Prognostic and clinicopathological significance of pretreatment mean platelet volume in cancer: a meta-analysis

Objective Our study aimed to evaluate the prognostic and clinicopathological significance of pretreatment mean platelet volume (MPV) on cancer by using meta-analysis of published studies. Design Meta-analysis. Data sources Relevant studies available before 22 December 2019 were identified by searching MEDLINE, EMBASE. Eligibility criteria All published studies that assessed the prognostic and clinicopathological significance of pretreatment MPV on cancer were included. Data extraction and synthesis Studies were identified and extracted by two reviewers independently. The HR/OR and its 95% CIs of survival outcomes and clinicopathological parameters were calculated. Results A total of 38 eligible studies (41 subsets) with 9894 patients with cancer were included in the final meta-analysis. MPV level was not significantly associated with both overall survival (HR 0.98, 95% CI 0.84 to 1.14) and disease-free survival (HR 1.22, 95% CI 0.86 to 1.73) of patients with cancer. Neither advanced nor mixed-stage tumour patients showed significant association between MPV and overall survival (HR 1.36, 95% CI 0.96 to 1.94, HR 0.90, 95% CI 0.74 to 1.09). However, high MPV had the strongest relationship with poor overall survival (HR 2.01; 95% CI 1.08 to 3.41) in gastric cancer, followed by pancreatic cancer (HR 1.54; 95% CI 1.31 to 1.82). Whereas in the subgroup using receiver operating characteristic curve method to define cut-off values, low MPV was significantly related to poor overall survival (HR 0.78, 95% CI 0.64 to 0.95). In addition, MPV had no significant association with age (OR 0.96, 95% CI 0.90 to 1.02), sex (OR 1.04, 95% CI 1.00 to 1.09), depth of cancer invasion (OR 0.90, 95% CI 0.77 to 1.04) and tumour stage (OR 0.91, 95% CI 0.78 to 1.07). Conclusions Pretreatment MPV level is of no clearly prognostic significance in cancers and no significant association with clinicopathological parameters of patients with cancers.