Correlation between PD-L1 expression status and efficacy of immunotherapy as second-line or later-line therapy in advanced non-small cell lung cancer patients

Objective The objective of this study is to evaluate the correlation between tumor proportionality scores (TPS) and the effectiveness of immune checkpoint inhibitors (ICIs) as the second or subsequent line therapies for individuals who received diagnoses of advanced non-small cell lung cancer (NSCLC). Methods The retrospective analysis was conducted on the medical records of a total of 143 patients who received diagnoses of stage IIIB/IV NSCLC and were admitted to our hospital from the beginning of 2019 to the end of September 2022. The follow-up period ended on 01 January 2023. The study used Kaplan–Meier survival curves to assess the progression-free survival (PFS) and overall survival (OS) of patients. Univariate and multivariate Cox proportional risk models were used to analyze the factors associated with the PFS and OS of advanced-stage NSCLC patients who received ICIs as the second or subsequent lines. Results Patients diagnosed with NSCLC who had a TPS ≥1% and got treatment with ICIs exhibit notably elevated rates of partial response, objective response rate, disease control rate and extended PFS in comparison to NSCLC patients with a TPS of <1% ( P < 0.05). NSCLC patients with TPS within 1–49% [hazard ratio (HR) = 0.372; 95% confidence interval (CI), 0.140–0.993; P = 0.048] or ≥50% (HR = 0.276; 95% CI, 0.095–0.796; P = 0.017) were significantly associated with prolonged PFS, which were conducted by multivariate Cox regression analysis. Conclusion Programmed death protein-1 expression status may be predictive markers of the effectiveness of ICIs as the second or subsequent lines of therapies in advanced NSCLC are influenced by TPS.