This study is an observational study evaluating the treatment patterns and clinical outcomes after progression on first-line Tislelizumab treatment in advanced NSCLC. Based on the inclusion and exclusion criteria, patients with advanced NSCLC who received first-line Tislelizumab treatment and progressed will be retrospectively screened and collected from January 1, 2020, to the study initiation date, and followed up for observation.

Inclusion Criteria:

• Histologically or cytologically confirmed unresectable locally advanced or metastatic NSCLC based on the 8th edition of the AJCC staging system.
• Previously received first-line treatment with Tislelizumab for advanced NSCLC.
• Medical records of disease progression after first-line treatment.

Exclusion Criteria:

• Patients with incomplete key baseline and treatment information，including clinical stage, pathological type, treatment regimen, tumor assessment record after treatment ect.
• Patients included in anti-tumor drug intervention or unblinded clinical trials, in which the treatment being administered is unknown.

Patients with advanced NSCLC who progressed after first-line treatment with Tislelizumab