Radiation therapy in the conservative treatment of carcinoma of the anal canal.

ABSTRACT

PURPOSE: Radiotherapy is the standard treatment of anal canal carcinoma. We retrospectively analyzed our experience with 108 patients. Special attention was given in evaluating 51 patients who received concomitant chemotherapy with 5-FU-CDDP. METHODS AND MATERIALS From January 1980 to December 1989, 108 patients with anal canal carcinoma were treated with exclusive radiotherapy at the Centre Hospitalier Lyon Sud. There were 11 men and 97 women, mean age was 65 years (30-86). Histologic types were 94 epidermoid carcinomas, 13 basaloid carcinomas, and one adenocarcinoma. The TNM classification (UICC 87) was 16 T1 (14.8%), 53 T2 (49%), 33 T3 (39.5%), six T4 (5.5%), 77 N0 (71.3%), 20 N1 (18.5%), nine N2 (8.3%) and two N3 (1.8%). Papillon's radiotherapy technique with a Cobalt direct perineal field was used in 82 patients. Ninety-six patients were treated with an interstitial 192Ir implant with a mean delay of 55 days after the end of the radiotherapy. In 59 patients at least one course of either 5-FU-mitomycin (8) or 5-FU-CDDP was added with at least one course concomitantly to the radiotherapy in 53 patients. RESULTS: A complete response in 104/108 patients (96%) was obtained 2 months after the brachytherapy. A locoregional relapse (local and/or pelvic failure) was seen in 18 patients (16.6%) and inguinal node relapse in nine (8.3%). Eight patients with locoregional recurrence and five with inguinal relapse were salvaged. A systemic failure occurred in six (5.5%) patients. Twenty-nine patients died, 16 of progressive disease. One patient died of treatment related toxicity. The overall 5-year survival was 64% +/- 6 and specific survival 72% +/- 8. None of the patient parameters was found to be statistically significant but there was a trend toward longer 5-year survival in T1-T2 patients and in those with well or moderately differentiated tumors. Noteworthy are the same survival rates for N0 and N1-N3 patients (65 vs. 62%). The objective response and the locoregional failure rates were similar in the patients treated with or without chemotherapy. The difference did not reach statistical significance though it was important for the following parameters overall survival rates for T1-T2 with and without chemotherapy (94 vs. 61%) and for N1-3 patients (73% vs. 27%). The main prognostic factors in this series were differentiation (5-year overall survival with chemotherapy 95% vs. 27% without chemotherapy p = 0.02) and the response at 3 months after treatment initiation, before brachytherapy implant (5-year overall survival for complete responders and "very good responders" 71% vs. 34% in partial responders p = 0.002). The complications rate was acceptable (Grade III 9%, Grade II 14%). Anal preservation was possible in 85% of the patients (92/108). Nine abdominoperineal resection were performed for recurrence and seven for severe necrosis. The T3-T4 group abdomino perineal resection was 23% while it was 9.2% of the T1-T2 group. CONCLUSION: We confirm that exclusive radiotherapy is the treatment of choice for epidermoid carcinomas of the anal canal. The role of chemotherapy is still unclear.