Barriers to biomarker testing: An analysis of insurance denials at Tennessee Oncology.

280 Background: Comprehensive biomarker testing allows for selection of molecularly targeted therapies that improve patient outcomes and is considered a best practice. Despite its importance, access to biomarker testing is often hindered by gaps in insurance coverage, limiting the potential for personalized medicine. As of 2023, fifteen states and the District of Columbia have enacted legislation mandating insurance coverage for biomarker testing, acknowledging its clinical significance. However, Tennessee remains without such legal protections, creating barriers for patients in accessing this vital diagnostic tool. In this study, we obtain and assess instances of initial insurer denial for biomarker testing at a large community oncology practice. Methods: We conducted a retrospective analysis of electronic health record (EHR) data from Tennessee Oncology for patients whose insurance companies denied coverage for biomarker testing from one lab vendor. This limited cohort consisted of 45 patients with denials for comprehensive solid tumor tissue testing documented between June 2023 and December 2024. Data extracted included cancer type, reason for biomarker testing, and if there were actionable mutations based on clinical notes and testing results. Additionally, we analyzed whether testing was guideline concordant based on National Comprehensive Cancer Network (NCCN) guidelines for specific cancer type and stage. Results: The most common diagnoses prompting biomarker testing were stage IV non-small cell lung cancer (NSCLC) (n = 9), stage IV breast cancer (n = 7), stage III NSCLC (n = 5), and stage IV colorectal cancer (CRC) (n = 4). A majority of tests (73%) were performed in accordance with National Comprehensive Cancer Network (NCCN) guidelines. Among those tested, 45% revealed actionable mutations with the potential to influence therapeutic decision. Finally, 16% (7/45) of tests were conducted for recurrent disease. Conclusions: Our analysis highlights significant barriers to biomarker testing for patients with advanced solid tumors. Despite a high rate of guideline-concordant testing and identification of actionable mutations in nearly half of the cases, insurance denials remain a barrier to accessing precision medicine, and thereby, appropriate targeted therapies. These findings underscore the need for policy reform in states that do not already have mandated insurance coverage for biomarker testing.