Objective:Activating platelets are associated with tumor development and progression.Platelet distribution width(PDW) is an early index of activated platelets.The goal of this study was to investigate the association between prognosis and preoperative PDW in gastric cancer.Methods:A total of 126 gastric cancer patients were retrospectively analyzed from January 2010 to January 2012.The optimal cutoff value of PDW was determined by time-dependent receiver-operating curves.The patients were divided into low and high PDW groups.The prognostic analysis was carried out with univariate analysis and the Cox regression model,which evalu-ated the association of PDW,with progression-free survival(PFS)and overall survival(OS).Results:PDW was closely related with differ-entiation and platelet count.Moreover,lower PDW was associated with decreased PFS and OS in gastric cancer.Multivariate analysis showed that patients with higher PDW had a lower risk of disease progression(hazard ratio:0.562,95% confidence interval:0.184-0.926,P=0.012)and death(hazard ratio:0.468,95% confidence interval:0.263-0.834,P=0.010).Conclusions:Lower preoperative PDW is a poor prognostic factor in gastric cancer,which may also be a prognostic marker in resectable gastric cancer.