Overview

Cancer occurs when cells in the body become abnormal and start to multiply without control or order. These cells form a growth of tissue, called a tumor. A tumor can be benign (noncancerous) or malignant (cancerous, meaning it can spread to other parts of the body). A parathyroid tumor begins in one of four small glands, called the parathyroid glands. These glands are located in the neck near the thyroid gland and are part of the endocrine system. The endocrine system regulates the hormones in the body.

Like all parts of the endocrine system, the parathyroid glands play an important role in the body. These glands make parathyroid hormone (PTH), which regulates the levels of calcium and phosphorus in the blood. When a parathyroid tumor occurs, whether it is benign or malignant, it can cause significant effects because the amount of calcium in the blood rises, called hypercalcemia.

Statistics

Parathyroid cancer is quite rare. Most tumors starting in the parathyroid gland are benign, with parathyroid cancer accounting for less than 100 cases per year in the United States. Men and women are equally affected by parathyroid cancer, which generally occurs in middle age.

Researchers have estimated that the 10-year survival rate (the percentage of people who survive at least ten years after the cancer is detected, excluding those who die from other diseases) has increased from about 49% to 77% mainly due to improved prevention of complications from elevated levels of calcium in the blood.

Cancer survival statistics should be interpreted with caution. These estimates are based on data from thousands of cases of this type of cancer in the United States, but the actual risk for a particular individual may differ. It is not possible to tell a person how long he or she will live with parathyroid cancer. Because the survival statistics are measured in ten-year (or sometimes one-year) intervals, they may not represent advances made in the treatment or diagnosis of this cancer.

Sources: American Cancer Society, National Cancer Institute.

Find out more about basic cancer terms used in this section.