Efficacy of postoperative 5-FU, high-dose leucovorin, and sequential radiation therapy for clinically resectable rectal cancer.

We report the local control and survival in a previously reported phase I dose escalation trial of combined postoperative 5-FU, high dose leucovorin (LV), and sequential radiation therapy followed by maintenance LV/5-FU for the treatment of patients with clinically resectable rectal cancer. Following surgery for stages T3-4N0-2M0 primary (21) or recurrent (4) rectal cancer, 25 patients received 5-FU/LV x 1 cycle. Radiation therapy (5040 cGy) began on day 8. A second cycle of 5-FU/LV was given concurrent with the fourth week of radiation. Patients received an additional 10 cycles of LV/5-FU. The median follow-up was 40 months (range 18-52). The incidence of grade 3+ acute toxicity in the 9 patients who received the recommended dose of 5-FU was 44%. The local failure rate was 28%. Abdominal and distant failure rates were 24%. The 3-year actuarial disease-free survival was 74% and the overall survival was 80%. Our preliminary data reveal reasonable local control and survival rates. However, further follow-up is needed to assess our results at 5 years. Postoperative combined modality therapy with high-dose LV may be an option for the adjuvant treatment of patients with resectable rectal cancer.