A comprehensive review published in JAMA Oncology has strengthened evidence that Exact Sciences' Oncotype DX Breast Recurrence Score test provides accurate and reliable information for breast cancer treatment decisions across all racial and ethnic groups.
The peer-reviewed article, titled "Genomic Assays for Breast Cancer in Diverse Populations: Prognostic and Predictive Insights," comes at a critical time when breast cancer outcomes continue to show significant disparities. While overall mortality rates have declined, non-Hispanic Black women still face a 40% higher mortality rate compared to non-Hispanic White women.
"This study helps deepen our understanding of the multifaceted factors driving disparities in breast cancer outcomes," said Dr. Yara Abdou, assistant professor of medicine and breast cancer clinical trial program leader at the University of North Carolina Lineberger Comprehensive Cancer Center and the first author of the paper. "By building on insights from landmark clinical trials, we further validate the utility of genomic tests across diverse populations."
Consistent Performance Across Diverse Populations
The publication confirms that despite prognostic differences between racial and ethnic groups, the Oncotype DX test accurately predicts chemotherapy benefit regardless of race or ethnicity. This finding is particularly significant given the persistent healthcare disparities in breast cancer treatment and outcomes.
Supporting this conclusion is the largest real-world SEER registry analysis to date, which examined more than 171,000 breast cancer patients. Presented at ASCO 2024 but not included in the JAMA Oncology review, this analysis demonstrated that the Recurrence Score result predicted chemotherapy benefit consistently across Hispanic, non-Hispanic Black, and non-Hispanic White patients.
These findings build upon evidence from key clinical trials—including NSABP-B20 and SWOG-8814—which established Oncotype DX as the only genomic test proven to predict chemotherapy benefit. The test's utility was further confirmed in randomized clinical trials including TAILORx and RxPONDER.
Clinical Implications for Precision Oncology
The review highlights several key points about the Oncotype DX test's clinical value:
- It provides precise estimates of distant recurrence risk for breast cancer patients
- It accurately identifies which patients may or may not benefit from chemotherapy
- Secondary analyses of TAILORx and RxPONDER confirm consistent chemotherapy benefit across racial and ethnic groups
- Worse prognostic outcomes do not necessarily translate to greater chemotherapy benefit
Dr. Rick Baehner, chief medical officer of Precision Oncology at Exact Sciences, emphasized the company's commitment to equity: "We're proud that the Oncotype DX test continues to stand alone as the only genomic test validated to predict chemotherapy benefit in randomized trials—and that it performs consistently across racial and ethnic groups."
Addressing Healthcare Disparities
While the Oncotype DX test provides reliable guidance regardless of race or ethnicity, the publication acknowledges that broader systemic changes are needed to address the complex factors behind breast cancer outcome disparities.
The paper suggests that continued research is essential to understanding the biological, social, and systemic drivers of these disparities—and to ensuring equitable access to genomic tools like the Oncotype DX test.
Exact Sciences has expressed commitment to partnering with global clinical leaders to reduce disparities and ensure every patient has access to the Oncotype DX test, which remains a trusted tool to help guide breast cancer treatment decisions for all patients.
About the Oncotype DX Test
The Oncotype DX Breast Recurrence Score test is designed to help guide treatment decisions by providing information about a patient's individual tumor biology. By analyzing the activity of 21 genes in breast cancer tissue, the test helps identify which patients are likely to benefit from chemotherapy and which could safely avoid it.
Exact Sciences Corp., the provider of the Oncotype DX test, is a leading developer of cancer screening and diagnostic tests. The company continues to invest in its pipeline to develop innovative solutions for use before, during, and after a cancer diagnosis, building on the success of both the Oncotype DX and Cologuard tests.
