EXPRESSION OF EPIDERMAL GROWTH-FACTOR RECEPTOR (PROTOONCOGENE C-ERBB-1) AND ESTROGEN-RECEPTOR IN HUMAN BREAST-CARCINOMA - AN IMMUNOCYTOCHEMICAL STUDY OF 70 CASES

In vitro studies have shown that growth factors may mediate the growth stimulatory effect of estrogen in hormone-dependent human breast carc inomas while the constitutive expression of same growth factors might by-pass the need for estrogenic stimulus in hormone-independent neopla sms. We have performed immunocytochemical analysis of the expression o f epidermal growth factor receptor (EGF-R or proto-oncogen c-erbB-1) a nd estrogen receptor (ER) in 70 cases of human breast carcinoma. We fo und an inverse relationship between the expression of EGF-R and ER (Ke ndall's tau b = -0.1997, P < 0.03), which promts us to conclude that E R(-) breast carcinomas may grow in a hormone-independent manner throug h the over-expression of the proto-oncogene c-erbB-1, which is the rec eptor for epidermal (EGF) and alpha transforming (TGFalfa) growth fact ors.