Intraoperative calcitonin stimulation testing in an individualized surgical strategy of medullary thyroid cancer - primum non nocere
K. Obtulovicova1, A. Kalis1, K. Dancova2, M. Pura2, P. Vanuga2, A. Vanuga2 & M. Sicak1
Context and Objectives: The prognosis of medullary thyroid carcinoma (MTC), derived from parafollicular C-cells, depends on the completeness of the first surgical treatment. The C-cells produce calcitonin, a peptid hormone that is used as biochemical and immunohistochemical tumor marker. The aim of study was to evaluate an individualized approach to patients with C-cell disease, i.e. MTC and C-cell hyperplasia (CCH), using the intraoperative calcitonin testing-assisted surgical strategy as a predictor of the final outcome after surgery.
Design: An unicentral cross-sectional study.
Patients and Methods: Since June 2009 to September 2011, sixteen patients with MTC/CCH were surgically treated primarily (n=11) or were reoperated for persistence of the disease (n=5). Depending on the result of an intraoperative calcitonin stimulation testing (iCST), patients underwent total thyroidectomy with or without lymph node dissection. All patients were tested repeatedly in postoperative period (range 2 to 27 months).
Results: The results of iCST correlated with postoperative findings - if intraoperative testing was negative, it stayed negative in postoperative follow-up period. If serum calcitonin showed increase in iCST, it persisted positive postoperatively.
Discussion: Surgical treatment is the only modality that possibly can lead to complete cure of the patient. An importance of initial operation, including total thyroidectomy and lymph node dissection of adjusting metastases including micrometastases is indubitable. The aim of the surgery is to be equally radical, avoiding an over-resection and considering complications.
Conclusions: The results encourage to use the individual approach to patients with MTC/CCH, e.g. to be less radical surgically in cases of negative iCST, and to be more radical in those patients with persistent increase of serum calcitonin. The absence of poststimulation calcitonin elevation in iCST seems to be a good prognosis indicator, but longer follow-up is needed.
Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.
Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector