title: Preoperative plasma levels of interleukin-6 and its soluble receptor predict disease recurrence and survival of patients with bladder cancer.
abstract: OBJECTIVE
  Elevated levels of interleukin-6 (IL-6) are associated with metastasis and poor prognosis in various malignancies. Since the IL-6 soluble receptor (IL-6sR) potentiates the systemic effects of IL-6, each may independently impact the disease process. We tested the hypothesis that preoperative plasma IL-6 and IL-6sR levels would predict cancer stage and prognosis in patients with transitional cell carcinoma of the bladder.
  
  
  METHODS
  The study group consisted of 51 patients who underwent radical cystectomy for transitional cell carcinoma and 44 men without cancer. Preoperative plasma levels of IL-6 and IL6sR were measured by enzyme-linked immunosorbent assay and correlated with pathological features and clinical outcome.
  
  
  RESULTS
  IL-6 levels were higher in patients with bladder cancer than in healthy controls (p <0.001). In bladder cancer cases elevated levels of IL-6 and IL-6sR were associated with adverse pathological features, including muscle invasion, lymphovascular invasion and lymph node metastases (p <0.05). High levels of IL-6sR were also associated with pathological tumor grade (p = 0.036). In separate multivariate models that included clinical stage and grade IL-6 and IL-6sR levels were independent predictors of lymphovascular invasion, metastases to lymph nodes, disease recurrence and disease specific survival (p <0.05). In a preoperative Cox proportional hazards model IL-6 (p = 0.050) and IL-6sR (p = 0.035) predicted disease specific survival.
  
  
  CONCLUSIONS
  We found that plasma IL-6 levels were higher in patients with bladder cancer than in healthy controls. Levels of IL-6 and IL-6sR were associated with cancer stage and metastases, and were strong independent predictors of disease recurrence and disease specific survival.
authors.affiliation: Scott Department of Urology, Baylor College of Medicine and The Methodist Hospital, Houston, Texas, USA.
authors.forename: Ben
authors.initials: B
authors.lastname: Andrews
authors.forename: Shahrokh F
authors.initials: SF
authors.lastname: Shariat
authors.forename: Ja-Hong
authors.initials: JH
authors.lastname: Kim
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Wheeler
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Slawin
authors.forename: Seth P
authors.initials: SP
authors.lastname: Lerner
mesh_terms: D000328:Adult; D000368:Aged; D002295:Carcinoma, Transitional Cell / Q000097:blood* / Q000473:pathology / Q000601:surgery; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000097:blood*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009364:Neoplasm Recurrence, Local / Q000097:blood*; D009367:Neoplasm Staging; D016016:Proportional Hazards Models; D019947:Receptors, Interleukin-6 / Q000097:blood*; D016019:Survival Analysis; D001749:Urinary Bladder Neoplasms / Q000097:blood* / Q000401:mortality* / Q000473:pathology / Q000601:surgery
chemical_list: D015850:Interleukin-6; D019947:Receptors, Interleukin-6