Changes of expression level of the differentiation markers in papillary thyroid carcinoma under thyrotropin suppression therapy in vivo immunohistochemical detection of thyroglobulin, thyroid peroxidase, and thyrotropin receptor

Background and Objectives: Differences in the expression levels of Thyroglo bulin (Tg), Thyroid peroxidase (TPO) and thyrotropin receptor (TSH-R) in pr imary and recurrent specimens under a suppressive serum TSH condition were elucidated in 26 papillary carcinoma patients. Methods: Immunohistochemical detection was performed by use of each monoclo nal antibody against Tg, TPO, and TSH-R. The staining concentrations of the three markers in each specimen were measured for comparison. Results: The mean staining concentrations of Tg, TPO, and TSH-R in the enti re primary tumor were 103.92, 104.6 and 89.25, respectively. Five cases sho wed stronger expression of all the differentiation markers and eight cases showed weaker expression of all these markers in recurrent tissue than in p rimary tumors. The weaker expression of TSH-R at the recurrent site as comp ared with that at the primary site significantly demonstrated the shortness of the disease free interval or overall survival. There were significant d ifferences between the death due to cancer and the weaker expression of TSH -R in the recurrent tumor as compared with that in the primary tumor. Conclusions: Under the TSH suppressive condition, the markers were not expr essed uniformly among recurrent tumors. Even under that state, however, low expression of TSH-R in the recurrent tissue was strongly related to a poor er outcome in the patients. J. Surg. Oncol. 2000;75:108-116. (C) 2000 Wiley -Liss, Inc.