Cytological prediction of thyroid cancer aggression as a new promising direction in clinical thyroidology

Abstract

Abstract. Despite the favorable prognosis for most patients with papillary thyroid cancer (PTC) there are problems of timely prediction of aggressive subtypes, metastasis, radioiodine resistance (RIR) of PTC, differentiation of indolent from aggressive forms of microcarcinomas, since the treatment tactics depend on this. This report considers a new direction in the development of clinical thyroidology – cytological prediction of aggression and RIR of PTC.

The aim was to analyze the literature data and present the results of our own studies on the determination of cytological manifestations of aggression and RIR of PTC, which will allow us to develop effective methods for early preoperative prediction of tumor aggression, which will help determine adequate treatment tactics.

Material and methods. A review of literature sources was conducted, and the data of our own studies were analyzed. Methods of cytological and immunocytochemical examinations of PTC and their metastases smears obtained as a result of fine-needle aspiration biopsy (FNAB) were used.

Results. Literature data indicate that the latest approach in thyroidology is the determination of certain cytological features (adhesive properties of cells, architecture of cell layers, nuclear-cytoplasmic ratio, presence of atypical histiocytoid cells, multinucleated cells of the foreign body type) as prognostic factors. We have conducted for the first time a comprehensive cytological and immunocytochemical studies of PTC and their metastases punctates of patients with the development of aggression and RIR compared to patients with a positive effect of radioiodine therapy (RIT). This allowed us to propose a decrease in the expression of thyroid peroxidase (TPO), high expression of cytokeratin 17 (CK17) and the emergence of special cellular phenotypes as cytological markers for predicting aggression and RIR of PTC.

Conclusions. The results of the analysis of literary data and our own studies demonstrate fundamentally new possibilities for using the method of cytological examination of the FNAB material for PTC.