Colorectal cancer is the third most common cancer both in men and womenin the United States. Advances in adjuvant treatment of colon cancer have came to consist of a successionof small improvements by large-scale clinical trials. The National Surgical Adjuvant Breast and BowelProject (NSABP) colon trials reflect the exciting history of progress in adjuvant treatment of coloncancer. Since 1977, the NSABP has successfully designed and conducted seven large-scale prospective randomizedclinical trials for colon cancers that has altered and improved the standard of care for patients withthis disease. More than 5,000 physicians, nurses, and other medical professionals at nearly 200 medicalsites from across the United States, Canada, Puerto Rico, Australia and New Zealand assist the NSABPin its mission to eliminate colorectal and breast cancers. These medical sites include several universityhospitals and many other local medical centers that treat patients from a variety of social, and economicbackgrounds contributed to the trials. The NSABP clinical trials are distinctive because of the largenumber of patients and elimination of social, cultural and economic influences. The ongoing trials ofthe NSABP should continue to provide information used to determine principals of neoadjuvant treatmentfor colon cancer. In this article we review seven prospective randomized clinical trials with their publishedresults and discuss the combined analysis of the first four trials.

Keywords: Chemotherapy, Adjuvant - statistics & numerical data, Clinical Trials as Topic, Colonic Neoplasms - therapy, Combined Modality Therapy, Disease-Free Survival, Follow-Up Studies, Time Factors