Impact of a 31-gene Expression Profiling Test for Cutaneous Melanoma on Dermatologists' Clinical Management Decisions

Importance: Current guidelines for cutaneous malignant melanoma (CMM) provide general recommendations regarding surveillance while indicating that management should be tailored to patients' individual probability of recurrence. A 31-gene expression profile (31-GEP) test to predict metastatic risk has been previously validated, and classifies patients as either Class 1 (low risk) or Class 2 (high risk).

Objective: To determine the impact of the 31-GEP test's result on clinical decision-making.

Design, Setting, and Participants: Dermatology residents who attended a national educational conference were presented with clinical validity evidence for the 31-GEP. Respondents were given six CMM patient vignettes with descriptions of clinical features and answered questions about their willingness to recommend sentinel lymph node biopsy (SLNBx) or imaging based on each scenario. Additionally, respondents were asked to provide the Breslow thickness (BT), ranging from 0.7-1.5mm in 0.1mm increments, at which they would recommend SLNBx, imaging, or oncology referral.

Main Outcomes and Measures: The number of respondents who would recommend each management modality based upon three outcomes (no result, Class 1, or Class 2) was quantified. Differences between response groups were assessed using Fisher's exact test.

Results: The majority of respondents (62%, 57%, and 55%, respectively) indicated a 1.0mm BT as the guiding modality, reflecting adherence to current guidelines. After inclusion of a Class 2 result, the BT used to guide SLNBx, oncology referral, and imaging was changed in 47%, 50% and 47% of the responses, respectively, with 95%, 84% and 97% of the cases, respectively, changed in a risk-appropriate direction (decreased BT). Based on a 31-GEP Class 1 or Class 2 result, risk appropriate recommendations were more likely to be made for each management modality tested in five of the six patient vignettes (P less than 0.05).

Conclusions and Relevance: The 31-GEP test had a significant and appropriate impact on management while remaining within the context of established guidelines.

J Drugs Dermatol. 2017;16(5):428-431.