Castle Biosciences announces publication of two studies on DecisionDx-SCC test

Castle Biosciences (CSTL) announced the publication of two new studies related to its DecisionDx-SCC test, adding to its validated uses for patients with high-risk cutaneous squamous cell carcinoma. Key highlights of the studies include the following: Among 414 NCCN high-risk SCC patients with negative margins following Mohs surgery, DecisionDx-SCC significantly stratified both local recurrence and metastatic risk. Three-year survival rates decreased progressively across risk classes: local recurrence-free survival was 95.3% vs. 85.5% vs. 71.4%, P=0.001; metastasis-free survival was 97.1% vs. 89.3% vs. 57.1%. In contrast, BWH and AJCC staging systems failed to significantly stratify LRFS and MFS. DecisionDx-SCC test results, immunosuppression and perineural invasion were significant predictors of local recurrence, with hazard ratios of 2.6, 5.3, 2.3 and 3.7, respectively. When combined with these two clinicopathologic factors which have a well-established association to a high risk of metastasis, DecisionDx-SCC demonstrated significant improvement in predictive accuracy compared to the clinicopathologic factors alone. The 244 clinicians surveyed in the second study most often recommended ART for patients with greater than or equal to20% risk of local recurrence or metastasis, and surveillance imaging for patients with greater than or equal to10% risk of metastasis. Accordingly, DecisionDx-SCC Class 2A results accurately predicted risk above the 10% threshold where most clinicians would recommend surveillance imaging and consider ART, while Class 2B results predicted risk above the 20% threshold where most clinicians would recommend proceeding with ART.