Prevalence of Epidermal Growth Factor Receptor and Programmed Death Ligand 1 Testing in a Population-Based Lung...

Biomarker-directed therapy requires biomarker testing. We assessed the patterns of epidermal growth factor receptor (EGFR) and programmed death ligand 1 (PDL1) testing in a non-small cell lung cancer (NSCLC) resection cohort. We hypothesized that testing would increase but be unevenly distributed across patient-, provider- and institution-level demographics.

We examined the population-based Mid-South Quality of Surgical Resection (MS-QSR) cohort of NSCLC resections. We evaluated the proportions receiving EGFR and PDL1 testing before and after approval of biomarker-directed adjuvant therapy (2018-2020 vs. 2021-2022). We used association tests and logistic regression to compare factors.

From 2018 to 2022, 1,687 patients had NSCLC resection across 12 MS-QSR institutions: 1,045 (62%) from 2018 to 2020 and 642 (38%) from 2021 to 2022. From 2018 to 2020, 11% had EGFR testing versus 38% in 2021 to 2022 (56% in those meeting ADAURA trial inclusion criteria, P < 0.0001). From 2018 to 2020, 8% had PDL1 testing versus 20% in 2021 to 2022 (P < 0.0001). EGFR testing did not significantly differ by age (P = 0.07), sex (P = 0.99), race (P = 0.33), or smoking history (P = 0.28); PDL1 testing did not differ significantly by age (P = 0.47), sex (P = 0.41), race (P = 0.51), or health insurance (P = 0.07). Testing was significantly less likely in nonteaching and non-Commission on Cancer-accredited hospitals and after resection by cardiothoracic or general surgeons (vs. general thoracic surgeons; all P < 0.05).

EGFR and PDL1 testing increased after approval of biomarker-directed adjuvant therapies. However, testing rates were still suboptimal and differed by institutional- and provider-level factors.

The association of institutional, pathologist, and surgeon characteristics with differences in testing demonstrate the need for more standardization in testing processes.