Prognostic Significance of the Lung Immune Prognostic Index in Patients with Resected Esophageal Squamous Cell Carcinoma

Background: The lung immune prognostic index (LIPI), a novel index combined with serum lactate dehydrogenase (LDH) and derived neutrophil to lymphocyte ratio (dNLR), is recently proposed to predict prognosis in lung cancer. The LIPI is not a unique indicator for lung cancer. However, the prognostic role of LIPI has not yet been evaluated in extrapulmonary cancer. The aim of this study was to determine whether LIPI is still a useful prognostic indicator for patients with resected esophageal squamous cell carcinoma (ESCC). Methods: The clinical data including preoperative laboratory results for 361 consecutive resected ESCC cases from 2007 to 2010 were retrospectively analyzed. A LIPI based on serum LDH and dNLR was conducted, characterizing into 3 groups (LIPI 0, 1 and 2). The association between LIPI and cancer-specific survival (CSS) was analyzed according to the Kaplan-Meier method and Cox regression analysis with hazard ratio (HR) and 95% confidence interval (CI). A nomogram model was conducted by R 3.6.0 software. Results: In this study, 220 (60.9%), 100 (27.7%) and 41 (11.4%) patients had a LIPI of 0, 1 and 2, respectively. The 5-year CSS for LIPI 0, 1 and 2 was 40.9%, 19.0% and 9.8%, respectively (P<0.001). Subgroup analysis based on TNM stage revealed that HALP was also significantly related to CSS in any stage (TNM I: P=0.002; TNM II: P=0.009; TNM III: P=0.031). The LIPI serves as an independent predictor regarding CSS in multivariate analyses in patients with resected ESCC. Compared to LIPI 0, LIPI 1 and 2 had an HR of 1.419 (95% CI: 1.063-1.895, P=0.018) and 2.064 (95% CI: 1.403-3.036, P<0.001) regarding CSS, respectively. A nomogram was also developed in individualized CSS prediction based on LIPI in patients with resected ESCC. Conclusion: To the best of our knowledge, the present study is the first study to explore the association between LIPI and prognosis in patients with extra-pulmonary cancer. The LIPI, combined with LDH and dNLR, is still a potential independent prognostic marker in patients with resected ESCC.