Disparities in utilization of genomic risk assays in early-stage hormone-positive breast cancer: A retrospective analysis using National Cancer Database (NCDB).

Abstract

537 Background: Prognostic genomic assays (GA) have become crucial in the management of early-stage hormone receptor positive breast cancer, particularly in guiding adjuvant chemotherapy decisions. Despite this, GA remain underutilized. This study aimed to identify predictors of GA utilization and associated survival outcomes. Methods: The 2023 NCDB PUF dataset was used to identify patients aged ≥ 18 years with HR positive, HER2 negative breast cancer diagnosed between 2010-2023. Patients with T1-T4, N0-N1 disease who underwent surgical resection were included, while those with T1aN0 stage, M1 disease, unknown GA status, or receipt of BCI alone were excluded. Patients were stratified by the receipt of the GA. Descriptive and multivariable analyses were performed to identify factors associated with GA utilization, and survival was assessed using Kaplan-Meier (KM) analysis. Results: 594,872 patients were included in our study, of whom 63.12% (N=375,506) underwent GA testing. GA utilization increased over time from 52.7% in 2010-2015 period to 68.7% in 2021-2023 (p<0.001). Using multivariable analysis, higher odds of GA testing were seen among Whites vs Blacks (OR 1.13 (1.11-1.16)), those with T2 tumors vs T1 (OR 1.26 95% CI 1.24-1.27), Grade 2 (OR 1.49 (1.47-1.51) or Grade 3 (1.42 (1.39-1.45)) histology vs Grade 1, receiving regional lymph node surgery vs not (OR 2.47 (2.33-2.62)), hormonal therapy vs not (OR 2.39 (2.34-2.43)), radiation vs not (OR 1.32 (1.30-1.34)), and recent year of diagnosis, 2021+ vs 2010-2015 (OR 2.08 (1.99-2.18)). The odds of GA testing were lower for uninsured vs government insured patients (OR 0.86 (0.82-0.91)), those with higher T stages (T3: OR 0.63 (0.61-0.65) and T4: OR 0.26 (0.24-0.30)) vs T1, N1 disease vs N0 (OR 0.73 (0.72-0.74)) and increasing age with the lowest odds among patients aged>80 (OR 0.13 (0.13-0.14)) compared to 18-64 years old. KM analysis showed survival benefit favoring receipt of GA (HR= 0.4 (0.39-0.41), p<0.001). Conclusions: Our study portrays low utilization of GA despite increasing use over time reflecting the impact of the TAILORx and RxPONDER trials. Significant disparities persisted by age, insurance status, race, and tumor characteristics. Older, Black and uninsured patients were substantially less likely to receive testing, despite an associated survival benefit, underscoring the need for more equitable implementation of guideline-recommended GA.