To investigate the prognostic role of site of origin for primary anorectal melanoma.
Data regarding patients affected by primary melanoma of the anal canal and rectum were retrieved from the surveillance, epidemiology, and end results database. Age, gender, tumor stage, tumor location, receipt of radiotherapy, and type of surgical intervention were introduced as covariates in a Cox proportional hazards regression model.
Our population constituted of 177 patients affected by anal canal melanoma and 110 by rectal melanoma. Tumor stage resulted to be the only independent predictor of survival (P = 0.002; hazards ratio 1.819; 95 % confidence interval 1.255–2.636). Tumor location failed to reach statistical significance.
Site of origin of anorectal melanoma does not affect overall survival in patients undergoing surgery.