title: Elevated serum endostatin levels are associated with poor survival in patients with advanced-stage nasopharyngeal carcinoma.
abstract: OBJECTIVE
  To evaluate the prognostic value of serum endostatin levels in patients with advanced-stage nasopharyngeal carcinoma (NPC).
  
  
  METHODS
  Between August 2003 and March 2005, 218 patients with advanced-stage NPC were enrolled in this study, including 70 patients in the training cohort and 148 in the validation cohort. The pre-treatment serum endostatin and vascular endothelial growth factor (VEGF) levels were measured using competitive enzyme immunoassays. For the normal control, serums samples from 20 healthy individuals were also collected.
  
  
  RESULTS
  Serum endostatin levels in the patients with advanced-stage NPC were significantly higher than those of controls, but VEGF levels were similar in the two groups. Univariate analysis revealed significant differences between the high and low endostatin level groups regarding 5 year overall survival (63.9% versus 90.5%; P = 0.003), progression-free survival (PFS) (50.2% versus 79.3%; P = 0.003) and distant metastasis-free survival (DMFS) (59.1% versus 85.3%; P = 0.01) in the training cohort. Using the same cut-off value generated from the training cohort, there were also significant unfavourable correlations between serum endostatin levels and overall survival (P = 0.001), PFS (P = 0.001) and DMFS (P = 0.002) in the second independent validation cohort. Multivariate analysis using the entire group (n = 218) revealed that the serum endostatin level was an independent unfavourable prognostic factor for overall survival (hazard ratio 4.8; 95% confidence interval 2.48-9.23; P < 0.0001), PFS (hazard ratio 3.44; 95% confidence interval 2.06-5.74; P < 0.0001) and DMFS (hazard ratio 3.65; 95% confidence interval 1.92-6.94; P < 0.0001) in patients with advanced-stage NPC. No associations were observed between the outcomes and the serum VEGF levels in patients with advanced-stage NPC.
  
  
  CONCLUSIONS
  High endostatin levels are associated with poor survival and this knowledge may improve the risk stratification of patients with advanced-stage NPC.
authors.affiliation: State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, China.
authors.forename: Hao-Yuan
authors.initials: HY
authors.lastname: Mo
authors.forename: Dong-Hua
authors.initials: DH
authors.lastname: Luo
authors.forename: Hui-Zhi
authors.initials: HZ
authors.lastname: Qiu
authors.forename: Huai
authors.initials: H
authors.lastname: Liu
authors.forename: Qiu-Yan
authors.initials: QY
authors.lastname: Chen
authors.forename: Lin-Quan
authors.initials: LQ
authors.lastname: Tang
authors.forename: Zong-Liang
authors.initials: ZL
authors.lastname: Zhong
authors.forename: Pei-Yu
authors.initials: PY
authors.lastname: Huang
authors.forename: Zheng-Jun
authors.initials: ZJ
authors.lastname: Zhao
authors.forename: Chang-Qing
authors.initials: CQ
authors.lastname: Zhang
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.forename: Hai-Qiang
authors.initials: HQ
authors.lastname: Mai
mesh_terms: D000328:Adult; D014408:Biomarkers, Tumor / Q000097:blood*; D002277:Carcinoma; D015331:Cohort Studies; D043169:Endostatins / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000097:blood* / Q000473:pathology; D009367:Neoplasm Staging; D011379:Prognosis; D016019:Survival Analysis; D042461:Vascular Endothelial Growth Factor A / Q000097:blood
chemical_list: D014408:Biomarkers, Tumor; D043169:Endostatins; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A