VALUE OF C-ERBB-2 AND P53 ONCOPROTEIN CO-OVEREXPRESSION IN HUMAN BREAST-CANCER

p53 and c-erbB-2 protein expression was immunohistochemically examined in a consecutive series of 49 primary breast cancer patients with a 1 0-year follow-up. The study was performed on paraffin sections using t he monoclonal antibodies DO7 and CBE1; the former recognizes both the wild-type and the mutant p53 forms, the latter recognizes the external domain of the transmembrane c-erbB-2 protein. Positive staining was e xpressed in 12.2% and 16.3% of cases for p53 and c-erbB-2 proteins, re spectively. The results were related to clinicopathological parameters by the chi(2) test. A significant correlation was found between posit ive c-erbB-2 immunostaining and poor survival (P=0.04) and between p53 and c-erbB-2 overexpression (P=0.003); this co-overexpression correla ted well with a poor clinical outcome (P=0.040). From our results, we may speculate that simultaneous expression of p53 and c-erbB-2 oncopro teins could be a critical event in breast tumor progression, and there fore, of prognostic value to identify patients at high risk.