[Receptors for epidermal growth factor in breast cancer].

Epidermal growth factor receptor (EGFr) and cytosolic (cER) and nuclear (nER) estradiol receptors were quantified in 220 primary breast cancers. The EGFr was significantly more frequent (X2 = 5.9; P less than 0.025) and its concentration was significantly higher (P less than 0.001) among ER- tumors than in ER+ tumors. There was a significantly greater proportion (X2 = 6.4; P less than 0.05) of node involvement in EGFr+/ER+ tumors than in EFGr/ER+. Increases in the proportion of EGFr+ in ER- tumors are parallel to Scarff-Bloom scores (X2 = 6.1; P less than 0.05) and there is a significant trend towards increased EGFr concentrations with histologic dedifferentiation. In ER+ tumors the median concentrations of EGFr in the different age groups show linear correlation and follow a parallel profile with the medians of nER. These findings support the hypothesis that considers EGFr as a bad prognosis factor and suggest that EGFr expression and concentration in ER+ tumors might be considered an estrogenic action mediated through the binding of ER to their nuclear acceptors.