Systemic therapy in anorectal melanomas: Does choice of systemic therapy matter?

731 Background: Anorectal melanomas are relatively uncommon and there is no consensus on the optimal systemic therapy regime with survival advantage. Methods: Retrospective analysis of prospectively maintained database of patients treated at our institute between January 2102 and July 2015. SPSS 20 used for statistical analysis. The survival benefit was assessed in the form of progression free survival (PFS) and overall survival (OS) with the systemic therapy. Results: Out of 74 anorectal melanoma patients seen during this period 50 patients had metastatic disease and were evaluated for outcome analysis. Median follow up of patients was 8 months. Of these 50 patients, 36 received chemotherapeutic regimes (taxanes with platinums with or without oral metronomic therapy (OMT), dacarbazine/temozolamide or OMT alone) as per the description of treating physician, while 11 patients did not receive any systemic therapy due to poor general condition at presentation, or refused therapy. 3 patients defaulted during the initial work up. Median age at presentation was 54 years and common sites of metastasis were Liver, lung and lymph nodes. Median OS for patients who underwent excision was 22 months. In patients who received systemic therapy median OS was 13 months versus 8 months for those who did not receive it (p = 0.253). The Median PFS after 1st line systemic therapy was 3 months. 5 patients had grade III toxicities in the form of neutropenia, diarrhea. PFS was 3 months for temozolamide/dacarbazine, OMT along with chemotherapy or OMT alone whereas it was 5 months for taxanes with platinum. (p = 0.045). OS was 11 months for OMT with or without chemotherapy and 18 months for taxanes with platinum (p = 0.43). Conclusions: Palliative systemic therapy has some survival advantage in metastatic anorectal Melanomas. Taxanes with platinums appear to be the most efficacious among the presently used regimens even in anorectal melanomas. OMT also has the survival benefit with the advantage of oral therapy in palliative setting