Neutrophil-to-Lymphocyte Ratio, Platelet-to-Lymphocyte Ratio, and Prognostic Nutritional Index as Prognostic Markers for Lung Carcinoma

<b>Aims/Background</b> Lung cancer (LC) remains one of the most common malignant tumours worldwide, and assessment of its progression is important for ensuring better prognostic outcomes for patients. This study was designed to explore the prognostic role of certain indices, including the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and prognostic nutritional index (PNI) in patients with LC, to help clinics to better determine the prognosis of patients with LC, and to allow them to intervene in a timely manner. <b>Methods</b> A retrospective analysis of 116 initially diagnosed patients with LC in China from 2018 to 2020 was conducted. The counts of neutrophils (NEU), lymphocytes (LYM), and monocytes (MON), as well as albumin levels, were obtained from laboratory databases. The PNI was calculated using a specific formula. The progression-free survival (PFS) curves were plotted using the Kaplan-Meier method, and the Log-rank test was used to compare survival among different groups. The potential prognostic role of these indicators was assessed with univariate and multivariate regression analysis. <b>Results</b> Multivariate Cox regression demonstrated that the PNI (hazard ratio (HR): 0.513, 95% confidence interval (CI): 0.288-0.917, <i>p</i> = 0.024), NLR (HR: 2.038, 95% CI: 1.128-3.682, <i>p</i> = 0.018), and tumour type (small cell lung cancer vs. non-small cell lung cancer) (HR: 2.145, 95% CI: 1.308-3.520, <i>p</i> = 0.003) were significantly associated with PFS. The median PFS for patients with low and high PNI was 10 and 11.5 months, respectively. <b>Conclusion</b> The NLR, PLR, and PNI are all significantly associated with the prognostic survival of LC patients.