Lung immune prognostic index (LIPI) as a prognostic factor in patients with extensive-stage small cell lung cancer treated with first-line chemoimmunotherapy.

Introduction: The lung immune prognostic index (LIPI) is a biomarker that combines the lactate dehydrogenase (LDH) value and the derived neutrophil/lymphocyte ratio (dNLR). Its prognostic ability has been reported in non-small cell lung cancer (NSCLC) with immunotherapy. In the context of extensive-stage small cell lung cancer (ES-SCLC) with chemoimmunotherapy, its role remains to be determined.

Methods: A retrospective, multicenter study of patients with ES-SCLC who received atezolizumab plus chemotherapy as first-line treatment was conducted. 101 patients were divided into three groups: LIPI good (n = 33), LIPI intermediate (n = 41), and LIPI poor (n = 27). The Kaplan-Meier method was used for analysis of overall survival (OS) and progression-free survival (PFS), using the log-rank test for comparisons. Univariate and multivariate Cox models were developed to assess the LIPI as an independent predictor of survival.

Results: The good LIPI group had a significantly longer median PFS than the intermediate and poor LIPI groups: 9.6 vs 5.4 vs 5.2 months, respectively (p < 0.001). Significant differences in OS between good, intermediate, and poor LIPI were also observed, with median OS of 23.4 vs 9.8 vs 6.0 months, respectively (p < 0.001). Multivariate Cox regression analysis for PFS identified liver metastases and intermediate and poor LIPI as worse prognostic factors (p < 0.050). For OS, a worse prognosis was confirmed in both the intermediate LIPI group (HR: 2.18, 95% CI: 1.07-4.41, p = 0.031) and the poor LIPI group (HR: 5.40, 95% CI: 2.64-11.07, p < 0.001).

Conclusions: In patients with ES-SCLC treated with chemoimmunotherapy, an intermediate and poor pretreatment LIPI score was associated with worse PFS and OS prognosis.