Surgical management of primary anorectal melanoma

Background: This aim of this study was to analyse outcome after surgery for primary anorectal melanoma and to determine factors predictive of survival. Methods: Records of 40 patients treated between 1977 and 2002 were reviewed. Results: Twelve men and 28 women of mean age 58.1 (range 37-83) years were included in the analysis. Overall and disease-free survival rates were 17 and 14 per cent at 5 years. Median overall survival was 17 months and disease-free survival was 10 months. The 5-year survival rate was 24 per cent for patients with stage I turnouts, and zero for those with stage II or stage III disease. There was no significant difference in overall survival after wide local excision (49 and 16 per cent at 2 and 5 years respectively) and abdominoperineal resection (33 per cent at both time points). In patients with stage I and stage II disease, there was a significant association between poor survival and duration of symptoms (more than 3 months), inguinal lymph node involvement, tumour stage and presence of amelanotic melanoma. Conclusion: Anorectal melanoma is a rare disease with a poor prognosis. Wide local excision is recommended as primary therapy if negative resection margins can be achieved.