Estimation of Prognosis in Invasive Cutaneous Melanoma: An Independent Study of the Accuracy of a Gene Expression Profile Test

BACKGROUND Cutaneous melanomas (CMs) with similar clinical and histopathologic features can harbor differing capacities for metastasis. A validated gene expression profile (GEP) test offers prognostic information by classifying CMs as low risk (Class 1A/1B) or high risk (Class 2A/2B) for metastasis. OBJECTIVE The authors sought to perform an independent study of the predictive accuracy of the GEP test, to determine what clinical and histopathologic features predict high-risk classification, and to evaluate how intermediate classes (1B & 2A) performed clinically. MATERIALS AND METHODS Using our institution's prospectively collected melanoma registry, the authors identified patients who had been treated for CM within the last 5 years and undergone GEP testing. Clinical, histopathologic, and outcomes data were analyzed. A subcohort of patients with known metastatic disease were identified and tested. RESULTS The GEP test accurately identified 77% of metastatic CMs as high risk (Class 2). The GEP had a negative predictive value of 99% for Class 1 CMs. Class 2 CMs were 22 times more likely to metastasize. CONCLUSION The GEP test's performance in our independent cohort corresponded with previous industry-sponsored studies and proved to be a helpful clinical prognostic tool with the potential to direct patient care protocols. Address correspondence and reprint requests to: Bradley N. Greenhaw, MD, 516 Pegram Drive, Tupelo, MS 38801, or e-mail: bgreenhaw@gmail.com The authors have indicated no significant interest with commercial supporters. The study received IRB exemption for patients who had previously undergone the GEP test. IRB approval was obtained to test patients with known metastatic disease. © 2018 by the American Society for Dermatologic Surgery, Inc. Published by Wolters Kluwer Health, Inc. All rights reserved.

https://ift.tt/2m8oSar