Inclusion Criteria:  Descriptive cross-sectional survey (Population B)  Adult patients (≥ 18 years old), Patients newly treated in first line (1L) for locally advanced or metastatic NSCLC, Patients with activating EGFR mutation-positive, Patient informed and not opposed to these data collection.  Prospective cohort (Population A)  Patient meeting part B inclusion criteria, Patients newly treated in 1L by osimertinib, Patient with common EGFR mutation-positive (exon 19 deletion or L858R mutation, alone or co-occuring with other EGFR mutations).  Exclusion Criteria (Population A):  Patients enrolled in interventional clinical trials (first line treatment for a NSCLC) during the study period.