Abstract
Background
Thyroid-stimulating hormone acts as a growth factor for thyroid follicular cells, so some patients with differentiated thyroid carcinoma (DTC) are placed on thyroid hormone suppressive therapy. However, (TSH) suppression is not without risks.
Aims
We thought to assess the potential benefits and cardiovascular risks among patients on TSH suppressive therapy following thyroid surgery for DTC.
Methods
A systematic electronic search was conducted in PubMed, MEDLINE, and Google Scholar for relevant articles. All human and cell lines studies published during the period 2009-October 2019 were eligible. The keywords TSH suppression, differentiated thyroid carcinoma, TSH level, cardiovascular risk, cardiovascular morbidity, cardiovascular mortality, atrial fibrillation, and left ventricular volume were used One hundred and eighty-five articles were retrieved and only eighteen met the inclusion and exclusion criteria.
Results
Out of 185 articles, eighteen studies were included, more than half (55.6 per cent)were published in Europe, 22.2 per cent were from Asia,11.1 per cent from Latin America and one study was from the USA, the majority (72.2 per cent were observational studies),. Patients on TSH suppression were at a high risk of cardiovascular morbidity and mortality that increases at lower TSH levels. Levels <.1mU/L are beneficial in patients with micro or macroscopic disease. However it may induce tumour growth among patients with aggressive recurrent disease, no benefit was observed in low-intermediate DTC.
Conclusion
Physicians may need to suppress TSH in patients with micro or macroscopic DTC. However, caution is needed in aggressive recurrent disease. The available level of evidence showed no benefit of TSH lowering therapy in low-intermediate disease.