CATHEPSIN-D IMMUNOCYTOCHEMICAL ASSAYS IN BREAST CARCINOMAS - IMAGE-ANALYSIS AND CORRELATION TO PROGNOSTIC FACTORS

Immunocytochemical assays of cathepsin D were assessed in a series of breast carcinomas (n=257) using monoclonal M1G8 anti-total cathepsin D and the avidin-biotin-peroxidase complex. Cathepsin immunoreactivity was compared in frozen and paraffin sections. All tumours were anti-ca thepsin-positive. Positive staining was observed in carcinoma and stro mal cells and in the extracellular matrix. The amount of immunodetecta ble cathepsin in tissue was measured by computer-assisted image analys is (SAMBA 2005). Both the percentage of immunostained tumour surface a nd the mean optical densities were processed as continuous variables f or statistical analysis and correlated with prognostic factors. It was shown that cathepsin D was independent of the tumour size, the lymph node status, hormone receptors, and pHER-2/neu overexpression. Catheps in was significantly correlated with anti-EGFR (P=0.012) and Ki67 (P=0 .002) immunoreactivity, tumour grade (P=0.032), vascular invasion (P=0 .0081), proliferation index (P=0.0045), and, to a lesser extent with A gNORs (P=0.0504) and the degree of hyperploidy (P=0.057). Tissue fixat ion and paraffin embedding significantly decreased cathepsin immunorea ctivity. These results show that cathepsin D is not a totally independ ent prognostic factor in breast carcinomas.