Parathyroid cancer: What you need to know

Parathyroid cancer is quite rare, can be dangerous to the patient's health if treated late. Currently, there are many methods to help treat parathyroid cancer that patients can choose from, such as surgery, chemotherapy, radiation therapy, supportive care, ...

The parathyroid gland is located behind the thyroid gland, consisting of 4 pea-sized regions. These 4 regions are divided into 2 main groups, including the superior parathyroid glands and the inferior parathyroid glands. These glands are responsible for the production of the hormone Parathormone (PTH) or Parathyrin, and help control blood calcium levels, which are essential for kidney, bone, and gut health.
When you have parathyroid cancer, cancer cells will grow abnormally in this gland, which can produce benign or malignant tumors. Benign tumors have uncontrolled growth of cells, but are not able to invade normal tissues or metastasize to other organs. In malignant parathyroid tumors, the cancer can invade tissues and spread locally, or even metastasize, to distant sites in the body.
Malignant parathyroid tumors are rare and slow growing. In general, parathyroid cancer can form in the tissues of 1 of 4 parathyroid glands.

Parathyroid cancer is usually diagnosed in people between the ages of 40 and 50, with an equal degree of impact on both men and women. Currently, the cause of parathyroid cancer is still unknown, however there are a number of risk factors that increase the likelihood of this type of cancer, including:
Presence of an enlarged jaw tumor parathyroid glands (HPT-JT). Isolated familial hyperparathyroidism (FIHP). Multiple endocrine neoplasia type 1 (MEN1). Radiation exposure in the neck.

There are 3 main signs of parathyroid carcinoma, including weakness, fatigue, and a lump in the neck. Increased calcium in the blood is the main cause of the above symptoms, along with a number of other symptoms that patients may experience such as:
Weakness and fatigue. Nausea, vomiting. Loss of appetite. Unexplained weight loss. Increased frequency of urinating more than usual. Constipation . Thought disorder. In addition, patients with parathyroid cancer may also have the following other signs:
Pain in the side, abdomen or back that does not seem to go away. There is a tumor in the neck. Fracture . Pain in the bones. Voice changes (eg hoarseness). Difficulty swallowing.

The most commonly used testing modalities in diagnosing parathyroid cancer are a physical exam of the neck, imaging tests, and blood tests. Parathyroid tumors are sometimes difficult to feel when palpated in the neck during physical examination because of their small size.
In general, parathyroid cancer is quite difficult to diagnose, mainly because benign and malignant parathyroid adenomas look relatively similar on imaging tests. Imaging tests alone will not be able to distinguish if this is a benign or malignant parathyroid tumor. At that time, blood tests that measure calcium and parathyroid hormone levels as well as evaluation of tumor characteristics will be used to make a diagnosis.
If the blood test results show elevated PTH levels, the doctor may recommend the patient to have a Sestamibi/SPECT (the type of CT scan done in the nuclear medicine department). In this method, single Proton emission computed tomography is used. Meanwhile, a Sestamibi scan is a radiopharmaceutical or a radioactive bead-binding protein. This substance will be injected into the patient's vein, when abnormal parathyroid tissue is detected, it will absorb the material and show up the radioactive particles on the CT scan. Normal parathyroid tissue will not absorb material, which helps doctors distinguish between normal and abnormal parathyroid glands.
To diagnose any type of cancer, tissue or cells need to be examined by a pathologist through a biopsy. During the biopsy, cells from the suspected tumor are removed and examined under a microscope. In cases where an MRI or CT scan shows the presence of cancer, a biopsy will be done as part of a surgical procedure to help remove the parathyroid gland.

Unlike other cancers, parathyroid cancer does not have a standard staging system. After diagnostic tests are performed, the cancer can be considered as localized or metastatic, specifically:
Localized: Cancer is found in the parathyroid glands and may have spread to tissues near the glands . Metastasis: Parathyroid cancer has spread to other parts of the body, such as the liver, bones, lungs, pancreas, glands around the heart, or nodes.

Many patients wonder whether parathyroid cancer is curable? In fact, there are many treatment options for this type of cancer, and the type of treatment a patient receives will depend on the type of parathyroid cancer and risk factors for recurrence or spread.
6.1. Treatment of parathyroid cancer with surgery Surgery is the main and most effective option for patients with parathyroid cancer. There are currently 3 types of surgery used in the treatment of parathyroid cancer, including:
Tumor resection: Removal of the entire abnormal parathyroid gland and the cysts around it. Sometimes the lymph nodes, half of the thyroid gland on the same side of the body as the cancer, and tissues, muscles, and nerves in the neck are also removed. Tumor surgery: Used in cases where the parathyroid tumor cannot be completely removed. Tumor surgery removes as much of the tumor as possible. Removal of tumors in other organs: Used when cancer has spread to other areas of the body, such as the lungs. Patients should talk to their doctor about the best surgical option for them to get the most out of their treatment. In many cases, surgery for parathyroid cancer can damage the nerves of the vocal cords. When this damage occurs, the patient may need treatment with methods to help address the voice problems caused by this sequelae.
6.2. Radiation therapy for patients with parathyroid cancer The radiation used in the treatment of parathyroid cancer is usually external radiation. This type of radiation, generated from a machine outside the body, is mainly used to treat localized, metastatic, or recurrent parathyroid cancer after treatment.
6.3. Chemotherapy for parathyroid cancer Chemotherapy is the use of drugs in pill form or given intravenously (IV). Chemotherapy goes into the bloodstream and throughout the body to destroy cancer cells. This is considered a major advantage of chemotherapy. However, this method is not usually recommended for the treatment of parathyroid cancer because it is not very effective. However, in some patients with metastatic and recurrent parathyroid cancer, chemotherapy is still used if surgery is not possible.
Currently there is no standard chemotherapy regimen for parathyroid cancer . Chemotherapy drugs that can be used alone or in combination include: Cyclophosphamide, Dacarbazine (DTIC), Methotrexate, 5-fluorouracil, Lomustine, or Doxorubicin.
6.4. Clinical trials in the treatment of parathyroid cancer Clinical trials can be helpful for most cancers and all stages of disease. Clinical trials are designed to help doctors determine the value of a particular treatment for parathyroid cancer.
In general, clinical trials will be designed to treat a certain stage of cancer and be considered a first-line treatment or treatment option after other methods have failed . They are also used to evaluate therapeutic drugs that help prevent cancer, detect disease earlier, and control side effects. Therefore, clinical trials are extremely important in increasing our knowledge about diseases.
6.5. Supportive care for patients with parathyroid cancer Supportive care is a treatment used to help manage calcium levels in the body, including:
Intravenous fluids . The medicine helps to make more urine. The drug prevents the body from absorbing too much calcium from food. Medicines that stop the parathyroid gland from making too much hormone. In general, parathyroid cancer is difficult to diagnose, but there are many treatment options, depending on the type of parathyroid cancer and risk factors for recurrence or spread.

Reference source: oncolink.org