What is Parathyroid Cancer?
Parathyroid cancer is a rare disease in which malignant (cancer) cells form in the tissues of a parathyroid gland. Having certain inherited disorders can increase the risk of developing parathyroid cancer.
Anatomy of Parathyroid glands
The parathyroid glands are four pea-sized organs found in the neck near the thyroid gland. The parathyroid glands make parathyroid hormone (PTH or parathormone). PTH helps the body use and store calcium to keep the calcium in the blood at normal levels.
A parathyroid gland may become overactive and make too much PTH, a condition called hyperparathyroidism. Hyperparathyroidism can occur when a benign tumour (noncancerous), called an adenoma, forms on one of the parathyroid glands, and causes it to grow and become overactive. Sometimes hyperparathyroidism can be caused by parathyroid cancer, but this is very rare.
Risk factors of Parathyroid Cancer
Anything that increases the chance of getting a disease is called a risk factor. Risk factors for parathyroid cancer include the following rare disorders that are inherited (passed down from parent to child):
• Familial isolated hyperparathyroidism (FIHP).
• Multiple endocrine neoplasia type 1 (MEN1) syndrome.
Signs and symptoms
Most parathyroid cancer signs and symptoms are caused by the hypercalcemia that develops. Signs and symptoms of hypercalcemia include the following:
- Feeling very tired.
- Nausea and vomiting.
- Loss of appetite.
- Weight loss for no known reason.
- Being much more thirsty than usual.
- Urinating much more than usual.
- Trouble thinking clearly.
Other signs and symptoms of parathyroid cancer include the following:
- Pain in the abdomen, side, or back that doesn’t go away.
- Pain in the bones.
- A broken bone.
- A lump in the neck.
- Change in voice such as hoarseness.
- Trouble swallowing.
Parathyroid cancer may be hard to diagnose because the cells of a benign parathyroid adenoma and a malignant parathyroid cancer look alike. The patient’s symptoms, blood levels of calcium and parathyroid hormone, and characteristics of the tumour are also used to make a diagnosis
- Blood chemistry studies:
A procedure in which a blood sample is checked to measure the amounts of certain substances released into the blood by organs and tissues in the body. An unusual (higher or lower than normal) amount of a substance can be a sign of disease. To diagnose parathyroid cancer, the sample of blood is checked for its calcium level.
- Parathyroid hormone test:
A procedure in which a blood sample is checked to measure the amount of parathyroid hormone released into the blood by the parathyroid glands. A higher than normal amount of parathyroid hormone can be a sign of disease.
- Sestamibi scan:
A type of radionuclide scan used to find an overactive parathyroid gland. A very small amount of a radioactive substance called technetium 99 is injected into a vein and travels through the bloodstream to the parathyroid gland. The radioactive substance will collect in the overactive gland and show up brightly on a special camera that detects radioactivity.
Parathyroid cancer is described as
Localized parathyroid cancer is found in a parathyroid gland and may have spread to nearby tissues.
Metastatic parathyroid cancer
Metastatic parathyroid cancer has spread to other parts of the body, such as the lungs, liver, bone, sac around the heart, pancreas, or lymph nodes.
There are different types of treatment for patients with parathyroid cancer.
Treatment includes control of hypercalcemia (too much calcium in the blood) in patients who have an overactive parathyroid gland.
Four types of standard treatment are used:
- Radiation therapy
In order to reduce the amount of parathyroid hormone that is being made and control the level of calcium in the blood, as much of the tumour as possible is removed in surgery. For patients who cannot have surgery, medication may be used.
Four types of standard treatment are used:
Surgery (removing the cancer in an operation) is the most common treatment for parathyroid cancer that is in the parathyroid glands or has spread to other parts of the body. Because parathyroid cancer grows very slowly, cancer that has spread to other parts of the body may be removed by surgery in order to cure the patient or control the effects of the disease for a long time. Before surgery, treatment is given to control hypercalcemia.
The following surgical procedures may be used:
• En bloc resection: Surgery to remove the entire parathyroid gland and the capsule around it. Sometimes lymph nodes, half of the thyroid gland on the same side of the body as the cancer, and muscles, tissues, and a nerve in the neck are also removed.
• Tumor debulking: A surgical procedure in which as much of the tumor as possible is removed. Even after this procedure, some tumors cannot be completely removed.
• Metastasectomy: Surgery to remove any cancer that has spread to distant organs such as the lung.
- Radiation therapy
Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells or keep them from growing. There are two types of radiation therapy:
• External radiation therapy: It uses a machine outside the body to send radiation toward the cancer.
• Internal radiation therapy: It uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer.
Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping them from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). When chemotherapy is placed directly into the cerebrospinal fluid, an organ, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy). The way the chemotherapy is given depends on the type and stage of the cancer being treated.
The prognosis (chance of recovery) and treatment options depend on the following:
- Whether the calcium level in the blood can be controlled.
- The stage of the cancer.
- Whether the tumor and the capsule around the tumor can be completely removed by surgery.
- The patient’s general health
Patients are able to go home on same day or day after surgery, depending on the overall health and other parameters.