Study on Prevalence and Impact of Brain Metastases on Survival in Lung Cancer by Line of Treatment

Inclusion Criteria: 1. Diagnosis of mNSCLC in study period (01/01/2015-06/30/2023) including newly diagnosed at metastatic stage or progression from advanced stage NSCLC 2. Age 18+ years at the time of diagnosis of mNSCLC Additional inclusion criteria for 1st Line of Therapy cohort: 3. Treated with systemic anti-cancer therapy in 1L setting Additional inclusion criteria for 2nd Line of Therapy and 3rd Line of Therapy cohorts: 4. Treated with systemic anti-cancer therapy in 2L setting treated with systemic anti-cancer therapy in 3L setting Exclusion Criteria: 1. Evidence of other primary malignancy in the 365-day baseline period immediately prior to the first mNSCLC diagnosis in the study period 2. Evidence of stereotactic radiosurgery (SRS), stereotactic radiation therapy (SRT), or whole brain radiotherapy (WBRT) in the baseline period