Прогностическое значение экспрессии натрий-йодного симпортера для высокодифференцированного рака щитовидной железы

The clue function of thyroid follicular cells is iodide (I) uptake and thyroid hormones production. NIS mediates the active transport of I into the thyroid follicular cells. It is impossible to perform effective 131 I radioablation ( 131 I RA) up to 10% of all differentiated thyroid cancer (DTC) owing to dedifferentiation and lost ability to cumulate I. To distinguish this group of patient preoperatively is difficult. Aim . To assess the utility of using membrane located NIS detection as marker of unfavorable prognosis for DTC after 131 I RA. Materials and methods . We enrolled in our study retrospectively sixty patients with DTC operated from 2005 to 2008. Based on postop routine histology examination we performed TNM staging. Forty-five patients received 131 I RA postoperatively. During 60 month of follow up recurrence were detected in 20 cases. In all 60 patients' level of membrane located NIS expression were detected immunohistochemicaly (IHC) in primary thyroid tumor. All statistical analysis performed using PC program Statistica 7.0. Results . We found that mean level of membrane located NIS expression in DTC is 4.5%, with maximum up to 10%, whereas mean level of NIS expression in normal tissue is 30—40%. Least mean level of NIS expression was in patients group with recurrence of DTC after 131 I RA (p=0.00083). We proved that crutial for recurrence of DTC after 131 I RA were decreased level of membrane located NIS expression less than 1%. As well as we found statistically significant correlation between Recurrence Free Survival (RFS) and level of NIS expression (p <0.005). Conclusion . Membrane location of NIS determines its functional activity, and membrane located NIS amount decreases in DTC. Detection of membrane located NIS in DTC has prognostic value.