Januvia (sitagliptin) has been linked to at least two cases of thyroid cancer, but it is unknown if Januvia causes thyroid cancer. There is no long-term safety data on Januvia because it is a relatively new drug. Thyroid cancer is very rare and can take many years to develop.
Does Januvia Cause Thyroid Cancer?
No one knows if Januvia causes thyroid cancer. Januvia has only been sold in the U.S. since 2006, and thyroid cancer often takes many years to develop. Thyroid cancer is also very rare. It will likely take researchers many years before they have enough data to conclusively determine whether Januvia causes thyroid cancer.
In 2011, a study published in Gastroenterology found two cases of Januvia thyroid cancer in the U.S. Food and Drug Administration (FDA) database. These reports do not prove that Januvia caused thyroid cancer. According to the researchers:
“This analysis of the FDA database does not establish that pancreatitis, pancreatic cancer and thyroid cancer are caused by GLP-1 therapy. It simply raises the level of concern that they may be, and that the appropriate prospective studies are required to rule them out.”
Thyroid Cancer Causes
Thyroid cancer is caused when a cell divides, makes a mistake when copying its DNA, and creates a new cell with mutated DNA that causes the cell to start dividing out of control. No one knows what causes these cancerous mutations in DNA, or how to stop them from dividing out of control.
The following possible causes of thyroid cancer have been identified:
- Drugs that influence the hormone GLP-1 (Januvia)
- High doses of radiation to the neck, especially in childhood
- Genetic or family history of thyroid cancer or diseases
- Goiters (enlarged thyroid)
- Asian ancestry
- Age (between 25-65 years old)
- Female (women make up 75% of people who get thyroid cancer)
- Certain other medical conditions, such as:
- Hashimoto’s thyroiditis
- Cowden’s syndrome
- Thyroid adenoma
- Familial adenomatous polyposis
- And more