ADJUVANT RADIATION-THERAPY FOR COLON-CANCER

Post-operative radiation therapy has been used in selected patients wi th colon cancer. In contrast with rectal cancer, the primary failure p attern in colon cancer is abdominal. Local failure does occur, but is less frequent and more difficult to detect. Retrospective data suggest a benefit from local/regional radiation therapy on local control and disease-free survival in subsets of patients compared to historical co ntrols. An ongoing phase III intergroup trial (INT 0130) will determin e if local/regional radiation therapy improves the results of chemothe rapy in subsets of patients with high-risk colon cancer. In general, t he results of whole abdominal radiation plus 5-fluorouracil (5-FU) hav e been disappointing. However, the more recent data from the Southwest Oncology Group pilot trial are encouraging. In contrast to rectal can cer, where adjuvant chemotherapy plus radiation therapy is standard tr eatment in high-risk patients, the use of radiation therapy (either lo cal/regional or whole abdomen) in colon cancer remains investigational .