Association between PD-L1 expression and driver gene mutations in non-small cell lung cancer patients: correlation with clinical data

Lung cancer is the leading cause of cancer death worldwide. Recently, promising therapies have emerged based on PD-1/PD-L1 immune checkpoint inhibitors, which have been approved even as frontline treatment for patients with non-small cell lung cancer (NSCLC). We examined the association between PD-L1 expression and clinicopathological parameters as well as overall survival in 220 NSCLC patients. PD-L1 expression was estimated by immunohistochemistry using 22C3 PharmDx Dako assay and was defined as high, if TPS was ≥ 50%, low, if TPS was 1%–49%, and absent, if TPS was