Introduction: Lung cancer remains a leading cause of cancer-related mortality worldwide. Detecting mutations in the epidermal growth factor receptor (EGFR) is crucial for treatment selection due to the response to tyrosine kinase inhibitors (TKIs) in these patients.

Objective: Describe the prevalence and identify factors associated with survival in stage IV lung cancer patients harboring EGFR mutations in a real-world setting.

Materials and methods: A retrospective cohort study was conducted to identify factors associated with progression-free survival (PFS), overall survival (OS) and response rate in stage IV lung cancer patients with EGFR mutations.

Results: Data from 771 patients diagnosed with lung cancer between 2017 and 2021 at the Hospital Italiano de Buenos Aires were analysed. The prevalence of EGFR mutations was 18% (139), with a median follow-up of 30 months. Of these, 118 were treated with EGFR TKIs, with a higher objective response rate observed with osimertinib compared to first or second-generation TKIs. Adverse prognostic factors included an ECOG performance status greater than 1, uncommon mutations, high disease burden and the presence of brain or hepatic metastases. Osimertinib was associated with a reduced risk of progression or death, even after adjusting for these prognostic factors. The median PFS was 13 months, with a significant OS difference between patients treated with osimertinib versus first or second-generation inhibitors.

Conclusion: This study underscores the importance of EGFR mutation detection in stage IV lung cancer patients and supports the need for personalised therapeutic approaches to improve outcomes in this patient population.