The combination of immune checkpoint inhibitors (ICI) and platinum-based chemotherapy has rapidly become the standard first-line treatment for advanced or metastatic non-small cell lung cancer (NSCLC). However, identifying reliable predictive factors of treatment response remains a significant clinical challenge. This study comprehensively analyzed pretreatment predictive factors in patients with advanced lung cancer who received first-line ICI–chemotherapy combination therapy.

We retrospectively analyzed clinical data from 100 patients with advanced NSCLC who received first-line ICI–chemotherapy. Univariate and multivariate Cox proportional hazards regression analyses were used to identify prognostic factors for progression-free survival (PFS) and overall survival (OS). Univariate logistic regression analysis was used to identify factors affecting the incidence of immune-related adverse events (irAEs).

Multivariate analysis for PFS identified Eastern Cooperative Oncology Group performance status (ECOG-PS), number of metastases, lactate dehydrogenase level, cytokeratin 19 fragment antigen level, and programmed death-ligand 1 expression as independent predictors of PFS. Multivariate analysis for OS identified ECOG-PS, number of metastases, and neutrophil-to-lymphocyte ratio as significant independent predictors of OS. Patients with liver metastases showed a significantly lower incidence of irAEs than patients without liver metastases (8.3% vs. 29.7%, P = 0.013). The occurrence of irAEs was associated with longer PFS and OS.

This study identified pretreatment clinical and hematological factors that could predict the efficacy of ICI–chemotherapy. Furthermore, the absence of liver metastases was associated with a higher incidence of irAEs. These results underscore the critical need for individualized treatments and potential adjustment of strategies for high-risk groups to achieve a long-term durable response and better survival.