Ethnic disparities in biomarker testing of patients with metastatic NSCLC in the United States: A real-world analysis

Newswise — Background:National Comprehensive Cancer Network guidelines recommend biomarker testing prior to intervention in metastatic non-small cell lung cancer (mNSCLC). However, biomarker testing remains low, particularly in minorities, especially when targeted therapy against actionable driver mutations improves outcomes and quality of life significantly. We sought to determine testing rates and assess disparities between Hispanic and non-Hispanic Whites.

Methods:A retrospective cohort study was conducted in accordance with "strengthening the reporting of observational studies in epidemiology" (STROBE) guidelines. All Hispanic and non-Hispanic White patients across a US oncology-focused hospital consortium (Guardian Research Network) were identified from 01/2018 to 01/2023. Socio-demographic details, clinical profiles, and details related to biomarker testing, treatment, and clinical outcomes were extracted. We also ascertained the area deprivation index (ADI) based on zip code as a surrogate for socio-economic stratification. We grouped patients into validated quintiles of ADI. We extracted testing details of the most common driver mutations – EGFR, ALK, KRASG12C, and PDL1. Data were analyzed using descriptive and inferential statistics.

Results:Out of 4898 eligible patients with mNSCLC, 9.89% (n = 484/4898) were Hispanic, and 90.11% (n = 4414/4898) were non-Hispanic Whites. Overall testing rates for EGFR, ALK, KRASG12C and PD-L1 were 36.07% (n = 1767/4898), 33.60% (n = 1646/4898), 3.76% n = 184/4898) and 48.42% (n = 2372/4898). EGFR and ALK testing revealed significant differences showing reduced testing in the non-Hispanic White population (Table 1.) Multivariate logistic regression revealed no significant association between ADI, ethnicity and biomarker testing. Four hundred and eighty-three individuals underwent biomarker testing but did not receive treatment. Forty-three percent (n = 205/483) were alive at the time of data extraction, with 5.18% (n = 25/483) identified as Hispanic.

Conclusions:Our analysis reveals that biomarker testing remains low in patients with mNSCLC, showing decreased testing rates of EGFR and ALK in non-Hispanic Whites when compared to Hispanic Whites. Purposeful strategies such as education and testing awareness campaigns are warranted to overcome low testing rates in patients diagnosed with mNSCLC.