Abstract
This case study examines using a 40-gene expression profile (40-GEP) as an independent predictor of metastatic risk in a 74-year-old male with cutaneous squamous cell carcinoma on the scalp. The patient's previous medical history included melanoma and non-melanoma skin cancers. While conventional staging methods, such as the American Joint Committee on Cancer 8th edition (AJCC8) and Brigham and Women's Hospital (BWH) staging, indicated a higher metastatic risk, the 40-GEP testing classified the patient as low risk (Class 1 result) for metastasis within three years. The patient underwent successful Mohs surgery with no evidence of perineural invasion. This case highlights the discrepancy between current staging techniques and gene expression profile testing, demonstrating the potential of the 40-GEP as a more accurate predictor of metastatic risk. The study contributes to the growing body of literature on the use of gene expression profile testing in cutaneous cancers, emphasizing the need for further research in this area to improve patient care outcomes using 40-GEP testing.