[Comparative study on estrogen receptor, epidermal growth factor and epidermal growth factor receptor using...

Estrogen receptor (ER), epidermal growth factor (EGF) and epidermal growth factor receptor (EGFR) were examined by immunocytochemical and biochemical assays in 86 breast carcinomas. The following results were obtained. 1. ER was stained in cellular nuclei by immunocytochemical assay using anti-ER monoclonal antibody. ER positive stained tumor cells were distributed in the various patterns. 2. Immunocytochemical analysis of ER was evaluated with the percentage of ER positive cells and the staining intensity. ER values between immunocytochemical and biochemical assays accorded in 79 out of 86 cases (91.9%). Significant correlation was obtained in both assays (p less than 0.01). A high tendency of the percentage of ER positive cells was demonstrated in PgR positive cases. 3. EGFR was evaluated as positive in 12 out of 38 cases (31.6%) by immunocytochemical assay and in 13 out of 38 (34.4%) by biochemical competitive binding assay using 125I labeled EGF, respectively. A significant inverse relationship was obtained between ER and EGFR values (p less than 0.05). 4. EGF was evaluated as positive in 22 out of 38 cases by immunocytochemical assay. EGF expression was observed in all EGFR positive tumors. Compared with ER and EGF staining, the percentage of ER positive cells was higher in EGF negative tumors than in EGF positive ones (p less than 0.05).