Relationship between c-erbB-2 oncoprotein, epidermal growth factor receptor, and estrogen receptor expression in patients with ductal breast carcinoma. Association with tumor phenotypes.

The expression of c-erbB-2 oncoprotein, epidermal growth factor receptor (EGFR) and estrogen receptor (ER) was evaluated by the immunoperoxidase technique (PAP) in ductal breast carcinomas. The relationship between these cell growth regulatory factors was considered and compared with tumor grading, tumor size, lymph node involvement and age of patients. Stratifying of patients on the basis of c-erbB-2, EGFR and ER status indicated that the combination of c-erbB-2 overexpression accompanied by high EGFR value and undetectable ER, identified poorly differentiated tumors and patients with high incidence of axillary lymph node metastases, while high EGFR expression and negative c-erbB-2 staining was connected only with poor tumor grade. The undetectability of molecular markers was associated with higher histological grade and lack of lymph node involvement. Our results indicate that the comparison of c-erbB-2, EGFR and ER status seems to be a powerful tool in discriminating breast carcinomas with different biological phenotypes.