Clinicopathological and prognostic significance of platelet-lymphocyte ratio (PLR) in gastric cancer: an updated meta-analysis

Background Pre-treatment PLR (platelet-lymphocyte ratio) was reported to be associated with the prognosis in gastric cancer (GC), but the results remain inconclusive. This meta-analysis aimed to investigate the prognostic potential of the pre-treatment PLR in gastric cancer. Methods We performed a systematic literature search in PubMed, Embase, and the Cochrane Library to identify eligible publications. The hazard ratio (HR)/odds ratio (OR) and its 95% confidence (CI) of survival outcomes and clinicopathological parameters were calculated. Results A total of 49 studies (51 cohorts), collecting data from 28,929 GC patients, were included in the final analysis. The pooled results demonstrated that the elevated pre-treatment PLR was significantly associated with poor overall survival (OS) (HR 1.37, 95% CI 1.26-1.49,p< 0.001;I-2= 79.90%,P-h< 0.001) and disease-free survival (DFS) (HR 1.52, 95% CI 1.22-1.90,p< 0.001,I-2= 88.6%,P-h< 0.001). Furthermore, the patients with the elevated PLR had a higher risk of lymph node metastasis (OR = 1.17, 95% CI 1.02-1.33,p= 0.023), serosal invasion (T3+T4) (OR = 1.34, 95% CI 1.10-1.64,p= 0.003), and increased advanced stage (III+IV) (OR = 1.20, 95% CI 1.06-1.37,p= 0.004). Conclusions An elevated pre-treatment PLR was a prognostic factor for poor OS and DFS and associated with poor clinicopathological parameters in GC patients.