Predicting response to therapy and disease progression in stage IV NSCLC patients treated with pembrolizumab monotherapy, chemotherapy-pembrolizumab combination therapy or chemotherapy alone in the first-line setting.

Inclusion Criteria:

• Adult ≥18 years old
• Patient diagnosed with Stage IV NSCLC (de novo or earlier stage progression to stage IV)
• Absence of oncogene activating mutations eligible patients to targeted therapy (EGFR, ALK)
• Cohort A: Received first line treatment with pembrolizumab monotherapy
• Cohort B: Received first line treatment with chemotherapy and pembrolizumab combination therapy
• Cohort C: Received first line treatment with chemotherapy doublet

Exclusion Criteria:

• Prior anti-cancer therapy for actual stage IV NSCLC
• Critical data missing (e.g., PD-L1 status, baseline millimetric imaging, first evaluation millimetric imaging)
• Patients participating in other clinical trials that modify the standard of care

Adult patients diagnosed with stage IV NSCLC (de novo or earlier stage progression to stage IV), without oncogene-activating mutations eligible for targeted therapy, that are treated in the first-line setting with either pembrolizumab monotherapy, chemotherapy and pembrolizumab combination therapy, or chemotherapy.