Data from 1,868 Surveillance, Epidemiology and End Results (SEER)-linked patients show DecisionDx-Melanoma significantly stratifies five-year melanoma-specific survival within American Joint Committee on Cancer (AJCC) stages and T categories, identifying patients whose mortality risk is substantially higher or lower than staging alone would predict

FRIENDSWOOD, Texas, March 27, 2026 /PRNewswire/ -- Castle Biosciences, Inc. (NASDAQ:CSTL), a company improving health through innovative tests that guide patient care, will present new data at the 2026 American Academy of Dermatology (AAD) Annual Meeting, taking place March 27–31 in Denver, demonstrating that its DecisionDx-Melanoma test refines mortality risk within AJCC stages for patients with cutaneous melanoma (CM). The data show that DecisionDx-Melanoma identifies clinically meaningful differences in mortality risk among patients within the same stage, which may help clinicians more confidently escalate care for higher-risk patients while avoiding unnecessary interventions in those at lower risk of poor outcomes.

Detailed findings from this analysis will be presented in the following poster at AAD:

  • ePoster: 76747 – The 31-GEP provides actionable risk stratification of 5-year melanoma specific survival rates within AJCC subgroups
  • Lead Author: Harrison Nguyen M.D., MBA, MPH, Harrison Dermatology & Research Group, Missouri City, Texas

This poster from Castle's ongoing collaboration leveraging data from the National Cancer Institute's SEER Program registries evaluates risk stratification using the DecisionDx-Melanoma test in patients with CM across T categories and AJCC stages.

Traditional AJCC staging groups biologically distinct tumors based on clinicopathologic features alone, which can underestimate or overestimate a patient's true risk of poor outcomes. In this analysis, registry data from 22 SEER sites were linked to data from patients with stage I–III CM who were clinically tested with the DecisionDx-Melanoma test and had at least five years of follow up or death from their disease (n=1,868; 2013–2019). The test significantly stratified five-year melanoma-specific survival (MSS) within T categories and AJCC substages. In patients with T1 tumors, five-year MSS was 96.7% for those with low-risk (Class 1A) results versus 70.0% for high-risk (Class 2B) results, and among patients with Stage IIB–III disease, MSS was 87.4% for low-risk versus 48.5% for high-risk results (log-rank test; p<0.05).

Overall, the data show that DecisionDx-Melanoma can identify patients at higher or lower risk than predicted by AJCC staging alone, including high-risk T1 (thin) tumors with mortality risk approaching that of thicker melanomas, while also distinguishing lower-risk patients who may be appropriate for less intensive follow-up. These findings support integrating DecisionDx-Melanoma with staging to inform more precise, risk-aligned management decisions for patients with CM.