title: A chronic obstructive pulmonary disease negatively influences the prognosis of patients with bladder urothelial carcinoma via hypoxia inducible factor-1α.
abstract: OBJECTIVE
  In this study, we investigated the relationship between the expression of hypoxia inducible factor-1α (HIF-1α) and tumor hypoxia, which is caused by chronic hypoxemic hypoxia in chronic obstructive pulmonary disease (COPD), and the prognostic value of COPD in patients with bladder urothelial carcinoma (BUC).
  
  
  METHODS
  The clinicopathological variables of 80 patients with BUC who underwent surgery were analyzed by retrospective methods. Overall survival (OS), disease-specific survival (DSS) and progression-free survival (PFS) were analyzed with clinicopathological variables including concomitant COPD, pulmonary function test (PFT), serum hemoglobin level and smoking history, using Kaplan-Meier survival analysis. The Cox proportional hazards regression model was used for multivariate analysis. The localization of HIF-1α expression was analyzed by immunohistochemistry.
  
  
  RESULTS
  Both the median OS and PFS of patients with COPD were shorter than the patients without COPD (P < 0.001). High levels of HIF-1α expression were associated with BUC of higher clinicopathological stage and histological grade (P < 0.001). COPD was an independent prognostic variable for OS, PFS and DSS. The clinicopathological stage was an independent prognostic variable for OS and DSS. The level of HIF-1α expression was an independent prognostic variable for PFS.
  
  
  CONCLUSIONS
  COPD is an independent prognostic variable for BUC, and contributes to poor prognosis.
authors.affiliation: Department of Urology, The Second Xiangya Hospital, Central South University Changsha 410011, Hunan, China.
authors.forename: Zhichao
authors.initials: Z
authors.lastname: Huang
authors.affiliation: Department of Urology, The Second Xiangya Hospital, Central South University Changsha 410011, Hunan, China.
authors.forename: Ran
authors.initials: R
authors.lastname: Xu
authors.affiliation: Department of Urology, Shanghai Changhai Hospital 168 Changhai Road, Shanghai 200433, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Lv
authors.affiliation: Department of Urology, The Second Xiangya Hospital, Central South University Changsha 410011, Hunan, China.
authors.forename: Zhaohui
authors.initials: Z
authors.lastname: Zhong
authors.affiliation: Department of Urology, The Second Xiangya Hospital, Central South University Changsha 410011, Hunan, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Urology, The Second Xiangya Hospital, Central South University Changsha 410011, Hunan, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Zhu
authors.affiliation: Department of Anesthesiology, The Third Xiangya Hospital, Central South University 138 Tong Zhipo Road, Changsha 410013, Hunan, China.
authors.forename: Yongzhong
authors.initials: Y
authors.lastname: Tang
authors.affiliation: Department of Urology, The Second Xiangya Hospital, Central South University Changsha 410011, Hunan, China.
authors.forename: Xiaokun
authors.initials: X
authors.lastname: Zhao
keywords: Bladder urothelial carcinoma; chronic hypoxia; chronic obstructive pulmonary disease; hypoxia inducible factor-1α; prognosis