The Expression and Clinical Signification of PD-1 in Lymph Nodes of Patients with Non-small Cell Lung Cancer

To screen anti-programmed cell death protein 1 (PD-1) antibody treatment of the dominant population, it is necessary to understand the expression of PD-1 in tumor metastasis microenvironment. The aim of the present study was to detect the expression of PD-1 in lymph nodes of 51 patients with non-small cell lung cancer (NSCLC) by using flow cytometry (FCM). The results showed that the PD-1 expression on CD3⁺ T cells was significantly increased in NSCLC metastatic lymph nodes (50.08 ± 8.03%) compared with nonmetastatic lymph nodes (36.25 ± 11.27%) (t = 5.208, p < 0.001).We also found that PD-1 expression was not associated with age, sex, and smoking, and it is associated with pathological type and staging of lung cancer. This study demonstrated that PD-1 may involve in lymph nodes metastasis and promote the understanding of the mechanism of immunotherapies in the NSCLC.