Inequalities Within and Between Practices Contribute to NGS Testing Disparities in NSCLC

Inequities both within and between practices contributed to overall racial and ethnic inequities in the timely use of next-generation sequencing (NGS) testing for advanced advanced non–small cell lung cancer (NSCLC), according to a study of patients with the cancer treated in the community setting in the United States.

“While biomarker testing in routine clinical practice has increased over time, rates of timely NGS testing continue to lag behind recommendations. As a result, patients who are eligible for targeted therapy may receive potentially less effective or more toxic therapies when targeted oncogenic drivers are not identified due to delays or missed biomarker testing,” said Gregory A. Vidal, MD, PhD, medical oncologist at West Cancer Center and Research Institute, while presenting the findings at the 2023 American Society of Clinical Oncology Annual Meeting.

Vidal added that Black patients with nonsquamous advanced NSCLC are less likely to undergo NGS testing than White patients, which could have survival implications.

A growing body of evidence highlights the overall inequities in the use of NGS testing among eligible patients across cancer types, and this study explored individual elements that may contribute to the known racial and ethnic disparities in advanced NSCLC. The findings suggest that practice- and provider-level inequities are substantial contributors to overall disparities in NGS use.

Using data from the Flatiron Health database, which encompasses deidentified electronic health records from a nationwide population, the researchers examined timely testing rates among patients with advanced NSCLC whose cancer was diagnosed in April 2018 or later and treated in the community oncology setting. Quality testing was defined as an NGS result reported by 60 days after advanced diagnosis.

Regardless of race or ethnicity, the overall rate of timely biomarker testing among 12,045 patients was 51%, which the authors noted is lower than a previously reported rate of 80%. Of the overall study group, 9981 patients were non-Latinx White, 1528 were non-Latinx Black, and 536 patients were Latinx.

Overall inequity was measured as the average percentage point difference between rates of timely testing among non-Latinx Black or Latinx patients compared with White patients. Within practices, inequity was the average percentage point difference in testing rates weighted by how often different demographics are seen in the practice. Between practices, inequity was the relationship between overall testing rates and the practice-level racial or ethnic underrepresentation.

At the practice level, the overall mean percentage point difference estimate was 7.49 between non-Latinx Black vs White patients and 8.26 in Latinx vs non-Latinx White patients. Within practices, the estimates were 3.56 and 4.97, respectively. And across practices, the percentage point differences were 3.92 and 3.29.

Based on these estimates, 52% of the total inequity among non-Latinx Black vs White patients and 40% of the inequity seen in Latinx vs White patients were contributed by across-practice inequity, Vidal explained. The remaining 48% and 60% of the total inequity, respectively, could be attributed to within-practice inequity in the study population.

“[This] means that we see meaningful contributors to the practice-level inequity for both practices who are testing their Black or Latinx patients at different rates compared with the non-Latinx White patients—the within-practice inequity—and practices who see more Black or Latinx patients being low testers in general—the across-practice inequity,” Vidal said.

Inequities were also seen at the provider level, with across-provider differences in testing being the dominant contributors in disparities in both non-Latinx Black and Latinx patients vs White patients. Across-provider inequities in testing rates contributed to 77% and 67% of mean total inequities, respectively.

“At the provider level—that is, at the level of the primary treating oncologist—we observed that individual providers do not appear to treat their patients differently based on race or ethnicity, but that minorities tend to get their care from providers who generally are low testers,” Vidal said.

In a subgroup analysis focusing on patients with only nonsquamous histology, which has more actionable oncogenic mutations, the researchers saw trends consistent with those in the overall group. Vidal noted that the low overall rate of testing seen in the study population and the disparities between racial and ethnic groups are causes for concern.

“These findings have implications as we move from characterizing inequities to designing, implementing, and evaluating interventions and policies aimed at improving equitable and timely NGS testing as a quality care metric in advanced non–small cell lung cancer,” Vidal concluded.

Reference

Vidal GA, Jain N, Fisher A, et al. Practice- and provider-level inequities in next-generation sequencing (NGS) testing by race/ethnicity for patients (pts) with advanced non-small cell lung cancer (aNSCLC) treated in the community setting. J Clin Oncol. 2023;41(suppl 16):6508 doi:10.1200/JCO.2023.41.16_suppl.6508