Usually this test is used to evaluate patients suspected of having medullary cancer of the thyroid. Up to 75% of these patients have elevated secretion of calcitonin despite having normal blood calcium levels. This test is also used as a screening aid in persons with a family history of thyroid cancer, as a tool to monitor progress of treatment of thyroid cancer. Having a screening calcitonin level can detect thyroid cancer in the early stages while there is good chance for a cure. Also associated with elevated calcitonin levels is C-cell hyperplasia, a benign disease.
In addition to thyroid cancer, elevated calcitonin levels may also be seen in cancers of the lungs, breast, or pancreas. Sometimes levels are elevated in normal pregnant females and in neonates. Other causes for calcitonin elevation include kidney disease, certain medications, thyroid inflammation, primary hyperparathyroidism, anemia, and liver cirrhosis.
A doctor may decide to order the tests if you are having symptoms of a problem such as a lump or swelling at the front of the neck, throat pain or frontal neck pain, hoarseness or voice changes, difficulties with breathing or swallowing, or unexplained cough. Recent studies also suggested that the test should be performed prior to surgery in all patients with thyroid nodules; however, this is controversial.
