Current management of epidermoid carcinoma of the anal canal.

Treatment with a combination of radiation therapy and chemotherapy currently allows about 80 per cent of patients with epidermoid carcinomas of the anal canal to retain anorectal function, with about a 70 per cent likelihood of cure at 5 years. In these programs, radical surgery is reserved for the management of residual cancer or of radiation- or chemotherapy-induced anorectal toxicity. Several different schedules of combined modality therapy are in use, but an important common element in most schedules appears to be the concurrent administration of radiation and 5-fluorouracil. The improvement in local control rates with combined radiation and chemotherapy, as compared to most series treated by either radical radiation or radical surgery, has not been matched by a marked improvement in survival rates, and the risk of distant metastases does not appear to have been altered by these combinations. The success of the combinations in improving local control has allowed the indications for local excision to be defined more narrowly, and should reduce the risks of local recurrence associated with conservative surgery.