Independent Study Demonstrates Performance and Clinical Value of i31-GEP Test for Predicting SLN Positivity Results from a single center study investigat-ing the performance of the integrated 31-gene expression profile (i31-GEP) test for predicting sentinel lymph node (SLN) positivity add to ev-idence about the utility of this risk stratification tool for guiding decisions for performing SLN biopsy (SLNB). The study was conducted by researchers at the ChristianaCare Helen F. Graham Cancer Center & Research Institute in Newark, DE, as an inde-pendent validation trial. It included 156 patients who underwent SLNB, of whom 45 (29%) had a T1 tumor, 46 (30%) had a T2 tumor, and 65 (41%) had a T3-T4 tumor. The i31-GEP test identified 30 (19.2%) patients as having <5% risk for SLN positivity, 32 (20.5%) as being at 5-10% risk, and 94 (60.5%) having a >10% risk. Thirty of the 94 patients identified as having a >10% risk of SLN positivity had a T1-T2 tumor, while no patient with a T3-T4 tumor was identified by the i31-GEP as having <5% risk of SLN positivity. Looking at SLNB results, the study showed that none of the 30 patients considered low risk for SLN positivity by i31-GEP testing had a positive SLNB while the SLNB was positive in 30 (31.9%) of the 94 patients estimated to have a >10% risk of SLNB positivity. The actual SLN positivity rate was similar in patients with a T1-T2 tumor and i31-GEP predicted risk of SLN positivity >10% compared to patients with T3-T4 tumors (31.3%). Applying the i31-GEP results to patient care decisions such that SLNB would not have been performed in the 30 low-risk individuals with an i31-GEP predicted SLN positivity risk <5% would reduce the number of unnecessary biopsies by 19.2% ( P < .001) when the analysis considered the entire study population of 156 patients. Within the subgroup of 91 patients with T1-T2 tumors, foregoing SLNB in the 30 patients with a <5% predicted risk of SLN positivity would have reduced the number of unnecessary biop-sies by 33.0%. Based on their findings, the investigators con-cluded that used preoperatively as an additional tool to guide shared decision-making, the i31-GEP can beneficially alter patient care, avoid unnecessary biopsies, and increase the positivity rate when SLNB is performed. TO READ MORE: Kriza C, Martin B, Bailey CN, et al. Integrating the melanoma 31-gene expression profile test with clinical and pathologic features can provide personalized precision estimates for sentinel lymph node positivity: an independent performance cohort. World J Surg Oncol. 2024;22(1):228. https://pubmed.ncbi.nlm.nih.gov/39215342/ Prospective Study Validates i31-GEP Test Performance for Guiding SLNB Decisions The integrated 31-gene expression profile test (i31-GEP) offers an accurate and precise clinical tool for identifying patients with T1-T2 cutane-ous melanoma who may safely forego sentinel lymph node biopsy (SLNB), thereby reducing the number of patients who undergo this costly and invasive procedure, according to findings from DECIDE that were presented at the 2024 annual meeting of the Society of Surgical Oncology. DECIDE is a prospective, multicenter validation study designed to investigate the impact of the i31-GEP test on SLNB decisions and clinical outcomes in patients with a recent diagnosis of T1-T2 melanoma being considered for SLNB. Its results showed that among patients with an i31-GEP predicted risk of SLN positivity <5%, no patient had a positive SLN. An additional analysis of data collected in DECIDE showed that had the i31-GEP test result been used to inform management decisions for SLNB for all patients, it could have reduced the number of unnecessary SLNB procedures by approximately 25%. As further evidence supporting use of the i31-GEP test for identifying patients who may safely forego SLNB, data from 3 years of fol-low-up in DECIDE showed that 100% of patients who had a Class 1A 31-GEP test result remained recurrence-free. Participants in DECIDE were adults (aged ≥18 years) being considered for SLNB after having a primary melanoma diagnosis within the previous 2 months. The decision to proceed with SLNB was made on a shared basis between An additional analysis of data collected in DECIDE showed that had the i31-GEP test result been used to inform management decisions for SLNB for all patients, it could have reduced the number of unnecessary SLNB procedures by approximately 25%. November/December 2024 Supplement | 5
The Dermatology Digest Innovations in Personalized Medicine November/December 2024 Supplement: Page 5
