Carcinoma of the anus.

Carcinoma of the anus represents about 2% of cancers of the large bowel. From 1950 to 1970, 20 patients were treated for this condition. Included were 113 patients with squamous cell carcinoma (31 perianal), 64 with basalid squamous carcinoma, 8 with Paget's disease of the anus, 7 with melanoma, 6 with basal cell carcinoma, and 6 with adenocarcinoma. Combined abdomino-perineal resection was the treatment of choice except for perianal lesions; for these, local excision was used most frequently. Inguinal node dissection was used infrequently, and it is not possible to draw meaningful conclusions from the data. Overall survival rates for patients having anal squamous cell carcinoma are similar except when lymphatic invasion is present; then basaloid lesions have a significantly better prognosis. For rare anal carcinomas, histopathologic findings dictate the end results-- the better the findings and more satisfactory the results.