Real-world outcomes and progression patterns with first-line osimertinib in patients with advanced EGFR-mutant non-small cell lung cancer: a nationwide Turkish Oncology Group study

Abstract

We aimed to evaluate the real-world outcomes of first-line osimertinib in patients with advanced EGFR-mutant non-small cell lung cancer, together with the progression patterns, including the management and outcomes of oligoprogressive disease in the real-world setting. Methods: Patients who received first-line osimertinib at 33 oncology centers across Türkiye were retrospectively analyzed. Results: The median (IQR) age of 143 patients was 59.4 (50.9–68.9), 62.9% were female, and 68.5% were non-smokers. The most frequently identified EGFR mutations were exon 19 deletion (64.3%) and exon 21 L858R (28.7%). The median progression-free survival (PFS) was 17.6 months (95% CI 14.6–20.6). Exon 19 deletion subgroup had significantly longer median PFS than exon 21 L858R subgroup (22.0 vs. 11.7 months; HR = 0.40 [95% CI 0.25–0.64]; p