Researchers have suggested that advanced genetic testing could help erase the gaping disparities in breast cancer survival rates between white and black patients – black women in the United States having a significant 40% higher breast cancer mortality rate than white women, despite a 5% lower incidence of the disease, reports Reuters.
Applying genetic testing to early breast cancer tumour samples collected from more than 1 000 women, the scientists found that black women had more high-risk tumours that are often missed by standard testing of clinical biomarkers, such as oestrogen receptor status.
That leads to under-treatment, which is likely to result in worse outcomes.
When tumours were analysed by commercially available gene-profiling tools and patients had received appropriate care, black women had the same “excellent” outcomes three years later as white women, according to a report of the study in NPJ Breast Cancer.
Tumour gene expression profiling was done using the MammaPrint and BluePrint tests from molecular diagnostic company Agendia, which classify early-stage tumours as being at Ultra Low, Low, High 1, or High 2 risk for spreading throughout the body over the next 10 years.
The results help to determine whether chemotherapy is necessary.
Three-year recurrence-free survival was driven by genomic subtype, not by race, the researchers found.
Black females with low-risk tumours based on MammaPrint and BluePrint had “excellent 10-year outcomes, with a 97.7% recurrence-free survival rate, the same outcome as white females”, the researchers reported.
Patients with high-risk tumours were five to 10 times more likely to develop distant metastases than those with low-risk tumours, regardless of race.
Roughly half of patients initially characterised as low-risk turned out to have more aggressive tumours based on genomic profiling, the researchers also found.
“The data suggest tumour genomic testing for all patients may help guide treatment decisions to ultimately reduce racial survival disparities among black females with breast cancer,” said study co-author Dr Andrea Menicucci of Agendia.
Study details
Identification of racial disparities across MammaPrint and BluePrint subtypes in HR + HER2- breast cancer
Sonya Reid, Lindsay Venton, Jennifer Whisenant et al.
Published in Nature on 19 March 2026
Abstract
We compared clinicopathologic features, MammaPrint and BluePrint molecular subtype, and outcomes by race among females with hormone receptor-positive (HR+), HER2- early-stage breast cancer (EBC). Of 1018 participants with HR+ HER2- EBC enrolled from two registries (BEST and FLEX), 509 white females were propensity score matched 1:1 to 509 Black females based on age and/or menopausal status. MammaPrint classified tumours as High-Risk or Low-Risk; and with BluePrint, classified tumours as Luminal A-Type, Luminal B-Type, or Basal-Type. Recurrence-free survival (RFS) was analysed by race and molecular subtype. Cox proportional hazards models assessed association of clinicopathologic features with outcomes. Basal-Type tumours were more prevalent among black vs white participants (11.0% vs 4.8%, p < 0.001). Independent of race, participants with Basal-Type tumours had lower 3-year RFS (83.7%) compared to Luminal B-Type (93.7%) and Luminal A-Type (96.5%, p < 0.0001). Multivariate analysis revealed that participants with High-Risk, Luminal B- and Basal-Type tumours had significantly worse 3-year outcomes compared to Low-Risk Luminal A-Type, after controlling for race and potential confounders. Genomic classification identified higher proportions of High-Risk HR+ HER2- EBC among black participants. Molecular subtype was independently prognostic of 3-year survival, supporting the prognostic and potentially predictive importance of genomic testing to reduce racial survival disparities among black females with EBC.
Reuters article – Genetic testing improves survival for black breast cancer patients (Open access)
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Durban doctor leads the way with research on breast cancer trends
Global study to determine why black people have worse cancers