Objective: To assess the clinical efficacy of osimertinib in patients with advanced non-small cell lung cancer and its effect on serum carcinoembryonic antigen (CEA) and vascular endothelial growth factor (VEGF) expression.

Methods: Between July 2018 and January 2020, 80 patients with advanced non-small cell lung cancer were assessed for eligibility and recruited. The patients were assigned at a ratio of 1 : 1 to receive either the PC regimen (pemetrexed + cisplatin) (conventional group) or osimertinib (experimental group). The primary endpoint was the clinical efficacy, and the secondary endpoints were the adverse events, expression of serum CEA and VEGF, and 2-year survival.

Results: Osimertinib was associated with a significantly higher response rate and disease control rate versus pemetrexed plus cisplatin (P< 0.05). Osimertinib resulted in a significantly lower incidence of adverse events versus the PC regimen (P< 0.05). Patients given osimertinib had significantly lower levels of CEA and VEGF versus those given pemetrexed plus cisplatin (P< 0.05). Osimertinib was associated with a significantly higher 1-year and 2-year survival rate versus pemetrexed plus cisplatin.

Conclusion: Osimertinib could inhibit the expression of serum CEA and VEGF in patients with advanced non-small cell lung cancer and reduce the adverse events with significant efficacy, so it is worthy of clinical promotion and application.