Racial Differences in Breast Cancer 21-Gene Recurrence Scores


Key Points

  • Black women had higher mean 21-gene recurrence score vs white women.
  • Black women were more likely to have high-risk tumors.

In a study reported in the Journal of Clinical Oncology, Holowatyj et al found that among women with hormone receptor–positive, HER2-negative, node-negative invasive breast cancer, non-Hispanic black women had higher 21-gene recurrence scores  at diagnosis vs non-Hispanic white women.

Study Details

The study involved data on recurrence score testing (10-year risk of distant recurrence = low for score ≤ 18, intermediate for 18–30, and high for ≥ 31) among 1,824 non-Hispanic white women and 392 non-Hispanic black women from the Metropolitan Detroit Cancer Surveillance System between 2010 and 2014.

Recurrence Scores

Among all patients, mean recurrence score was 19.3 in non-Hispanic black women vs 17.0 in non-Hispanic white women (P = .0003), and non-Hispanic black women were more likely to present with high-risk tumors (14.8% vs 8.3%, P = .0004). The differences in recurrence scores were limited to patients aged < 65 years at diagnosis: mean recurrence score was 23.6 vs 17.3 (P < .001) among patients aged 20 to 49 years and 19.6 vs 17.4 (P = .023) among those aged 50 to 64 years. On analysis adjusting for age, clinical stage, tumor grade, and histology, non-Hispanic black women remained significantly more likely to have high-risk tumors (odds ratio [OR] = 1.75, 95% confidence interval = 1.18–2.59).

The investigators concluded, “[Non-Hispanic black patients] who met clinical criteria for 21-gene [recurrence score] testing had tumors with higher estimated risks of distant recurrence compared with [non-Hispanic white patients]. Further study is needed to elucidate whether differences in recurrence are observed for these women, which would have clinical implications for 21-gene [recurrence score] calibration and treatment recommendations in [Non-Hispanic black] patients.”

The study was supported by Komen for the Cure; an Epidemiology Core, Health, and Human Services contract; and a grant from the National Institutes of Health.  

Kristen S. Purrington, PhD, MPH, of Wayne State University School of Medicine, is the corresponding author for the Journal of Clinical Oncology article. 

The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.