medwireNews: Black women with breast cancer are more likely than non-Hispanic White women to have a high-risk 21-gene Oncotype DX Breast Recurrence Score, and are more likely to die of breast cancer than their non-Hispanic White counterparts with a comparable score, US research shows.
Kent Hoskins (University of Illinois at Chicago) and colleagues report that the “recurrence score also provided less prognostic information for Black women” and the researchers therefore suggest that “[g]enomic prognostic assays may require recalibration for racial/ethnic minority groups.”
Their study included data for 86,033 women from the SEER Oncotype DX 2004–2015 database who had primary stage I to III, estrogen receptor (ER)-positive, HER2-negative breast cancer.
Of these, 74.4% were non-Hispanic White, 9.2% were Hispanic, 8.0% were Asian/Pacific Islander, 7.8% were non-Hispanic Black, and 0.4% were American Indian/Alaska Native women.
The majority (98.7%) had stage I or II disease and axillary lymph node-negative tumors (85.6%).
As reported in JAMA Oncology, after adjusting for age, year of diagnosis, tumor size, and nodal status, Black women were a significant 21% more likely than non-Hispanic White women to have a high-risk recurrence score (>25 points), with rates of 17.7% and 13.7%, respectively.
After a median 54 months of follow-up, Black women had a significantly higher cumulative risk for breast cancer-specific mortality than non-Hispanic White women in each recurrence score risk category, with further analysis showing that the? difference occurred primarily among women with node-negative disease.
Overall, Black women had a 1.66-fold increased risk for breast cancer mortality compared with non-Hispanic White women, after adjustment for age, year of diagnosis, tumor size, progesterone receptor status, type of surgery, and administration of radiotherapy and chemotherapy.
However, the researchers found that the excess risk varied by recurrence score. Black women with a low-risk recurrence score (0–10 points) had a significant 2.54-fold increased risk for breast cancer mortality relative to non-Hispanic White women, while those with moderate (11–25 points) and high-risk recurrence scores had significant 1.64-fold and 1.48-fold increased mortality risks, respectively.
Hoskins and team also found that the recurrence score had significantly less prognostic accuracy in Black women than in non-Hispanic White women, at 65.6% and 70.0%, respectively.
The authors conclude that their “findings suggest that Black women disproportionately develop aggressive ER-positive tumors and that the Oncotype DX Breast Recurrence Score test incompletely defines prognosis in these women.”
In an accompanying editorial, Joseph Sparano (Albert Einstein College of Medicine, New York, USA) and Otis Brawley (Johns Hopkins School of Medicine, Baltimore, Maryland, USA) say that the findings “are of great importance” because they use real-world data to confirm results from clinical trials such as TAILORx.
The add that in future “biologically driven, evidence-based clinical trials focused on racial disparities” may help to achieve “health equity for racial and ethnic minorities with breast cancer and other cancer types.”
medwireNews is an independent medical news service provided by Springer Healthcare Ltd. © 2021 Springer Healthcare Ltd, part of the Springer Nature Group