Epidermal growth factor receptor and thyrotropin response in human thyroid tissues.

The content of epidermal-growth-factor receptor (EGFr) and its relation to TSH-response were examined in 27 malignant thyroid tumors (5 follicular, 6 papillary, 5 medullary, 11 anaplastic carcinomas) and in 30 tumor-like lesions (21 hyperplastic goiters and 9 toxic adenomatous goiters). Normal 12 thyroid tissues adjacent to benign tumors with no evidence of macroscopic or microscopic abnormalities were used as control. All thyroid plasma membranes tested showed specific EGF binding. In membranes from toxic adenomas (2.18 +/- 0.73 fmoles/mg protein) and papillary carcinomas (2.80 +/- 0.80) the EGF binding was similar to that of normal thyroid membranes (2.32 +/- 0.73). Hyperplastic goiters showed an EGF binding (4.4 +/- 0.82) slightly higher than normal tissue. The highest and the lowest EGF binding values were found in anaplastic (11.8 +/- 2.78) and medullary (0.50 +/- 0.39) carcinomas, respectively. An inverse correlation between EGFr content and TSH-response was found when anaplastic thyroid tumors were compared to tumor-like lesions. However no correlation was observed in medullary carcinomas which also failed to respond to TSH and in papillary carcinomas which partially respond to thyrotropin.