Treatment of epidermoid carcinoma of the anal canal.

Epidermoid carcinoma of the anal canal should be differentiated from that of the anal margin because of the different clinical presentations, pathologic characteristics, treatments and prognosis. The traditional treatment for carcinoma of the canal, abdominoperineal resection, produced a 55 per cent absolute five year survival rate but at the expense of permanent colostomy. Initial treatment with 5-fluorouracil and mitomycin C combined with external beam radiation therapy reduced the size of the tumor in 72 per cent of the patients and, with subsequent local excision or abdominoperineal resection, resulted in a 78 per cent survival rate in five years. The long term results from combined treatment are better than abdominoperineal resection alone with preservation of anal function in 45 per cent of the patients.