The Influence Of A Gene Expression Signature On The Diagnosis And Recommended Treatment Of Melanocytic Timbers By Dermatopathologists

TPS9111 Background: Many studies have documented suboptimal accuracy and reproducibility in the diagnosis of melanocytic lesions by histopathology, even by experienced dermatopathologists. Therefore, adjunctive methods that provide objective and reliable data have been sought. Recently, a 23-gene expression signature that assesses immune signaling and cell differentiation and uses quantitative reverse-transcription polymerase chain reaction was developed using a cohort of 464 melanocytic neoplasms. (J Cutan Pathol. 2014; 41:144-275 [abstr 292263]) The assay has been clinically validated to differentiate benign nevi from malignant melanoma with a sensitivity of 90% and a specificity of 91% in a second, independent cohort of 437 melanocytic lesions representing a broad spectrum of histopathologic types. (Pending publication) This study aims to quantify the impact of this assay on diagnosis and management recommendations made by dermatopathologists. Methods: Forty-nine dermatopathologists submitted 821 representative histological sections of difficult to diagnose melanocytic lesions encountered during routine practice to a clinical laboratory for gene expression testing. Currently, 513 cases are eligible for study inclusion based upon completed pre- and post-test surveys accompanying each case. Surveys document the physician’s diagnosis, predicted biologic behavior (benign, malignant, or indeterminate), level of confidence, and recommendations for management. Study endpoints include the measured level of change in diagnosis, confidence, and treatment recommendations between the pre- and post-test surveys.