title: Simultaneous expression of Cathepsins B and K in pulmonary adenocarcinomas and squamous cell carcinomas predicts poor recurrence-free and overall survival.
abstract: OBJECTIVE
  Patient survival after resection of non-small cell lung cancer (NSCLC) strongly correlated with the occurrence of distant metastasis. Cathepsins are members of the lysosomal cysteine proteases family and can support the metastatic process by degrading the extracellular matrix. The purpose of this study was to identify members of the Cathepsin family that correlate with recurrence-free and overall survival of NSCLC patients.
  
  
  METHODS
  The expression of 13 Cathepsins was examined using DNA-microarray technology in tumor tissues of 89 surgically treated NSCLC patients. All NSCLC samples were classified according to median Cathepsin expression value into either a high or a low expression group. All Cathepsin expression groups were subjected to clinical prognostic analyses regarding survival and local as well as distant recurrences.
  
  
  RESULTS
  Patients with high Cathepsin C tumor expression showed higher tumor recurrence rate compared to patients with low Cathepsin C expression (p = 0.02). The tumor expression of Cathepsins K and B significantly correlated with recurrence-free and overall survival as determined by multivariate analysis. A high expression of Cathepsin B or K was associated with a considerable reduction of recurrence-free as well as overall survival. NSCLC patients with a high expression of both Cathepsin B and K had a significantly (p = 0.001) poorer outcome (5-year survival rate: 13%) than patients with low expression of both genes (5-year survival rate: 75%).
  
  
  CONCLUSIONS
  The combined expression level of Cathepsins B and K identifies high-risk NSCLC patients. A selection of gene expression panels is theoretically superior to established clinical and pathological criteria.
authors.affiliation: Department of Cardio-Thoracic Surgery, Martin Luther University Halle-Wittenberg, Halle, Germany.
authors.forename: Colja
authors.initials: C
authors.lastname: Cordes
authors.forename: Babett
authors.initials: B
authors.lastname: Bartling
authors.forename: Andreas
authors.initials: A
authors.lastname: Simm
authors.forename: Dany
authors.initials: D
authors.lastname: Afar
authors.forename: Christine
authors.initials: C
authors.lastname: Lautenschläger
authors.forename: Gesine
authors.initials: G
authors.lastname: Hansen
authors.forename: Rolf-Edgar
authors.initials: RE
authors.lastname: Silber
authors.forename: Stefan
authors.initials: S
authors.lastname: Burdach
authors.forename: Hans-Stefan
authors.initials: HS
authors.lastname: Hofmann