Castle Biosciences' i31‑SLNB Test Validates Predictive Accuracy In Melanoma Study, Supports Safe SLNB Avoidance

Study results were recently shared at the Society of Surgical Oncology (SSO) 2026 Annual Meeting in Phoenix.

NCCN Cutaneous Melanoma Guidelines recommend avoiding a sentinel lymph node (SLN) biopsy (SLNB) if the predicted SLN positivity rate is less than 5%. This report shows that patients with a less than 5% predicted risk of SLN positivity by the DecisionDx-Melanoma test had an actual SLN positivity rate of just 2.6%, and only 1.4% in patients with T1b–T2a tumors specifically, again confirming the clinically actionable performance of DecisionDx-Melanoma.

FRIENDSWOOD, Texas, March 09, 2026 (GLOBE NEWSWIRE) -- Castle Biosciences, Inc. (NASDAQ:CSTL), a company improving health through innovative tests that guide patient care, today announced new data from the largest prospective multicenter study to date evaluating DecisionDx-Melanoma's integrated sentinel lymph node biopsy (i31-SLNB) test result. The study data, recently shared at the SSO 2026 Annual Meeting, confirm that the i31-SLNB accurately predicts SLN positivity and identifies low-risk patients who may safely consider forgoing SLNB while maintaining favorable long-term outcomes. These results expand upon earlier publications from the same prospective multicenter clinical study and further strengthen the growing body of evidence supporting the role of DecisionDx-Melanoma in guiding SLNB decision-making.