A type of cancer that begins to develop in the tissue of the parathyroid glands is called parathyroid cancer. These glands are a part of the endocrine system, and they are located behind the thyroid gland in the neck. This part of the endocrine system is very important because it produces hormones that control the amount of Calcium in the blood. If you are diagnosed with parathyroid cancer, doctors often recommend surgery to remove it.
In general, this type of cancer occurs quite rarely, and physicians do not use the four-stage naming system for parathyroid cancer. However, the stages of this type of cancer are divided into 3 categories. For example:
- Localized – In such cases, the tumor is located only in the parathyroid glands.
- Metastatic – It means the cancerous cells have spread to other parts of the body, including nearby lymph nodes, liver, lungs, bones, or pancreas. Moreover, about 10% to 30% of people who develop parathyroid cancer will have metastatic cancer. Commonly, it spreads to the lungs, bones, or liver.
- Recurrent – This stage means that the cancer returns even after successful treatment (such as surgery to remove the tumor). Approximately 50% of people will experience recurrence. Mostly, it returns between 2 to 5 years after the first surgery, but in some cases, it may take 20 years before it recurs.
Parathyroid Glands
In normal circumstances, people have 4 small glands behind the thyroid gland. They are called parathyroid glands and are a part of the endocrine system. Sometimes, parathyroid glands are found along the esophagus (the tube that carries drinks and food from the mouth to the stomach) or in the chest. In such cases, they are called ectopic parathyroid glands.
These glands produce parathyroid hormone (PTH) that helps control Calcium levels in the blood. Some people may develop a condition called hyperparathyroidism (overactive parathyroid glands). In such cases, they produce too much PTH, which significantly increases the levels of Calcium in the blood. As a result, it may also lead to hypercalcemia.
Types of Parathyroid Cancer
In general, there are two types of parathyroid cancer. The most common one is when cancerous cells cause the parathyroid glands to produce too much PTH, which significantly increases the Calcium levels in the blood.
Another type of parathyroid cancer is non-functioning (also known as non-secreting) parathyroid carcinoma. In such cases, Calcium and PTH levels in the blood are not increased. The second type of parathyroid cancer accounts for less than 10% of all diagnosed parathyroid cancers, which makes it extremely rare.
This type of cancer occurs very rarely and accounts for 0.005% of all cancers, and 0.5% to 1% of all parathyroid disorders.
Symptoms
Commonly, people who develop parathyroid cancer often experience symptoms of hypercalcemia (increased levels of Calcium in the blood). Check below some examples:
- Frequent urination
- Increased thirst
- Nausea
- Vomiting
- Appetite changes
- Constipation
- Extreme tiredness (fatigue)
- Depression
- Memory loss
- Muscle aches, cramping, or weakness
- A lump in the neck
- Voice changes or hoarseness
- Swallowing problems (dysphagia)
If you or a loved one experiences any of the previous symptoms, contact your healthcare provider right away.
Causes and Risk Factors
Healthcare providers do not fully understand why this type of cancer occurs. However, they think some genetic disorders and environmental factors could play a role. Check below some risk factors for parathyroid cancer:
- Multiple endocrine neoplasia type I (MEN1)
- Familial isolated hyperparathyroidism (FIHP)
- Hyperparathyroidism-jaw tumor syndrome
- Previous radiation therapy to the head or neck
- A family history of parathyroid cancer
- Age – This type of cancer mostly affects people over 30 years old
This article does not contain a full list of factors that may increase your risk of developing parathyroid cancer.
What Are The Potential Complications of Parathyroid Cancer?
People who develop this type of cancer may also experience some complications. However, treatments used to treat it can also cause complications. Check below some examples:
- Hypercalcemia (this condition may cause bone pain, kidney problems, and other problems)
- Metastasis
- Hypocalcemia
- Voice changes
- Infection
- Scarring
- Bleeding
- Hypercalcemic crisis
- Cardiovascular problems
However, you can consult with your healthcare professional about ways to reduce the risk or even prevent previous complications.
Unfortunately, it is not possible to reduce the risk or prevent parathyroid cancer. Thus, if you have a family history of this type of cancer, you should get regular screenings to make sure you do not develop it.
Diagnosis
Sometimes, it is difficult to diagnose parathyroid cancer because the cells of this type of cancer look similar to the cells of a benign (noncancerous) parathyroid adenoma. That’s why doctors often diagnose this condition when a person develops hyperparathyroidism. Therefore, the overactive parathyroid glands are surgically removed, and then further testing is done to check the tissue. However, before surgery, doctors may perform some tests and procedures. For example:
- Blood calcium test
- Parathyroid scan (usually doctors perform a radioactive sestamibi or CT scan)
- Blood PTH test
Once you are diagnosed with parathyroid cancer, physicians may perform additional imaging tests to determine the extent (stage) of the cancer. In most cases, doctors perform CT (computerized tomography) scans or MRI (magnetic resonance imaging) scans.
Treatment
The primary treatment for parathyroid cancer is surgery to remove the tumor. Check below some procedures often recommended by doctors:
- En bloc resection – During this procedure, surgeons will completely remove the parathyroid glands and the capsule around them. Sometimes, surgeons also need to remove a part of the thyroid gland and the surrounding muscle and nerves. It helps make sure there are no remaining cancerous cells.
- Tumor debulking – In such cases, the surgeons will remove as much of the tumor as possible. In some cases, tumors cannot be removed.
- Metastasectomy – This surgery is often recommended by doctors when the cancerous cells spread to other tissues and organs in the body (such as the lungs).
Furthermore, usually chemotherapy and radiation therapy are not used to treat parathyroid cancer. However, if it spreads to other parts of the body, these treatments may help destroy cancerous cells throughout the body.
In some cases, doctors may also recommend some medicines for hypercalcemia symptoms. For example, Cinacalcet, Bisphosphonates, or Denosumab. In severe cases, people are hospitalized for IV (intravenous) fluids and other treatments.
Frequently Asked Questions
What is the difference between parathyroid cancer and adenoma?
The parathyroid adenoma is a noncancerous growth (tumor) in the parathyroid glands. However, parathyroid cancer occurs when the malignant (cancerous) cells begin to develop in the same glands. In general, parathyroid adenomas occur more commonly than cancer. However, both types of tumors can cause hypercalcemia.
Will my parathyroid cancer come back?
Roughly 50% of people with parathyroid cancer will have recurrence within several years (from 2 to 5 years). Rarely, parathyroid cancer may return even 20 years after surgery.
What are the symptoms of parathyroid cancer?
The symptoms of parathyroid cancer occur because of the overproduction of PTH that causes hypercalcemia. These include weakness, a lump in the neck, extreme tiredness, weight loss, appetite changes, and others. If you have additional questions, ask your healthcare provider.
