Surgical therapy for anorectal melanoma.

Background: Anorectal melanoma is a rare but highly lethal malignancy. Historically, radical resection was considered the "gold standard" for treatment of potentially curable anorectal melanoma. The dismal prognosis of this disease has prompted us to recommend wide local excision as the initial therapeutic approach. The purpose of this study was to review our results in patients who underwent wide local excision or radical surgery (abdominoperineal resection [APR]) for localized anorectal melanoma.
Study Design: We reviewed the charts of all patients referred for resection of anorectal melanoma between 1988 and 2002. Endpoints included overall survival, disease-free survival, and local, regional, or systemic recurrence.
Results: Fifteen patients underwent curative-intent surgery; four underwent APR and 11 underwent wide local excision. Eight patients (53%) are alive; 7 (47%) are disease-free (followup 6 months to 13 years). Of 12 patients who have been followed for more than 2 years, 4 are alive (33%) and 3 are disease-free (25%). Seven patients have been followed for more than 5 years and two are alive and disease-free (29%). All of the longterm survivors underwent local excision as the initial operation. There were no differences in local recurrence, systemic recurrence, disease-free survival, or overall survival between the APR group and the local excision group. Local recurrence occurred in 50% of the APR group and 18% of the local excision group; regional recurrence occurred in 25% versus 27%. Distant metastases were common (75% versus 36%).
Conclusion: In patients who have undergone resection with curative intent for anorectal melanoma, most recurrences occur systemically regardless of the initial surgical procedure. Local resection does not increase the risk of local or regional recurrence. APR offers no survival advantage over local excision. We advocate wide local excision as primary therapy for anorectal melanoma when technically feasible.