Low utility of Oncotype DX® in the clinic

Abstract

Precision medicine tools are currently making their way into the clinic and being utilized to diagnose, prognose, and individualize cancer care. The multi-gene expression-based assay, Oncotype DX® (ODX), is a genomic tumor profiling tool that determines the expression of 21 tumor- associated genes; it helps determine the risk for distant recurrence and whether chemotherapy is an appropriate course of treatment in patients with early stage, estrogen receptor (ER) positive, HER2 negative, and lymph node negative (or 1–3 positive lymph nodes) invasive BCa. The aim of this study was to determine the overall utilization and uptake of the ODX genomic test in a cross-sectional analysis of the Virginia Tumor registry, compare utilization in African Americans (AAs) and Caucasian Americans (CAs), and determine the profile of patients referred for testing. Caucasian (89.7%) patients made up the majority of the ODX testers compared to AAs (10.3%) (P < 0.0001). Those who received ODX testing were less likely to have higher grade and higher stage tumors, and were less likely to be ER negative (RR = 0.21, 95% CI: 0.01–0.31), progesterone receptor (PR) negative (RR = 0.35, 95% CI: 0.27–0.45), HER2 amplified (RR = 0.27, 95% CI: 0.17–0.43), or triple negative (RR = 0.21, 95% CI: 0.14–0.33). Of the patients that were eligible (n = 3924), 10.5% (n = 412) received ODX testing. Specifically, 11.7% of the Caucasian patients and 5.1% of AAs patients received ODX testing (P < 0.001). Our analysis confirmed that the utilization of ODX was low and that AAs were much less likely to receive ODX testing.