Treatment and outcome trends and predictors of overall survival of rectal melanoma: Analysis of the National Cancer Database.

Background: We aimed to assess characteristics, treatment, and outcomes of rectal melanoma (RM).
Methods: This retrospective cohort study looked at patients with RM from National Cancer Database (2004-2019) analyzed characteristics and outcomes of the entire cohort and across three time periods (2004-2009; 2010-2014; 2015-2019). Main outcome measures were change in treatment and survival trends across time periods and overall survival (OS).
Results: 641 patients (58.5% female; mean age: 68.2 ± 13.6 years) were included. OS rate was 26%; median survival duration was 17.9 (IQR: 15.93-20.67) months. There was a significant decrease in the use of chemotherapy (17.3%-6.6%; p = 0.001) and surgery (62.9%-41.8%; p = 0.00004) but increased use of immunotherapy (11.9%-52%; p < 0.001) across time periods. OS was longer in the last time period than in the first two (21.8 vs 16.8 vs 16.5 months; p = 0.09). Surgical excision was an independent predictor of improved OS (HR = 0.266, 95%CI: 0.089-0.789, p = 0.017) whereas older age (HR = 1.039, 95%CI: 1.007-1.072, p = 0.016), positive resection margins (HR = 5.06, 95%CI: 1.902-13.48, p = 0.001) and metastasis (HR = 34.62, 95%CI: 3.973-301.6, p = 0.001) were predictors of poor survival.
Conclusions: Over time, chemotherapy and surgery have been used less often in the treatment of RM while the use of immunotherapy increased by more than four-fold. Older age, surgical treatment, positive resection margins, and metastasis were predictive of survival of RM.
Competing Interests: Declaration of competing interest None of the authors have any relevant financial disclosures. Non-relevant: Dr. Wexner received royalties from ARC/Corvus, Baxter, Becton Dickinson, GI Supply, ICON Clinical Research Limited, Intuitive Surgical, Leading BioSciences/PalisadeBio, Livsmed, Medtronic, Stryker, Takeda; and royalties from Intuitive Surgical, Karl Storz Endoscopy America Inc, Medtronic, Unique Surgical Innovations LLC.
(Copyright © 2023. Published by Elsevier Ltd.)