CYTOKERATIN 17 AND THYROID PEROXIDASE AS IMMUNOCYTOCHEMICAL MARKERS FOR REOPERATIVE PREDICTION OF RADIOIODINE RESISTANCE AND THE EFFECTIVENESS OF RADIOIODINE THERAPY OF PAPILLARY THYROID CARCINOMA

Zelinska G.V.

Objective: immunocytochemical studies of the expression of thyroid peroxidase and cytoke­ratin 17 in thyroid papillary carcinomas and their metastases in order to determine the correlation between the expression of these antigens and the radioiodine resistance of papillary carcinoma. Object and me­thods: imunocytochemical studies with using monoclonal antibody against cytokeratin 17, thyroid peroxi­dase of the epithelium were performed on the material of Fine Needle Aspiration Biopsy of 32 pa­pillary thyroid carcinomas and their metastases detected in the postoperative period (79 — radioiodine-resistant metastases, 24 — radioiodine-sensitive metastases) in patients of both sexes aged 8–40 years. Results: it was shown the correlation between the content of the cytokeratin 17-positive cells in the punctates of primary papillary carcinoma and the efficacy of radioiodine therapy for them. When the percentage of cells with cytokeratin 17 in punctates exceeded 5%, radio-resistant metastases were developed in 70% of ca­ses. Thus, cytokeratin 17 can be used as a cytolo­gic marker of preoperative prediction of radioactivity with a 70% concurrence, which will provide a similar indicator for natrium-iodine symporter protein and increase the level of early preoperative testing. This allows to identify the risk group of patients with papillary thyroid cancer with a high probability of occurrence of radioiodine-resistant metastases and more closely to observe them, even when receiving radiiode negative scenograms. To predict the radioiodine resistance of papillary thyroid cancer metastases that arose in the postoperative period, immunocytochemical determination of the expression of thyroid peroxidase was proposed. In the absence or insignifi­cant expression of this antigen, the ineffectiveness of radioiodine therapy, the radioiodine resistance of the metastasis and the need for its surgical removal are projected. If the content of tumor cells containing thyroid peroxidase exceeds 77.5%, the possibility of successful radioiodine the­rapy is predicted. Conclusions: detection by immunocytochemical me­thods of markers of cytokeratin 17 and thyroid peroxidase in tumor puncture cells and its metastases can be used for preoperative monitoring of radioiodine resistant meta­stases of pa­pillary carcinoma thyroid gland; and will allow accurately predict radioiodine resistance and choose the right treatment tactics (radioiodine the­rapy or surgical remo­val of metastases).