Prognostic value of the serum neutrophil-to-lymphocyte ratio in patients with lung cancer undergoing pleurodesis during best supportive care: A retrospective cohort study

BACKGROUND: Pleurodesis is a palliative treatment for malignant pleural effusion (MPE). Guidelines recommend pleurodesis for patients with a better prognosis. However, accurately predicting survival is challenging. The neutrophil-to-lymphocyte ratio (NLR) has emerged as a prognostic biomarker in various cancers. This study aimed to investigate the prognostic significance of NLR in patients with lung cancer who underwent pleurodesis and subsequently received best supportive care (BSC) without further antitumor therapy. METHODS: In this retrospective observational study conducted at two Japanese hospitals, we reviewed the medical records of 47 consecutive patients diagnosed with both lung cancer and MPE who underwent pleurodesis between April 2011 and 2024. The primary analysis involved evaluating the predictive value of NLR for in-hospital mortality using receiver operating characteristic (ROC) curve analysis. RESULTS: Among the 47 patients included, 25 were non-survivors with significantly elevated NLR and C-reactive protein levels compared with the survivors. ROC curve analysis revealed that NLR was predictive of in-hospital mortality, with an area under the curve of 0.744 (p = 0.0187). The optimal cutoff value for NLR, determined by the Youden index, was 8.252. Furthermore, an NLR >9 was independently associated with increased mortality during hospitalization and at 60 days after adjusting for the LENT score (in-hospital adjusted odds ratio: 18.52; 95 % confidence interval, 2.210-405.0; p = 0.0049; 60-day p = 0.0157). CONCLUSIONS: Among patients with lung cancer who underwent pleurodesis during BSC, an NLR >9 was associated with significantly higher mortality at both in-hospital and 60 days.