Effect of exogenous thyroid-stimulating hormone on thyroid papillary carcinoma cells in tissue culture

Background. To determine the prognostic value of thyroid suppression therapy in patients with thyroid carcinoma, we studied the effect of thyroid-stimulating hormone (TSH) on the morphology, proliferation rate, and the T3, T4 production rate of primary thyroid carcinoma cells in culture. Methods. From August 1997 to February 1998 tissues were collected for immediate culture from 13 patients undergoing surgery for thyroid cancer. Cells were incubated for 48 h with TSH in different concentrations. T3 and T4 production was measured by radioimmunoassay; cell proliferation was measured in a radioactive counter. Morphology was determined by cytologic examination. Results. Ten samples were eligible for analysis. Changes in TSH affected T3 and T4 levels. The proliferation rate was not influenced by TSH levels. Conclusions. Thyroid papillary carcinoma cells grown in culture maintain their T3 and T4 synthesis ability. This ability is TSH-dependent and correlates with TSH concentration. The morphology of the cells is also maintained. However, their proliferation is not TSH-dependent, placing the current postthyroidectomy treatment policy in question. (C) 2001 John Wiley & Sons, Inc.