Background: Oncotype DX recurrence score (ODX RS) is a prognostic biomarker for early-stage, node-negative, estrogen receptor-positive (ER+) breast cancer. Whether test uptake, associated factors, and the test's prognostic values differ by race/ethnicity is unknown.
Methods: From the National Cancer Database, 2010-2014, we identified 227,259 early-stage ER+, node-negative breast cancer cases. Logistic regression was used to examine ODX RS uptake and associated factors among non-Hispanic White (White), non-Hispanic Black (Black), Hispanic, and Asian American patients. Cox regression was used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for overall mortality with ODX RS by race/ethnicity.
Results: White patients were more likely to receive an ODX RS test compared with Black, Hispanic, and Asian American patients (36.7%, 32.8%, 31.6%, and 35.5%, respectively; P < 0.001). Disparities persisted after adjustments for demographics, clinical characteristics, and access-to-care, with rate ratios of 0.87 (95% CI, 0.85-0.88), 0.82 (95% CI, 0.80-0.85), and 0.89 (95% CI, 0.87-0.92), respectively, for Black, Hispanic, and Asian American compared with White patients. Black patients had higher proportions of high-risk scores (≥26) compared with White, Hispanic, and Asian American patients (19.1%, 14.0%, 14.2%, and 15.6%, respectively; P < 0.0001). ODX RS was predictive for total mortality across all races/ethnicities, particularly younger patients (<50). No significant race/ethnicity interactions were observed.
Conclusions: Although ODX RS uptake and risk distribution varied by race/ethnicity, ODX RS was prognostic for mortality across groups.
Impact: These findings emphasize the importance of developing strategies to increase ODX RS uptake among racial/ethnic minorities and call for more investigations on potential racial/ethnic differences in breast cancer biology. See related commentary by Wang et al., p. 704.
©2022 American Association for Cancer Research.