Randomized study on preoperative radiotherapy in rectal carcinoma. Stockholm Colorectal Cancer Study Group.

Abstract

A population based prospective randomized trial on preoperative radiotherapy in operable rectal cancer was conducted in Stockholm, Sweden. Five hundred fifty-seven patients from 12 institutions were included with histologically proven, clinically resectable rectal adenocarcinoma. Patients planned for local excision or previously irradiated to the pelvis were excluded. A total of 272 patients were allocated to preoperative irradiation with 25 Gy in five cycles during 5-7 days to the rectum and the pararectal tissues (RT+ group) and 285 patients were allocated to surgery only (RT- group). The median follow-up time was 50 months. No patient was lost to follow-up. Surgery was considered curative in 479 patients (86%). Locoregional recurrence occurred in 10% of the patients in the RT+ group versus 21% in the RT- group (p < 0.01). Among the curatively operated patients, distant metastases occurred in 19% in the RT+ group versus 26% in the RT- group (p = 0.02). The overall survival was improved in the irradiated patients (p = 0.02). Postoperative complications were more common after irradiation but were usually mild. The postoperative mortality was low in both groups. Preoperative short-term, high-dose radiotherapy as given in this trial reduces the risk of local and distant recurrence and improves survival after curative surgery for rectal carcinoma.