Neutrophil or platelet-to-lymphocyte ratios in blood are associated with poor prognosis of pulmonary large cell neuroendocrine carcinoma

BACKGROUND: Pulmonary large cell neuroendocrine carcinoma (LCNEC) is a rare clinical subtype of lung cancer which has a poor prognosis for patients. This study aimed to explore the relationship between blood-based inflammatory markers, namely neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR), and the prognosis for pulmonary LCNEC. METHODS: Peripheral leukocyte and platelet counts of 106 LCNEC patients were measured within the week leading up to their surgery. Serum neuron specific enolase (NSE) was detected by ELISA. Overall survival (OS) was analyzed by Kaplan-Meier method and compared by log-rank test. RESULTS: The NLR and PLR cut-off values based on survival receiver operating characteristic curve (ROC) were 2.52 and 133.6, respectively. A correlation was found between dichotomized NLR and tumor size (P=0.006), and PLR and NLR were significantly correlated with each other (P<0.001). Patients with high NLR or PLR had shorter survival than those with low NLR (HR =2.46, 95% CI: 1.508–4.011, P<0.001) or PLR (HR =2.086, 95% CI: 1.279–3.402, P=0.003). Serum NSE also had a significant effect on patient survival (HR =2.651, 95% CI: 1.358–5.178, P=0.004). The effects of peripheral blood lymphocytes (P=0.001), neutrophils (P=0.023) and platelets (P=0.051) on patient survival were compared by log-rank test. In multivariate survival analysis, NLR (P<0.001) and T category were vital for the prognoses of LCNEC patients. CONCLUSIONS: The inflammatory or immunological markers, NLR and PLR in blood, were independent factors of survival prediction for patients with LCNEC, which implied that cellular immunity was involved in the progression of LCNEC. Peripheral blood lymphocytes and neutrophils have a fundamental effect on survival. Whether or not NLR and PLR can be useful biomarkers in efficacy prediction of immunotherapy in LCNEC calls for further investigation.