Treatment Patterns and Survival Outcomes in a Real-World Cohort of 263 Patients with EGFR L858R-Mutant Non-Small Cell...

Compare the treatment efficacy of EGFR TKIs in patients with non-small cell lung cancer with the EGFR L858R exon 21 mutation.

This retrospective analysis included 263 patients with advanced non-small cell lung cancer harboring the EGFR L858R mutation who were treated with EGFR tyrosine kinase inhibitors (TKIs) at Nghe An Oncology Hospital, Vietnam, between January 2018 and June 2025. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method, and differences between groups were compared using the log-rank test. The association of clinical factors with survival outcomes was assessed using Cox proportional hazards regression models.

The median progression-free survival (PFS) and overall survival (OS) for the study population were 14.1 months and 24.9 months, respectively. In the entire population (n=263), osimertinib demonstrated superior efficacy compared to first-and second generation EGFR TKIs (PFS: HR = 0.37, 95% CI: 0.21-0.63, p < 0.001; OS: HR = 0.31, 95% CI: 0.15-0.63, p = 0.001). In multivariate analyses (n = 232), afatinib was not associated with a statistically significant improvement in survival outcomes compared to first generation EGFR TKIs (PFS: HR = 0.70, 95% CI: 0.43-1.13, p = 0.143; OS: HR = 0.71, 95% CI: 0.42-1.19, p = 0.199). Subgroup analysis showed that the benefits of osimertinib were maintained in patients with malignant pleural effusion (PFS: HR = 0.40, 95% CI: 0.16-0.95, p = 0.040; OS: HR = 0.31, 95% CI: 0.11-0.87, p = 0.027).

In patients with the EGFR L858R exon 21 mutation, our real-world data demonstrate that osimertinib is the most effective TKI, while afatinib offers no significant survival advantage over first-generation TKIs. This underscores the importance of mutation-specific treatment strategies.