Calcitonin Test
About Calcitonin Test
A calcitonin test measures the amount of calcitonin in the blood. Calcitonin is a hormone that regulates the level of calcium in the blood by decreasing it in the body. This hormone is produced by the “C cells” (parafollicular cells) of the thyroid gland, which is a butterfly-shaped gland present in the neck region. Calcitonin is opposite in action to the parathyroid hormone, which is a hormone responsible for increasing calcium levels in the blood.
Typically, a calcitonin test is used to detect or screen for C-cell hyperplasia or medullary thyroid carcinoma.
Calcitonin test is also known as
Thyrocalcitonin, CT, Human calcitonin, hCT
Indications for Calcitonin test
Lump in the front of the neck
Swollen lymph nodes in the neck
Pain in the throat
Difficulty in swallowing or breathing
Change in voice (e.g. hoarseness)
Persistent cough
Diarrhea
When should someone get tested? A calcitonin test can be done for either one of the following cases
For diagnosis and treatment of medullary thyroid cancer (MTC)
For diagnosis of C-cell hyperplasia
In case of a family history of multiple endocrine neoplasia, type 2 (MEN 2) e.g. Conditions like medullary thyroid cancer (MTC)
Test preparation
Anyone who is to undergo a calcitonin test may need to fast (neither eat nor drink) for several hours before the test. Your healthcare provider will inform you if you need to take any special instructions prior to the test.
Interpretation of results
A calcitonin test is usually done to diagnose or screen for C-cell hyperplasia or medullary thyroid cancer. The following is the result interpretation for the above conditions:
|
Reference Group |
Normal range in pg/mL (picograms per milliliter) |
|
Males |
< 8.4 |
|
Females |
< 5.0 |
Normal calcitonin levels indicate that both C-cell hyperplasia and medullary thyroid cancer may be absent. However, these cannot be ruled out completely.
In general, some deviations from the above results may be seen and interpreted as follows:
· Decrease in calcitonin levels, which are still higher than the normal range, indicates that you still have cancer cells in your body and, hence, require more tests and treatment.
· High calcitonin levels indicate that C-cells are making too much calcitonin, which is likely to indicate either of the two conditions. Certain cancers and pregnancy can also cause high calcitonin levels.
· Increase in calcitonin that remains high over time is usually seen in case where cancer has returned or metastasized (spread) to other parts of the body.
· Low calcitonin levels are typically not considered a medical problem.
· Lower calcitonin levels that stay stable over time usually mean that your cancer treatment is working.
FAQs
What happens during a calcitonin test?
A blood sample is taken for conducting the calcitonin test. For this, a small needle may be inserted into a vein in your arm to draw out a small amount of blood. Then the sample is collected into a vial or test tube.
Does the calcitonin test involve any risks?
Calcitonin test does not involve any potential risks to a person. At times, one may feel slight pain or bruising at the site the needle was pricked. These symptoms usually go away with time.
What is a “calcitonin stimulation test” used for?
Sometimes, a blood test is followed by the administration of medicine to produce more calcitonin in the body. This is given intravenously (by IV) into a vein, and more blood samples are taken a few minutes apart. If each blood sample shows a large increase in calcitonin levels, it indicates that you may either have C-cell hyperplasia or medullary thyroid carcinoma. In such cases, your healthcare provider may call for more confirmatory tests.
What’s the difference between calcitonin and calcitriol?
Both calcitonin and calcitriol are hormones that regulate calcium levels. However, both have different effects. While calcitonin decreases blood calcium levels, calcitriol increases blood calcium levels.
Does having too low calcitonin levels indicate a problem?
Low calcitonin levels are generally seen in people who have had their thyroid gland removed. There are no evident negative signs or symptoms as a result of low calcium levels in the blood. Having a low calcitonin level is not considered a medical problem.