Calcitonin

"Calcitonin is most commonly used in the management of Medullary Thyroid Carcinoma (MTC), but raised concentrations may also be found in other malignancies such as breast, lung, pancreas, as well as phaeochromocytoma, renal failure, hyperparathyroidism and Paget's disease. In early MTC disease, basal concentrations of calcitonin may be normal. Increased sensitivity may be achieved by use of pentagastrin stimulation. Most patients with sporadic medullary thyroid cancer have high plasma calcitonin concentrations at the time of diagnosis, whilst 30% of patients with familial medullary thyroid cancer or MENII have normal concentrations at the time of diagnosis. These cases may require molecular genetic testing for the RET proto-oncogene.
Following successful surgical removal of medullary carcinoma, plasma calcitonin concentrations gradually decrease into the undetectable range over a period of several weeks.

Persistently elevated concentrations usually indicate incomplete cure. A rise in a previously undetectable or very low postoperative calcitonin concentration is highly suggestive of disease recurrence.
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