Management and outcomes of primary anorectal melanoma in the United States

To analyze outcomes in primary anorectal melanoma, a rare disease with limited data and treatment guidelines. We analyzed 305 subjects in the National Cancer Database from 2004 to 2015. The primary end point was overall survival (OS). Surgery was predictive of OS (median 2.24 vs 1.18 years; p = 0.009) with no survival difference between local and transabdominal approaches (p = 0.77). No OS benefit was seen with chemotherapy (p = 0.16), radiotherapy (p = 0.31) or adjuvant therapy post surgery (p > 0.05 for all groups). Targeted therapy trended toward higher survival in metastatic patients (1.33 vs 0.55 years; p = 0.06). In nonmetastatic patients, surgery of any method is associated with a survival benefit. The trend for improved survival following targeted therapy in metastatic patients merits further exploration.