Racial disparities in utilization of gene expression testing in breast cancer patients at an academic medical center.

Abstract

142 Background: Gene expression profiling of breast cancers, such as the OncotypeDx (ODX) test, PAM 50 and Mammaprint, can define the risk of distant recurrence and assist with decisions about adjuvant chemotherapy. A recent study of all breast cancer patients in Virginia found that only 11.7 % of Caucasian Americans (CA) and 5.1% of African Americans (AA) received genomic testing. Methods: We utilized the Virginia Commonwealth University Health System (VCUHS) Tumor Registry and billing data from 2010-2017 to identify all patients that met the following criteria per NCCN guidelines for genomic testing: early stage (stage I or II) breast cancer, estrogen and/or progesterone receptor positive and lymph node-negative breast cancer. We also obtained records from Genomic Health on ODX testing ordered through VCU Health. Additionally, ODX utilization was stratified by race. We then performed Chi Square analysis. Results: 1080 patients were eligible per NCCN Guidelines. Of these, 248 were eliminated due to having only radiation performed at VCU. 39 were eliminated because initial treatments were at outside hospitals. Of the remaining 793, 536 were CA, 232 AA, 9 Asian and 16 other. Among the patients for whom a genomic test was appropriate, the proportion who actually had such a test performed were: 83.4% for CA, 71.98% for AA, 55.56% for Asians, 81.25 % for Others and 79.7% overall. There was a significant difference between utilization in CAs and AAs (p < 0.001). Conclusions: Breast cancer patients at VCU Health are far more likely to receive gene expression profiling overall compared to the Commonwealth of VA as a whole. This may reflect more equitable and guideline-compliant care in an academic/safety net health system.