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 presentation of a development update and validation data for its cutaneous squamous cell carcinoma (SCC) prognostic test, DecisionDx®-SCC.
The study titled, “Development and validation of a prognostic gene expression profile (GEP) for stratification of cutaneous squamous cell carcinoma (SCC) patients by 3-year risk of regional or distant metastases,” was presented during an Oral Abstract session at the American Society for Dermatologic Surgery (ASDS) Annual Meeting, October 24-27 in Chicago.
Study Background
- Approximately 1 million patients are diagnosed with SCC in the U.S. each year, and the incidence continues to grow.
- Many patients with SCC will have a favorable prognosis, but an estimated 15,000 people in the U.S. die from SCC each year, surpassing the number of U.S. deaths from cutaneous melanoma estimated to be as high as 9,000.
- National guidelines define different treatment pathways and follow-up schedules for low-risk and high-risk SCC patients, but the low positive predictive value (PPV) of available staging systems means that the majority of high-risk patients do not develop metastases. Thus, many high-risk patients may be over-treated with radiation, chemotherapy or other interventions even when they may not be needed.
- There is a clear need for more accurate methods to identify high-risk SCC patients to appropriately direct work-up and treatment plans.
To address this need, Castle Biosciences has developed DecisionDx-SCC, a proprietary 40-gene prognostic test. The test was designed to improve upon existing clinicopathologic staging systems and identify SCC patients who are classified as high risk based upon clinicopathologic staging, but who are actually at a low biological risk for metastasis, and thus, can be considered for de-escalation in their treatment plan. Conversely, the test is also designed to identify a biologically high-risk group that has a significantly higher risk of metastasis than would be determined by clinicopathologic staging alone.
Study Findings
- Successful development of a 40-gene signature that identifies three groups of patients with significantly different risk for regional/distant metastasis using a training set of 122 patients.
- The multicenter validation study included 321 patients, of which 93% had one or more high-risk features and 52 patients experienced metastasis.
- Patients with a Class 1 result (n=203; lowest risk group) had a 91.6% 3-year metastasis-free survival (MFS) rate, significantly better than the MFS rate for patients with a high-risk Class 2A (80.6%; n=93) or highest risk Class 2B (44%; n=25) test result (p