The National Surgical Adjuvant Breast and Bowel Project (NSABP) is a clinical trials cooperative group supported since its inception by the National Cancer Institute (NCI). We have a more than 50-year history of designing and conducting clinical trials that have changed the way breast cancer is treated, and, more recently, prevented. It was the NSABP's breast cancer studies that led to the establishment of lumpectomy plus radiation over radical mastectomy as the standard surgical treatment for breast cancer. We were also the first to demonstrate that adjuvant therapy could alter the natural history of breast cancer, increasing survival rates, and the first to demonstrate on a large scale the preventive effects of the drug tamoxifen in breast cancer.

Since its beginning the NSABP has enrolled more than 110,000 women and men in clinical trials in breast and colorectal cancer. We are headquartered in Pittsburgh, Pennsylvania and have research sites at nearly 1000 major medical centers, university hospitals, large oncology practice groups, and health maintenance organizations in the United States, Canada, Puerto Rico, Australia, and Ireland. At those sites and their satellites, more than 5000 physicians, nurses, and other medical professionals conduct NSABP treatment and prevention trials. Their presence at local hospitals and medical facilities means that state-of-the-art clinical trials can be provided to patients near their homes.

The NSABP was one of the first organizations to undertake large-scale studies in the prevention of breast cancer, and our Breast Cancer Prevention Trial (BCPT), which included more than 13,000 women at increased risk for breast cancer, demonstrated the value of the drug tamoxifen in reducing the incidence of the disease in this population. The second prevention trial, the Study of Tamoxifen and Raloxifene (STAR) entered more than 19,000 women to compare the effects of these two drugs in reducing the incidence of breast cancer.