Significance of p53, Bcl-2, and HER-2/neu protein expression in Omani Arab females with breast cancer.

Racial disparity in the presentation of breast cancer and the outcome of its treatment is well established. However, the causes remain unexplained. The scarcity of reports about the prognostic significance of p53, bcl-2, and HER-2/neu in Arab females with breast cancer has been the impetus to this study. We evaluated the prognostic significance of altered expression of p53, bcl-2, HER-2/neu in Omani Arab females with non-metastatic breast cancer with correlation to other established prognostic factors. We have retrospectively analyzed the immunohistochemical expression of p53, HER-2/neu and bcl-2 in paraffin embedded blocks of 72 females diagnosed with invasive breast cancer between 1992 and 2002. The expression of the above proteins was correlated with other prognostic factors and univariate and multivariate analysis was carried out for all prognostic factors. Overexpression of p53 significantly correlated with younger age (<40), pre-menopausal status, poor differentiation with inverse correlation with bcl-2 expression. Expression of bcl-2 immunopostivity significantly correlated to low histological grade and positive estrogen and progesterone receptor status. On univariate and multivariate p53 overexpression and lack of bcl-2 immunostaining resulted in worse survival outcome, but not Her-2/neu overexpression. Expression patterns of p53 and bcl-2 are independent predictors of survival in Omani Arab population which may help to stratify these patients into different risk groups.