Outcomes of radical surgical resections for nonmetastatic anorectal melanomas: Experience from a tertiary care centre

The outcome of radical surgery in nonmetastatic anorectal melanoma (AM) patients is studied infrequently. Here, we aimed to explore the stage-wise outcomes and the impact of radical resections in these patients.

In this single-centre retrospective study, data of 154 eligible patients were recorded and analysed. Data were obtained from November 2010 to September 2019 with follow-up until November 2020. Overall survival (OS) and disease-free survival (DFS) was calculated by Kaplan Meir method and univariate analysis of prognostic factors by Cox regression.

Of 154 patients, 110 were metastatic (stage III) and 44 were nonmetastatic (stage I:22, stage II:22) and underwent curative resections. Median follow-up was 48 months (14-119 months). A total of 39 patients underwent total mesorectal excisions (TME) and five transanal excision (TAE) were performed. Seven patients underwent extended resections. Stage I and II patients had 3- and 5-year OS of 40% and 36%; and DFS of 45% and 33.2%, respectively. Median OS and DFS were 31 and 24 months, respectively. Stage II (node-positive) patients had better median OS compared to stage III (21 vs. 4 months; p = 0.000), and 54.5% patients had recurrences, most commonly both systemic and nodal (45.83%). Median OS of patients without recurrence was 34 months.

In this large surgical series of AMs, outcome in stage I and II patients was significantly better than stage III and patients with stage II disease can have acceptable oncological outcomes. Radical surgical resections with or without lymphadenectomy could be considered in these patients. The role of adjuvant systemic therapy and radiation needs to be explored as part of multimodality treatment.