Hyperparathyroidism is a medical condition characterized by abnormal blood calcium and parathyroid hormone (PTH) levels. This serious but treatable disease is sometimes associated with different cancers. Understanding the link between hyperparathyroidism and cancer is critical to ensuring correct diagnosis and treatment.
Is Hyperparathyroidism Linked to Cancer?
Studies have linked hyperparathyroidism (HPT) and different cancers, including breast, prostate, thyroid, and kidney cancer. This link should be a consideration for physicians who diagnose either disease, prompting them to look for both diseases after diagnosing one in some cases. The specific cause-and-effect requires further study to understand whether hyperparathyroidism leads to hyperparathyroidism cancer or if cancer leads to a higher prevalence of HPT.
Causes of Hyperparathyroidism
The four tiny parathyroid glands are behind the thyroid gland. A benign tumor (adenoma) can form in one or more parathyroid glands, causing the gland to release excess amounts of PTH. Additional PTH leads to elevated calcium levels in the bloodstream, affecting many body organs and systems. An adenoma will continue to grow, while the normal parathyroid glands will stop functioning and may even shrink over time.
In most cases, an adenoma is the primary cause of hyperparathyroidism. Hyperplasia, an abnormal growth in all parathyroid glands, is another cause. Kidney disease, vitamin D deficiency, or other medical conditions may lead to parathyroid hyperplasia.
Parathyroid cancer can also cause hyperparathyroidism, although it only occurs in less then 0.5% of all cases. A malignant tumor forms on one of the parathyroid glands instead of a benign adenoma. Cancer symptoms are similar to those of hyperparathyroidism, however, the laboratory values (calcium & PTH) quickly elevate in the parathyroid cancer cases. Correctly assessing the affected parathyroid gland will identify the malignancy.
While it is difficult to predict who might develop parathyroid cancer, certain risk factors contribute to this disease:
- Hyperparathyroidism-Jaw Tumor Syndrome is a condition that can lead to benign and malignant tumors.
- Multiple Endocrine Neoplasia Type 1 (MEN1) is a rare genetic disorder affecting the endocrine glands.
- Familial Isolated Hyperparathyroidism (FIHP) is a rare hereditary disorder that affects cell growth and division.
When a patient is diagnosed with hyperparathyroidism due to parathyroid cancer, the treatment for the cancer is often more extensive then treating hyperparathyroidism. An expert surgeon removes the affected parathyroid gland, the thyroid gland on that side and the adjacent lymph nodes. This cancer has the best prognosis when it is diagnosed and treated in the early stages. Often, symptoms of hyperparathyroidism bring the patient to a physician, who then diagnoses both conditions using similar imaging tools.
Hyperparathyroidism and Cancer Risk
A recent review studying hyperparathyroidism and cancer found hyperparathyroidism was linked to an approximately 28% increased risk of malignant neoplasm. A malignant neoplasm (or cancerous tumor) is an abnormal mass of tissue that can invade into nearby tissues and spread to other parts of the body.
Another study published in the journal Endocrinology and Metabolism found a high prevalence of papillary thyroid cancer in patients with primary and secondary hyperparathyroidism. Papillary thyroid cancer is the most common type of thyroid cancer. Most form in one lobe of the thyroid and respond well to treatment, although some can spread to neck lymph nodes and other areas of the body.
Finally, a study in the European Journal of Internal Medicine connected hyperparathyroidism and cancer risk. Researchers looked at neoplasia in patients with osteoporosis or hypercalcemia, discovering the incidence of breast, kidney, and skin cancer was statistically higher in patients with hyperparathyroidism. While PTH may play a role, researchers are unsure of exactly how PTH might contribute to cancer development.
Association of Hyperparathyroidism and Thyroid Cancer
Thyroid cancer is one of the most common cancers, specifically papillary thyroid cancer. This type of thyroid cancer is most often slow growing and have a low tendency to spread; having said that a small proportion of patients have aggressive variants that can invade the surrounding tissue and spread rapidly. Majority of these cancers are found incidentally when a scan is done for other reasons, such as MRI of neck for spine issues, or a carotid ultrasound. So most of the cases are smaller tumors found to be contained inside the thyroid gland.
Similarly, when patients are being examined for hyperparathyroidism and undergo imaging studies ultrasound, or CT scan thyroid nodules may be found that are suspicious. Ultrasound is by far the best imaging study for the thyroid gland because it can tell you if a nodule (a lump in the thyroid) appears suspicious (minority of cases) or very benign appearing (majority of cases). If the lesion is suspicious a needle biopsy can be done to determine if the nodule is cancerous or not.
So in summary, in a minority of patients with hyperparathyroidism when the patient undergoes imaging study to identify which parathyroid is abnormal a thyroid cancer may be identified (at an earlier stage, before it gets big and spreads). And it can be surgically managed at the same time as Parathyroidectomy.
Hyperparathyroidism has been associated with a slight increase in thyroid cancer in some studies, but is not clear that is a true association or if it is becasue the thryoid is also examined and the thryoid cancer is identified more often.
Recognizing Symptoms of Hyperparathyroidism
Since hyperparathyroidism can potentially lead to other cancers, it is important that you and your physicians first identify if you have hyperparathyroidism, and then be more diligent in looking for these potential cancers. Especially because if they are caught at an earlier stage, cure will be easier and more likely to be achieved. Common symptoms of hyperparathyroidism include:
- Ongoing fatigue
- Memory loss or forgetfulness
- Concentration and focus issues
- Bone, joint, or muscle pain
- Stomach aches and constipation
- Frequent urination
- Difficulty sleeping
Parathyroid cancer often presents with similar symptoms but might also include a loss of appetite and weight loss for no known reason. But the laboratory values for calcium and PTH are either very elevated or rise up at an alarming rate.
If you experience any of these symptoms, schedule an appointment with a physician specializing in the parathyroid for a full assessment.
Treatment for Hyperparathyroidism and Cancer
If you suspect hyperparathyroidism, with or without cancer, contact a parathyroid specialist like Dr. Babak Larian. Dr. Larian is a board-certified otolaryngologist and director of the CENTER for Advanced Parathyroid Surgery. He specializes in diseases of the parathyroid, including cancer, and performs an innovative, minimally invasive parathyroidectomy to treat many parathyroid conditions.
Dr. Larian can also help patients with thyroid or other cancer types. Because he treats each patient individually, he takes the time to note all a patient’s symptoms to diagnose hyperparathyroidism or related diseases. To learn more, contact Dr. Larian at 310-461-0300 or online, or book your consultation now.
