Endocrine Abstracts

Background and aims: The use of serum calcitonin to screen patients with nodular thyroid disease for medullary thyroid cancer (MTC) remains controversial due to conflicting data regarding its sensitivity, specificity and cost effectiveness. Currently, the use of calcitonin is recommended by the European consensus group but not the American Thyroid Association. We aimed to formally evaluate the utility of calcitonin as a screening tool for MTC in patients presenting to the thyroid nodule clinic at our institution.

Methods: Patients referred to a thyroid nodule clinic in a tertiary centre between 1st January 2010 and 31st July 2013 were evaluated using serum calcitonin, TPO antibodies and TFTs with cytology/histology and radiology assessment. Exclusion criteria included known MTC or positive MEN status. Calcitonin was deemed elevated if ≥4.8 ng/ml for females and ≥11.8 ng/ml for males.

Results: 302 patients (age: 49.8 (±15.7) years; female: 84.1%) were included in the audit. 20 patients had an elevated calcitonin of which two were confirmed to have MTC. 12 cases had no features of malignancy on cytological and/or histological evaluation. Three cases remain under investigation and three cases were lost to follow-up. MTC accounted for 13.3% of all thyroid malignancies detected.

Conclusion: Our results revealed that in patients referred for evaluation of thyroid nodular disease, 6.6% had an elevated calcitonin and 10% of those elevated values were associated with a new diagnosis of MTC. This is in keeping with other reported studies (10–40%). Both cases of MTC had abnormal radiological and cytological findings. Calcitonin screening did not identify any cases of MTC with otherwise normal or indeterminate parameters. Although case numbers were low, it is uncertain whether calcitonin provides added value as a screening tool for MTC in thyroid nodular disease.