There are 4 small parathyroid glands. They are attached to the thyroid gland in the front of the neck. The thyroid gland and the parathyroid glands are close to each other and have similar names, but they are different and do different things.
We have information about thyroid cancer, which is a different type of cancer and is treated differently.
The parathyroid glands are part of the endocrine system. This system makes hormones that help to control the way your body works.
The parathyroid glands make parathyroid hormone (PTH). This helps control calcium levels in the blood. Calcium helps your muscles and nerves work, builds strong bones and helps your blood to clot.
Most of the calcium in the body is stored in the bones. PTH makes the bones release calcium into the blood. When calcium levels in the blood are high, the parathyroid glands produce less PTH and calcium levels drop.
Most people with parathyroid cancer (about 9 in 10) make too much PTH. This causes high levels of calcium in the blood (hypercalcaemia).
Common symptoms of hypercalcaemia include:
- feeling thirsty and passing a lot of urine
- feeling sick or being sick (vomiting)
- changes in mood – feeling low, depressed, irritable or nervous
- pain in the tummy or back
- loss of appetite
- muscle weakness.
Untreated hypercalcaemia can cause bone thinning, due to the bones losing calcium. This can lead to bone damage, including broken bones (fractures) and pain.
High calcium levels in the blood can affect the kidneys. Some people develop kidney stones, or their kidneys may become damaged and not work as well.
Rarely, people with parathyroid cancer have a lump or swelling in their neck. This can sometimes cause difficulty swallowing and a hoarse voice.
We don’t know what causes parathyroid cancer in most people. But people who have genetic conditions such as multiple endocrine neoplasia 1 (MEN1) or familial hyperparathyroidism have a higher risk of parathyroid cancer. These are rare conditions caused by a gene change (mutation) passed on from parent to child (inherited).
People who have had radiotherapy treatment to their neck area have an increased risk of developing non-cancerous (benign) parathyroid tumours. They may also have an increased risk of developing cancer of the parathyroid gland.
You usually start by seeing your GP, who will examine you and ask about your symptoms and general health. Your GP may arrange tests. If they are unsure what the problem is, or think that your symptoms could be caused by cancer, they will refer you to a hospital for specialist advice and treatment.
Sometimes it can be difficult to diagnose parathyroid cancer before an operation to remove the tumours in the parathyroid glands. This is because the symptoms can be similar to those caused by non-cancerous tumours.
Parathyroid cancer is sometimes diagnosed following a routine blood test, and you may have no symptoms at all. If the blood test shows a high calcium level, it may suggest a parathyroid tumour.
Tests for parathyroid cancer may include the following.
Blood and urine tests
Samples of blood and urine will be taken to check your calcium and PTH levels. For the urine test, your doctor may ask you to collect all the urine you pass in 24 hours. For some blood tests, the doctor will ask you to not eat (to fast) overnight before they take the sample. You should follow any instructions carefully to get clear results.
An ultrasound scan uses sound-waves to build up a picture of the parathyroid glands and other structures inside the neck.
You will be asked to lie on your back for the scan. Once you are lying comfortably, the person doing the scan spreads a gel over your neck. Then they move a small hand-held device like a microphone around your neck area. A picture of the inside of your neck shows up on a screen. An ultrasound only takes a few minutes and is painless.
Parathyroid scan (sestaMIBI scan)
This scan shows the size and position of the parathyroid glands, and any abnormal areas. To have this scan, you visit the hospital scanning department twice on the same day.
Before the scan, you have an injection of a radioactive substance (called sestaMIBI). The radiation dose is low and very unlikely to harm you. But always tell your doctor or staff in the scanning department before the scan if:
- you are, or think you could be, pregnant
- you are breastfeeding.
The person doing the scan injects the radioactive substance into a vein in your arm. Then you wait for about 10 minutes for your parathyroid glands to absorb the substance. After this, a camera that can detect radioactivity (a gamma camera) moves around your head and takes pictures of your neck. You need to lie still for about 40 minutes while this happens. Tell your doctor or the staff doing the scan if:
- you think you might not be able to lie still
- you find it difficult to be in closed-in spaces (claustrophobia).
After the first part of the scan, you can leave the scanning department. Then you go back after three hours to have more pictures taken of your neck. This may take 30 to 40 minutes.
If you are taking thyroid medications, you may need to stop taking them before you have the scan. Your doctor will advise you about this.
You should avoid close contact with pregnant women and very young children for 24 hours after this test. This is because your body will release a small amount of radioactivity. The staff doing the test can tell you more about this.
You may have further tests to see if there are signs the cancer has spread outside the parathyroid glands.
CT (computerised tomography) scan
MRI (magnetic resonance imaging) scan
PET (positron emission tomography) scan
Staging describes if the cancer has spread from where it first started to other parts of the body.
Parathyroid cancer is staged as localised or metastatic:
- Localised parathyroid cancer is in a parathyroid gland and may have spread to nearby tissues such as the thyroid, gullet (oesophagus), the nerve for the voicebox (laryngeal nerve), or nearby muscle.
- Metastatic parathyroid cancer is also called secondary or advanced cancer. It means it has spread to other parts of the body, such as the lymph nodes, lungs, liver or bones.
The treatment you have will depend on the stage of the cancer and your general health.
Surgery is the main treatment for parthyroid. It is often the only treatment needed. Surgery can also be used to treat cancer that comes back again, or if the cancer spreads to other areas of the body.
We have more information about surgery for parathyroid cancer.
Radiotherapy uses high-energy rays to destroy cancer cells. Radiotherapy for parathyroid cancer is sometimes used:
- after surgery to reduce the risk of the cancer coming back
- if the cancer comes back (recurs).
You will need to have a mould or mask made before your treatment is planned. This is to keep your head still while you have your treatment.
You may develop side effects during radiotherapy to the neck. These can include:
- pain when swallowing
- a dry mouth or throat
- taste changes
- dark or red sore skin
- a hoarse voice
- tiredness (fatigue).
Your doctor, specialist nurse or radiotherapist will discuss any possible side effects with you before you start your treatment.
This treatment uses anti-cancer (cytotoxic) drugs to destroy cancer cells.
Chemotherapy is rarely used to treat parathyroid cancer, but may be used if surgery isn’t possible. Your doctor or specialist nurse will give you more information.
Research trials are done to try to find new and better treatments for cancer. Because parathyroid cancer is rare, it is difficult to research new treatments. Ask your doctor or specialist nurse if there are any clinical trials suitable for you.
ClinicalTrials.gov is a website that has up-to-date international clinical trials, including UK trials.
Treatments for hypercalcaemia
If the levels of calcium in your blood are high (hypercalcaemia), you will need treatment to control this. Some people stay in hospital for a short while to have a drip (infusion) into a vein to prevent dehydration and drugs to lower the calcium levels. You may need to take medicines for a longer time to keep your calcium levels stable.
You may have treatment to lower your calcium levels:
- before surgery to remove a parathyroid cancer
- if the cancer has spread
- if the cancer cannot be removed with surgery.
You may have the following drugs.
Most of the calcium in the body is stored in the bones. Bisphosphonates are drugs that stop the bones releasing calcium into the blood.
Some types of bisphosphonate are given as a drip into a vein. You can have this treatment as an outpatient. It takes 15 to 60 minutes and you usually have it every 3 to 4 weeks.
You can also take bisphosphonates as tablets or capsules. If you are prescribed these, your doctor, specialist nurse or pharmacist will explain how you should take them.
Denosumab is a type of cancer drug called a monoclonal antibody. Monoclonal antibodies are also called targeted therapies, because they work by ‘targeting’ specific proteins that are either produced by cells or found on the surface of cells (receptors).
Denosumab is used to lower calcium levels and to prevent bones breaking (fractures) in people with advanced cancer.
Denosumab is given as an injection, just under the skin (subcutaneous injection).
Drugs that reduce parathyroid hormone production
These drugs work by reducing the amount of parathyroid hormone (PTH) made in the body. PTH makes the bones release calcium into the blood. The most common drug of this type is a tablet called cinacalcet (Mimpara®). Your doctor, specialist nurse or pharmacist will give you more information. They will tell you how often you should take the tablets and how often you should get your calcium and PTH levels checked.
You have this drug as an injection under the skin (subcutaneously) or into a muscle. You usually have it every 6 to 8 hours. If the level of calcium in your blood is very high, you may have calcitonin as a drip (infusion). It is given over six hours during a short stay in hospital.
You will have regular check-ups and blood tests after your treatment has finished. These will probably continue for several years. Because parathyroid cancer is rare, you will usually be followed up by a specialist endocrinology team.
If you have any problems or notice any symptoms between check-ups, let your doctor or specialist nurse know as soon as possible.