Pre-operative urinary cathepsin D is associated with survival in patients with renal cell carcinoma.
BACKGROUND
No circulating markers are routinely used for renal cancer. The objective of this pilot study was to investigate whether conditioned media (CM) from renal cancer cell lines contains potential biomarkers that, when measured in clinical fluids, have diagnostic or prognostic utility.


METHODS
Comparative 2D PAGE profiling of CM from renal cell carcinoma (RCC) and normal renal cultures identified cathepsin D that was subsequently validated in urine samples from 239 patients and healthy and benign disease subjects.


RESULTS
Urinary cathepsin D was found to be significantly associated with overall (OS) (hazard ratio, HR, 1.33, 95%CI [1.09-1.63], P=0.005) and cancer-specific survival (HR 1.36, 95%CI [1.07-1.74], P=0.013) in RCC patients on univariate analysis. An optimal cut point (211 ng ml(-1) micromolCr(-1)) around which to stratify patients by OS was determined. Five-year OS equal to/above and below this value was 47.0% (95%CI 35.4%, 62.4%) and 60.9% (48.8%, 76.0%), respectively. On multivariable analysis using pre-operative variables, cathepsin D showed some evidence of independent prognostic value for OS (likelihood ratio test P-value=0.056) although requiring further validation in larger patient numbers with sufficient statistical power to determine independent significance.


CONCLUSIONS
These data establish an important proof of principle and show the potential of proteomics-based studies. Cathepsin D may be of value as a pre-operative urinary biomarker for RCC, alone or in combination.
Cancer Research UK Clinical Centre, Leeds Institute of Molecular Medicine, St James's University Hospital, Leeds, UK.
N S
NS
Vasudev
S
S
Sim
D A
DA
Cairns
R E
RE
Ferguson
R A
RA
Craven
A
A
Stanley
J
J
Cartledge
D
D
Thompson
P J
PJ
Selby
R E
RE
Banks
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000652:urine*; D015153:Blotting, Western; D002292:Carcinoma, Renal Cell / Q000401:mortality* / Q000652:urine; D002402:Cathepsin D / Q000652:urine*; D045744:Cell Line, Tumor; D017077:Culture Media, Conditioned; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000401:mortality* / Q000652:urine; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010865:Pilot Projects; D011379:Prognosis; D040901:Proteomics
D014408:Biomarkers, Tumor; D017077:Culture Media, Conditioned; D002402:Cathepsin D