Serum calcitonin reference values for calcium stimulation tests by electrochemiluminescence immunoassay in Japanese men with non-medullary thyroid carcinoma

Abstract

Purpose

Calcitonin is the most sensitive tumor marker of medullary thyroid carcinoma (MTC) and a calcium stimulation test is used to improve this sensitivity. In Japan, the electrochemiluminescence immunoassay (ECLIA) is currently the only test performed to measure serum calcitonin. There is a gender difference in the reference value of serum calcitonin; however, a reference upper limit for use with ECLIA has been reported only for women, but not for men.

Methods

We conducted the calcium stimulation test using ECLIA in 21 men with non-medullary thyroid carcinoma (non-MTC), before and after total thyroidectomy.

Results

Preoperatively, the basal calcitonin values were within normal limits in all patients. They increased to a mean value of 37.6 pg/mL after calcium stimulation, and we calculated that the reference upper limit was 83.7 pg/mL. The stimulation test results after total thyroidectomy showed undetectable basal and stimulated calcitonin values in every patient (<0.5 pg/mL).

Conclusions

To our knowledge, this is the first study to calculate reference values for this stimulation test using an ECLIA in men with non-MTC. We propose that men can be regarded as biochemically cured or as having normal serum calcitonin values when the stimulated calcitonin values obtained by ECLIA are <83.7 pg/mL before and <0.5 pg/mL after total thyroidectomy.

http://ift.tt/2v7Alcd