Real-World Application of a Noninvasive Two-Gene Expression Test for Melanoma Diagnosis

Abstract

A two-gene noninvasive molecular test (pigmented lesion assay [PLA], DermTech, La Jolla, CA) for the diagnosis of melanoma is commercially available in the United States. The test measures gene expression for LINC00518 and PRAME from stratum corneum samples ( Gerami et al., 2017 Gerami P. Yao Z. Polsky D. Jansen B. Busam K. Ho J. et al. Development and validation of a noninvasive 2-gene molecular assay for cutaneous melanoma. J Am Acad Dermatol. 2017; 76: 114-120.e2 Abstract Full Text Full Text PDF PubMed Scopus (57) Google Scholar ). However, the 2017 validation study and 2018 registry study provided different estimates of the test’s diagnostic accuracy (sensitivity of 91–95% and specificity of 53–91%) ( Ferris et al., 2018 Ferris L.K. Gerami P. Skelsey M.K. Peck G. Hren C. Gorman C. et al. Real-world performance and utility of a noninvasive gene expression assay to evaluate melanoma risk in pigmented lesions. Melanoma Res. 2018; 28: 478-482 Crossref PubMed Scopus (31) Google Scholar ; Gerami et al., 2017 Gerami P. Yao Z. Polsky D. Jansen B. Busam K. Ho J. et al. Development and validation of a noninvasive 2-gene molecular assay for cutaneous melanoma. J Am Acad Dermatol. 2017; 76: 114-120.e2 Abstract Full Text Full Text PDF PubMed Scopus (57) Google Scholar ). The factors that contribute to different estimates of the PLA’s diagnostic accuracy are not well characterized, which has raised concerns about its validity and potential for harm ( Beatson and Weinstock, 2019 Beatson M. Weinstock M.A. Further consideration of the pigmented lesion assay. JAMA Dermatol. 2019; 155: 393 Crossref PubMed Scopus (2) Google Scholar ). In this study, we used 2020 registry data ( Brouha et al., 2020 Brouha B. Ferris L.K. Skelsey M.K. Peck G. Moy R. Yao Z. et al. Real-world utility of a non-invasive gene expression test to rule out primary cutaneous melanoma: a large US registry study. J Drugs Dermatol. 2020; 19: 257-262 Crossref PubMed Google Scholar ) to model the real-world application and utility of the PLA.