Association between PD-L1 expression with EGFR , ALK , and ROS1 driver oncogene mutations in non-small cell lung...

Driver mutations and immunological expressions have gained importance in recent years for targeted therapies and immunotherapies of nonsmall cell lung cancer (NSCLC).

This study examined the association between PD-L1 expression and ALK , ROS1 , and EGFR driver oncogene mutations in patients with NSCLC.

A total of 501 NSCLC patients were included for analysis. Immunohistochemistry was performed with a PD-L1 clone 22c3. EGFR mutations were detected by PCR. ALK and ROS1 rearrangement analysis was performed with FISH. Results: There was a highly statistically significant difference between PD-L1 expression and EGFR mutation. PD-L1 expression was higher in the EGFR wild-type than in mutated EGFR ( P = 0.0002). There was no relationship between PD-L1 expression and ALK and ROS1 mutations ( P = 0.8899, P = 0.2512, respectively). PD-L1 expression was higher in nonadenocarcinomas (non-AC) than in adenocarcinomas (AC) ( P = 0.0438). The ALK rearrangement and EGFR mutations were higher in ACs ( P = 0.0073, P = 0.0012, respectively). ALK , ROS1 rearrangements, and EGFR mutations were higher in nonsmokers ( P < 0.05). EGFR mutations were detected more frequently in females than males ( P = 0.001). There was no relationship between gender and ALK , ROS1 , and PD-L1 ( P > 0.05). The prevalence of EGFR , ALK , and ROS1 driver mutations in the Turkish population was 9.3%, 5.3%, and 2.4%, respectively.

In conclusion, PD-L1 expression and mutated EGFR status have a highly negative association. PD-L1 expression was higher in EGFR wild-type patients. Therefore, it shows that the opportunity to receive PD-L1-related treatment may be higher in these patients. We think that PD-L1 immunohistochemical evaluation will increase the clinical predictive importance in EGFR wild-type cases.