Clinical Outcomes of Osimertinib Combined with Platinum-Based Chemotherapy in EGFR-Mutant Non-Small Cell Lung Cancer: A Retrospective Study

Objective: To assess the clinical outcomes of osimertinib combined with platinum-based chemotherapy in patients with epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) and to describe associated changes in angiogenesis-related and tumor marker levels. Methods: A retrospective analysis was performed on 112 NSCLC patients with EGFR-sensitive mutations treated from June 2018 to October 2020. Patients received either pemetrexed plus cisplatin (control group, n=56) or the same regimen with osimertinib (experimental group, n=56). Evaluation parameters included objective response rate (ORR), disease control rate (DCR), vascular endothelial growth factor (VEGF), angiopoietin-2 (Ang-2), carcinoembryonic antigen (CEA), cytokeratin-19 fragment (CYFRA21-1), progression-free survival (PFS), overall survival (OS), and treatment-related adverse events. Results: ORR was comparable between groups (P> 0.05), whereas the experimental group showed a significantly higher DCR (P< 0.05). Post-treatment VEGF, Ang-2, CEA, and CYFRA21-1 levels decreased in both groups, with greater reductions observed in the experimental group (P< 0.05). Median follow-up was 18.8 months. The experimental group demonstrated longer median PFS (15.7 vs 10.6 months, χ 2 =18.337, P< 0.001) and OS (24.6 vs 17.5 months, χ 2 =24.679, P< 0.001). The incidence of adverse reactions did not differ significantly between groups (P> 0.05). Conclusion: In this retrospective cohort, the addition of osimertinib to platinum-based chemotherapy was associated with improved disease control and prolonged survival, along with greater reductions in angiogenesis-related and tumor marker levels, without increasing treatment-related toxicity. Keywords: EGFR mutation, NSCLC, chemotherapy, osimertinib, clinical outcomes, angiogenesis