WEDNESDAY, Aug. 6, 2025 (HealthDay News) -- When using the 40-gene expression profile (GEP) test to assess the risk for cutaneous squamous cell carcinoma (cSCC) progression, clinicians recommend surveillance imaging and adjuvant radiation therapy (ART) at risk thresholds of 10 and 20 percent, respectively, for local recurrence or regional/distant metastasis, according to a study published in the July issue of SKIN.

Milaan Shah, M.D., from the Medical University of South Carolina in Charleston, and colleagues examined the actionable clinical risk thresholds for patients with high-risk cSCC that clinicians use to guide ART and surveillance imaging decisions and how management decisions are impacted by use of the 40-GEP test. A total of 244 physicians, physician's assistants, and nurse practitioners with at least 10 recent or 12 total 40-GEP requisitions completed an online survey.

The researchers found that the preferred formalized staging or risk assessment strategies were highly variable. Clinicians most commonly reported recommending ART and surveillance imaging at 20 and 10 percent risk, respectively, for local recurrence or regional/distant metastasis. At a minimum risk threshold of 10 percent for local recurrence or regional/distant metastasis, ART was considered. The top two most important high-risk factors for ART and surveillance imaging decision-making included a 40-GEP Class 2B result, along with extensive perineural invasion.

"Based on previous data confirming the independent risk stratification of the 40-GEP, clinicians should use 40-GEP testing to inform ART and surveillance imaging to identify patients above and below established risk thresholds to more closely risk-align established management strategies to improve outcomes for patients with high-risk cSCC," the authors write.

Several authors are employees and shareholders of Castle Biosciences, which provided materials and funding for the study.

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