Use of the 40-gene Expression Profile (40-GEP) Test in Medicare-eligible Patients Diagnosed with Cutaneous Squamous Cell Carcinoma (cSCC) to Guide Adjuvant Radiation Therapy (ART) Decisions Leads to a Significant Reduction in Healthcare Costs.

Objective: Adjuvant radiation therapy (ART) is often recommended for high-risk cSCC patients but carries significant costs and risks. This study aims to determine if utilizing the 40-GEP test to guide ART can reduce healthcare costs in cSCC management. Methods: Medical claims data with new diagnoses of cSCC for the 12 months ending June 2022 in the Medicare (≥65 years) population (source: IQVIA claims database) were obtained and normalized to the general population for missingness. CPT codes associated with radiation therapy within one-year post diagnosis were used to establish adjuvant RT use (defined as 'ART'). Average weighted direct costs for four major ART modalities were calculated from published studies and (IQVIA). Sensitivity analysis was used to assess the financial impact of ART treatment using varying distributions of 40-GEP Class results. Results: Normalized medical claims data identified 22,917 Medicare-eligible cSCC patients who received ART within the United States. The weighted average direct cost for ART, which includes the four most used CPT code-defined modalities (IGRT, IMRT, IMPT, and XRT), was $60,693 per patient, amounting to an annual projected ART cost of $1.4 billion. Using the distribution of 40-GEP results from published studies, utilization of a 40-GEP test result to avoid ART in these patients could save up to $972 million in Medicare-eligible population. Sensitivity analysis shows, depending upon the distribution of the 40-GEP results, that for every 10% of Class 2A test results omitting ART, an extra $38-66 million in annual savings is expected. Limitations: Potential limitations include a need for more comprehensive patient information and the cost of ART-related complications. Conclusion: Utilizing the 40-GEP test results to guide ART decision-making would result in material savings to Medicare.