Squamous cell carcinoma of the anal margin.

Purpose: To define the optimal treatment of patients with squamous cell carcinoma (SCCA) of the anal margin.

Methods: Nineteen patients treated with curative intent by radiotherapy (RT) alone or combined with adjuvant chemotherapy (CTX) between 1979 and June 2000 were analyzed. The pertinent literature was reviewed and discussed as it related to our experience.

Results: Local control after RT or RT and CTX was observed in all 19 patients (100%). One T1 patient developed inguinal lymph node metastases and subsequently died secondary to regional and distant disease. This patient did not receive elective inguinal node RT; the lymph nodes of the other 18 patients in this analysis were irradiated. Four patients died of intercurrent disease at 25, 29, 37, and 113 months after RT, respectively. The remaining 14 patients were alive and disease-free from 52 to 143 months after treatment. No patient suffered a severe complication or required a diverting colostomy or an abdominoperineal resection (APR) after treatment. Review of the literature reveals that the probability of cure is similar after RT alone or combined with CTX compared with surgery. Therefore, the choice of treatment depends on the anticipated functional result.

Conclusions: Patients with SCCA of the anal margin have a high likelihood of cure with sphincter preservation after RT or RT and CTX. Patients with well to moderately differentiated T1 tumors may undergo excision if it can be accomplished without compromising the sphincter. The remainder are treated with RT. Adjuvant CTX is indicated for those with T3-T4 tumors and/or involved regional nodes.