Parathyroid Cancer

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What is parathyroid cancer? 

Parathyroid cancer is a type of cancer that affects the parathyroid glands. Parathyroid glands are small endocrine glands located near or attached to the thyroid glands in the neck. These glands play an essential role in regulating calcium levels in the body by secreting parathyroid hormone (PTH). 

Parathyroid hormone (PTH) balances calcium levels in the body by stimulating calcium release from bones, increasing calcium absorption in the intestines, and minimising calcium loss in the kidneys. 

When cells within one or more of the parathyroid glands start to grow uncontrollably, they may become cancerous, ultimately causing parathyroid cancer. Parathyroid cancer can result in excessive production of the parathyroid hormone, which raises the calcium levels in the blood—a condition known as hypercalcaemia

thyroid and parathyroid glands 
Parathyroid glands, located in the neck, regulate calcium levels by producing parathyroid hormone (PTH).

What causes parathyroid cancer? 

The exact causes of most parathyroid cancer are not yet fully understood. However, recent advances in medical research have progressed on how specific DNA changes can trigger the development of cancerous cells within the parathyroid gland. DNA influences both your physical traits and your susceptibility to certain diseases, including cancer.

Key genetic factors can include:

  • Oncogenes: oncogenes facilitate uncontrolled cell growth and division.
  • Tumour suppressor genes: tumour suppressor genes are responsible for slowing down cancer cell division or prompting them to die at the right time.

The exact cause of these genetic changes that result in parathyroid cancer is not fully understood, and it is considered a rare disease. While the specific triggers for parathyroid cancer are not known, some risk factors have been identified, though they may not be definitively linked to the development of the disease. 

What are the symptoms of parathyroid cancer? 

As parathyroid cancer is a rare condition, its symptoms can vary from one individual to another. Some individuals with parathyroid cancer may not experience noticeable symptoms in the early stages, while others may have more pronounced symptoms. 

The most common symptom of parathyroid cancer is the overproduction of parathyroid hormone (PTH), which leads to abnormally high levels of calcium in the bloodstream, a condition known as hypercalcaemia. Symptoms of hypercalcaemia can include:

  • Fatigue: feeling unusually tired or weak.
  • Weakness: experiencing muscle weakness, especially in the legs and arms.
  • Frequent urination: an increased need to urinate, often with large amounts of urine.
  • Excessive thirst: feeling very thirsty (polydipsia).
  • Kidney stones: kidney stones due to increased calcium levels in the blood. 
  • Bone pain: patients with parathyroid cancer may experience pain or discomfort in the bones, joints, or back.
  • Gastrointestinal issues: nausea, vomiting, constipation, or abdominal pain are common symptoms of hypercalcaemia. 
  • Mental and emotional symptoms: cognitive changes, confusion, irritability, or depression, which may be more common in severe cases of hypercalcaemia.

It is important to note that other medical conditions can also cause these symptoms, so experiencing one or more symptoms does not necessarily indicate parathyroid cancer. 

Hypercalcaemia can result from various causes, including benign parathyroid tumours (parathyroid adenomas) or primary hyperparathyroidism (link to service page), which are much more common than parathyroid cancer. 

If you suspect you have symptoms of parathyroid cancer or are concerned about your parathyroid health, consult with an endocrinologist for a proper evaluation and diagnosis.

Is parathyroid cancer painful?

Parathyroid cancer itself may not be typically painful. However, the symptoms associated with the disease, particularly hypercalcaemia resulting from the overproduction of parathyroid hormone (PTH), may cause discomfort or pain. 

These symptoms include bone pain from calcium removal, kidney stones, abdominal pain from gastrointestinal issues, muscle weakness, and, in severe cases, cognitive changes and emotional disturbances. While parathyroid cancer may not directly cause pain, its associated complications can lead to various forms of discomfort. 

Who is at risk of parathyroid cancer in Singapore? 

Parathyroid cancer is rare, and its exact causes and risk factors are not yet fully understood. Most cases of parathyroid cancer appear to be sporadic, with no apparent identifiable risk factors. 

However, potential risk factors that can make an individual somewhat more susceptible to hypercalcaemia or parathyroid cancer include: 

  • Hereditary conditions: people with certain genetic syndromes, such as multiple endocrine neoplasia type 1 (MEN1) and the hyperparathyroidism-jaw tumour syndrome, may be more susceptible to parathyroid tumours, including parathyroid cancer.
  • Radiation exposure: individuals who have undergone head or neck radiation may be more susceptible to the condition. 
  • Gender and age: parathyroid cancer is more commonly diagnosed in women than in men. It also tends to occur more frequently in individuals over 30, with the highest incidence in those aged 50 to 60.
  • Previous benign parathyroid tumours: in some cases, individuals with benign parathyroid tumours, such as parathyroid adenomas, may be more susceptible to parathyroid cancer. However, the majority of people with benign parathyroid tumours do not develop cancer.

It is essential to note that the majority of parathyroid disorders are non-cancerous, and parathyroid cancer is a rare condition. Also, most cases of hyperparathyroidism are due to benign parathyroid tumours or other non-cancerous causes. 

How is parathyroid cancer diagnosed? 

Your endocrinologist may use a combination of medical tests to assess your parathyroid glands and confirm the diagnosis of parathyroid cancer. The common methods for diagnosis include: 

  • Detailed physical examination and medical history: your endocrinologist will review your complete medical history and conduct a detailed physical examination. They will inquire about your family’s medical history, risk factors, and symptoms that you are experiencing. 
  • Blood tests: blood tests may be recommended for monitoring the calcium levels in your blood and parathyroid hormone to check for hypercalcaemia, a common symptom of parathyroid disorders, including parathyroid cancer. 
  • Imaging studies: imaging studies may be conducted to confirm the diagnosis.
    • Ultrasound: a neck ultrasound may be performed to evaluate the parathyroid glands and assess their size and characteristics. 
    • Computed tomography (CT) or magnetic resonance imaging (MRI): these imaging techniques may be conducted for more detailed images of the parathyroid glands and to confirm if any tumours or abnormalities are present.
    • Technetium sestamibi scan: this nuclear medicine scan can be utilised to identify abnormal parathyroid tissue or tumours. 
    • SPECT scan (single photon emission computed tomography scan): sometimes, a SPECT/CT scan is used to assess if malignant tumour cells are present in the neck. 
    • Biopsy: in case the imaging studies confirm the presence of a suspicious parathyroid mass, your rheumatologist will perform a biopsy to collect a tissue sample for examination to confirm whether cancerous cells are present in the parathyroid gland.
  • Pathology examination: the tissue sample obtained from the biopsy will be sent for examination and analysed to determine if it contains malignant (cancerous) cells, which is crucial for confirming the diagnosis of parathyroid cancer.
diagnosing parathyroid cancer
An MRI provides detailed images of the parathyroid glands that can help find tumours or abnormalities.

Once a diagnosis of parathyroid cancer is confirmed, further evaluation and staging may be required to determine the extent of the disease and plan appropriate treatment.

What are the treatment options for parathyroid cancer in Singapore? 

The primary treatment for parathyroid cancer includes surgical removal of the cancerous parathyroid gland(s) and surrounding tissues. The goal of surgery is to eradicate the cancer and, if necessary, any nearby lymph nodes that may be affected. 

The stage and specific characteristics of the cancer will determine the extent of the surgical procedure. Treatment options for parathyroid cancer may include:

  • Surgery: surgery may involve removing the cancerous parathyroid gland along with the attached thyroid gland and any surrounding lymph nodes and tissues that are affected. Examples of parathyroid surgery include focused parathyroid surgery for image localised tumours (link to service page). In case the cancer has spread to nearby lymph nodes, the surgeon will remove them during the surgery. Tumour debulking helps remove as much tumour as possible in cases where removing all of the tumour may not be possible. In some rare cases, metastasectomy may be performed to remove any cancer that has spread to distant organs such as the lungs.
  • Radiation therapy: radiation therapy is typically used as adjuvant therapy, specifically for cancers that have progressed to higher stages, and their complete removal is not an option. It may also be recommended in some cases, either before or after surgery, to target any remaining cancer cells or reduce the risk of recurrence. 
  • Long-term medical management: after surgery, the patient will be regularly monitored. Your endocrinologist may also recommend medications, dietary changes, and regular monitoring to prevent hypercalcaemia (elevated blood calcium levels).

Parathyroid cancer is very rare, and treatment will be individualised to each patient's unique circumstances. The choice of treatment usually depends on factors such as the stage of cancer, the location and size of the tumour, whether it has spread to other areas, and the overall health condition of the patient.

If you are suffering from a parathyroid disorder, have a family history of parathyroid disorders, or are concerned about developing parathyroid cancer, schedule an appointment with ACE Surgery and Endoscopy for a detailed examination and individualised treatment plan. 

Frequently Asked Questions

Can parathyroid cancer be prevented or avoided?

Parathyroid cancer's exact cause is not well understood, and prevention strategies are not established. Regular health check-ups and early detection may improve the symptoms and the treatment outcomes. 

Is parathyroid cancer hereditary, and should I be concerned about my family's risk?

While parathyroid cancer is rare, there may be a genetic component in some cases. If you have a family history of parathyroid disorders, get yourself examined by an endocrinologist .

What follow-up care is recommended after treatment for parathyroid cancer?

After treatment, patients may require regular check-ups and blood tests to monitor calcium levels. Long-term follow-up is important to detect any recurrence or complications associated with hypercalcaemia.

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Reyaz Moiz

Dr Reyaz Singaporewalla
Senior Consultant Endocrine and General Surgeon

MBBS (Bom), MS (Surg), DNB (Surg), FRCS (Edin), MMed (Singapore), FRCSEd.