Prognostic significance of neutrophil-to-lymphocyte ratio in patients with malignant pleural mesothelioma: a meta-analysis

Our plain-English summary of Prognostic significance of neutrophil-to-lymphocyte ratio in patients with malignant pleural mesothelioma: a meta-analysis, by N. Chen, S. Liu, L. Huang, et al (Oncotarget, 2017).

The study

• Authors: N. Chen, S. Liu, L. Huang, W. Li, W. Yang, T. Cong, L. Ding, M. Qiu
• Journal: Oncotarget
• Published: 2017;8(34):57460-57469
• Cited by: 32 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Systemic inflammation responses can be reflected by peripheral blood count and combine index like the neutrophil-to-lymphocyte (NLR). The NLR has been reported to be a poor prognostic indicator in cancer recently. However, the prognostic effect of the NLR in patients with malignant pleural mesothelioma (MPM) still unclear yet. We conducted this meta-analysis aiming to evaluate the pooled value of NLR in prognosis as well as clinical characteristics in malignant pleural mesothelioma. A total of 11 studies with 1533 patients were included in this meta-analysis, in which 10 studies investigated the prognosis role of NLR using hazard ratio (HR) and 95% confidence intervals (95% CI). The elevated NLR was detected to be associated with a poor overall survival (OS)(HR=1.48, 95%CI=1.16-1.89, P < 0.001). The significant prognostic roles of NLR were also indicated in subgroup analyses. NLR level was also associated with histology instead of gender, stage or performance status (PS) score. These findings suggested that the elevated NLR could be a potential prognostic factor for malignant pleural mesothelioma patients and might be associated with histology as an efficient clinical index to stratify patients.

In plain English

This was a meta-analysis pooling results from earlier published studies. The authors searched PubMed, Embase and Web of Science up to June 26, 2016 for studies of the neutrophil-to-lymphocyte ratio (NLR), a blood-count measure of inflammation, in patients with malignant pleural mesothelioma. They included 11 studies with 1533 patients from Turkey, Spain, the UK, Australia and Japan; the article's table of studies lists publication years from 2010 to 2015. Ten of these studies (1378 patients) were pooled to examine NLR and overall survival. Across these, a high NLR was associated with poorer overall survival (hazard ratio 1.48, 95% confidence interval 1.16 to 1.89, P=0.001). Some subgroups, including studies using only univariate analysis, were not statistically significant. Pooling four studies (526 patients), NLR level was associated with tumor histology, and the authors reported higher NLR in non-epithelioid subtypes. No association was found with gender, tumor stage or performance status. The authors concluded that elevated NLR predicted poor survival and might be associated with histology. They named three limitations: few studies, differences between studies, and a mix of univariate and multivariate data. The study did not examine asbestos exposure.

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: Meta-analysis of published studies (most of the included studies were retrospective)
• Who was studied: Patients with malignant pleural mesothelioma in 11 studies (1533 patients) from Turkey, Spain, the UK, Australia and Japan, which Table 1 dates from 2010 to 2015; 10 studies (1378 patients) were pooled for the survival analysis; databases searched up to June 26, 2016
• Exposure: Elevated versus low blood neutrophil-to-lymphocyte ratio (NLR), with cut-off values of 3 to 5 across studies; asbestos exposure was not studied
• Main results:
  • Pooled across 10 studies, elevated NLR was associated with poorer overall survival: HR 1.48, 95% CI 1.16 to 1.89, P=0.001
  • In studies using multivariate analysis, the association remained: HR 1.50, 95% CI 1.15 to 1.95, P=0.003
  • In the univariate-analysis subgroup (2 studies, 200 patients), the pooled HR was 1.261 (95% CI 0.473 to 3.362, P=0.644), which was not statistically significant
  • In the pooled analysis of four studies (526 patients), NLR level was associated with histology (OR 0.59, 95% CI 0.40 to 0.86, P=0.005); the authors reported that non-epithelioid subtypes were more likely to have elevated NLR
  • No association was observed between NLR level and gender, tumor stage or performance status score
  • Begg's funnel plot and Egger's test did not detect publication bias for overall survival
• The authors' conclusion: The authors concluded that elevated NLR predicted poor survival in malignant pleural mesothelioma, that NLR might be associated with histology, and that further studies were warranted
• Limitations the authors state:
  • Only 11 studies were included, and the limited patient numbers may have influenced the outcomes
  • Heterogeneity between studies (histology, treatment, NLR cut-off, follow-up) may reduce the accuracy of the results
  • Some studies gave univariate and others multivariate data, which may bias the pooled results

Topics

Medical terms in this study, explained in our Lexicon: Pleural Mesothelioma, Meta-Analysis, Inflammation, Prognosis, Hazard Ratio, confidence interval, Overall Survival, Histology.

Related studies

• 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)
• Are neutrophil/lymphocyte ratio and platelet/lymphocyte ratio reliable parameters as prognostic indicators in malignant mesothelioma? — S. Tural Onur, S.N. Sokucu, et al. (2016)
• 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)
• Comment on 'Existing prognostic models, but not neutrophil-to-lymphocyte ratio, are prognostic in malignant mesothelioma' — S.C. Kao, N. van Zandwijk, et al. (2014)
• Response to comment on 'Existing prognostic models, but not neutrophil-to-lymphocyte ratio, are prognostic in malignant mesothelioma' — T.M. Meniawy, J. Creaney, et al. (2014)

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