Levothyroxine suppressive therapy in differentiated thyroid cancer treatment.

Levothyroxine therapy in management of diferentiated thyroid carcinoma (DTC) has been common practice for decades. Levothyroxine is being administered to patiens with DTC after total thyreoidectomy (with or without postopreative radioiodine treatment) not only to restore euthyroidism but to suppress the production of thyroid-stimulating hormone (TSH) as well because TSH is considered as a growth factor for thyroid follicular cells. However there has been a downside to this threatment recently. The main concerns are the known risks related to iatrogenic subclinical or even mild but clinicaly overt iatrogenic hyperthyroidism. Therefore individualized treatment approach aiming to balance between the risk of tumor recurence and the risks related to hypertyhroidism in view of pateints age, risk factors and comorbidities is essential. Close folow-up is therefore necessary with frequent dose adjustments according to target TSH values published in American Thyroid Association guidelines.