Prognostic value of systemic inflammatory markers in ovarian Cancer: a PRISMA-compliant meta-analysis and systematic review

BACKGROUND: The prognostic effect of elevated systemic inflammatory markers, including neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR), remains controversial in cancer patients. This meta-analysis was conducted to evaluate the predictive values of these markers for prognoses in ovarian cancer patients. METHODS: Potentially relevant publications in PubMed, ISI Web of Science, and EBSCO were searched. Pooled hazard ratios (HRs) and corresponding 95% confidence intervals (95% CIs) for overall survival (OS) and progression-free survival (PFS) were determined using a fixed or random effects model. RESULTS: Ten studies involving 2919 patients were included in this meta-analysis. In multivariate analysis, the group with higher NLR had worse OS (HR = 1.34, 95% CI = 1.16-1.54) and shorter PFS (HR = 1.36, 95% CI = 1.17-1.57) than the control group. Furthermore, PLR values higher than the cut-off were associated with not only poorer OS (HR = 1.97, 95% CI = 1.61-2.40) but also more unfavorable PFS (HR = 1.79, 95% CI = 1.46-2.20). Univariate analysis also indicated the same results. Additionally, subgroup analysis showed that when the cut-off values for NLR and PLR were higher, their predictive effects became stronger. CONCLUSION: This comprehensive meta-analysis suggested that the values of inflammatory markers such as NLR and PLR were associated with ovarian cancer survival. Therefore, inflammatory markers can potentially serve as prognostic biomarkers. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s12885-018-4318-5) contains supplementary material, which is available to authorized users.