Radiotherapy and rectal cancer.

Studies utilizing preoperative radiotherapy as an adjunct to surgery are reviewed, with results indicating marked increase in survival. Results of postoperative irradiation also appear beneficial, although less extensive data are available. Irradiation for inoperable and recurrent rectal cancer has demonstrated symptomatic relief, particularly avoidance of colostomy, and can render some patients operable and resectable. Adjuvant immunotherapy after irradiation and operation is suggested for further research.