Clinical Significance of p53 and bcl-2 Protein Coexpression Phenotypes in Molecular Breast Cancer Subtypes of Pre-menopausal and Post-menopausal African-American Women

Abstract

With the current classification of breast carcinoma into molecular subtypes with distinct prognosis and response to therapy, we sort to assess the clinical significance of p53 and bcl-2 coexpression phenotypes in invasive breast tumors and correlate this to the different molecular breast cancer subtypes in African-American women. We performed a retrospective analysis of data on p53 and bcl-2 expression. Results were correlated to molecular breast cancer subtypes, and clinicopathologic variables of prognostic significance. Our study sample included all African-American women diagnosed with breast cancer from 1998 to 2005. Twenty-seven (27.6%) per cent of cases in our study sample over-expressed p53, whereas 69.3 per cent over-expressed bcl-2 protein. A significant inverse correlation was observed between expression of p53 and bcl-2. Combined analysis of p53 and bcl-2 showed that 53.2 per cent of the tumors displayed p53(-)bcl-2(+) phenotype which was significantly associated with the luminal A subtype, whereas 11.6 per cent displayed the p53(+)bcl-2(-) phenotype which was significantly associated with the basal cell-like and Her-2/neu. Neither p53 expression nor bcl-2 expression individually or in combination were of independent prognostic significance. p53(+)bcl-2(-) phenotype is significantly correlated with the basal cell-like subtype and may be associated with the biologic aggressiveness of this cohort of molecular breast cancer.