The immune-metabolic-prognostic index and clinical outcomes in patients with non-small cell lung carcinoma under checkpoint inhibitors

Abstract

This prospective study evaluated whether peripheral blood biomarkers and metabolic parameters on F-18 fludeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT) could be associated with clinical outcome in non-small cell lung carcinoma (NSCLC) patients treated with immune checkpoint inhibitors (ICI). Data from 33 patients with NSCLC and treated with ICI were collected. Complete blood cell counts before and at the first restaging were measured. All patients underwent F-18 FDG PET/CT at baseline, while 25 patients at the first restaging. Progression-free survival (PFS) and overall survival (OS) were determined and compared using the Kaplan-Meier and the log-rank test. The median follow-up was 11.3months (range 1-17months). Multivariate analyses demonstrated that low neutrophil-to-lymphocyte ratio (NLR < 4.9) and low total lesion glycolysis (TLG < 541.5ml) at the first restaging were significantly associated with PFS (both p = 0.019) and OS (p = 0.001 and p = 0.048, respectively). An immune-metabolic-prognostic index (IMPI), based on post-NLR and post-TLG was developed, categorizing 3 groups: high risk, 2 factors; intermediate risk, 1 factor; low risk, 0 factors. Median PFS for low, intermediate and high risk was 7.8months (95% CI 4.6-11.0), 5.6months (95% CI 3.8-7.4), and 1.8months (95% CI 1.6-2.0) (p < 0.001) respectively. Likewise, median OS was 15.2months (95% CI 10.9-19.6), 13.2months (95% CI 5.9-20.3), and 2.8months (95% CI 1.4-4.2) (p < 0.001), respectively. IMPI at the first restaging, combining both inflammatory and metabolic biomarkers, was correlated with PFS and OS. IMPI can be a potentially valuable tool for identifying NSCLC patients who are likely to benefit from ICI.