Patterns of failure in anorectal melanoma. A guide to surgical therapy.

Anorectal melanoma is an aggressive tumor with a reported 5-year survival rate of 6%. Recommendations for local surgical therapy vary from local excision to abdominoperineal resection. Therapy, patterns of failure, and survival were retrospectively examined in 32 patients with anorectal melanoma. Twenty-six patients were treated surgically, 14 with abdominoperineal resection and 12 with local excision. Local recurrence occurred less frequently in patients undergoing abdominoperineal resection (4 [29%] of 14) compared with patients undergoing local excision (7 [58%] of 12) but developed concomitantly with distant or regional metastasis in all but 2 of the 11 patients whose operations failed locally. Inguinal nodal disease developed in 15 patients (47%). Pelvic nodal disease became apparent in only 2 patients (7%). There was no difference in overall survival between the two surgically treated groups (median survival, 19.5 months for patients treated with abdominoperineal resection vs 18.9 months for patients treated with local excision). Therefore, local excision is recommended when technically feasible since these patients eventually succumb to metastasis regardless of surgical therapy.