THE INCIDENCE OF EGFR MUTATIONS IN PATIENTS WITH ADENOCARCINOMA

pared to SCLC (P = 0.004). There was significant difference in PD-L1 expression between different histologic types in NSCLC (P < 0.001). There was higher PD-L1 expression in EGFR wild type than in EGFR mutation type (P < 0.001). There was higher PD-L1 expression in ALK mutation than in EGFR mutation (P = 0.005). Longer tumor tissue storage time correlated with lower PD-L1 expression in lung cancer (P < 0.001 for linear trend). Conclusion: Significant differences in PD-L1 expression were found between SCLC and NSCLC and between different histologic types in NSCLC. EGFR and ALK mutation statuses and tumor tissue storage time may influence PD-L1 expression level.