Total abdominal irradiation for cancer of the colon.

A retrospective analysis of 55 patients treated with whole abdominal irradiation following surgical excision for cancer of the colon is presented. Three groups of patients were given whole abdominal irradiation, eight with gross residual tumor following surgery, 17 with peritoneal seeding, and 30 who had complete surgical excision of the tumor but were felt to be at high risk for relapse. Only one of the eight patients with gross residual tumor, and one of the 17 with peritoneal metastases, are currently alive and well, with the majority dying from local or peritoneal metastases. The 5 year actuarial survival for the 30 patients irradiated following complete surgical excision is 55%. The treatment was well tolerated and few complications were observed. It is concluded that whole abdominal irradiation is ineffective for the treatment of colon cancer if peritoneal metastases are present, or if gross residual tumor is left behind following surgery. A randomized controlled clinical trial is being organized to test whether total abdominal irradiation is of benefit in terms of survival in high risk colon cancer patients following complete surgical removal.