PURPOSE: 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. MATERIALS AND 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). CONCLUSION: The proposed quanitative radioligand binding assay is easy to perform, rapid and well reproducible, and we recommend it for routine clinical use.
PURPOSE: 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. MATERIALS AND 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 humanEGF. 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). CONCLUSION: The proposed quanitative radioligand binding assay is easy to perform, rapid and well reproducible, and we recommend it for routine clinical use.