Preoperative radiation therapy for rectal cancer. An effective therapy in need of a clinical trial.

Sixty patients with locally advanced adenocarcinoma of the rectum have been treated with preoperative high-dose pelvic irradiation in an attempt to improve operability and increase local control. Fifty-six patients showed no evidence of distant metastases at surgery and their records have been analyzed with respect to recurrence patterns, survival, and complications. The results have been compared with those of a similar analysis of 106 patients treated with curative surgery alone. There was a statistically significant improvement in local control between groups, with 16% of patients in the radiotherapy group having a component of local failure compared with 40% in the surgery group. A dose response was observed, with 67% local control at 4000 rad (4000 cGy) and 91% local control at 5000 rad (5000 cGy). Despite the more advanced clinical stage of the irradiated patients, no significant difference in survival was seen between groups, with a five-year survival rate of 52% in the irradiated patients and 48% in patients treated by surgery alone. Preoperative high-dose radiotherapy was well tolerated, with a 5% incidence of major complications in both groups.