BACKGROUND.
Hormone receptors and oncoproteins are receiving increased attention as possible prognostic factors in different carcinomas. Few data are available regarding quantification of their levels of expression in gynecologic malignancies. METHODS. Epidermal growth factor (EGF) receptor specific binding capacities and affinities were measured by ligand binding assay using I'"I]EGF in a competition mode with AccufitB software (Lundon Software, Inc., Middlefield, OH). HER-2/ rzeii oncoprotein was extracted from membranes and measured using a n enzymelinked immunosorbent assay. Cathepsin D was measured by a n immunoradiometric assay using cytosols for steroid receptor analyses. RESULTS. EGF receptors in 23 nonmalignant uteri ranged from undetectable to 50 fmol/mg membrane protein (median, 01, with dissociation constant values of 1.2 x lo-' M to 8.5 x lo-'" M, compared with EGF receptors in 76 endometrial cancers that ranged from undetectable to 7674 fmollmg (median, 32). HER-2/ r m c oncoprotein ranged from undetectable to 2.9 HER-2/nezi units (HNU)/pg protein (median, 0.6) in 41 nonmalignant uteri and from undetectable to 5.8 HNUlpg protein (median, 2.5) in endometrial cancers (n = 53). Cathepsin D ranged from 5 to 32 pmollmg cytosol protein (median, 11) in 42 nonmalignant uteri and 18 to 144 pmollmg protein (median, 42) in 29 endometrial cancers. CONCLUSIONS. Determination of the frequency and levels of EGF receptors, HER-2 / r i ~z i protein. and cathepsin D in uteri with and without cancer and the availability of reference materials developed in our laboratory will allow evaluation of their prognostic value in cancers of the uterus. Cancer 1996; 72710-6. ic 1996 Aiiier icar2 Cnricer Society KEYWORDS uterus, endometrial carcinoma, prognostic factors, EGF receptors, cathepsin 0, HER-Slneu oncoprotein.
here is a need to better assess the prognosis of patients with endome-