The second-line treatment options in clinical practice for immunotherapy progress are complex. Treatment strategies need to be selected based on different progression patterns. It is difficult to simultaneously explore multiple treatment modalities through previous clinical studies. Observational studies through real-world research can efficiently convert clinical practice data into clinical treatment evidence. This study aims to observe the treatment patterns and clinical outcomes of advanced NSCLC patients who received first-line immunotherapy checkpoint inhibitor treatment after progression, in order to provide guidance for the second-line treatment options for patients with first-line immunotherapy progress.

Inclusion Criteria:

• Locally advanced or metastatic NSCLC that is not curable and confirmed by histological or cytological examination based on the 8th edition of AJCC staging.
• Previously received advanced first-line treatment based on immune checkpoint inhibitor drugs.
• Has a medical record of disease progression during the first-line treatment.
• Complete clinical and pathological data, such as age, gender, smoking history, primary tumor location, differentiation, metastatic site, and imaging and serological review as required.

Exclusion Criteria:

• First-line treatment with immune checkpoint inhibitor drugs was ≤ 2 cycles.
• Excluding patients with incomplete key baseline and treatment information.
• Have other potential factors that may affect the study results or result in the premature discontinuation, as determined by the investigator

Hospital-based

Whether IPD will be provided will be determined by the results of subsequent clinical trials. At present, it is impossible to determine.