Prognostic significance of the receptor for epidermal growth factor in human mammary carcinomas.

125I-EGF binding technique was used to demonstrate high affinity receptor binding for epidermal growth factor (EGF-R) in 72 human mammary carcinomas. 27% of the tumors were EGF-R positive and the presence of this receptor was correlated with receptor levels for estradiol, DNA-pattern, proliferative index, thymidine kinase, tumor size, number of lymph node metastases and 6-year relapse probability. Our results confirm previous reports of an inverse relation between the cellular content of EGF-R and ER. In addition, we could associate EGF-R positivity with an aneuploid DNA-pattern and an increased growth rate, as measured by proliferative index. No correlation was found between EGF-R positivity in the primary tumor and presence of axillary lymph node metastasis at the time of operation. The 6-year relapse rate was somewhat higher for patients whose primary tumors were EGF-R positive. Moreover patients who had lymph node metastases at the time of operation and EGF-R positive tumors experienced a significantly lower 6-year disease free survival rate as compared to those who were node negative and had receptor negative tumors. It remains to be shown whether EGF-R alone can be used as an independent prognostic factor.