Role of Radiotherapy in High-Risk Colon Cancer

For selected subsets of colon cancer (T4 lesions or those with cancers in areas of the colon where anatomic factors preclude surgery with adequate resection margins), local failure rates are similar with those of rectal cancers. The role of adjuvant external beam radiation therapy in this subset of patients has been evaluated in both retrospective and prospective studies.

Postoperative radiation with or without 5-FU improved local control and disease-free survival when compared with historical controls in many single-institution studies such as MGH series, however, there is no phase-III prospective randomized study to elucidate the role of postoperative radiation therapy. One must treat each patient on the basis of through evaluation of stage, operative findings, and results of pathologic and imaging studies.