Preliminary results of preoperative 5-fluorouracil, low-dose leucovorin, and concurrent radiation therapy for clinically resectable T3 rectal cancer

PURPOSE: We report the downstaging, sphincter preservation, acute toxicity, and preliminary local control and survival results of preoperative 5-fluorouracil (5-FU), low-dose leucovorin (ZN), and concurrent radiation therapy followed by postoperative LV/S-FU for treatment of patients with clinically resectable T3 rectal cancer. MATERIALS AND METHODS: A total of 32 patients received two monthly cycles of preoperative LV/5-FU (bolus daily X 5). Radiation therapy (5,040 cGy) began concurrently on day 1. Postoperatively, patients received a median of two monthly cycles of LV/S-FU (range, 0-10). RESULTS: The complete response rate was 9 percent pathologic and 13 percent clinical, for a total of 22 percent. Total Grade 3+ acute toxicity during the preoperative combined modality segment was 25 percent (8/32). Of the 20 patients who were thought to initially require an abdominoperineal resection and for whom the intent of treatment was sphincter preservation, 17 (85 percent) were able to undergo sphincter-preserving surgery. With a median follow-up of 22 (3-59) months, none have developed local failure, and the three-year actuarial disease-free survival rate was 60 percent. CONCLUSION: Our data reveal encouraging downstaging, sphincter preservation, and acute toxicity with this regimen. Additional follow-up is needed to assess the long-term local control and survival rates.