Correlation of inflammatory markers with progression-free survival in advanced lung cancer patients treated with immune checkpoint inhibitors in combination with chemotherapy: a real-world study

Immune checkpoint inhibitors (ICIs), principally represented by programmed death 1/programmed death ligand 1 (PD-1/PD-L1) inhibitors have been used in the first-line treatment of advanced lung cancer by Chinese Society of Clinical Oncology (CSCO) since 2018. Biomarkers like PD-L1 and tumor mutational burden (TMB) help to differentiate patients who benefited from ICI therapy. This study aimed to confirm and assess the predictive value of inflammatory markers in advanced lung cancer patients with the treatment of ICIs plus chemotherapy in the real world. The parameters of patients were collected in this retrospective study. Inflammatory markers were mainly calculated at different treatment periods. Hazard ratios (HR) and 95% confidence intervals (CI) were calculated with the univariate and multivariate Cox proportional hazard model. The Cox multivariate regression analysis indicated that a higher eosinophil-to-lymphocyte ratio (ELR) (HR 0.399, 95% CI: 0.189-0.842, P=0.02) and a higher monocyte-to-lymphocyte ratio (MLR) (HR 2.162, 95% CI: 1.116-4.191, P=0.02) at the time of maximizing therapeutic benefits, a higher lactate dehydrogenase (LDH) (HR 2.456, 95% CI: 1.334-4.523, P=0.004) at the time of disease progression were independent risk factors. A higher ELR and a lower MLR at maximizing therapeutic benefits and a lower LDH at disease progression were positive protectors for the progression-free survival (PFS) of advanced lung cancer treated with ICI combined with platinum-based chemotherapy.