Patients with differentiated thyroid cancer (DTC) are usually managed with total thyroidectomy and subsequent radioiodine ablation of the remnant thyroid tissue. Since these patients become athyrotic, L-throxine (L-T4) therapy is required for life, in order to replace the thyroid hormones and also to suppress the endogenous thyroid stimulating hormone (TSH) which may have a growth-promoting effect on any residual thyroid cancer cells. The approximate dose required to achieve this suppression is about 2 g/kg. However, there is wide variation between patients in their L-T4 requirement. Although factors such as the timing of the dose, compliance, weight and age play important roles, genetic factors are also thought to be important in this dose variability. Therefore, the aims of this study are to identify and evaluate the association of polymorphisms in six genes [(iodothyronine deiodinases (DIO) 1, 2 and 3, paired box gene 8 (PAX8), thyroid stimulating hormone subunit β (TSHβ), and sodium iodide symporter (NIS)], involved in thyroid hormone metabolic and functional pathways with DTC risk and L-T4 dose requirement.
|Date of Award||Sept 2013|