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 extra-pulmonary 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.