Is Evaluation of Serum Calcitonin Levels Significant for Patients with Thyroid Nodules?

Abstract

INTRODUCTION: The overdiagnostic analyses can be performed for evaluation of thyroid nodules which are commonly seen pathology in the population. Diagnostic tests in the evaluation of thyroid nodules, commonly-seen pathology in the population, mostly cause overdiagnosis. In fact, serum calcitonin(SC) measurement is a sensitive and specific method in the diagnosis of medullary thyroid cancer(MTC). If the patients with Bethesda Category III(atypia of undetermined significance -AUS) cytologies have also high risk clinical and ultrasonographical features, they can be evaluated for thyroidectomy. In this study, we aimed to evaluate the value of screening with serum calcitonin in patients with cytologies of Bethesda I and III categories. METHODS: The medical records of patients who had thyroidectomy between 2007-2018 were screened retrospectively. The patients with preoperative calcitonin, cytology results and postoperative histopathology reports were included in the study. RESULTS: Of the 6905 thyroidectomized patients, 881 had SC values. SC levels were evaluated as <2, 2-10 and >10pg/mL and classified as Group 1, 2, and 3; respectively. 217 patients(24.6%) had nondiagnostic(ND) and 275(31.2%) had AUS cytologies. The gender distribution was similar between ND and AUS groups(p=0.7). However, SC levels of group 1, 2, and 3 were found in 84.8%, 14.3%, and 0.9% of patients with ND, it was found in 82.9%, 15.6%, and 1.5% in patients with AUS cytologies, respectively(p=0.786). In histopathology, malignancy was detected in 30% of patients with AUS and 11.6% patients with ND(p=0.006). Calcitonin levels of patients with malignant histopathology were evaluated in 82.9%, 15.4%, and 1.7% of patients as Group 1, 2, and 3, respectively. This was similar compared to patients with benign histopathology (p=0.16). In the present study, 2 female patients had high calcitonin levels(144pg/mL and 655pg/mL). Both patients had preoperative AUS cytologies and final malignant histopathologies. DISCUSSION AND CONCLUSION: We think that preoperative assessment of serum calcitonin levels can be useful in treatment decision of patients especially with Bethesda Category III thyroid nodules such as in follow-up and extent of surgery for cases planning surgery.

Keywords

• bethesda category i
• bethesda category iii
• calcitonin
• thyroid nodule