New research has identified an oral anti-diabetic drug, metformin, as a potential therapeutic agent in thyroid cancer.
Thyroid cancer is a malignant tumour that starts in the cells of the thyroid. The most common types of thyroid cancer are papillary carcinoma and follicular carcinoma. They are usually grouped together as differentiated thyroid cancer, which makes up more than 90% of all thyroid cancers. Less common and rare types of thyroid cancer include poorly differentiated carcinoma, anaplastic carcinoma, medullary carcinoma, non-Hodgkin lymphoma and soft tissue sarcoma.
Metformin has been shown to have anti-cancer effects in several types of cancer such as breast, lung and ovarian. The drug decreases blood glucose and circulating insulin levels by inhibiting hepatic gluconeogenesis and increasing glucose uptake by muscles. The proposed mechanisms in cancer include activation of the Adenosine Mono-phosphate-activated Protein Kinase (AMPK) pathway and inhibition of the mTOR pathway, which promotes growth and proliferation.
A study led by Dr. Safar Kheder at the University of Sheffield in United Kingdom explored the effect of metformin on the growth and proliferation of thyroid cancer cell lines. The researchers found that metformin suppressed growth of all thyroid cancer cell lines, at concentrations considered to be within in the therapeutic range for diabetic patients on metformin (<0.3 mM).
The results from this study were published in the Journal of Cancer.