Overview Parathyroid cancer is a rare disease in which malignant (cancer) cells form in the tissues of a parathyroid gland.
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 tumor (noncancer), 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.
The extra PTH causes:
• The calcium stored in the bones to move into the blood. • The intestines to absorb more calcium from the food we eat.
This condition is called hypercalcemia (too much calcium in the blood).
The hypercalcemia caused by hyperparathyroidism is more serious and life-threatening than parathyroid cancer itself and treating hypercalcemia is as important as treating the cancer.
Symptoms Most parathyroid cancer symptoms are caused by the hypercalcemia that develops. Symptoms of hypercalcemia include the following:
• Weakness. • 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. • Constipation. • Trouble thinking clearly.
Other 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.
Other conditions may cause the same symptoms as parathyroid cancer. Consult a doctor if any of these problems occur.
Treatment Different types of treatment are available for patients with parathyroid cancer. Some treatments are standard (the currently used treatment, often referred to as “standard of care”), and some are being tested in clinical trials. A treatment clinical trial is a research study meant to help current treatments or obtain information on new treatments for patients with cancer. When clinical trials show that a new treatment is better than the standard treatment, the new treatment may become the standard treatment. Patients may want to think about taking part in a clinical trial. Some clinical trials are open only to patients who have not started treatment.
Four types of standard treatment are used:
Surgery 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: Surgery to remove as much of the tumor as possible. Sometimes, not all of the tumor can be removed. • Metastasectomy: Surgery to remove any cancer that has spread to distant organs such as the lung.
Surgery for parathyroid cancer sometimes damages nerves of the vocal cords. There are treatments to help with speech problems caused by this nerve damage.
Radiation therapy Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells or stop them from growing. There are two types of radiation therapy. External radiation therapy uses a machine outside the body to send radiation toward the cancer. Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer. The way the radiation therapy is given depends on the type and stage of the cancer being treated.
Chemotherapy 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 spinal column, 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.
Supportive care Supportive care is given to lessen the problems caused by the disease or its treatment. Supportive care for hypercalcemia caused by parathyroid cancer may include the following:
• Intravenous (IV) fluids. • Drugs that increase how much urine the body makes. • Drugs that stop the body from absorbing calcium from the food we eat. • Drugs that stop the parathyroid gland from making parathyroid hormone.