Postoperative radiotherapy in Dukes' B and C carcinoma of the rectum and rectosigmoid: A randomized multicenter study

Results obtained during the first 5 years of a randomized study of postoperative radiotherapy (50 Gy) are presented. Criteria for randomization were fulfilled in 494 of 861 patients with Dukes' B and C tumors, when the trial was closed. Severe complications from radiotherapy approximated 10%. Probability of survival without local failure within 24 months was significantly higher after radiotherapy in patients with Dukes' C tumors, and the time of local failure was delayed 1 year. Patients with Dukes' B tumors had no benefit from radiotherapy. Risks of distant metastases and death were not influenced by radiotherapy in the main groups. Plasma‐CEA measurements were evaluated blindly, and radiotherapy changed the critical levels of CEA for detection of recurrent cancer. It was concluded that patients with Dukes' C tumors may benefit from radiotherapy and plasma‐CEA levels are influenced by radiotherapy, which may be important, when these are used in screening for recurrent cancer. Cancer 58:22–28, 1986.