Preoperative Platelet to Lymphocyte Ratio as a Prognostic Factor for Resectable Pancreatic Cancer: A Systematic Review and Meta-Analysis

Introduction: Various inflammatory markers have been investigated for a prognostic role in patients with resectable pancreatic cancer. However, the value of preoperative platelet to lymphocyte ratio (PLR) remains controversial. We performed a systematic review and meta-analysis of PLR as a preoperative prognostic factor for resectable pancreatic cancer. Material and Methods: Systematic literature search was conducted for studies assessing PLR influence as a preoperative prognostic factor in resectable pancreatic cancer patients. Random-effects model was applied for pooling hazard ratios and 95% confidence intervals related to overall survival (OS) and disease-free survival (DFS). Results: Fourteen articles with 2,743 patients were included in the study. According to the analysis, high PLR had no correlation with decreased OS. Due to high heterogeneity among studies, subgroup analysis was performed. Better OS was associated with low PLR in Asian patients, patients with mixed type of operation performed, and patients with preoperative PLR <= 150. Low PLR was associated with significantly better DFS. Conclusions: PLR is a predictive factor of better DFS in patients with resectable pancreatic cancer. However, available evidence does not support PLR as a reliable prognostic factor for OS.