Preoperative platelet lymphocyte ratio as independent predictors of prognosis in pancreatic cancer: A systematic review and meta-analysis

BACKGROUND Recently, the preoperative platelet to lymphocyte ratio (PLR) has been found reported to predict oncologic outcomes in multiple malignancies. However, its prognostic value in patients with pancreatic cancer (PC) remains controversial. The aim of this study was to assess the prognostic value of preoperative PLR in PC. METHODS MEDLINE, EMBASE, and Cochrane databases were searched to identify studies evaluating the prognostic significance of preoperative PLR in PC. Pooled hazard ratios (HRs) for overall survival (OS) were calculated using fixed-effects/random-effects models. RESULTS A total of eight studies comprising 1,904 patients with PC were included in the meta-analysis. The pooled analysis demonstrated that elevated PLR had an association with decreased OS (HR: 1.22, 95% CI: 1.04-1.43, p = 0.02). Subgroup analysis showed that a high PLR significantly predicted poor OS in Asian studies (HR: 1.25, 95% CI: 1.03-1.52, p = 0.02), patients with metastatic disease (HR: 1.34, 95% CI: 1.01-1.77, p = 0.04) and patients with PLR >150 (HR: 1.73, 95% CI: 1.21-2.49, p = 0.003). CONCLUSIONS The preoperative PLR may be a significant independent prognostic factor in patients with PC.