Disparities in Biomarker Testing and Clinical Trial Enrollment Among Patients With Lung, Breast, or Colorectal Cancers in the United States.

Abstract

Comprehensive tumor biomarker testing is a fundamental step in the selection of highly effective molecularly driven therapies for a variety of solid tumors. The primary objective of this study was to examine racial differences in biomarker testing and clinical trial participation in the United States using a real-world database. Patients in a real-world deidentified database diagnosed with advanced/metastatic non-small-cell lung cancer (NSCLC), metastatic colorectal cancer (CRC), or metastatic breast cancer were eligible. Biomarker testing and clinical trial participation was compared between Black and White racial groups using chi-squared test and stepwise logistic regression controlling for baseline covariates. A total of 23,488 patients met eligibility criteria. Next-generation sequencing (NGS) testing rates differed significantly between White versus Black race before first-line therapy (36.6% <i>v</i> 29.7%, <i>P</i> < .0001) and at any given time (54.7% <i>v</i> 43.8%, <i>P</i> < .0001) in the nonsquamous NSCLC cohort. Similar disparities in NGS testing rates at any time during the study were observed among patients with CRC (White 51.6%; Black 41.8%, <i>P</i> < .0001). No differences were observed in the breast cancer cohort. Patients of Black race were less likely to be treated in a clinical trial in the overall NSCLC cohort when compared with White counterparts (3.9% <i>v</i> 2.1%, <i>P</i> = .0002). A statistically significant relationship between biomarker/NGS testing and clinical trial enrollment was observed in all cohorts (<i>P</i> < .003) after adjusting for covariates. In a real-world database, significant disparities in NGS-based testing rates were observed between Black and White races in NSCLC and CRC. NGS and any biomarker testing were both associated with trial enrollment in all cohorts. There is a need for interventions to promote access to comprehensive testing for patients with advanced/metastatic tumors.