Efficacy and Prognostic Factors of Immune Checkpoint Inhibitors in the Treatment of Advanced Non-small Cell Lung Cancer

Objective: To discuss the efficacy and potential prognostic factors of immune checkpoint inhibitors (ICIs) in patients with advanced non-small cell lung cancer (NSCLC). Methods: A retrospective study was conducted to analyze the medical history of patients (n=111) confirmed with advanced NSCLC in the Affiliated Hospital of Putian University from 2018 to 2020. All enrolled patients with adenocarcinoma (n=69), squamous cell carcinoma (n=28), and other types of lung cancer (n=14) were treated with the programmed death-ligand 1 (PD-1) inhibitors. They were divided into groups of PD-1 inhibitors, PD-1 inhibitors in combination with chemotherapy, and PD-1 inhibitors in combination with chemotherapy and angiogenesis inhibitors according to the treatment regimen. General clinical data of all patients were collected, and the Kaplan-Meier analysis was applied to estimate progression-free survival (PFS) and overall survival (OS). In addition, univariate and multivariate Cox regression analyses were performed to analyze prognostic factors associated with PFS and OS after treatment. Results: Of 111 patients with advanced NSCLC treated with ICIs, 6 were fully responsive, 33 were partially responsive, 55 were stable, and 17 were progressive. There was no significant difference in objective response rate between the 3 groups. In the subgroup analysis according to the lines of therapy, the objective response rate of patients receiving first-line treatment was 46.7%, which was significantly higher than that of other line treatment groups ( P =0.014). The results of multivariate Cox regression analysis indicated that the history of hormone use (HR=1.593; P =0.033), second-line or further lines of therapy (HR=2.871; P <0.001), and high neutrophil/lymphocyte ratio (NLR; HR=1.498; P =0.045) were independent risk factors for PFS after immunotherapy for advanced NSCLC. And the history of hormone use (HR=1.518; P =0.015) and high NLR (HR=3.053; P =0.001) were as well the independent risk factors for OS after immunotherapy for advanced NSCLC. Conclusion: ICIs therapy clearly had a greater survival benefit in patients who received first-line therapy, had no history of hormone use, and showed low NLR after initial treatment. ICIs can be an effective treatment for advanced NSCLC.