EPIDERMAL GROWTH-FACTOR RECEPTOR AND ESTROGEN AND PROGESTERONE RECEPTORS IN BREAST CANCERS OF PREMENOPAUSAL AND POSTMENOPAUSAL PATIENTS

Aims and backround: The purpose of our research was to investigate the relations between the levels of epidermal growth factor receptor and estrogen and progesterone receptors in breast cancers of premenopausal and postmenopausal Polish women. Methods: Cell membrane levels of epi dermal growth factor receptor (EGF-R), and cytosol (c) estrogen (ER) a nd progesterone (PR) receptors were determined in 221 specimens of pri mary breast cancers. ERc and PRc were assayed using the dextran-coated charcoal procedure, and EGF-R were assayed by the radioligand method of specific saturation of the crude membrane fraction with I-125-EGF R esults: A statistically significant inverse correlation was found in a ll tumors between the concentrations of EGF-R and ERc, whereas for PRc significance of this correlation was not fully confirmed. ERc concent rations in tumors were positively correlated with age of patients, whe reas EGF-R and PRc were not. In all, in premenopausal, and in postmeno pausal EGF-R-positive tumors (less-than-or-equal-to 10 fmol/mg of memb rane protein), mean concentrations of ERc did not differ significantly . These groups of tumors seem to be homogeneous with respect to ERc co ncentrations. In EGF-R-negative (< 10 fmol/mg of membrane protein) pos tmenopausal tumors, the mean ERc concentration was significantly highe r than in premenopausal tumors, hence these groups of tumors appear to be heterogeneous with regard to ERc contens: Conclusions: The present findings may have significance in differentiation of postmenopausal b reast cancer.