Young pre-menopausal women with breast carcinomas have an overall worse prognosis than older, post-menopausal women. Because histologic grade is a major predictor of tumor behavior and correlates with biomarker expression, we assessed the immunohistochemical expression of epidermal growth factor receptor (EGFR), p185(erbB-2) and Bcl-2, and nuclear accumulation of p53 in breast carcinomas in pre- and post-menopausal women with equivalent histologic grades. This allowed identification of differences in biomarker expression and prognostic significance in pre- and post-menopausal women independent of histologic grade. We investigated 100 infiltrating ductal carcinomas (IDC) in pre-menopausal women, ages 45 years and younger, and 100 IDC in post-menopausal women, ages 65 years and older. The IDC were selected so that the proportions of high and low/moderate grade carcinomas were equal in the pre- and post-menopausal groups. Prognostic utility of biomarker expression in pre- and post-menopausal groups was determined by product limit and multivariate analysis of survival. There were statistically significant differences in cytoplasmic expression of EGFR and Bcl-2 and nuclear accumulation of p53, but not in the expression of p185(erbB-2), in carcinomas of high vs. low histologic grade. There was no difference in the expression of EGFR, p185(erbB-2) or Bcl-2, or in nuclear accumulation of p53 in these IDC from pre- vs. post-menopausal women. Bcl-2 and the nuclear accumulation of p53 were of prognostic significance in our overall study population; however, when assessing pre- and post-menopausal women separately, Bcl-2 and p53 were of prognostic significance only in pre-menopausal, but not post-menopausal women. In summary expression of EGFR and Bcl-2 and nuclear accumulation of p53 were significantly associated with histologic grade, but not with menopausal status. In addition, there were differences in the prognostic effectiveness of these biomarkers in pre- vs. post-menopausal women.