Prognostic role of the pre-treatment platelet-lymphocyte ratio in pancreatic cancer: a meta-analysis

Recently, the pre-treatment platelet-lymphocyte ratio (PLR), which is based on blood parameters, was accepted as a prognostic factor for patients with various cancers. Numerous studies have investigated the prognostic role of the PLR in pancreatic cancer; however, it remains unclear. Therefore, we conducted this meta-analysis to evaluate the relationship between the pre-treatment PLR and overall survival (OS) in pancreatic cancer. We performed a systematic literature search of the PubMed, Embase and Web of Science databases for relevant studies that explored the prognostic role of the pre-treatment PLR in pancreatic cancer. The hazard ratios (HRs) and 95% confidence intervals (CIs) related to OS were pooled using a random effects model. Fourteen retrospective cohort studies involving 2,260 patients were included in this meta-analysis. Compared with low PLR, high PLR was a predictor of shorter OS (HR = 1.24, 95% CI: 1.10-1.39, I = 74%). In this meta-analysis, high pre-treatment PLR was a bio-predictor of short OS in patients with pancreatic cancer, suggesting that PLR could be used to predict prognosis of patients with pancreatic cancer before treatment. However, additional well-designed and large-scale studies are necessary.