Radical surgery and postoperative radiotherapy as combined treatment in rectal cancer. Final results of a phase III study of the European Organization for Research and Treatment of Cancer.

Abstract

There is controversy whether adjuvant radiotherapy should be given before or after surgery for locally advanced, resectable rectal cancer. Preoperative radiotherapy substantially reduces local recurrence rates but may increase postoperative complications. In addition, patients found to have early cancers are treated unnecessarily. This study is a randomized trial of postoperative radiotherapy in patients who had a potentially curative resection for locally advanced rectal carcinoma. Following complete excision of a Dukes B or C rectal cancer, 172 patients were randomized to adjuvant radiotherapy (46 Gy 5 days per week in 30-38 days) (84 patients) or controls (88 patients). After a median follow-up of 85 months, no benefit from postoperative radiotherapy had been observed in disease-free survival (P = 0.81), overall survival (P = 0.52), local recurrence-free interval (P = 0.46) or in the number and sites of recurrence. Acute toxicity following radiotherapy included diarrhoea (20 per cent), cystitis (13 per cent), delayed wound healing (7 per cent), pneumonia (5 per cent) and seizures (1 per cent). Late complications included reoperation for small bowel obstruction (5 per cent), chronic diarrhoea (20 per cent), chronic cystitis (12 per cent) and persistent perineal sinus (9 per cent). In the group who had surgery alone, late morbidity was found in 11 per cent. This trial failed to demonstrate any improvement in overall survival or local control when postoperative irradiation was given following resection of locally advanced rectal carcinoma.