THE BIOLOGY OF COLORECTAL-CARCINOMA

Rapid progress in understanding the biology of colorectal carcinoma has occurred in the last decade. During this time, the importance of tumor suppressor genes has been delineated. Mutations in proto-oncogenes, and some of the genetic and epigenetic defects that occur during neoplastic transformation, have been characterized. The very recent identification of a technology that detects some mutations in genes by analyzing fecal specimens offers the real prospect of effective, low-cost screening of large segments of the population at risk for the development of large bowel cancer. A better understanding of the mechanisms involved in metastasis is slowly leading to better methods of prognostication for patients with carcinoma of the colon or rectum. This is important because a better biologic identification of patients at high risk for subsequent metastasis will help determine which patients should receive adjuvant therapy. Further, the development of new approaches to inhibit various aspects of the cascade of events necessary to produce metastasis, notably die inhibition of neovascularization, suggests the real possibility that established metastases may be treated by relatively nontoxic medical therapies. As a result, further knowledge of the biology of colorectal cancer will translate into strategies that will continue to improve the control of this prevalent carcinoma.