Tumor mutation burden 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 tumor mutation burden in advanced NSCLC patients. The present study aims to evaluate whether tumor mutation burden 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)