A prospective, multicenter analysis of the integrated 31-gene expression profile test for sentinel lymph node biopsy (i31-GEP for SLNB) test demonstrates reduced number of unnecessary SLNBs in patients with cutaneous melanoma
J. Michael Guenther, Andrew Ward, Brian Martin, Mark Cripe, Rohit Sharma, Stanley P. L. Leong, Joseph I. Clark, John B. Hamner, Timothy L. Beard
Abstract
BACKGROUND: National Comprehensive Cancer Network guidelines recommend sentinel lymph node biopsy (SLNB) for patients with > 10% risk of positivity, consider SLNB with 5-10% risk, and foregoing with < 5% risk. The integrated 31-gene expression profile (i31-GEP) algorithm combines the 31-GEP with clinicopathologic variables, estimating SLN positivity risk. METHODS: The i31-GEP SLNB risk prediction accuracy was assessed in patients with T1-T2 tumors enrolled in the prospective, multicenter DECIDE study (n = 322). To determine if incorporating the i31-GEP into decision-making resulted in fewer SLNBs performed, propensity score-matching was performed to a non-overlapping cohort for whom the 31-GEP was not used for SLNB decision-making. RESULTS: No patients with < 5% i31-GEP predicted risk had a positive SLNB (0/35). Propensity matching demonstrated an 18.5% reduction in SLNBs performed (43.7% vs. 62.2%. p < 0.001). The i31-GEP could have reduced the number of unnecessary biopsies by 25.0% (35/140). CONCLUSIONS: This prospective study confirmed the performance and clinical utility of the i31-GEP for SLNB for improving risk-aligned care and demonstrated a significantly reduced SLNB performance rate when incorporating the i31-GEP into clinical decision-making.