title: The independent association of platelet parameters with overall survival in pancreatic adenocarcinoma receiving intensity-modulated radiation therapy.
abstract: BACKGROUND
  Platelets are involved in multiple links of the process of thrombus formation and development. The aim of this study is to investigate the impact of pretreatment platelet parameters, such as plateletcrit (PCT), platelet mean distribution width (MDW), and mean platelet volume (MPV) in a cohort of patients with locally advanced pancreatic adenocarcinoma treated with a combination of chemotherapy and radiation therapy.
  
  
  METHODS
  A retrospective analysis was conducted of 163 locally advanced unresectable consecutive pancreatic adenocarcinoma patients who received chemoradiotherapy in Zhejiang cancer hospital from January 2009 to December 2011. The effects of platelet parameters on overall survival (OS) were assessed using Kaplan-Meier analysis. Independent prognostic factors were identified in the multivariate Cox analysis.
  
  
  RESULTS
  The median of the PC, PCT, MDW, MPV and CRP were 175×10(9), 20.0%, 14.0%, 10.8 fl and 7.0 mg/L, respectively. MDW was positively correlated with PC (r=0.156, P=0.047) and CRP (r=0.591, P<0.001). The median survival time of high MDW group was significantly worse than that of low MDW group (14.0 m Vs 11.0 m, P=0.008). Patients with high PCT were found to have shorter overall survival time (15.0 m Vs 11.0 m, P=0.018). Multivariate analysis indicated that MDW and N stage were two independent prognostic factors for overall survival (P<0.05). Patients with higher MDW had a 1.48-fold increased risk of death compared to those with low MDW.
  
  
  CONCLUSIONS
  MDW is an independent negative prognostic factor for overall survival in pancreatic adenocarcinoma patients.
authors.affiliation: Department of Radiotherapy, Zhejiang Cancer Hospital Hangzhou, Zhejiang, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Radiotherapy, Zhejiang Cancer Hospital Hangzhou, Zhejiang, China.
authors.forename: Liming
authors.initials: L
authors.lastname: Sheng
authors.affiliation: Department of Radiotherapy, Zhejiang Cancer Hospital Hangzhou, Zhejiang, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Liu
keywords: Pancreatic adenocarcinoma; platelet; platelet parameters; prognosis