JAMA Study Confirms Oncotype DX Test Reliability Across Races and Ethnicities
Exact Sciences Corp. (Nasdaq: EXAS), a leader in cancer screening and diagnostics, announced the publication of a comprehensive review in JAMA Oncology that reinforces the reliability and predictive power of its Oncotype DX® Breast Recurrence Score® test across diverse populations. The peer-reviewed article, titled “Genomic Assays for Breast Cancer in Diverse Populations: Prognostic and Predictive Insights,” strengthens the evidence supporting the test’s ability to guide breast cancer treatment decisions for patients of all racial and ethnic backgrounds.
The study underscores the importance of precision oncology in addressing disparities in breast cancer outcomes. Although overall mortality from breast cancer has declined in recent years, significant racial and ethnic gaps remain. Non-Hispanic Black women, for example, experience a 40% higher mortality rate than their non-Hispanic White counterparts. These differences reflect a complex interplay of biological, social, and systemic factors.
Importantly, the review highlights that the Oncotype DX test accurately predicts chemotherapy benefit across racial and ethnic lines. Despite differing prognoses, the test consistently delivers reliable results to guide treatment, helping ensure that all patients receive care based on their individual tumor biology—not their race or ethnicity.
Real-World Evidence from Over 171,000 Patients
In addition to the JAMA Oncology publication, new data presented at the 2024 American Society of Clinical Oncology (ASCO) Annual Meeting offer further support for the test’s broad applicability. The data come from the largest real-world study of its kind, using the National Cancer Institute’s SEER (Surveillance, Epidemiology, and End Results) registry to examine outcomes in over 171,000 patients with breast cancer.
This extensive analysis demonstrated that the Oncotype DX Breast Recurrence Score reliably predicted chemotherapy benefit in Hispanic, non-Hispanic Black, and non-Hispanic White patients alike. Though this study is separate from the JAMA review, it adds substantial weight to the growing body of evidence validating the test’s performance across diverse patient populations.
The findings align with results from landmark clinical trials, including NSABP B-20 and SWOG 8814, which established Oncotype DX as the only genomic test proven to predict chemotherapy benefit. Randomized trials like TAILORx and RxPONDER further confirmed its value in personalizing treatment—showing no racial or ethnic differences in the test’s predictive ability.
Expert Perspective
“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 leader of the breast cancer clinical trial program at the University of North Carolina Lineberger Comprehensive Cancer Center. Dr. Abdou is the first author of the JAMA Oncology paper.
“By building on insights from landmark clinical trials, we further validate the utility of genomic tests across diverse populations. Our findings reinforce the value of using genomic assays to help guide treatment decisions for all racial and ethnic groups,” she added.
Key Takeaways
- Validated Across Populations: The Oncotype DX Breast Recurrence Score test provides accurate and consistent predictions of distant recurrence risk and chemotherapy benefit in women with early-stage breast cancer, regardless of their racial or ethnic background.
- Support from Landmark Trials: Secondary analyses from the TAILORx and RxPONDER trials confirm that racial disparities in breast cancer prognosis do not translate into differences in genomic test performance or chemotherapy benefit.
- Call for Continued Research: While genomic tools like Oncotype DX help guide personalized treatment, the review emphasizes the ongoing need to explore and address systemic, social, and biological factors driving disparities in cancer outcomes.
- Commitment to Equity: Ensuring equitable access to genomic testing remains a central focus for Exact Sciences and its partners in the medical community.
“At Exact Sciences, 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,” said Dr. Rick Baehner, chief medical officer of Precision Oncology at Exact Sciences.
“We remain deeply committed to reducing disparities and working with global clinical leaders to ensure every patient—regardless of background—has access to this essential tool.”
About Oncotype DX
The Oncotype DX Breast Recurrence Score test analyzes the expression of 21 genes in a breast tumor to provide a score that predicts the likelihood of distant cancer recurrence and the potential benefit of chemotherapy. It is widely used to guide treatment decisions in early-stage, hormone receptor-positive, HER2-negative breast cancer.
