[EGF receptors in human breast cancer. Relation to hormonal receptors].

EGF membrane receptors (R-EGF) were assayed in 65 human breast cancer biopsies. The Scatchard analysis of the binding of 125I-EGF indicated a single class of sites with an apparent dissociation constant of 1 nM. Fourty-eight percent of the tumors are R-EGF positive (specific binding greater than 1% of total radioactivity), the level of receptors reaching 14%. We have not observed any relationship between R-EGF and hormone receptors (estradiol, progesterone and prolactin) or clinical and histological characteristics of the tumor. Taking into account the role of EGF in growth of some human breast cancer epithelial cells culture and the possible production of R-EGF by oncogenes, these results suggest that R-EGF could be an uindependent biochemical marker of human breast cancer.