Oncotype DX recurrence score implications for disparities in chemotherapy and breast cancer mortality in Georgia.

Collin LJ1, Yan M1, Jiang R1, Ward KC1,2, Crawford B3, Torres MA2,4, Gogineni K2,5, Subhedar PD2,6, Puvanesarajah S7, Gaudet MM7, McCullough LE1,2.

Author information

1: 1Department of Epidemiology, Emory University Atlanta, Atlanta, GA 30322 USA.
2: 2Glenn Family Breast Center, Winship Cancer Institute, Emory University, Atlanta, GA 30322 USA.
3: 3Department of Epidemiology and Biostatistics, University of South Carolina, Columbia, SC 29208 USA.
4: 4Department of Radiation Oncology, Emory University School of Medicine, Atlanta, GA 30322 USA.
5: 5Department of Hematology and Medical Oncology, Emory University School of Medicine, Atlanta, GA 30322 USA.
6: 6Department of Surgery, Emory University School of Medicine, Atlanta, GA 30322 USA.
7: 7American Cancer Society, Atlanta, GA 30303 USA.

Abstract

Among women diagnosed with stage I-IIIa, node-negative, hormone receptor (HR)-positive breast cancer (BC), Oncotype DX recurrence scores (ODX RS) inform chemotherapy treatment decisions. Differences in recurrence scores or testing may contribute to racial disparities in BC mortality among women with HR+ tumors. We identified 12,081 non-Hispanic White (NHW) and non-Hispanic Black (NHB) BC patients in Georgia (2010-2014), eligible to receive an ODX RS. Logistic regression was used to estimate the odds of chemotherapy receipt by race and ODX RS. Cox proportional hazard regression was used to calculate the hazard ratios (HRs) comparing BC mortality rates by race and recurrence score. Receipt of Oncotype testing was consistent between NHB and NHW women. Receipt of chemotherapy was generally comparable within strata of ODX RS-although NHB women with low scores were slightly more likely to receive chemotherapy (OR = 1.16, 95% CI 0.77, 1.75), and NHB women with high scores less likely to receive chemotherapy (OR = 0.77, 95% CI 0.48, 1.24), than NHW counterparts. NHB women with a low recurrence score had the largest hazard of BC mortality (HR = 2.47 95% CI 1.22, 4.99) compared to NHW women. Our data suggest that additional tumor heterogeneity, or other downstream treatment factors, not captured by ODX, may be drivers of racial disparities in HR+ BC.