National Surgical Adjuvant Breast and Bowel Project's Breast Cancer Prevention Trial.

The Breast Cancer Prevention Trial is the largest breast cancer prevention study ever undertaken. Administered by the National Surgical Adjuvant Breast and Bowel Project, it is the first trial seeking to demonstrate whether a drug, tamoxifen, can prevent breast cancer in high-risk women. The objectives of this trial are to determine whether tamoxifen is effective in 1) reducing the incidence of invasive breast cancer, 2) reducing breast cancer mortality, 3) reducing deaths from cardiovascular disease, and 4) reducing bone fractures. In addition, the study will evaluate side effects, toxicity, and the quality of life of all study participants.