PURPOSE: Radiation and concomitant 5-Fluorouracil (5-FU) and Mitomycin-C (MMC) chemotherapy has reported efficacy in the treatment of anal cancer. Because of the significant toxicities observed with 5-FU and MMC, a regimen of concomitant radiation therapy and continuous infusion 5-FU and Cis-Platin (CDDP) was evaluated for the treatment of epidermoid cancer of the anal canal.MATERIALS AND METHODS: A retrospective analysis of 62 patients with invasive squamous cell or cloacogenic carcinoma of the anus was performed. Treatment was administered between November, 1989 and December, 1995. A continuous infusion of 5-FU (250 mg/m2) and CDDP (4 mg/m2) was administered concurrently with radiation to the lower pelvis. The radiation fields encompassed the primary tumor and involved regional lymphatics. Throughout the course of treatment 180 cGy/fraction was administered. Initially, 30.6 Gy was administered through AP-PA fields. Subsequently, an additional 25 Gy was delivered using the three field (posterior field and two lateral portals) belly board technique. The dose to inguinal node metastases was supplemented with the appropriate electron beam energy. A total dose of 55 Gy was administered to the primary and involved inguinal nodes. Patients were evaluated at 8 weeks after completion of therapy. Those with residual or recurrent local disease were surgically salvaged.RESULTS: The stage of disease at presentation was: TX-10%; T1-2%; T2-40%; T3-37%; T4-11%; 35% had nodal disease. The prescribed therapy was completed in 48 cases (77%). Only 3 patients (5%) did not complete the prescribed chemotherapy and radiation. Chemotherapy was interrupted in an additional 11 patients (18%), but all of the prescribed radiation was administered in this group. Hematological toxicity was not the cause of treatment interruption in any case. The most frequent acute side effects were nausea, vomiting, diarrhea, and skin reaction. There were no treatment related deaths. Late radiation complications were unusual. Complete clinical response was observed in 52 patients (84%). Median follow-up was 34 months. The actuarial local control rate at 5 years was 76%. Fourteen patients had persistent or recurrent disease, and surgical salvage was possible in 10 patients. The actuarial disease free survival rate was 76%. With surgical salvage, the disease-specific and overall survival rates at 5 years were 94%, and 90%, respectively.CONCLUSION: Compared to other regimens, radiation and concomitant continuous infusion 5-FU and CDDP appears to be effective for the treatment of epidermoid cancer of the anus with acceptable acute and late toxicities.