External beam radiotherapy for rectal adenocarcinoma.

A series of 243 patients with adenocarcinoma of the rectum treated with radiotherapy is presented. In the early part of the study radiotherapy was combined with 5-fluorouracil (5FU). Later, radiotherapy was given alone. Seventy-four patients were treated with radical external beam radiotherapy for recurrent or inoperable rectal adenocarcinoma. One hundred and forty-five patients with advanced pelvic tumours or with metastases were treated with palliative pelvic radiotherapy. Twenty-four patients who had small-volume residual pelvic tumour or who were felt to be at high risk of pelvic recurrence following radical resection received postoperative radiotherapy. Complete tumour regression was seen in 38 per cent of radically treated patients, and 24 per cent of palliatively treated patients. Partial regression was observed in 56 per cent of radically treated patients, and 58 per cent of palliatively treated patients. Long-term local tumour control was more commonly observed for small tumours (less than 5 cm diameter). Fifty-eight per cent of patients treated with postoperative radiotherapy remained free of local recurrence. Survival was significantly better in patients with small tumours. The addition of 5FU did not appear to improve survival or tumour control. The value of radiotherapy in the relief of distressing symptoms related to the presence of pelvic tumour has been confirmed.