Squamous cell carcinoma of the anus.

The institution of proper therapy for squamous cell carcinoma of the anus requires an intimate knowledge of the histology and anatomy of this region. It also requires an awareness of the disease entity by the physician and a realization that everything that bleeds around the anus is not due to hemorrhoidal disease. Once the diagnosis and extent of the disease are established, several known facts can be applied in the decision for specific therapy. For small lesions (less than 3 cm in diameter) located in the perianal skin, it is now clear that wide local excision, usually with skin graft, is a safe, reliable method of treatment. However, if these lesions are invading deeply, one should resort to a more radical form of therapy. The combined abdominoperineal resection is the definitive treatment for lesions in the anal canal. In this way, local recurrence can be prevented insofar as possible, invasive lesions can be completely eradicated, and patients with lymph node involvement will be given the greatest opportunity for survival. As is the case in all radical types of therapy, the anal sphincter mechanism of a few patients will be sacrificed unnecessarily. If a lesion is located in the anal canal and does not invade beyond the submucosa, such as those lesions discovered during routine hemorrhoidectomy, it might be safe to undertake wide local excision of the region. Precise pathologic study must be available, however, and the patient must be apprised of this compromise in management and be willing to be examined frequently for evidence of recurrent disease. With present knowledge and development of the operation, radical removal of inguinal lymph nodes should be undertaken when the nodes are thought to contain tumor. It must be realized, however, that the overall salvage rate in this situation is low. Finally, the treatment of recurrent and metastatic squamous cell carcinoma of the anus remains a great dilemma. The first choice of treatment for local recurrence should be excision whenever possible. Radiation may have some value, but excellent responses are rare. Lastly, several chemotherapeutic regimens are available for use in specific cases.