Background and aims: Patients with sporadic medullary thyroid carcinoma (MTC) have a variable clinical course. Our aim was to analyse the reduction of tumour markers after thyroidectomy with meticulous dissection and relate it to clinical outcome.
Materials and methods: Twenty consecutive patients with palpable sporadic MTC underwent thyroidectomy with central and uni- or bilateral modified radical neck dissection; three were subjected to mediastinal dissection. Basal (b-) and stimulated (s-) calcitonin (CT) and carcinoembryonic antigen (CEA)-levels were measured before and 6-8 weeks after primary surgery, and the reduction of these tumour markers was determined.
Results: Median CT (b- and s-) were markedly reduced after surgery (98.5% and 99.1%, respectively), and CEA decreased 11 times. CT (b-) fell >99% in seven patients after surgery; in these and four additional patients, CT (s-) showed a similar reduction. During follow-up (median 52.5 months), two patients (stages IV B and C) died of MTC; they had <95% reduction of CT. Four patients (stage IV A) are alive with verified metastases. Eight patients (one stage III, seven stage IV A) are alive with hypercalcitoninemia. Five stages I-III patients and one stage IV A patient are disease-free.
Conclusions: Thyroidectomy and meticulous dissection caused a pronounced reduction of tumour markers. A postoperative reduction of CT (s-) >or=97% seems to be associated with less aggressive clinical course, while CEA had lower predictive value.