Clinical Utility of the 40-Gene Expression Profile (40-GEP) Test for Improved Patient Management Decisions and Disease-Related Outcomes when Combined with Current Clinicopathological Risk Factors for Cutaneous Squamous Cell Carcinoma (cSCC): Case Series

INTRODUCTION: While improvements have been made to risk assessment of cutaneous squamous cell carcinoma (cSCC) patients, there is a critical need for a uniform and more precise stratification system of their care. To address this unmet clinical need, a prognostic 40-gene expression profile (40-GEP) test has recently been developed and independently validated to show improved stratification of metastatic risk in high-risk cSCC patients compared with current staging systems. METHODS: Two cSCC cases, both male with similar patient profiles and the same staging status across two different staging systems, yet with opposing outcomes, were chosen for retrospective review of their primary biopsy using the 40-GEP test. RESULTS: Case 1 declined further treatment, even when presented with evidence of a small focus of cSCC found in the last layer of nonmarginal tissue obtained from Mohs micrographic surgery (MMS). Case 1 remained recurrence free, and retrospective analysis of the initial biopsy with the 40-GEP test provided a Class 1 result (low likelihood of metastasis). Case 2, even with subsequent clearing of the primary cSCC with MMS, noted another metastatic cSCC 3 months later. Case 2, after multimodal adjuvant treatments, died due to disease progression. Retrospective analysis of the initial biopsy with the 40-GEP test provided a Class 2B result (high likelihood of metastasis). CONCLUSIONS: The cases discussed highlight the utility in 40-GEP to provide additional information to guide treatment decisions and improve outcomes. Integrating novel molecular prognostication with traditional clinicopathological risk factors can improve stratification of high-risk cSCC patients and may inform selection of risk-appropriate treatment and surveillance strategies.