PD-L1 is identified as an important biomarkers for predicting PD-1/PD-L1 inhibitors in advanced Non-Small Cell Lung Cancer. Several previous clinical trials have demonstrated that chemotherapy could enhance the efficacy of PD-1/L1 immunotherapy in NSCLC such as Checkmate-227, Impower-150, Keynote-189, etc. Pre-clincial experiment shows that chemotherapy could increase CD8 TIL infiltration in tumor microenvironment, activate T cell immune reaction. However, it remains unclear whether chemotherapy could affect PD-L1 in advanced NSCLC patients. The present study aims to evaluate whether PD-L1 will change after receiving chemotherapy in advanced NSCLC patients.

Inclusion Criteria:

• Advanced NSCLC diagnosed histologically; Expected survival ≥ 6 month;
• Without Druggable molecular events (EGFR, ALK, c-Met, BRAF, Ret, etc)
• ECOG / PS score: 0-2, and the main organ function to meet the following criteria: HB ≥ 90g / L, ANC ≥ 1.5 × 109 / L, PLT ≥ 80 × 109 / L,BIL <1.5 times the upper limit of normal (ULN); Liver ALT and AST <2.5 × ULN and if liver metastases, ALT and AST <5 × ULN; Serum Cr ≤ 1 × ULN, endogenous creatinine clearance ≥50ml/min

Exclusion Criteria:

• Patient can not comply with research program requirements or follow-up;
• Patient will receive immunotherapy;

Advanced NSCLC without druggable molecular events (EGFR, ALK, c-Met, BRAF, Ret, etc)