Parathyroid Cancer

Parathyroid cancer is a type of cancer that develops in one of the four parathyroid glands, which are located in the neck behind the thyroid. This type of cancer is incredibly rare, accounting for only 0.005 percent of cancer diagnosed in the United States.

The parathyroid glands are pea-sized organs near the thyroid gland. While they’re tiny, they play a big role in the body by producing parathyroid hormone, which helps the body store and use calcium.

Like the thyroid gland, the parathyroid glands can become overactive—a condition known as hyperparathyroidism. When this happens, the glands produce an excess of parathyroid hormone, which may cause calcium usually stored in the bones to move into the blood or cause the intestines to absorb more of the calcium in the foods we eat. This can lead to too much calcium in the blood, a condition known as hypercalcemia. 

While in most cases hyperparathyroidism is caused by a benign tumor (an adenoma), it can also be caused by a cancerous parathyroid gland tumor.  There are two types of parathyroid cancer:

• Functional parathyroid cancer, which causes the production of excessive parathyroid hormone

• Non-functional parathyroid cancer, which doesn’t cause excessive hormone production

Non-functioning parathyroid cancer is also called non-secreting parathyroid carcinoma. This type of parathyroid cancer is less common, accounting for only 10 percent of cases.

What causes parathyroid cancer?

In the vast majority of cases, parathyroid cancer has a genetic component. According to the National Library of Medicine, up to 70 percent of parathyroid cancer cases occur in those who have a CDC73 genetic mutation. 

In addition to being more likely to develop this type of cancer, those with the CDC73 genetic mutation are seven times more likely to have metastatic parathyroid cancer, where cancer spreads outside the parathyroid glands, or recurrent cancer.

Other risk factors for parathyroid cancer include:

• Having familial isolated hyperparathyroidism
• Having hyperparathyroidism-jaw tumor syndrome
• Having multiple endocrine neoplasia type 1

Having had radiation therapy to the head or neck in the past also increases the risk of parathyroid cancer.

What are the signs and symptoms of parathyroid cancer?

Because most cases of parathyroid cancer cause an excessive production of parathyroid, many of the disease’s symptoms are actually associated with hypercalcemia. Symptoms may include:

• Constipation
• Depression
• Fatigue
• Forgetfulness
• Frequent urination
• Increased thirst
• Loss of appetite
• Muscle aches
• Nausea and vomiting
• Weakness
• Weight loss with no known cause

Some symptoms of parathyroid cancer are unrelated to hypercalcemia. These symptoms may include a neck lump, voice changes, and difficulty swallowing. 

How is parathyroid cancer diagnosed?

Parathyroid cancer may be suspected if you have hypercalcemia with no discernible underlying cause. A medical provider may use multiple tools for diagnosing a parathyroid tumor:

• Blood testing, including a parathyroid hormone test and blood chemistry studies
• Imaging, such as a CT scan to visualize the parathyroid glands
• Sestamibi scan, a type of radionuclide test used to find an overactive parathyroid gland
• Venous sampling, which can help determine which parathyroid gland is affected

In many cases, parathyroid cancer is diagnosed after the removal of an overactive parathyroid gland. Once a diagnosis is made, further testing, including an MRI or a PET scan, may be used to determine whether the cancer has metastasized.

Parathyroid Cancer Treatment at NGMC

If you are diagnosed with parathyroid cancer, your team of medical providers, including a medical oncologist, will recommend a treatment plan based on your specific needs. 

Surgery is the primary treatment option for parathyroid cancer, and in some cases, a hyperactive parathyroid gland may be removed surgically before a cancer diagnosis. There are two types of surgery used to treat parathyroid cancer.

• En bloc resection removes the entire parathyroid gland and the surrounding capsule. In some cases, nearby lymph nodes, the closest thyroid gland, and muscles or tissues may also be removed.
• Tumor debulking removes as much of the parathyroid tumor as possible.

If the cancer has spread outside the parathyroid glands, cancer elsewhere in the body will be removed in a procedure known as a metastasectomy. 

Medications to treat hypercalcemia may be part of treatment for functional parathyroid cancer when the entire tumor cannot be removed. Less commonly, chemotherapy or radiation therapy may be used in conjunction with surgery to treat the disease.  

Choose NGMC for Parathyroid Cancer Care

While this type of cancer is very rare, when you’re diagnosed with the disease, it’s also very real. If you’ve been diagnosed with parathyroid cancer or are experiencing symptoms that may be related to the disease, you can rely on the team of providers at NGMC for comprehensive care from diagnosis through survivorship. We pair specialized expertise with advanced diagnostic tools and treatment methods to provide each of our patients with optimal care.

For more information about cancer care at NGMC or to learn about support groups, please call 770-219-8815.