Preoperative neutrophil-to-lymphocyte ratio correlates with PD-L1 expression in immune cells of patients with malignant pleural mesothelioma and predicts prognosis

Our plain-English summary of Preoperative neutrophil-to-lymphocyte ratio correlates with PD-L1 expression in immune cells of patients with malignant pleural mesothelioma and predicts prognosis, by R. Okita, N. Kawamoto, M. Okada, et al (Scientific Reports, 2023).

The study

• Authors: R. Okita, N. Kawamoto, M. Okada, H. Inokawa, N. Yamamoto, T. Murakami, E. Ikeda
• Journal: Scientific Reports
• Published: 2023;13(1):5263
• Cited by: 10 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

We assessed the prognostic value of five complex inflammatory and nutritional parameters, namely neutrophil-to-lymphocyte ratio (NLR), prognostic nutritional index (PNI), C-reactive protein-to-NLR ratio (C/NLR), platelet-to-lymphocyte ratio (PLR), and lymphocyte-to-monocyte ratio (LMR) using data from patients with malignant pleural mesothelioma (MPM) undergoing extrapleural pneumonectomy (EPP). Moreover, the correlation between these five parameters and programmed cell death protein 1 ligand-1 (PD-L1) expression in the tumor microenvironment was evaluated. This study included consecutive MPM patients who underwent EPP. The histological subtype of the eligible patients (n = 61) correlated with all five parameters. Moreover, the PD-L1 expression scores for immune cells correlated with NLR and PLR, and the PD-L1 expression scores for both tumor cells and immune cells were inversely correlated with both PNI and LMR. Univariate analysis elucidated that NLR, PNI, and C/NLR were predictors of 5-year overall survival (OS), and multivariate analysis revealed that NLR was an independent predictor of 5-year OS, suggesting that NLR is a preoperative, prognostic factor for patients with MPM who are scheduled for EPP. To the best of our knowledge, this is the first study to evaluate the prognostic potentials of NLR, PNI, C/NLR, PLR, and LMR simultaneously in patients with MPM who underwent EPP.

© 2023. The Author(s).

In plain English

This was a retrospective study at one hospital in Ube, Japan. It covered 61 consecutive patients with malignant pleural mesothelioma who had extrapleural pneumonectomy (major surgery removing the lung and lining) with macroscopic complete resection between June 2006 and March 2020. From blood tests taken within 7 days before surgery, the authors calculated five measures of inflammation and nutrition, including the neutrophil-to-lymphocyte ratio (NLR). They compared these with PD-L1 staining in the removed tumor and with survival up to 5 years. Asbestos exposure was not examined. Patients with high NLR (above 2.850) had poorer 5-year overall survival (hazard ratio 2.628, confidence interval 1.762–7.544). After allowing for sex, tumor subtype and side of the tumor, high NLR was still linked to poorer survival (hazard ratio 2.062, 95% CI 1.054–4.031). The other four measures were not. PD-L1 in immune cells was positively correlated with NLR. The authors concluded that NLR is an independent prognostic factor in these patients. They noted the small sample size and said it is unclear whether NLR is a definitive prognostic marker.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Retrospective, single-center, observational study
• Who was studied: 61 consecutive patients with malignant pleural mesothelioma (MPM) who underwent extrapleural pneumonectomy (EPP) and achieved macroscopic complete resection between June 2006 and March 2020 at the National Hospital Organization Yamaguchi Ube Medical Center, Japan; follow-up to April 30, 2021
• Exposure: Asbestos exposure was not assessed. The factors studied were preoperative blood-test measures taken within 7 days before EPP (neutrophil-to-lymphocyte ratio, prognostic nutritional index, CRP-to-NLR ratio, platelet-to-lymphocyte ratio, lymphocyte-to-monocyte ratio) and PD-L1 staining of tumor cells and immune cells in resected tissue
• Main results:
  • In Kaplan–Meier analysis, patients with high NLR (above 2.850) had poorer 5-year overall survival: HR 2.628, CI 1.762–7.544, p = 0.0007
  • Patients with high C/NLR (above 0.955) had poorer 5-year overall survival: HR 2.122 (CI 1.266 to 4.368)
  • Patients with high PNI (above 45.150) had better 5-year overall survival: HR 0.524, CI 0.277–0.908, p = 0.025
  • In univariate Cox analysis, NLR (HR 2.790, p = 0.001), PNI (HR 0.515, p = 0.027) and C/NLR (HR 2.183, p = 0.009) were significantly associated with 5-year overall survival
  • In multivariate analysis with sex, histological subtype and laterality, NLR was an independent predictor of 5-year overall survival (HR 2.062, CI 1.054–4.031, p = 0.034)
  • In multivariate analysis, PNI, C/NLR, PLR and LMR showed no significant effect on 5-year overall survival
  • The PD-L1 score in immune cells was positively correlated with platelet count, NLR and PLR, and inversely correlated with albumin, PNI and LMR
  • The PD-L1 score in tumor cells was inversely correlated with PNI and LMR
• The authors' conclusion: The authors concluded that NLR is an independent prognostic factor for patients with MPM who underwent EPP, and that preoperative NLR assessment could predict whether these patients' prognosis can be improved by EPP
• Limitations the authors state:
  • Small sample size
  • Only overall survival up to 5 years was evaluated, because most patients were followed up at other hospitals and accurate cause-of-death and long-term data were hard to collect
  • Given conflicting earlier studies, the authors said it is unclear whether NLR is a definitive prognostic marker and that further studies are required

Topics

The National Library of Medicine indexes this study under subjects our site covers: Mesothelioma.

Medical terms in this study, explained in our Lexicon: PD-L1, Pleural Mesothelioma, Prognosis, Extrapleural Pneumonectomy (EPP), Tumor Microenvironment, Histological Subtype, Overall Survival, Multivariate Analysis.

Related studies

• Malignant pleural mesothelioma: clinical experience and prognostic value of derived neutrophil-to-lymphocyte ratio and PD-L1 expression — L. Gutierrez-Sainz, P. Cruz, et al. (2021)
• Bladder cancer invasion predictability based on preoperative neutrophil-lymphocyte ratio — M. Kaynar, M.E. Yıldırım, et al. (2014)
• High blood neutrophil-to-lymphocyte ratio is an indicator of poor prognosis in malignant mesothelioma patients undergoing systemic therapy — S.C. Kao, N. Pavlakis, et al. (2010)
• Low calretinin expression and high neutrophil-to-lymphocyte ratio are poor prognostic factors in patients with malignant mesothelioma undergoing extrapleural pneumonectomy — S.C. Kao, S. Klebe, et al. (2011)
• Existing models, but not neutrophil-to-lymphocyte ratio, are prognostic in malignant mesothelioma — T.M. Meniawy, J. Creaney, et al. (2013)
• Relation between neutrophil/lymphocyte ratio and primary tumor metabolic activity in patients with malign pleural mesothelioma — B.A. Özyürek, Ö. Özmen, et al. (2018)

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