Castle Biosciences, Inc.’s DecisionDx-Melanoma test can accurately identify patients with a low risk of metastasis who can safely forgo sentinel lymph node biopsy (SLNB), thereby reducing unnecessary SLNB procedures and the associated costs and risks of complications that accompany them.
The data was presented in a poster and oral presentation at The European Congress on Dermato-Oncology in Vienna, Austria.
DecisionDx-Melanoma is a gene expression profile risk stratification test. It is designed to inform two clinical questions in the management of cutaneous melanoma: a patient’s individual risk of sentinel lymph node positivity and a patient’s personal risk of melanoma recurrence and/or metastasis.
Current National Comprehensive Cancer Network (NCCN) guidelines suggest foregoing SLNB when the likelihood of finding a positive SLN is less than 5%, considering SLNB when the risk is between 5-10% and offering the surgery when the likelihood of positivity is above 10%. As such, decision-making for patients whose staging-based-risk falls within or around the 5-10% threshold (i.e., patients with T1a tumors with high-risk features, T1b and T2a tumors) can be the most challenging. The new study included 471 patients with these tumor stages whose decision to pursue or forgo SLNB surgery was informed by DecisionDx-Melanoma test results.
The main takeaway? Integrating DecisionDx-Melanoma test results into SLNB decisions resulted in 25% fewer SLNBs performed compared to a matched patient cohort. Further, no patients with a DecisionDx-Melanoma-predicted risk of SLN positivity of less than 5% who decided to have an SLNB had a positive SLN (0/58 patients). Further, 9.8% of patients with a DecisionDx-Melanoma-predicted risk of SLN positivity of 5% or more who had the procedure did have a positive SLN.
These study results provide further evidence that the DecisionDx-Melanoma test can safely reduce the number of SLNBs performed in patients with a low risk of SLN metastasis while identifying patients for whom the risk of nodal positivity is sufficient to warrant consideration of the procedure, study authors conclude.
