The impact of 5-fluorouracil and intraoperative electron beam radiation therapy on the outcome of patients with locally advanced primary rectal and rectosigmoid cancer.

Abstract

To analyze the effects of 5-fluorouracil (5-FU) chemotherapy combined with preoperative irradiation and the role of intraoperative electron beam irradiation (IOERT) on the outcome of patients with primary locally advanced rectal or rectosigmoid cancer. From 1978 to 1996, 145 patients with locally advanced rectal cancer underwent moderate- to high-dose preoperative irradiation followed by surgical resection. Ninety-three patients received 5-FU as a bolus for 3 days during the first and last weeks of radiation therapy (84 patients) or as a continuous infusion throughout irradiation (9 patients). At surgery, IOERT was administered to the surgical bed of 73 patients with persistent tumor adherence or residual disease in the pelvis. No differences in sphincter preservation, pathologic downstaging, or resectability rates were observed by 5-FU use. However, there were statistically significant improvements in 5-year actuarial local control and disease-specific survival in patients receiving 5-FU during irradiation compared with patients undergoing irradiation without 5-FU. For the 73 patients selected to receive IOERT, local control and disease-specific survival correlated with resection extent. For the 45 patients undergoing complete resection and IOERT, the 5-year actuarial local control and disease-specific survival were 89% and 63%, respectively. These figures were 65% and 32%, respectively, for the 28 patients undergoing IOERT for residual disease. The overall 5-year actuarial complication rate was 11%. Treatment strategies using 5-FU during irradiation and IOERT for patients with locally advanced rectal cancer are beneficial and well tolerated.