Anorectal melanoma surgical management: A tertiary cancer centre analysis

Abstract

Background: Primary rectal malignant melanoma is an exceptionally rare neoplasm associated with an extremely poor prognosis despite aggressive treatment. The described management options for localized disease are abdominoperineal resection (APR) and wide local excision (WLE) with or without radiation. Objective: To assess the surgical outcomes of the patients with anorectal melanoma. Design and Setting: Retrospective study. Patients and Methods: This retrospective study describes the experience in surgical management of 18 cases of anorectal melanoma treated surgically at our center, between 2010 and 2015. Main Outcome Measures: To assess the median survival and recurrence rates of anorectal melanoma patients who underwent surgery. Sample size: Eighteen cases. Results: This is a retrospective study of 18 cases of anorectal melanoma. APR was performed in 77.8%, wide excision (WLE) in 16.7%, and posterior exenteration in 5.6%. The median survival of patients undergoing APR was 14.66 months and median survival of patients undergoing WLE was 18 months. No significant difference in median survival was observed in the patients undergoing abdominoperineal resection (APR) or wide local excision (P = 0.168). A significant difference in median survival between the node negative group and node positive group was observed (17 months vs 13.4 months P = 0.019). The median survival of patients with stage I, II, and III cancers were 17.28 months, 16 months, and 13.4 months, respectively. A statistically significant difference in median survival was found between patients with lympho-vascular invasive and noninvasive cancer (13.37 months vs 16.7 months P = 0.029). There was no significant difference in the recurrence rate between APR and WLE groups (86% vs 66% P = 0.893).Conclusion: Anorectal melanoma is an aggressive disease which require timely diagnosis. Nodal status is an important factor that impact median survival. There is no significant difference in survival when WLE compared to APR. Node positivity and lympho-vascular invasion confer poor prognosis. Recurrence rates are identical regardless of the surgical approach. Limitations: It is a retrospective series based on case records. A major drawback of this investigation is the limited detail available for each case. Not all patients who underwent local excision received radiotherapy. Conflict of Interest: None.