Only a Third of Eligible Breast Cancer Patients Receive Gene Expression Test, Study Finds

Only 33% of patients eligible for gene expression testing in breast cancer care receive the test, according to a 2023 analysis by the American Society of Clinical Oncology (ASCO). The finding highlights gaps in adoption of genomic tools that guide personalized treatment decisions, despite their proven clinical value.

What Is Gene Expression Testing and Why Does It Matter?

Gene expression tests, such as the Oncotype DX or MammaPrint, evaluate the activity of specific genes in a tumor to predict cancer recurrence risk and response to therapies like chemotherapy. These tests help avoid unnecessary treatments and improve outcomes, as noted by the National Cancer Institute (NCI).

“This technology has transformed how we tailor care,” said Dr. Laura Esserman, a breast cancer researcher at the University of California, San Francisco. “But access remains uneven.”

Why So Few Patients Receive the Test?

The ASCO study, published in *JAMA Oncology*, found disparities linked to geographic region, insurance type, and hospital resources. Patients in rural areas or those with Medicaid coverage were less likely to undergo testing compared to privately insured individuals in urban centers.

“Cost and lack of provider awareness are key barriers,” said Dr. Jennifer Brier, a medical oncologist at Memorial Sloan Kettering Cancer Center. “Some clinicians still rely on traditional staging methods over genomic data.”

How Do Testing Rates Compare to Guidelines?

Guidelines from the National Comprehensive Cancer Network (NCCN) recommend gene expression testing for early-stage breast cancer patients with certain tumor characteristics. However, the ASCO analysis found that only 41% of eligible patients in academic medical centers received the test, compared to 28% in community hospitals.

This gap underscores challenges in implementing evidence-based practices, as noted in a 2022 review in *The Lancet Oncology*. “Standardizing access to these tests is critical,” the authors wrote.

What Are the Consequences of Low Testing Rates?

Poor uptake of gene expression testing may lead to overtreatment or undertreatment. For example, patients who could avoid chemotherapy due to low recurrence risk might still receive it, while others might miss out on life-saving therapies.

A 2021 study in *Cancer* found that patients who underwent testing were 25% less likely to receive unnecessary chemotherapy, reducing side effects and healthcare costs.

What’s Being Done to Improve Access?

Efforts to expand access include policy changes and education initiatives. The Centers for Medicare & Medicaid Services (CMS) now covers gene expression testing for eligible patients, a decision praised by advocacy groups. Meanwhile, ASCO has launched training programs to educate providers on genomic testing.

“We’re seeing progress, but much work remains,” said Dr. Kathy Albain, a breast cancer expert at Loyola University Medical Center. “Equitable access requires systemic solutions.”

What Should Patients Know?

Patients diagnosed with early-stage breast cancer should discuss gene expression testing with their oncologist. Questions to ask include: “Am I eligible for this test?” and “How will the results influence my treatment plan?”

Organizations like the Breast Cancer Research Foundation offer resources to help patients navigate these conversations. “Knowledge is power,” said spokesperson Sarah Johnson. “Don’t hesitate to advocate for your care.”

As research continues to refine genomic tools, experts emphasize that closing the testing gap is essential to ensuring all patients benefit from precision oncology.