TOPLINE:
A review of the distribution of risk estimates from three commonly used genomic assays for breast cancer found that Black women were more likely to have aggressive tumor phenotypes, which contributed to poorer outcomes. Such disparities persisted after adjusting for genomic risk scores and tumor subtypes. While these tests remain valuable for guiding treatment decisions, they do not fully account for the complex factors contributing to racial disparities, necessitating a more comprehensive approach that integrates genomic data with social determinants of health for equitable cancer care.
METHODOLOGY:
- Despite recent declines in breast cancer mortality, significant disparities persist across racial and ethnic groups. Genomic assays help characterize tumor biology and predict prognosis and treatment response.
- This review evaluated the distribution and predictive capabilities of three genomic assays — 21-gene signature (Oncotype DX), 70-gene signature (MammaPrint), and 50-gene signature (PAM50) — across different racial and ethnic populations.
- The analysis included data from multiple trials including TAILORx with 9719 participants (405 Asian, 693 Black, 8189 White, and 432 other individuals) and RxPONDER with 4048 participants (324 Asian, 248 Black, 610 Hispanic, 33 Native American/Pacific Islander, and 2833 White individuals).
- Researchers examined breast cancer recurrence and survival outcomes across race and ethnicity, adjusting for genomic scores, clinical characteristics, and treatment approaches.
TAKEAWAY:
- In the TAILORx trial, Black women with a recurrence score of 11-25 had significantly worse outcomes than White women for invasive disease–free survival (adjusted hazard ratio [aHR], 1.43), recurrence-free interval (aHR, 1.85), distant recurrence–free interval (aHR, 1.60), and overall survival (aHR, 1.51). Chemotherapy did not improve outcomes in Black women across any clinical measure.
- In the RxPONDER trial, Black women had poorer outcomes for invasive disease–free survival (hazard ratio [HR], 1.37) and distant recurrence–free survival (HR, 1.65) than White women.
- MammaPrint data showed that Black women had a higher proportion of high-risk tumors than White women (93% vs 81%; P = .001), particularly in hormone receptor–positive/ERBB2-negative cancers (80% vs 64%; P = .04).
- PAM50 analysis demonstrated that Black women had more aggressive tumor subtypes, including basal-like (odds ratio [OR], 3.11), luminal B (OR, 1.45), and ERBB2-negative enriched tumors (OR, 2.04). Even after adjusting for subtype, treatment, comorbidities, and socioeconomic and reproductive factors, Black women remained at higher risk for recurrence (HR, 1.65) and breast cancer–specific mortality (HR, 1.71).
IN PRACTICE:
“This review of the most used genomic assays for breast cancer [Oncotype DX, MammaPrint, and PAM50] highlights substantial racial and ethnic disparities in outcomes, even when patients are stratified within risk categories by these assays,” the authors wrote. “Achieving equitable cancer outcomes necessitates a comprehensive approach that integrates rigorous research, promotes equitable healthcare access, and ensures the unbiased application of innovative technologies for all patients. A steadfast commitment to these efforts is essential for transforming cancer care and improving survival outcomes across all populations.”
SOURCE:
This study, led by Yara Abdou, MD, Division of Oncology, The University of North Carolina at Chapel Hill, was published online in JAMA Oncology.
LIMITATIONS:
The review could be affected by selection biases in registry data, and its findings might not reflect current practice patterns following recent clinical trials. It could not determine whether the predictive value of genomic assays for chemotherapy varies by race or ethnicity. Additionally, some trials lacked sufficient power to detect racial differences.
DISCLOSURES:
The authors did not disclose any funding information. One author reported receiving consulting fees from Pfizer and AstraZeneca outside the submitted work. Jennifer Racz reported equity in Exact Sciences during the conduct of the study.
This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.