Published Recently in the Journal of the American Academy of Dermatology
FRIENDSWOOD, Texas--(BUSINESS WIRE)-- Castle Biosciences, Inc. (Nasdaq: CSTL), a skin cancer diagnostics company providing personalized genomic information to improve cancer treatment decisions, today announced the publication of development and validation data for DecisionDx®-SCC, its prognostic test for patients diagnosed with high-risk cutaneous squamous cell carcinoma (SCC). The test is expected to be launched commercially in the second half of 2020.
The article titled, “Validation of a 40-Gene Expression Profile Test to Predict Metastatic Risk in Localized High-Risk Cutaneous Squamous Cell Carcinoma,” was published in the Journal of the American Academy of Dermatology (JAAD).
The study results demonstrate that DecisionDx-SCC is an independent predictor of metastatic risk that can complement current cancer risk-factor staging systems for patients with high-risk SCC.
“As clinicians, we struggle with treatment decisions for patients with high-risk cutaneous squamous cell carcinoma due to the limitations of clinicopathologic based staging systems,” said first author, Ashley Wysong, M.D., University of Nebraska Medical Center, Omaha NE. “Validation of the DecisionDx-SCC test demonstrates significant progress in this area by integrating tumor-specific genetic information into clinical decision making. Having better prognostic information helps us to identify patients as low risk by tumor biology and manage them more conservatively with clinical surveillance, as well as provides us with data to help guide implementation of adjuvant interventions and clinical trial recommendations for those identified as high risk.”
Disease and Study Background
- Approximately 1 million patients are diagnosed with SCC of the skin in the U.S. each year, and the incidence continues to grow; approximately 80% can be cured surgically, but it is estimated that approximately 200,000 patients are diagnosed with high-risk SCC.
- SCC National Comprehensive Cancer Network (NCCN) guidelines define treatment pathways based on risk of local recurrence or metastasis. For SCC, there are two clinicopathologically defined categories: low risk and high risk. NCCN defines high risk as SCC patients with one or more of several high-risk clinicopathologic features.
- Similar to the Brigham and Women’s Hospital (BWH) and American Joint Committee on Cancer version 8 (AJCCv8) staging systems, risk prediction based on NCCN exhibits low positive predictive value (PPV), meaning that the majority of patients classified as high risk do not develop metastasis.
- The study was designed to develop a prognostic test to predict risk of regional or distant metastasis in NCCN-defined high-risk SCC tumors, with the goal of improving risk-directed management.
Study Findings
- The 40-gene expression profile test (DecisionDx-SCC) was successfully developed to stratify high-risk SCC patients into three classes based on metastasis risk: Class 1 (low-risk), Class 2A (high-risk), and Class 2B (highest-risk), using a training set of 122 patients.
- The independent, multicenter validation study included 321 patients, of which 93% had one or more NCCN-defined high-risk features, and 52 patients experienced metastasis.
- DecisionDx-SCC demonstrated strong independent prognostic value in multivariate analyses compared to the BWH and AJCC v8 staging systems. When compared to the BWH staging system, DecisionDx-SCC Class 2B had a hazard ratio (HR) of 8.72 (p