OBJECTIVETo explore the surgical treatment patterns and clinicopathological prognostic factors of anorectal malignant melanoma (ARMM).

METHODSThe medical records and follow-up data of 64 patients with anorectal malignant melanoma undergoing surgical treatment from August 1972 to December 2015 were collected and analyzed retrospectively. Distant metastasis was discovered in 4 patients when diagnosis, of whom 3 underwent abdominoperineal resection(APR), the other underwent wide local excision (WLE). In the other 60 cases, 46 underwent ARP(1 case received additional right inguinal lymph node dissection), the other 14 underwent WLE(1 case received additional right inguinal lymph node dissection).

RESULTSThe median follow-up time of 64 cases was 24(4 to 139) months. The 1-year, 3-year and 5-year overall survival rate was 70.3%, 35.3% and 18.4%, respectively. The 5-year survival rate of 60 patients without distant metastasis undergoing APR and WLE was 19.7% and 23.1%, and the median survival was 19.6 and 24.3 months, respectively(P =0.634), which was not significantly different. According to the Kaplan-Meier method for univariate analysis, involved margins (P=0.024), lymph metastasis (P=0.018) and clinical staging(P=0.003) had significant effects on overall survival. Multivariate analysis indicated that only the lymph node metastasis was significant predictive factor (RR=16.614, 95%CI:1.165 to 236.847, P=0.038).

CONCLUSIONSThe prognosis of ARMM is poor. The lymph node metastasis is the main predictive factors. Operation procedure (APR or WLE) has no obvious effect on prognosis.