Leading Squamous Cell Carcinoma Practitioners Publish Consensus Guidelines Integrating DecisionDx-SCC into a Clinical Workflow to Improve Decision-Making Regarding the Use of Adjuvant Radiation Therapy

Castle Biosciences, Inc. (Nasdaq: CSTL), a company improving health through innovative tests that guide patient care, today announced the publication of an expert consensus article in the Journal of Clinical and Aesthetic Dermatology (JCAD) related to the utility of its DecisionDx-SCC test in clinical decision-making regarding the use of ART.² The consensus guidelines outline a recommended risk-based workflow that integrates DecisionDx-SCC and AJCC8 staging into current National Comprehensive Cancer Network (NCCN) guidelines to improve precision in ART recommendations based on which patients are at the highest risk for metastasis and most likely to benefit from treatment.

“ART is recommended by evidence-based guidelines to reduce the risk of recurrence in patients with high-risk SCC,” said Ramesh Gopal, M.D., Ph.D., lead author, radiation oncologist and associate professor of radiation oncology at the New Mexico Comprehensive Cancer Center in Albuquerque, New Mexico. “While the presence of perineural invasion (PNI) will typically trigger a conversation about whether to consider ART, the guidelines vary in their interpretation of which SCC patients should be considered for the treatment, which can carry a risk of side-effects for the patient and costs for our healthcare system.”

The expert panel convened in June 2023 to review validation and real-world data for the DecisionDx-SCC test and to discuss their experiences, rationales and scenarios in which they have used the test to improve risk stratification and more accurately identify SCC patients at high risk of metastasis who may benefit from ART. The panel identified gaps in current clinical practice where the DecisionDx-SCC test has utility in guiding treatment decisions, including its use regarding:

• Escalation of care for lower-stage patients with high-risk tumors,
• De-escalation of care for patients for whom the risks of ART may outweigh the benefits, and
• Decision-making regarding elective radiation to the nodal basin.

Based on these gaps, the panel developed risk-based clinical recommendations and a workflow for ART referral in patients with SCC, which can be viewed in the JCAD article. The workflow integrates DecisionDx-SCC testing, which analyzes a patient’s tumor biology to independently predict risk of nodal or distant metastasis, and AJCC8 staging, which is based on a patient’s clinicopathologic risk factors, into current NCCN guidelines with a goal of improving precision in ART recommendations in the SCC patient population.