Colorectal Cancer: An Amalgam of Failures, Progress, and Prospects.

Few biological puzzles are more intriguing than colorectal cancer. While the disease is common and appears to occur sporadically, familial syndromes are well documented. Tantalizing clues concerning the relationship between diet and colorectal cancer have been studied for years, but the incidence of the disease has not decreased despite wide public education of these associations. Colorectal cancer has afforded researchers a particular advantage for study because all of the malignant tumors have arisen from a precursor lesion, the adenoma.[1] Yet, only some adenomas develop into cancers, while others stop growing or regress. The adenoma-to-carcinoma sequence has profound implications for screening strategies and early intervention programs. More importantly, the sequence provides a unique opportunity for the molecular biological understanding of the process in which adenomas, and then cancers, arise from normal mucosa. Finally, this sequence of development suggests that chemical intervention in the progression of normal mucosa to cancer may prevent colorectal cancer.[2]