Combined Lung Immune Prognostic Index (LIPI)-Glasgow Prognostic Score (GPS) as a Prognostic Tool in Extensive-Stage Small-Cell Lung Cancer Treated with First-Line Chemo-Immunotherapy

Introduction: Inflammatory and immune-based prognostic markers such as the Lung Immune Prognostic Index (LIPI) and the Glasgow Prognostic Score (GPS) have gained increasing attention in ES-SCLC, particularly in patients receiving first-line chemoimmunotherapy. However, no prior study has explored a broader, integrated inflammatory framework that evaluates these parameters collectively. Methods: We retrospectively evaluated 166 patients with ES-SCLC treated with first-line platinum–etoposide plus atezolizumab or durvalumab between 2019 and 2025. LIPI could be calculated in 123 patients based on available dNLR and LDH values, while GPS and the Combined Inflammatory Prognostic Score (CIPS) could be assessed in 120 patients with accessible CRP and albumin data. Results: Median PFS and OS were 8.16 and 15.96 months, respectively. In univariate analyses, poor ECOG PS, liver and bone metastases, poor LIPI, poor GPS, and high-risk CIPS were associated with shorter PFS and OS. In multivariate analysis, only LIPI and GPS remained independent predictors of both PFS and OS, while ECOG PS was independently associated with OS. Although CIPS demonstrated clear prognostic separation in univariate analysis, it did not retain independent significance, likely due to sample size limitations and overlap with LIPI and GPS components. Conclusions: LIPI and GPS are strong independent prognostic markers in ES-SCLC receiving chemoimmunotherapy. While CIPS did not demonstrate independent prognostic value in multivariate analysis, its simplicity, balanced two-tier design, and use of routinely available biomarkers highlight its potential clinical utility. To our knowledge, this is the first study to assess a combined inflammatory prognostic model in this population. Prospective multicenter validation is warranted.