Dr Johnson the Accuracy of Genomic Testing in Black Women With ER+ Breast Cancer

Nathalie McDowell Johnson, MD, FACS, surgical oncologist, medical director, Legacy Cancer Institute, Legacy Breast Health Centers, president, the American Society of Breast Surgeons, discusses the accuracy of genomic testing in Black women with estrogen receptor (ER)–positive breast cancer.

Genomic testing conducted for patients with ER-positive breast cancer is not as accurate in Black women with breast cancer compared with White women, particularly in regard to recurrence score, Johnson begins.

In a retrospective study published in JAMA Oncology, findings showed that the prognostic accuracy of the recurrence score was significantly lower for Black women, with a C index of 0.656 (95% CI, 0.592-0.720) compared with 0.700 (95% CI, 0.677-0.722) for non-Hispanic White women (P = .002). Study authors wrote that a lower prognostic accuracy in Black women with the Oncotype DX Breast Recurrence Score test suggests that genomic assays used to identify candidates for adjuvant chemotherapy may require model calibration in populations with greater racial and ethnic diversity. Findings also showed that Black women in the United States were more likely to have a high-risk recurrence score and to die of axillary node–negative breast cancer vs non-Hispanic White women with comparable recurrence scores.

Kent F. Hoskins, MD, of the University of Illinois Cancer Center, and colleagues examined the Surveillance, Epidemiology, and End Results (SEER) Oncotype registry to complete the in-depth analysis of breast cancer–specific mortality in regard to race and ethnicity.

Notably, when looking at Black women with higher-risk recurrence scores, which lead to treatment with chemotherapy, their outcomes tended to be better. Therefore, improved recurrence score testing is needed to better identify women with low-risk scores are not truly low risk, Johnson explains.

Further works must be done to examine which recurrence scores are being used for Black women to provide a more accurate understanding of the biology of their tumor and better identify patients who should be candidates for chemotherapy, Johnson notes. The findings from the retrospective study were similar to those from the phase 3 TAILORx trial (NCT00310180), where Blakc patients had worse outcomes compared with White women with similar recurrence scores, Johnson concludes.