Molecular Profiling Gaps Persist Among Medicaid Patients With Breast Cancer

Molecular profiling was underused among Ohio Medicaid beneficiaries with nonmetastatic estrogen receptor (ER)–positive, human epidermal growth factor receptor 2 (HER2)–negative breast cancer, with testing rates varying by disease stage and sociodemographic factors, according to a retrospective analysis published in JCO Oncology Practice.¹

Investigators conducted a retrospective cohort study using linked data from the Ohio Cancer Incidence Surveillance System and Ohio Medicaid claims. The analysis included 1988 patients aged 18 to 65 years who were diagnosed with localized or regional-stage ER-positive/HER2-negative breast cancer between 2016 and 2020 and were continuously enrolled in Medicaid for at least 6 months after diagnosis or until death. The primary outcome was receipt of molecular profiling, defined as Oncotype DX or MammaPrint, within 6 months of diagnosis.

Key Finding: Fewer Than 40% Received Molecular Profiling

Overall, 752 patients (37.8%) received molecular profiling. Patients with localized disease accounted for 77.0% of those who received testing compared with 54.1% of those who did not. Regional-stage disease was associated with significantly lower odds of molecular profiling compared with localized disease (adjusted odds ratio [aOR], 0.35; 95% CI, 0.28-0.42).

Chemotherapy use was higher among patients who did not receive molecular profiling, at 75.5% compared with 34.1% among those who underwent testing. However, among patients with localized disease, chemotherapy rates were similar between the groups, at 17.3% and 18.7%, respectively.

The lower rate of molecular profiling among patients with regional-stage disease may partly reflect clinical decision-making, as the role of testing varies according to disease characteristics and treatment considerations. A sensitivity analysis excluding patients with N2 or N3 disease produced similar estimates, suggesting that the association was not explained solely by higher nodal burden.

Racial and Insurance-Related Disparities Persisted

Black patients had lower odds of receiving molecular profiling than White patients (aOR, 0.72; 95% CI, 0.56-0.91). Patients enrolled in Medicaid long-term care (LTC) also had lower odds of testing than those without LTC enrollment (aOR, 0.47; 95% CI, 0.33-0.66). In contrast, married patients had higher odds of receiving testing than single patients (aOR, 1.30; 95% CI, 1.01-1.67).

Among patients with localized disease, the differences by race and LTC status remained significant. Black patients had lower odds of molecular profiling than White patients (aOR, 0.71; 95% CI, 0.53-0.94), while those enrolled in Medicaid LTC had lower odds than patients without LTC enrollment (aOR, 0.46; 95% CI, 0.30-0.68). Patients aged 50 to 65 years also had lower odds of testing than those aged 18 to 49 years (aOR, 0.74; 95% CI, 0.58-0.95).

Clinical Implications

The findings highlight a need to distinguish appropriate clinical decisions about molecular profiling from barriers that may prevent patients from receiving testing. The investigators noted that differences by race and Medicaid LTC status persisted after adjustment for other factors, raising concern that access-related factors may contribute to disparities in testing. They also found no association between the Ohio Opportunity Index—a measure incorporating education, employment, housing, health, transportation, environment, and crime—and molecular profiling receipt, suggesting that administrative or institutional factors may play a greater role than neighborhood-level opportunity.

Ensuring equitable access is particularly relevant given the role of genomic assays in treatment decision-making across diverse patient populations. A 2025 review in JAMA Oncology found that multigene assays provide prognostic and predictive information across racial and ethnic groups, while also emphasizing that genomic assays do not fully capture the factors contributing to disparities in breast cancer outcomes.²

For patients with ER-positive/HER2-negative disease, consistent access to molecular profiling may therefore help ensure that treatment decisions are informed by available genomic and clinical risk information. The authors acknowledged that some patients may appropriately forgo testing based on disease characteristics, but called for health systems to prioritize consistent implementation of molecular profiling, particularly among groups with lower rates of testing.

“Failure to safeguard access to [molecular profiling] risks incomplete assessment of tumor biology, misalignment of systemic and surgical treatment intensity, and reinforcement of racial and socioeconomic disparities in breast cancer outcomes,” study authors Lal et al concluded in the publication. “Ensuring timely and equitable access to [molecular profiling] within Medicaid will be essential to realizing the promise of precision oncology for safety-net populations.”

REFERENCES

1. Lal T, Vu L, Abou Zeidane R, et al. Missed precision: gaps in molecular profiling among Medicaid patients with estrogen receptor–positive, human epidermal growth factor receptor 2–negative breast cancer. JCO Oncol Pract. Published online September 22, 2026. doi:10.1200/OP-26-00255.

2. Abdou Y, Kantor O, Racz J, et al. Prognostic and predictive insights from genomic assays for breast cancer in diverse populations: a review. JAMA Oncol. 2025;11(6):655-663. doi:10.1001/jamaoncol.2025.0178.