Receptors for epidermal growth factor in human mammary carcinomas and their metastases.

The tumor cell content of the receptor for epidermal growth factor (EGF-R) and estrogen receptor (ER) was analyzed in 36 primary breast carcinomas and their metastatic deposits. Twenty-five percent of the primary tumors and 48 percent of the metastases exhibited measurable levels of the receptor. The frequency of EGF-R positivity was the same for cutaneous and lymph node recurrences. No discrepancy was observed with respect to ER content between primary tumors and their metastases.