Characterization of prostate cancer in needle biopsy by Cathepsin B, cell proliferation and DNA ploidy

Background: Our objective was to determine localization patterns of three distinct groups of biomarkers (cathepsin B, MIB-1 and DNA ploidy) in prostate needle biopsy sections to establish localization similarities (or differences) in biopsy and retropubic prostatectomy specimens (RPs). Materials and Methods: Prostate needle biopsy specimens and matched RPs from 47 patients with cancer were evaluated. Biopsy and RP sections were stained with anti-cathepsin B (CB) and anti-stefin (cystatin) A (SA) and for cell proliferation and DNA ploidy. The ratio of CB to SA in stained cells was calculated for each biopsy cancer and matched benign prostatic hyperplasia (BPH) sample. Results: The geometric mean of CB to SA was 1.45 in BPH and 2.99 in cancer specimens (p=0.0001). The percentage of S-phase cells and DNA ploidy status in needle biopsy was associated with cancer volume in RP cases (p=0.03). Conclusion: Our study has indicated that the ratio of CB to SA is significantly higher in prostate cancer biopsy specimens than in BPH. The percentage of S-phase cells and DNA ploidy in needle biopsies predicts cancer volume of RPs. We have shown that localization of three distinct biomarkers in biopsies reliably assesses the nature of prostate cancer in biopsy sections.