HER-2/neu overexpression in breast cancer: An immunohistochemical study including correlations with clinicopathologic parameters, p53 oncoprotein and cathepsin-D

Purpose: To evaluate the relationship between HER-2/neu overexpression and standard as well as investigational prognostic factors in Greek females with invasive breast carcinoma. Materials and Methods: Paraffin - embedded tumor sections from 128 consecutive primary breast cancer patients were screened for HER-2/neu oncoprotein (p185) overexpression by immunohistochemistry using the polyclonal antibody A 0485. The relationship between HER-2/neu staining and other established markers of prognosis were examined using both a univariate and a multivariate analysis. Results: HER-2/neu overexpression was detected in 46.1% of tumors. No statistical correlation was found between HER-2/neu and age, tumor diameter, histologic type, nodal status, tumor grade, stage, estrogen and progesterone receptor status or cathepsin-D. A significant correlation was noted between HER-2/neu and p53 overexpression in the total sample (p=0.014) as well as in node-positive patients (p=0.026). In those groups, HER-2/neu and p53 co-expression was found in 19.5% and 21.6% of cases, respectively. In node-negative patients, HER-2/neu overexpression did not correlate with any other marker. Conclusion: HER-2/neu overexpression seemed to correlate only with p53 oncoprotein.