raloxifene had fewer side effects than raloxifene.  Recruitment to these trials required the ability to identify a study population of women who were at high risk for breast cancer development and to quantify the potential benefits and risks of treatment with the SERMs used in the trials. To accomplish these tasks it was necessary to develop a mathematical model to estimate a woman's future risk of developing breast cancer, define methods to estimate the potential risk/benefit profile of a woman who would take one of these SERMs to reduce her risk of developing breast cancer and create tools for communicating these risk-related entities to each woman.  My presentation will provide a synopsis of the findings from the BCPT and STAR trials and a description of the methods used to estimate benefits and risks associated with the chemoprevention of breast cancer with a focus on the risk communication tools that were developed, how they were utilized in the trials to related information to participants and the relevance of these methods to clinical practice and public health.