Long-term outcomes after local excision and radical surgery for anal melanoma: data from a population database.

PURPOSE: Anal melanoma is rare and associated with a poor outcome. Previous studies that have reported outcomes after surgical treatment are limited by both small number of participants and treatment at single centers only. This study evaluates survival of patients undergoing surgery for anal melanoma from a prospective, population-based database.
METHODS: Characteristics and survival of patients undergoing rectal resection or local excision for anal melanoma of the anus, anal canal, and overlapping region of the rectum from 1982 to 2002 were obtained from the Surveillance, Epidemiology and End Results database and compared.
RESULTS: A total of 160 patients were included in the study. Details of previous surgical procedures were available for 109 of the study patients: 60 (55%) underwent local excision and 49 (45%) rectal resection. Patients who underwent local excision were significantly older (73.5 vs 65.1 years, P < .001), whereas those who had undergone rectal resection had a greater proportion of regional disease (73.5% vs 16.7%, P < .001). The median survival of the 2 groups was similar (rectal resection vs local excision: 17 vs 28 months, P = .3). Rectal resection and local excision were associated with similar survival for patients in both regional (P = .6) and localized (P = .95) stages. Outcomes for patients who were appropriately pathologically staged after rectal resection depended on localized vs regional stage (5-year survival: 43.1% vs 12.5%, P = .17). Survival for patients in localized and regional stages who underwent rectal resection was similar to that for patients with corresponding clinical stage who underwent local excision.
CONCLUSION: Survival of patients with anal melanoma is similar after local excision or rectal resection irrespective of whether patients have localized or regional stage of disease.