title: Validation of serum C-reactive protein (CRP) as an independent prognostic factor for disease-free survival in patients with localised renal cell carcinoma (RCC).
abstract: OBJECTIVE
  To validate high-sensitivity C-reactive protein (hs-CRP) serum levels as an independent marker for disease-free survival (DFS) in clinically localised clear cell renal cell carcinoma (ccRCC).
  
  
  METHODS
  In all, 403 consecutive patients with clinically localised (T1-3N0M0) ccRCC treated by radical or partial nephrectomy were enrolled. Preoperative serum levels of hs-CRP were evaluated as both a continuous and categorical variables. Associations with clinical (age, gender) and pathological variables (T classification, grade, tumour necrosis) were assessed with the chi-square and Kruskal-Wallis tests. Univariable and multivariable Cox proportional hazards models were fitted. The prognostic accuracy (PA) was assessed with Harrell's C-index.
  
  
  RESULTS
  The mean hs-CRP level was 1.32 mg/dL. The hs-CRP levels were associated with T classification (P = 0.05), high-grade disease (P < 0.001) and tumour necrosis (P = 0.003). After a median follow-up of 43 months, 41 patients (10.1%) had developed disease recurrence. With each unit increase in hs-CRP levels, the risk of recurrence increased by 10% (hazard ratio 1.10, P = 0.015). The thresholds of 0.5 and 0.75 mg/dL showed the best discrimination for stratification of patients according to the probability of recurrence. These categorically coded hs-CRP levels were identified as independent prognostic factors in multivariable analyses (P < 0.001) and led to a significant increase in the PA of a multivariable base model containing the variables of the 'Stage, Size, Grade and Necrosis' (SSIGN) score.
  
  
  CONCLUSIONS
  This study validates preoperative serum hs-CRP levels as independent prognostic factor after surgery for localised ccRCC. Hs-CRP may be included in standard prognostic modelling after surgery and may guide surveillance and inclusion in adjuvant clinical trials.
authors.affiliation: Department of Urology, Medical University of Vienna, Vienna, Austria.
authors.forename: Michela
authors.initials: M
authors.lastname: de Martino
authors.forename: Tobias
authors.initials: T
authors.lastname: Klatte
authors.forename: Christoph
authors.initials: C
authors.lastname: Seemann
authors.forename: Matthias
authors.initials: M
authors.lastname: Waldert
authors.forename: Andrea
authors.initials: A
authors.lastname: Haitel
authors.forename: Georg
authors.initials: G
authors.lastname: Schatzl
authors.forename: Mesut
authors.initials: M
authors.lastname: Remzi
authors.forename: Peter
authors.initials: P
authors.lastname: Weibl
mesh_terms: D014408:Biomarkers, Tumor / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism*; D002292:Carcinoma, Renal Cell / Q000097:blood* / Q000473:pathology / Q000628:therapy; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007680:Kidney Neoplasms / Q000097:blood* / Q000473:pathology / Q000628:therapy; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009392:Nephrectomy; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D015203:Reproducibility of Results
chemical_list: D014408:Biomarkers, Tumor; D002097:C-Reactive Protein