Complete and Durable Response After Radiation Therapy to Primary Tumor Site of a Patient With Metastatic Anorectal Mucosal Melanoma With Oligoprogression on Nivolumab

• Type of Material: Article
• Authors: David G. Wallington, Western Michigan University; Arif S. Rashid, Emory University; Zachary Buchwald, Emory University; Lisa J. Sudmeier, Emory University; Mohammad Khan, Emory University
• Language: English
• Date: 2020-05-01
• Publisher: Elsevier
• Publication Version: Final Published Version
• Copyright Statement: © 2020 The Authors. Published by Elsevier Inc. on behalf of American Society for Radiation Oncology.
• License: Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1016/j.adro.2020.02.006
• Title of Journal or Parent Work: Advances in Radiation Oncology
• Volume: 5
• Issue: 3
• Start Page: 503
• End Page: 510
• Grant/Funding Information: Dr Khan reports funding from Merck Pharmaceuticals.
• Keywords: Tumor; Radiology, Nuclear Medicine & Medical Imaging; Radiation therapy; Metastatic Anorectal Mucosal Melanoma; Responses
• Research Categories: Health Sciences, Medicine and Surgery; Health Sciences, Oncology; Health Sciences, Radiology

Abstract

Mucosal melanoma is a rare subtype of melanoma, accounting for 1.4% of melanoma diagnoses in the United States.1 Median overall survival from time of diagnosis for mucosal melanoma has historically been less than that of cutaneous melanoma in part owing to the frequency of occult presentation and the relative lack of evidence-based guidelines specific to mucosal histology.2 Radiation therapy (RT) in mucosal melanoma has shown promise in certain settings but indications remain poorly defined.3,4 Immune checkpoint inhibitors have shown excellent response rates in metastatic melanoma and are increasingly used for mucosal melanoma; however, most patients will eventually progress. Response patterns are highly variable among patients who respond to immunotherapy. Although a small group of patients will experience complete response, many patients will have other types of responses such as pseudoprogression (disease enlargement followed by shrinking) or oligoprogression (progression at a limited number of sites).5, 6, 7 Patients with oligoprogression after treatment are of particular interest owing to the possibility of controlling the progressive disease with local therapy and achieving long-term survival. This concept has been demonstrated in retrospective studies of patients with melanoma; however, there have been no studies demonstrating this for patients with mucosal melanoma.5,8