Prognostic Value of the Lung Immune Prognostic Index May Differ in Patients Treated With Immune Checkpoint Inhibitor Monotherapy or Combined With Chemotherapy for Non-small Cell Lung Cancer

BACKGROUND: Lung immune prognostic index (LIPI) status was recently developed to predict responses to immune checkpoint inhibitor (ICI) treatments. However, it is unclear whether LIPI is a prognostic index for both patients treated with ICI monotherapy and patients treated with ICIs combined with chemotherapy (ICIs CC). METHODS: This retrospective study established the patterns of LIPI in Chinese patients with advanced non-small cell lung cancer. Lung immune prognostic index based on the derived neutrophil-to-lymphocyte ratio greater than 3 and lactate dehydrogenase greater than the upper limit of normal was developed to characterize good, intermediate, or poor LIPI status. Associations between LIPI status and progression-free survival (PFS) and overall survival (OS) were analyzed. Kaplan–Meier curves and Cox proportional hazards models were used to determine survival differences. RESULTS: Three hundred thirty patients were included in this study. Of these patients, 216 received ICI monotherapy and 114 received ICIs CC. A good LIPI status was associated with better PFS (6.1 months vs. 2.3 months vs. 2.1 months, P = 0.023) and OS (24.2 months vs. 14.5 months vs. 9.3 months, P < 0.001) in ICI monotherapy compared to intermediate or poor LIPI status. No differences in PFS (17.9 vs. 9.9 months vs. 7.6 months, P = 0.355, respectively) and OS (P = 0.346) were observed in patients who received ICIs CC. Moreover, we found that patients who had an improved LIPI status compared with the baseline value had a longer PFS with ICI monotherapy and LIPI intermediate status (8.4 months vs. 2.1 months vs. 1.4 months, P < 0.001). However, in patients treated with ICIs CC, these dynamic changes were not observed (P = 0.444). CONCLUSIONS: Lung immune prognostic index status and dynamic changes in LIPI could be prognostic markers of treatment response to ICI monotherapy, but not to ICIs CC. In particular, good LIPI status was associated with a better clinical outcome compared with intermediate and poor LIPI status in ICI monotherapy treatment.