What is the problem with Januvia?
Januvia (sitagliptin) is a new type of diabetes drug that works by inhibiting DPP-4, an enzyme that degrades the hormone GLP-1. Januvia increases levels of GLP-1, which causes the pancreas to produce more insulin. Insulin is a hormone that lowers blood-sugar levels.
Unfortunately, it is possible that Januvia could cause thyroid cancer. Several other drugs that influence DPP-4 and GLP-1 have been linked to potential risks of thyroid cancer, and the FDA has ordered drug-makers to conduct studies to investigate this risk.
Does Januvia Cause Thyroid Cancer?
It is unknown if Januvia causes thyroid cancer. The link between Januvia and thyroid cancer was highlighted in a study published in Gastroenterology in 2011 by researchers from UCLA. Researchers linked Januvia to two cases of thyroid cancer that were submitted to the U.S. Food and Drug Administration (FDA) between 2004 – 2009. Although these cases do not prove that Januvia causes thyroid cancer, it is a sign of a potential risk.
The researchers cautioned:
“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.”
It is difficult for researchers to investigate whether Januvia causes thyroid cancer. Januvia is a relatively new drug (only approved in 2006) and there is no long-term safety data. Thyroid cancer is also very rare. It will likely take many years before researchers have enough evidence to conclusively determine if Januvia causes thyroid cancer.
Thyroid Cancer Causes
Thyroid cancer is caused when a cell divides (makes a copy of itself) and makes a mistake in the DNA (mutation) that tells the cell to start dividing and growing uncontrollably. It is unknown what causes cancerous DNA mutations, but there are many potential risk factors.
Potential thyroid cancer causes include:
- Medications that influence GLP-1 (such as Januvia)
- Childhood exposure to high doses of radiation in the head and neck region
- Family history of thyroid cancer (genetics)
- Personal history of a goiter (overgrown thyroid gland)
- Asian race
- Being between the ages of 25-65 years old
- Gender (females make up 75% of people who get thyroid cancer)
- Other diseases, such as:
- Hashimoto’s thyroiditis
- Cowden’s syndrome
- Thyroid adenoma
- Familial adenomatous polyposis
- And more