Postoperative Adjuvant Chemoradiotherapy for Rectal Cancer: Analysis of Acute and Chronic Toxicity

Abstract

Aims and background

The aim of the study was to evaluate acute and chronic toxicity of combined postoperative standard radiation therapy to the pelvis and 5-fluorouracil plus levamisole in resectable rectal cancer.

Methods

Between July 1990 and September 1993, 58 patients with histologically confirmed adenocarcinoma of the rectum entered the prospective study. The schedule consisted of 5-fluorouracil, 450 mg/m² i.v. for 5 days, and from day 28 5-fluorouracil, 450 mg/m² i.v. weekly for 24 weeks, plus levamisole given orally at the dose of 150 mg every day for 3 days every 2 weeks for 6 months; radiotherapy (180 cGy/day) 5 days a week for a total dose of 45 Gy was administered from day 28.

Results

After the first cycle of chemotherapy (before radiotherapy), overall toxicity was mild. During chemoradiotherapy, dose-limiting toxicity was grade 3 diarrhea and proctitis, for which the combined treatment was interrupted for more than 7 cumulative days in 28 patients. During the 24 weeks of weekly 5-fluorouracil (after radiotherapy), no severe toxicity was reported. Three-year survival and progression-free survival were 65% and 50–55%, respectively.

Conclusions

Although adjuvant chemoradiotherapy is usually feasible, in our study toxicity was severe in a substantial proportion of patients, probably due to the schedule applied. We are evaluating the feasibility and toxicity of a combined treatment which includes 5-fluorouracil in continuous chronomodulated infusion during radiotherapy.