The use of radiation therapy combined with chemotherapy in the management of squamous cell carcinoma of the anus and marginally resectable adenocarcinoma of the rectum.

For many years surgery has been the treatment of choice for squamous cell carcinoma of the anus, but it is now becoming apparent that well-planned definitive radiation therapy combined with chemotherapy may obviate the need for an abdomino-perineal resection. Since 1976, 33 patients with this disease were treated at Highland Hospital by radiation therapy combined with 5-FU and Mitomycin-C for sensitization. Four of these patients underwent a planned abdomino-perineal resection following therapy; the operative specimens of all four patients were negative for tumor. Twenty-nine patients were treated by the above method without surgery in a definitive manner and local control was achieved in 89.6% of patients. Radiation therapy combined with 5-FU and Mitomycin-C for sensitization has also been used in an effort to improve the resectability rate of large rectal cancers and ultimately the 5-year survival of patients with this disease. Fifty-eight patients with marginally resectable carcinoma of the rectum were treated pre-operatively by this regimen. The method of administration of the chemotherapeutic agents used for sensitization appears to be an important factor in obtaining an increased therapeutic ratio. Thirty-three patients have been followed for a minimum of 5 years with an 84.9% local control rate; 63.7% are alive and well, and 9.1% have died of intercurrent disease. An additional 22 patients have been treated with this regimen for recurrent rectal disease and 9.9% are alive and well at 5 years. Radiation therapy combined with 5-FU and Mitomycin-C for sensitization purposes appears to be effective in downstaging rectal carcinoma at surgery with a resultant survival rate superior to that following surgery alone.