Clinical Summary

Sentinel lymph node biopsy (SLNB) helps assess melanoma recurrence risk but is often unnecessary, with up to 88% of results returning negative, leading to avoidable costs and complications. Traditional SLNB decision-making relies solely on clinicopathologic factors, which fail to identify some patients at risk of recurrence. The 31-gene expression profile (31-GEP) test objectively stratifies risk, identifying patients with <5% likelihood of SLN positivity who may safely forego SLNB. Studies suggest 31-GEP testing improves survival outcomes and enables earlier recurrence detection.

To assess recurrence in patients who would have been recommended to forego SLNB based on low-risk (Class 1A) 31-GEP results. We assessed whether these patients experienced any recurrence, particularly early recurrences, regardless of whether an SLNB was performed or SLNB positivity.

The DECIDE study is a prospective, multi-center study evaluating SLNB-eligible patients with T1-T2 tumors who underwent 31-GEP testing. Conducted across 22 institutions from May 2020 to May 2022, the study included patients whose clinicians considered SLNB and ordered the 31-GEP test for clinical decision-making. Data collection included 31-GEP results, SLNB performance, and recurrence outcomes, recorded through chart reviews and participant follow-ups at six-month intervals. This analysis focuses on early recurrence-free survival (RFS) in patients with Class 1A 31-GEP results who opted out of SLNB, ensuring these patients were not harmed by avoiding the procedure.

The current study demonstrates that patients with a Class 1A result may safely forgo the SLNB procedure. No patients had a recurrence within the study period, regardless of SLN status, supporting the clinical value of the 31-GEP test in guiding patient care.