All About Parathyroid Cancer
What is the parathyroid?
The parathyroid is a gland in your neck, behind your thyroid gland. The thyroid gland is at the base of the neck below the thyroid cartilage or “Adam’s apple.” The parathyroid consists of fourglands that are each about the size of a pea. The four glands are split into two groups called the superior parathyroid and the inferior parathyroid. The parathyroid glands produce a hormone called parathyroid hormone-PTH (parathormore) or parathyrin. The parathyroid gland controls the amount of calcium in your blood by producing parathyroid hormone. The calcium in your blood plays an important part in the health of your bones, kidneys, and intestines.
What is parathyroid cancer?
A tumor is a mass of abnormally growing cells. Tumors can be either benign or malignant. Benign tumors have uncontrolled cell growth but are not able to invade normal tissues and cannot spread to other parts of the body. A tumor that is malignant, or cancerous, is able to invade tissues and spread locally, as well as to other parts of the body. A parathyroid mass can be either benign or malignant (cancerous). Parathyroid cancer is a rare malignant (cancerous) tumor that is slow-growing. Parathyroid cancer forms in the tissues of one of the four parathyroid glands.
What causes parathyroid cancer and am I at risk?
The American Society of Clinical Oncology estimates that less than 100 cases of parathyroid cancer are diagnosed in the United States each year. Parathyroid cancer is often diagnosed in people in their 40s and 50s, and men and women are equally affected. The cause of parathyroid cancer is unknown, but there are some risk factors that can increase your chance of getting parathyroid cancer. There are certain inherited disorders (passed down from parent to child) that can increase the risk of developing parathyroid cancer. These are:
- Familial isolated hyperparathyroidism (FIHP).
- Hyperparathyroidism jaw tumor (HPT-JT).
- Multiple endocrine neoplasia type 1 (MEN1) syndrome.
Other risk factors include previous radiation exposure to the neck.
How can I prevent parathyroid cancer?
There is currently no way to prevent developing parathyroid cancer since the cause of the cancer is often unknown.
What screening tests are available?
There is no screening test for parathyroid cancer. However, there are many types of blood and urine test that can be done to find parathyroid gland problems. The most common test used is a serum calcium test. If this blood test shows elevated serum calcium levels it could be a sign of a parathyroid tumor. Another blood test checks for higher levels of parathyroid hormone (PTH) and phosphorus levels. If these blood tests show very high levels of serum phosphorus and/or parathyroid hormone it can be a sign of parathyroid cancer.
What are the signs of parathyroid cancer?
The three main signs of parathyroid cancer are weakness, feeling tired, and a lump in your neck. Hypercalcemia (high calcium in the blood) is the main cause of symptoms which can include:
- Feeling 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:
- 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. You should speak with your provider if you have any of these symptoms.
How is parathyroid cancer diagnosed?
The most commonly used tests to diagnose parathyroid cancer are blood work, a physical exam of the neck, and imaging. The parathyroid glands are sometimes hard to feel while palpating (feeling) the neck during a physical exam due to their small size. Parathyroid cancer can be hard to diagnose, mainly because benign parathyroid adenoma and a malignant parathyroid cancer look alike on an imaging test. Imaging tests alone cannot tell the difference between a benign or malignant mass. Blood work that measures the levels of calcium and parathyroid hormones, and characteristics of the tumor are also used to make a diagnosis.
If your blood work shows elevated levels of PTH, your provider may order a Sestamibi/SPECT scan. A SPECT is a type of CT scan done in the nuclear medicine department. It uses a technology called single proton emission computed tomography. Sestamibi is a radiopharmaceutical, or a protein that has a radioactive particle attached to it. This is injected into the patient’s vein. If abnormal parathyroid tissue is present, it will absorb the material, and the radioactive particle will be visible on the CT scan. Normal parathyroid tissue does not absorb the material which allows the radiologist to tell the difference between a normally functioning parathyroid gland and an abnormal one.
To confirm a diagnosis of any cancer, tissue or cells must be examined by a pathologist. To do this, a biopsy is done. During a biopsy, a needle is inserted into the suspected tumor. Cells are removed and looked at under a microscope by a pathologist. In some cases, the CT scan and/or MRI is so convincing that cancer is present, that the biopsy is done as part of the surgical procedure to remove the parathyroid.
How is parathyroid cancer staged?
After you have been diagnosed with parathyroid cancer, tests will be done to determine if the tumor has spread to other parts of the body. Unlike other cancers, there is no standard staging system for parathyroid cancer. After testing is complete, your team may refer to the cancer as localized (confined to one area) or metastatic (spread to areas away from the original tumor). The common areas of the body that parathyroid cancer spreads to are lung, liver, bone, sac around the heart, pancreas, oandlymph nodes.
How are parathyroid cancers treated?
There are several treatment options available for parathyroid cancer. The type of treatment you receive will depend on the type of parathyroid cancer, if it is localized or metastatic, and any factors that increase the risk of the cancer coming back or spreading.
Surgery is the primary and most effective choice of treatment for parathyroid cancer. There are three types of surgery that may be used to treat parathyroid cancer. A En bloc resection is a surgical technique to remove the entire abnormal parathyroid gland and the capsule around it. In some cases, lymph nodes, half of the thyroid gland on the same side of body as the cancer, muscle, tissue, and nerves in the neck are also removed.
In some cases, the tumor cannot be completely removed. Tumor debulking is a surgical procedure to remove as much of the tumor as possible. If the cancer has spread to other areas of the body, a surgical procedure may be done to remove the tumors in other organs in the body such as the lung.
Your team will talk to you about your best option for surgical treatment. Surgery for parathyroid cancer can sometimes damage the nerves of the vocal cords. If damage to the vocal cords occurs, you may need treatments to help with speech problems caused by this damage.
Radiation is the use of high-energy x-rays to kill the tumor. The type of radiation used for parathyroid tumors is called external beam radiation therapy. This type of radiation is generated from a machine outside of the body. Radiation can be used to treat parathyroid cancer that is localized, metastatic, or recurrent (came back after treatment). You and your care team will decide if radiation is needed for the treatment of your parathyroid cancer.
Chemotherapy is medications that are usually given intravenously (IV, into a vein) or in pill form. Chemotherapy travels through the bloodstream and throughout the body to kill cancer cells. This is one of the big advantages of chemotherapy. Generally, chemotherapy is not used to treat parathyroid cancer because it is not very effective, but in some cases of metastatic and recurrent parathyroid cancer chemotherapy is used when surgery can’t be done. There is no standard chemotherapy regimen used for parathyroid cancer. Though the following chemotherapy medications may be used, either alone or in combination, to treat parathyroid cancers: dacarbazine (DTIC), 5-fluorouracil, cyclophosphamide, methotrexate, doxorubicin, and lomustine.
There are clinical research trials for most types of cancer, and every stage of the disease. Clinical trials are designed to determine the value of specific treatments. Trials are often designed to treat a certain stage of cancer, either as the first form of treatment offered, or as an option for treatment after other treatments have failed to work. They can be used to evaluate medications of treatments to prevent cancer, detect it earlier, or help manage side effects. Clinical trials are extremely important in furthering our knowledge of disease. It is through clinical trials that we know what we do today, and many exciting new therapies are currently being tested. Talk to your provider about participating in clinical trials in your area. You can also explore currently open clinical trials using the OncoLink Clinical Trials Matching Service.
Follow-up Care and Survivorship
Your follow-up care will be determined by your care team and will vary depending upon the type of treatment you had and the stage of cancer. Your provider will tell you how often you need to be seen and when you should have labs and/or imaging done. You will likely need to have blood work done every year to measure blood calcium levels. If blood calcium levels rise, the following tests may be done to investigate further:
- Blood work to check PTH level (parathyroid hormone).
- Blood work to check Vitamin D levels.
- Ultrasound of the neck and/or parathyroid.
- Sestamibi SPECT Scan and/or 4D CT.
Parathyroid cancers often come back after treatment, so it is important to have yearly checkups for the rest of your life so that a recurrence can be detected early.
Fear of recurrence, relationships and sexual health, financial impact of cancer treatment, employment issues, and coping strategies are common emotional and practical issues experience by parathyroid cancer survivors. Your healthcare team can identify resources for support and management of these challenges faces during and after cancer.
Cancer survivorship is a relatively new focus of oncology care. With almost 17 million cancer survivors in the US alone, there is a need to help patients transition from active treatment to survivorship. What happens next, how do you get back to normal, what should you know and do to live healthy going forward? A survivorship care plan can be a first step in educating yourself about navigating life after care and helping you communicate knowledgeably with your healthcare providers. Create a survivorship care plan today at OncoLink.
Resources for More Information
Informative website covering many endocrine disorders, how endocrine organs function, and common tests used.
Cancer Hope Network
Provides one-on-one support to people undergoing treatment for cancer and to their families through training individuals who have recovered from cancer and matching them with cancer patients currently undergoing a similar experience
Cancer Care is the leading national organization providing free, professional support services and information to help people manage the emotional, practical, and financial challenges of cancer.
Canadian Cancer Society. Parathyroid Cancer. 2021.https://www.cancer.ca/en/cancer-information/cancer-type/parathyroid/treatment/?region=on
Cancer.Net. Parathyroid Cancer. 2021. https://www.cancer.net/cancer-types/parathyroid-cancer/introduction
Munson ND, Foote RL, Northcutt RC, Tiegs RD, Fitzpatrick LA, Grant CS, van Heerden JA, Thompson GB, Lloyd RV. Parathyroid carcinoma: is there a role for adjuvant radiation therapy? Cancer. 2003 Dec 1;98(11):2378-84. doi: 10.1002/cncr.11819. PMID: 14635072
National Cancer Institute. Parathyroid Cancer Treatment Professional Version. 2021. https://www.cancer.gov/types/parathyroid/hp/parathyroid-treatment-pdq#_108_toc
National Cancer Institute. Parathyroid Cancer Treatment Patient Version. 2021. https://www.cancer.gov/types/parathyroid/patient/parathyroid-treatment-pdq
NCCN Guidelines Version 2.2020 Neuroendocrine and Adrenal Tumors. 2021. https://www.nccn.org/professionals/physician_gls/pdf/neuroendocrine.pdf (log in required).