Immunohistochemical expression of p53 and c-erbB2 proteins in breast cancer in Egypt

The purpose of the present study was to estimate p53 and c-erbB2 expression in an Egyptian cohort and assess their relationships with other indicators of aggressive disease. Additionally, the frequency of both oncogenes was compared to that reported in other breast cancer populations. Parafin-embedded tissue sections obtained from 210 invasive ductal carcinomas were evaluated immunohistochemically for p53 and c-erbB2 oncoproteins using CM-I polyclonal antibody and mAb1 monoclonal antibody, respectively. Tumor proliferation was also assessed rising PC10 anti-PCNA (proliferation cell nuclear antigen) monoclonal antibody. Chi square test was used to assess the relationship between p53 and c-erbB2 and their associations with other prognostic factors. The results revealed that p53 and c-erbB2 were equally expressed, each accounting for 40% of the total cases (84 out of 210) Immunoreaction for p53 and/or c-erbB2 was demonstrated in 65% (136 out of 210) and 15% (32 out of 210) were positive for both oncogenes. Poor histologic grade was more significantly associated with p53 expression (P=0.0001) than c-erbB2 expression (P=0.01). The latter was also significantly associated with premenopausal status (P=0.01) and large tumor size (P=0.003). Both p53 and c-erbB2 oncoproteins were found to be unrelated to each other, nodal status ol PCNA immunostaining. These data suggest that p53 and c-erbB2 oncogenes correlate with poor prognostic features of breast cancer The differences between the frequency of p53 and c-erbB2 expression observed in this study and in the reports of Western authors will hopefully stimulate investigation of these oncogenes using molecular biologic techniques and matched comparative Egyptian and European breast cancer groups.