Integrating GEP Testing Into Melanoma Management 

In this episode of Topical Conversations, Aaron Farberg, MD, and David Cotter, MD, PhD, discuss how gene expression profiling (GEP) is changing the landscape of melanoma management, particularly in guiding sentinel lymph node biopsy (SLNB) decisions. Highlighting new data from a prospective, multicenter study, they explore how the DecisionDx-Melanoma 31-GEP test helps reduce unnecessary SLNB procedures in patients with intermediate-risk melanoma, improving patient care and reducing health care costs. 

New Data to Guide SLNB Decision-Making 

Dr Farberg references the prospective analysis showing that integrating the 31-GEP test into clinical decision-making reduced unnecessary SLNBs by approximately 20% in patients with T1 to T2 melanomas. Notably, patients classified as low risk by the test who still underwent SLNB had no positive nodes, reinforcing the test’s reliability. Dr Cotter emphasizes that beyond cost savings, this approach minimizes patient anxiety and reduces the risks associated with unnecessary surgery. 

Playing the Odds: Balancing Risk and Patient Care 

Although up to 88% of SLNBs in patients with thin melanomas are negative, both experts stress that forgoing biopsies altogether would leave some patients at risk for undetected metastases. GEP testing provides an objective tool to help dermatologists identify the right patients for SLNB and subsequent imaging. Dr Cotter notes that for node-negative melanoma patients, melanoma-specific survival is approximately 85%, underscoring the need for vigilant follow-up in high-risk cases. 

Beyond SLNB: GEP for Postbiopsy Management 

Dr Farberg explains that the utility of GEP testing extends beyond initial biopsy decisions. For node-negative patients, GEP results can guide imaging protocols and ongoing surveillance. He adds that high-risk patients may benefit from additional imaging, such as computed tomography or ultrasound, to monitor for recurrence or metastasis. 

Augmenting Staging and Improving Specificity 

Rather than replacing traditional T staging, GEP testing enhances it. Dr Cotter explains that combining GEP results with standard staging maintains high positive and negative predictive values while improving specificity. This approach further reduces unnecessary SLNBs by approximately 20% to 30%. 

Accessible and Equitable Care 

Drs Farberg and Cotter also discuss the broader implications of GEP testing in improving access to quality care nationwide. GEP testing, which uses formalin-fixed, paraffin-embedded tissue samples, helps standardize melanoma care in both academic and community settings, including areas where access to SLNB or advanced oncology services may be limited. 

A Commitment to High-Quality Care 

In closing, both physicians affirm their commitment to using tools such as DecisionDx-Melanoma to provide the highest standard of care for melanoma patients, focusing on patient outcomes while leaving cost considerations to health care systems and payers. 

By integrating GEP testing into melanoma care pathways, dermatologists can refine SLNB decisions, personalize postbiopsy management, and reduce health care disparities across diverse patient populations.