Estimation of epidermal growth factor receptor in 177 breast cancers: correlation with prognostic factors.

Steroid receptors (ER, PR) and EGF-receptor were determined on 177 loco-regional primary breast cancers. Binding assay for EGF receptor was performed using a single saturating concentration of 125I-EGF incubated with membranes in the presence or absence of unlabeled EGF. With threshold values of 5 fmol/mg and 10 fmol/mg for EGF-R and steroid receptors respectively, we noted an inverse relationship between the expression of EGF-R, and ER and PR. EGF-R expression is decreased with tumor differentiation.