Receptors for epidermal growth factor and thyrotropin in thyroid carcinoma

The EGF and TSH receptor properties in malignant thyroid tumours and adjacent normal thyroid tissues were characterized using radioreceptor assays. Ten patients with papillary, 4 with medullary, 1 with Hürthle cell type follicular carcinoma, and 2 with anaplastic thyroid carcinoma were studied. In 10 out of 12 patients with papillary and anaplastic thyroid carcinomas, more EGF receptors were found in the neoplastic tissue than in the adjacent normal tissue (P less than 0.01). The affinity of the EGF receptors varied between patients (from 0.5 X 10(9) l/mol to 1.9 X 10(9) l/mol), but was in each patient the same in the neoplastic and in the normal tissue. In medullary carcinomas and a follicular Hürthle thyroid carcinoma, the EGF receptor content was very low. The receptor number was unaltered or decreased in papillary carcinomas when compared with adjacent normal tissue. In anaplastic medullary and follicular (Hürthle cell) carcinomas, the neoplastic tissue had very few high affinity TSH receptor sites. The alterations in TSH receptor characteristics when thyroid neoplastic tissue was compared with adjacent normal tissue did not correlate to changes in EGF receptor characteristics. Our results demonstrate that the amount of EGF receptors in papillary and anaplastic thyroid carcinomas differ significantly from that in follicular and medullary carcinomas and that alterations in EGF receptor content in malignant thyroid tissues are independent of TSH receptor content.