Racial disparity in OncotypeDX score in early stage, hormone receptor positive, HER-2 negative, node negative breast cancers: A systemic review and meta-analysis.

Abstract

e12555 Background: Oncotype DX Breast Recurrence Score (RS) is the currently used risk-assessment tool for early-stage, hormone receptor-positive, HER-2 negative, node-negative breast cancer in the US. Studies showed inconsistency in RS distribution and treatment among races. Causes may include variations in somatic mutations like Ki-67, which have been reported to express higher in African American (AA) and Asian populations than in Non-Hispanic White (NHW) population, germline mutations in BRCA and TP53, that are not in the RS algorithm, and financial burden of the testing. We analyzed data from different countries to investigate racial disparity in RS. Methods: We searched Medline, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials, indexed from January 2010 to January 2021. More than 85% of studies were conducted in the pre-TAILORx study phase. To include data that are available and better represent different races, we included studies that used the previous cutoff value, low-risk ( < 18), intermediate-risk (18-30), high-risk ( > 30). Retrospective studies using Surveillance, Epidemiology, and End Results or National Cancer Database were excluded to avoid overlap data. A total of 17 studies, 9789 patients from seven countries (US, Japan, China, Taiwan, Kuwait, UAE, Israel) were pooled. The Odds Ratio (OR) was extracted with a 95% confidence interval (CI) for RS distribution and post-RS treatment. Both fixed-effect and random-effect meta-analysis were performed. Results: Among AA and NHW, AA were 1.7 times more likely to have high recurrence score (OR = 1.75; 95% CI = 1.46 - 2.10; P < 0.0001), with no heterogeneity among studies (I2 = 0%, heterogeneity P = 0.59). Asian were 1.59 more likely than NHW to be high-risk using a random effects model (OR = 1.59; 95% CI = 1.06 - 2.40; P = 0.0259). High-risk Asian were two times more likely to receive adjuvant chemotherapy post-RS comparing to NHW (OR: 2.31, CI: 1.07 - 4.98, fixed effect model; OR: 2.85, CI: 0.48, 17.05, random effects model), while high-risk AA were less likely to receive chemotherapy comparing to NHW (OR: 0.74, CI: 0.54-1.01, fixed effect model; OR: 0.73, CI: 0.54-0.99, random effects model). Intermediate-risk Asian and AA were more likely to receive chemotherapy compared to NHW (Asian to NHW; OR: 1.68, CI: 1.16-2.43, with fixed effect model, OR: 1.68, CI: 0.94-3.02, with random effects model; AA to NHW; OR: 1.16, CI: 0.93-1.46 with fixed effect model; OR: 1.06, CI: 0.62-1.79 with random effect model). Conclusions: We identified racial disparity in RS and post-RS treatment. Future research is required to elucidate the causes for AA and Asian receiving higher recurrence scores, a need for tailoring RS cutoffs for different races, and the utilization in adequate post-RS treatment.