title: Cathepsin D serum levels are not a valid serum marker in renal cell carcinoma.
abstract: BACKGROUND
  It was the aim of this study to evaluate the serum levels of cathepsin D (Cath D) as a diagnostic tool in patients with renal cell carcinoma (RCC) in comparison with healthy volunteers.
  
  
  METHODS
  Cath D serum levels were measured in serum samples obtained preoperatively from 32 patients with histologically confirmed RCC versus 30 healthy individuals using an enzyme immunoassay. Additionally, for the tumor group, Cath D serum levels were correlated with tumor stage and grade as determined according to the 2002 TNM classification.
  
  
  RESULTS
  The serum Cath D concentration was not significantly different in patients with RCC compared with healthy individuals (mean 16.58 vs. 16.64 ng/ml; p = 0.43). Furthermore, there was no significant association between Cath D serum levels and several patient or tumor characteristics such as tumor stage, tumor grade, lymph node status, presence of metastasis, gender or age.
  
  
  CONCLUSIONS
  In contrast to overexpression of Cath D in primary RCC tissue, serum Cath D is not altered in RCC patients when compared with healthy volunteers. In this small cohort, Cath D serum levels did not reveal additional clinical information in patients diagnosed with a small renal mass. Further prospective multicenter studies might shed more light on the value of Cath D in the diagnostics of RCC.
authors.affiliation: Department of Urology, Eberhard Karls University Tuebingen, Tuebingen, Germany.
authors.forename: Axel S
authors.initials: AS
authors.lastname: Merseburger
authors.forename: Joerg
authors.initials: J
authors.lastname: Hennenlotter
authors.forename: Arnulf
authors.initials: A
authors.lastname: Stenzl
authors.forename: Gundhild
authors.initials: G
authors.lastname: Beger
authors.forename: Ludwig
authors.initials: L
authors.lastname: Rinnab
authors.forename: Markus A
authors.initials: MA
authors.lastname: Kuczyk
authors.forename: Rainer
authors.initials: R
authors.lastname: Kuefer
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood*; D002292:Carcinoma, Renal Cell / Q000097:blood*; D002402:Cathepsin D / Q000097:blood*; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000097:blood*; D008297:Male; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012189:Retrospective Studies
chemical_list: D014408:Biomarkers, Tumor; D002402:Cathepsin D