PD-1/PD-L1 expression in non-small-cell lung cancer and its correlation with EGFR/KRAS mutations.

This study was aimed to detect the correlation among EGFR/KRAS status and PD-1/PD-L1 expression in non-small-cell lung cancer (NSCLC) patients. PD-1 and PD-L1 expressions were detected by immunohistochemistry in 100 surgically resected lung adenocarcinoma tissues and were statistically correlated with clinicopathological characteristics including EGFR and KRAS statuses. Besides, the overall survival (OS) times were analyzed. There was a statistical significances between PD-1 expression in tumor and KRAS status (P = 0.043), with a higher mutation rate in with lower PD-1 expression patients. There was a statistical significance between PD-L1 expression in tumor and EGFR status (P = 0.012), with a higher mutation rate in patients with lower PD-L1 expression. The OS of patients with EGFR mutation was significantly longer than those without EGFR mutation. The OS of patients with lower PD-L1 in tumor was significantly longer than those with higher PD-L1 expression. We found negative associations between PD-L1 expression in tumor and mutated EGFR status, as well as between PD-1 expression in tumor and mutated KRAS status.