Immune microenvironment and clinicopathological features in brain metastases of non-small cell lung cancer / 临床与实验病理学杂志

ABSTRACT

Purpose To investigate the expression of PD-1,PD-L1,CD3 and CD8 in the immune microenvironment of non-small cell lung cancer(NSCLC)and their clinical signifi-cance.Methods The clinical data of 39 patients with NSCLC brain metastasis(BM)were collected.The expression of PD-1,PD-L1,CD3 and CD8 in the tumor and stroma of BM was detec-ted using an immunofluorescence-based tissue microenvironment analysis panel.Targeted sequencing was carried out to catalog cancer-related genes.The clinical pathological features were an-alyzed with review of relevant literature.Results Thity-nine patients with NSCLC presented with tumor-infiltrating lympho-cytes(TIL)in different degree.CD3+TIL(P=0.000 7)and CD8+TIL(P=0.0006)were more prominent in the tumor stroma,and the positive PD-L1 expression was significantly higher in the interstitial tissues of tumor(P=0.025 8).Com-pared with the whole wild-type driver gene cohort,the expres-sion of PD-L1 in the stroma of BM was significantly increased in the EGFR mutation cohort(P=0.039).Patients with high in-filtration of stroma CD8+TIL had longer median overall survival than those with low infiltration(16 months vs 6 months,P=0.032);PD-L1-positive patients(36 months)were longer sur-vival time than PD-L1-negative patients(5.5 months,P=0.056).Compared with lung primary lesions,the variant allele frequencies(VAFs)in BM generally increased,and samples with higher VAFs corresponded to higher expression of PD-1,PD-L1,CD3 and CD8.Conclusion The TIL infiltration is most prominent in the stroma of NSCLC BM.The EGFR muta-tion of a tumor might affect the immune microenvironment of me-tastases;PD-L1 expression and TIL infiltration were correlated with overall survival.