Aids in the diagnosis and follow-up of medullary thyroid carcinoma
Aids in the evaluation of multiple endocrine neoplasia type II and familial medullary thyroid carcinoma
This test is not useful for evaluating calcium metabolic diseases.
Patient Preparation: For the 12 hours before specimen collection, do not take multivitamins or dietary supplements containing biotin (vitamin B7), which is commonly found in hair, skin, and nail supplements and multivitamins.
1. After collection, immediately place specimen on ice.
2. Refrigerate specimen during centrifugation and immediately transfer serum to a plastic vial.
Falsely elevated values may occur in serum from patients who have developed human antimouse antibodies or heterophilic antibodies.
In rare cases, interference due to extremely high titers of antibodies to analyte-specific antibodies, streptavidin, or ruthenium can occur.
Values obtained with different assay methods or kits may be different and cannot be used interchangeably. Test results cannot be interpreted as absolute evidence for the presence or absence of malignant disease.
1 month: < or =34 pg/mL
2 months: < or =31 pg/mL
3 months: < or =28 pg/mL
4 months: < or =26 pg/mL
5 months: < or =24 pg/mL
6 months: < or =22 pg/mL
7 months: < or =20 pg/mL
8 months: < or =19.0 pg/mL
9 months: < or =17.0 pg/mL
10 months: < or =16.0 pg/mL
11 months: < or =15.0 pg/mL
12-14 months: < or =14.0 pg/mL
15-17 months: < or =12.0 pg/mL
18-20 months: < or =10.0 pg/mL
21-23 months: < or =9.0 pg/mL
2 years: < or =8.0 pg/mL
3-9 years: < or =7.0 pg/mL
10-15 years: < or =6.0 pg/mL
16 years: < or =5.0 pg/mL
17 years and older:
Males: < or =14.3 pg/mL
Females: < or =7.6 pg/mL
Although most patients with sporadic medullary thyroid carcinoma (MTC) have high basal serum calcitonin concentrations, 30% of those with familial MTC or multiple endocrine neoplasia type II (MENII) have normal basal levels.
In completely cured cases following surgical therapy for MTC, serum calcitonin levels fall into the undetectable range over a variable period of several weeks. Persistently elevated postoperative serum calcitonin levels usually indicate incomplete cure. The reasons for this can be locoregional lymph node spread or distant metastases. In most of these cases, imaging procedures are required for further workup. Those individuals who are then found to suffer only locoregional spread may benefit from additional surgical procedures. However, the survival benefits derived from such approaches are still debated.
A rise in previously undetectable or very low postoperative serum calcitonin levels is highly suggestive of disease recurrence or spread, and should trigger further diagnostic evaluations.