Early toxicity from preoperative radiotherapy with continuous infusion 5-fluorouracil for resectable adenocarcinoma of the rectum: a Phase II trial for the Trans-Tasman Radiation Oncology Group.

Abstract

To assess the toxicity and the efficacy of preoperative radiotherapy with continuous infusion 5-fluorouracil (5-FU) for locally advanced adenocarcinoma of the rectum. Eligible patients had newly diagnosed localized adenocarcinoma of the rectum within 12 cm of the anal verge, Stage T3-4, and were suitable for curative resection. Eighty-two patients were treated with radiotherapy-50.4 Gy in 28 fractions in 5.6 weeks, given concurrently with continuous infusion 5-FU, using either 96-h/week infusion at 300 mg/m(2)/day or 7-days/week infusion at 225 mg/m(2)/day. The median age was 59 years (range, 27-87), and 67% of patients were male. Pretreatment stages of the rectal cancer were T3, 89% and resectable T4, 11%, with endorectal ultrasound confirmation in 67% of patients. Grade 3 acute toxicity occurred in 5 of 82 patients (6%; 95% confidence interval [CI], 2-14%). Types of surgical resection were anterior resection, 61%; abdominoperineal resection, 35%; and other procedures, 4%. There was no operative mortality. Anastomotic leakage after low anterior resection occurred in 3 of 50 patients (6%; 95% CI, 1-17%). The pathologic complete response rate was 16% (95% CI, 9-26%). Pathologic Stages T2 or less occurred in 51%. Preoperative radiotherapy with continuous infusion 5-FU for locally advanced rectal cancer is a safe regimen, with a significant downstaging effect. It does not seem to lead to a significant increase in serious surgical complications.