Abnormal expression of four novel molecular markers represents a highly aggressive phenotype in breast cancer. Immunohistochemical assay of p53, nm23, erbB-2, and cathepsin D protein.

Background: In view of the cumulative results to date, p53, nm23, erbB-2, and cathepsin D are the most promising investigational prognostic factors in breast cancer.
Objectives: The clinical utility of these molecular markers to predict recurrence was evaluated.
Methods: Archival pathology tissues of 100 breast cancer patients were analyzed by immunohistochemical assay. Molecular biologic data were merged with clinicopathologic variables.
Results: Thirty-two patients (32%) had recurrence of disease at a median follow-up of 48 months (range 26-72 months). Investigational factor expression had statistical correlation for recurrence with increasing coexpression: one variable 20.6%, two variables 34.2%, three variables 47.1%, four variables 80.0% (P = 0.003). In univariate analysis, lymph node metastasis, tumor size, erbB-2 protein overexpression, and loss of nm23 protein expression were significant variables to determine recurrence; in multivariate analysis, node status and tumor size emerged as the most significant variables for recurrence.
Conclusions: Coexpression of the studied investigational variables functioned as significant prognostic correlates for recurrence. These findings suggest that the studied investigational prognostic factors possess the ability to discriminate a highly aggressive phenotype in breast cancer.