The popular diabetes drug Victoza (generic: liraglutide) has recently been linked to thyroid cancer, a disease that occurs when abnormal cells begin to grow in the thyroid gland. Consumer watchdog group Public Citizen has filed a petition with the U.S. Food & Drug Administration (FDA) to take Victoza off the market because of the risk of thyroid cancer and other serious side effects. Signs and symptoms of Victoza thyroid cancer include abnormal lumps in the neck, difficulty swallowing or breathing, and frequent cough.
What’s the Problem?
Prior to the FDA’s 2010 approval of Victoza, the administration began to question whether the drug could cause thyroid cancer because clinical studies showed that Byetta, a similar diabetes drug, might. The FDA eventually concluded that Victoza caused the formation of thyroid C-cell tumors in rodents. For this reason, the administration has required that Victoza packaging include a so-called ‘black box warning’ – the strictest such warning allowed by law – informing consumers of the risk of thyroid cancer.
Thyroid Cancer Overview
Thyroid cancer is a disease that originates in the cells of the thyroid – a butterfly-shaped gland located at the base of the neck. The thyroid’s main function is to produce hormones that regulate the heart rate, blood pressure, body temperature and weight. Although the disease is quite rare in the U.S., thyroid cancer rates have increased significantly over the past several years. Many in the medical community believe this is because new technology is allowing them to diagnose mild cases of the disease that would have gone undetected in the past.
Types of Thyroid Cancer
There are four major classifications of thyroid cancer:
- Papillary Carcinoma – By far the most common variety of thyroid cancer, papillary carcinoma usually affects women of childbearing age. It spreads slowly and is the most treatable form of the disease.
- Medullary Carcinoma – Cancer of non-thyroid cells that are normally present in the thyroid gland. Medullary carcinoma tends to run in families, and has been conclusively linked with several types of specific genetic mutations. This type of the disease requires different methods of treatment than other kinds of thyroid cancer.
- Follicular Carcinoma – Having the highest recurrence rate of any type of thyroid cancer, follicular carcinoma accounts for about 10% of all cases. Mortality of the disease is highly related to the degree of vascular invasion.
- Anaplastic Carcinoma (also known as Giant and Spindle Cell Cancer) – By far the most dangerous form of thyroid cancer, anaplastic carcinoma is a rare form of the disease that spreads quickly and does not respond to radioiodine therapy.
According to recently published statistics from the National Cancer Institute, there are approximately 56,000 newly diagnosed cases of thyroid cancer in the United States each year, the vast majority of which are papillary thyroid cancer. Females are more likely to develop the disease than men by a ratio of 3:1, and though it can occur at any age, it is more likely to begin after the age of 30 (with the aggressiveness of the condition increasing with age). In many cases, thyroid cancer is asymptomatic; however, the first sign of the disease is usually a thyroid nodule.
Symptoms of Thyroid Cancer
Signs and symptoms of Victoza thyroid cancer vary significantly depending on the type of the disease, but may include:
- thyroid lump (nodule)
- difficulty swallowing
- enlargement of the thyroid gland
- hoarseness or changing voice
- neck swelling
Courses of treatment for thyroid cancer will depend on the type and stage of the tumor, as well as the patient’s overall health and medical history. While surgery is usually the first line of defense in treating the disease, a variety of other approaches may be implemented, which may include:
- radioactive iodine treatment
- thyroid hormone therapy
- external beam radiation therapy
In many cases, results are the most effective when two or more of these methods are used in conjunction.
Victoza Side Effects
In addition to having the potential to cause thyroid cancer, Victoza has also been linked to the following serious side effects: