Calcitonin is a peptide hormone secreted by thyroid C-cells. C-cells are laid even in the prenatal period, and in the adult population, the production of calcitonin is practically their only function.
Normally, calcitonin is an antagonist of the parathyroid hormone of the parathyroid glands, although it does not have such a significant effect on calcium metabolism in the body as parathyroid hormone – a decrease in the level of calcitonin after resection of the thyroid gland or its increase in thyroid cancer do not cause significant fluctuations in the level of calcium in the blood. In addition to the thyroid gland, this hormone can be produced by other organs, most of all by the lungs. To date, the main role of calcitonin in metabolic processes has not yet been clarified, therefore its main function is to diagnose thyroid carcinoma.
Calcitonin is a tumor marker of thyroid cancer associated with C-cell malignancy. Since the level of calcitonin can be increased in other pathologies, for differential diagnosis, samples with stimulation with calcium gluconate, gastrin, glucagon are used. After the administration of these drugs to a patient with thyroid cancer, the level of calcitonin is at least doubled.
Medullary thyroid cancer is a rather serious problem for Russians. Studies conducted in large regions of Russia have shown that medullary carcinoma is diagnosed in 100-150 people annually, while the detection rates in cancer centers that actively use calcitonin, a tumor marker in their work, are significantly higher than in small areas where this analysis was not obtained. wide application.
In patients with medullary thyroid cancer, the assessment of calcitonin levels can be used in the postoperative period to make a prognosis and early detection of metastases and tumor recurrence . Such patients are prescribed a comprehensive examination before the operation: calcitonin tumor marker, CEA, diagnostics of pheochromocytoma (determination of metanephrines, normetanephrines), parathyroid hormone, ionized and total calcium, blood albumin.
Medullary carcinoma of the thyroid gland is characterized by a hereditary predisposition, therefore, the calcitonin tumor marker is widely used not only for the diagnosis of thyroid cancer, control after surgery, but also for screening in the patient’s relatives who are at risk for thyroid cancer.
The importance of calcitonin testing cannot be overstated. Medullary thyroid cancer is a very slowly progressive tumor that manifests itself clinically in the late stages of the disease and is difficult to treat. Often, at the time of detection of a tumor, it metastasizes to regional and distant lymph nodes, other organs. That is why it is recommended to screen the relatives of a patient with medullary thyroid cancer for calcitonin tumor marker for early detection of a tumor and initiation of treatment (in the early stages, medullary cancer responds better to treatment).
Deciphering the results of the analysis of the tumor marker Calcitonin
The determination of the level of calcitonin can be carried out by different methods. The most modern and accurate diagnostic method is immunochemiluminescent. The outdated enzyme immunoassay method often gives an erroneous positive result, therefore, if high levels of calcitonin are obtained during the enzyme immunoassay, it is recommended to repeat the study in a laboratory equipped with more modern equipment.
The calcitonin rate for men is up to 8.4 pg / ml; for women up to 5 pg / ml. An excess of 100 pg / ml is characteristic of medullary thyroid carcinoma, leukemia, and lymphoproliferative pathology.
If a patient has a verified medullary thyroid cancer, the size of which does not exceed 5 mm, the presence of regional metastases to the lymph nodes will be indicated by a calcitonin level of more than 40 pg / ml, and an increase in the oncomarker calcitonin of more than 400 pg / ml indicates distant metastases.
In the postoperative period, it is recommended to control the level of calcitonin after two to three months. A tumor marker index of less than 10 pg / ml indicates a favorable prognosis. If the level of calcitonin exceeds 150 pg / ml, or its level after surgery doubles in less than six months, this significantly worsens the prognosis for the patient.
High calcitonin levels are indicative of medullary thyroid cancer; incomplete removal of the tumor during surgery; oncopathology of the kidneys, liver, lungs, pancreas and breast; neuroendocrine tumors; hyperplasia of C-cells of the thyroid gland without malignancy; Zollinger-Ellison syndrome; Paget’s disease; pernicious pernicious anemia; chronic renal failure with uremia; leukemia; lymphomyeloproliferative pathology; pregnancy; severe inflammatory pathology.
The level of calcitonin decreases against the background of heavy physical exertion.
Calcitonin test – tumor marker
For an immunochemical assay with chemiluminescence detection, the patient’s serum is used to determine the calcitonin level. The average time for issuing a result is 2-3 working days.
How to prepare for taking Calcitonin tumor marker
Special preparation for donating blood for calcitonin tumor marker is not required. 8-12 hours before the study, you should limit food intake, it is better to donate blood in the morning on an empty stomach, before 12:00. Immediately before blood sampling, rest should be observed, and physical exertion should be avoided.