Abstract 6122: Disparities in biomarker testing practices in patients with metastatic non-small cell lung cancer (NSCLC) in the United States (US)

Abstract Background: Molecular testing is recommended in National Comprehensive Cancer Network guidelines for nonsquamous mNSCLC patients. While testing rates have been increasing, data from other tumor types suggest possible disparities in access to and use of biomarker testing. This study investigated real-world biomarker testing characteristics stratified by demographics for the EGFR, ALK, ROS-1, BRAF, MET, RET, and PD-L1 biomarkers in US patients diagnosed with mNSCLC. Methods: This study of adults ≥18 years old with stage IV mNSCLC used the nationwide Flatiron Health electronic health record (EHR) -derived de-identified database (01/2011-04/2023). Biomarker testing rate (i. e. , proportion of patients with mNSCLC with at least one biomarker test) was quantified. Unadjusted biomarker testing rates were assessed in groups of patients stratified by demographic and clinical characteristics, including age group, sex, race, insurance type, Eastern Cooperative Oncology Group (ECOG) performance status (PS), smoking status, histology, and US region. Results: In 42, 037 patients with mNSCLC, 34, 510 (82. 1%) received at least one test. The rates for each test were: ALK: 71. 6%, BRAF: 48. 8%, EGFR: 74. 9%, MET: 41. 4%, PD-L1: 49. 3%, RET: 42. 3%, and ROS1: 54. 2%. Yearly testing rates increased, with the most recent year suggesting that anywhere from 78. 7% of patients to 88. 7% of patients received a test for at least one biomarker, with PD-L1 and EGFR being the least and most frequently tested, respectively. Rates of testing varied by age group, with 87. 2% of younger patients (ages 18 to 50) receiving a test compared to 80. 8% of older patients (ages ≥80). Asian patients had the highest testing rate (91. 5%) whereas Black and Hispanic/Latino patients had the lowest (80. 8% and 80. 6% respectively). 82. 2% of White patients, the largest racial demographic in this dataset, received at least one test. Commercial health plans had a slightly higher testing rate compared to Medicare or Medicaid (87. 1%, 81. 6% and 81. 2%, respectively). Rates decreased as ECOG PS increased; in patients with ECOG PS=0, 89. 6% received a biomarker test, whereas in patients with ECOG PS=3 and ECOG PS=4, 81. 1% and 76. 3% received a test, respectively. Smoking status (current or former) was associated with less testing (80. 7%) compared to patients with no history of smoking (91. 1%), and patients with non-squamous histology were more frequently tested (88. 0%) compared to squamous histology (61. 2%). The differences by sex and region were marginal. Conclusion: This study provides contemporary data on real-world biomarker testing and disparities in mNSCLC in the US. Results suggest that more work can be done to evaluate and address disparity gaps in specific subsets, including Black and Hispanic patients and those with a current or former history of smoking. Citation Format: Michael J. Dennis, Devin Abrahami, Maria Cecilia Vieira, Darrin Benjumea, Marley Boyd, Anran Shao, Kirsten Duncan, John Kelton, Sandip P. Patel. Disparities in biomarker testing practices in patients with metastatic non-small cell lung cancer (NSCLC) in the United States (US) abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts) ; 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84 (6Suppl): Abstract nr 6122.