Association of a 40-Gene Expression Profile With Risk of Metastatic Disease Progression of Cutaneous Squamous Cell Carcinoma and Specification of Benefit of Adjuvant Radiation Therapy

Adjuvant radiation therapy (ART) for cutaneous squamous cell carcinoma is recommended based on a number of wide-ranging clinicopathologic features, which encompass a broad array of patients. The 40-gene expression profile (GEP) test classifies cutaneous squamous cell carcinoma tumors into low (class 1), higher (class 2A), or highest (class 2B) risk of nodal and/or distant metastasis. This study's hypotheses are as follows: (1) local recurrence is associated with metastatic disease progression and (2) 40-GEP, by identifying high risk for metastasis, could predict a metastasis-specific benefit from ART.