ESTIMATION OF THE EPIDERMAL GROWTH-FACTOR RECEPTOR BY THE HYDROXYAPATITE METHOD IN HUMAN BREAST-CANCER

Results of epidermal growth factor (EGF) receptor in human breast tumo urs show large variations, mainly due to the lack of standardization o f the assays. Our EGF receptor values are higher than those reported p reviously which may be due to the use of the hydroxyapatite to separat e bound and non-bound ligand in a radioligand assay. We found EGF rece ptors in 58% (103/178) of the tumours (EGF receptor levels: 3 to 625 f mol/mg of membrane protein, (x) over bar = 33.3, median = 17.4), with a median K-d of 0.642 nmol/l. There was an inverse correlation between EGF receptors and estrogen receptors (r = -0.215, p = 0.00002, Kendal l correlation). There was a difference between EGF receptor content in grade II ((x) over bar = 16.9) and grade III tumours ((x) over bar = 59.3) (p = 0.027), but not between histopathological types and lymph n ode status.