A 35-Gene Expression Profile Test for use in Suspicious Pigmented Lesions Impacts Clinical Management Decisions of Dermatopathologists and Dermatologists

Main Article Content

Aaron Farberg
Kelli Ahmed
Christine Bailey
Brooke Russell
Kelly Douglas
Clare Johnson
Olga Zolochevska
Robert Cook
Matthew Goldberg

Keywords

35-GEP, melanoma, management, clinical utility, diagnostic test

Abstract

Purpose: Histopathological examination is sufficient for diagnosis of many melanocytic neoplasms, however, diagnostic discordance is common between dermatopathologists. A timely and confident diagnosis is optimal, especially in cases where both benign and malignant melanocytic neoplasms are considered in the differential diagnosis as treatment plans diverge significantly.


A 35-gene expression profile (GEP) test that classifies melanocytic lesions into categories (benign, intermediate-risk and malignant), has reported accuracy metrics of 99.1% sensitivity, 94.3% specificity, 93.6% positive predictive value and 99.2% negative predictive value in a validation cohort of 503 samples. The clinical utility of the 35-GEP is described.


Methods: Dermatopathologists (n=6) and dermatologists (n=14) were queried regarding diagnostic challenges and patient management strategies in 60 difficult-to-diagnose melanocytic neoplasms. Participants reviewed each lesion twice, once without the 35-GEP result and once with. Responses were evaluated for consistent trends in the utilization of the 35-GEP test result.


Results: Dermatopathologists utilized the 35-GEP result to refine their diagnoses by increasing overall lesion diagnostic concordance and confidence, while reducing additional work up requests. Dermatologists utilized the 35-GEP result to gauge overall prognosis and case difficulty. Alterations in office visit frequency, biopsies, and referrals to specialists were also influenced by the 35-GEP result and treatment plan modifications also matched the appropriate directionality of the 35-GEP result.


Conclusions: The diagnosis of challenging melanocytic neoplasms and subsequent clinical management decisions are influenced by 35-GEP results in a manner that agrees with the test result. The utility of the test provides the opportunity to improve patient care.

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