title: Radioligand binding assay determination of epidermal growth factor receptor in ovarian tumours.
abstract: OBJECTIVE
  To introduce a quantitative method for determination of epidermal growth factor receptor (EGFR) expression in tissue samples taken from normal ovaries, benign and malignant ovarian tumours, convenient for routine tests.
  
  
  METHODS
  About 1g of tissue was taken intraoperatively from 136 patients; 105 of them had histologically verified ovarian tumours (64 malignant, 42 benign) and 30 had normal ovaries. The tissue was frozen, preserved and transported in liquid nitrogen (-196 degrees C). The level and frequency of EGFR expression were determined by radioligand method, utilizing (125)I-labeled epidermal growth factor (EGF) and recombinant human EGF. The results were obtained as fmol bound EGF per mg protein from the membrane fraction. All samples having expression >/=3 fmol/mg were considered as positive.
  
  
  RESULTS
  The frequency of EGFR expression was 52% (70/136 patients), with a mean level of expression 45 +/-11 fmol/mg (range 0-1332). From the EGFR-positive patients with malignant ovarian tumours 21 (62%) had progressive disease (PD) while only 4 (13%) patients with negative EGFR had PD (p=0.001). The mean progression-free interval in the first group was 4 months, and in the second group it was 11 months (p=0.0028).
  
  
  CONCLUSIONS
  The proposed quanitative radioligand binding assay is easy to perform, rapid and well reproducible, and we recommend it for routine clinical use.
authors.affiliation: Clinic of Gynecologic Oncology, Oncologic Center, Medical University, Pleven, Bulgaria.
authors.forename: S
authors.initials: S
authors.lastname: Tomov
authors.forename: D
authors.initials: D
authors.lastname: Tzingilev
authors.forename: G
authors.initials: G
authors.lastname: Gorchev
authors.forename: A
authors.initials: A
authors.lastname: Velkova
authors.forename: T
authors.initials: T
authors.lastname: Vesselinova
authors.forename: S
authors.initials: S
authors.lastname: Popovska