Calcitonin Test- Why am I having this test?
Calcitonin test is done for the purpose of:
- Diagnosing or checking for the presence of medullary cancer of the thyroid.
- Monitoring your response to treatment for medullary cancer of the thyroid.
- Predicting whether this type of cancer will return (recur) after treatment.
- Screening for medullary cancer in people with a family history of this type of cancer.
What is being tested?
This test measures the amount of calcitonin in your blood. Calcitonin is a hormone that is produced (secreted) by the thyroid gland.
What kind of sample is taken?
A blood sample is required for this test. It is usually collected by inserting a needle into a blood vessel.
In some cases, more than one blood sample will be collected—one before and one after you receive a pentagastrininjection or calcium infusion. This is done if your health care provider has a high suspicion for medullary cancer of the thyroid, but your blood calcitonin levels are normal or only slightly elevated (equivocal). Pentagastrin injection and calcium infusion both cause the calcitonin level to rise significantly.
How do I prepare for this test?
Do noteat or drink anything other than water after midnight on the night before the test, or as directed by your health care provider.
How are the results reported?
Your test results will be reported as values. Your health care provider will compare your results to normal ranges that were established after testing a large group of people (reference ranges). Reference ranges may vary among labs and hospitals. For this test, common reference ranges are:
- Basal
(plasma):
- Males: less than or equal to 19 pg/mL or less than or equal to 19 ng/L (SI units).
- Females: less than or equal to 14 pg/mL or less than or equal to 14 ng/L (SI units).
- After
calcium infusion (2.4 mg/kg):
- Males: less than or equal to 190 pg/mL or less than or equal to 190 ng/L.
- Females: less than or equal to 130 pg/mL or less than or equal to 130 ng/L.
- After
pentagastrin injection (0.5 mcg/kg):
- Males: less than or equal to 110 pg/mL or less than or equal to 110 ng/L.
- Females: less than or equal to 30 pg/mL or less than or equal to 30 ng/L.
What do the results mean?
Values higher than the reference ranges may indicate:
- Medullary cancer of the thyroid.
- Other types of cancer.
- Overactive parathyroid gland (hyperparathyroidism).
- Pernicious anemia, or vitamin B12 deficiency anemia.
- Alcoholic cirrhosis.
- Other endocrine disorders.
Talk with your health care provider about what your results mean.
Questions to ask your health care provider
Ask your health care provider, or the department that is doing the test:
- When will my results be ready?
- How will I get my results?
- What are my treatment options?
- What other tests do I need?
- What are my next steps?
Summary
- The calcitonin test measures the amount of calcitonin in your blood. Calcitonin is a hormone secreted by the thyroid gland.
- This test is done to help diagnose suspected medullary cancer of the thyroid, to monitor response to treatment, and to predict recurrence.
- Calcitonin levels higher than the reference range can be seen in medullary cancer of the thyroid, other cancers, and several other conditions.
- Talk with your health care provider about what your results mean.
