Cure and survival of sporadic medullary thyroid carcinoma following systematic preoperative calcitonin screening

Background: The improvement in outcome of sporadic medullary thyroid carcinoma (MTC) during the last decades remains controversial, even if a trend toward a better prognosis has been recently proposed. This study was aimed to determine the time trend cure and survival rates in sporadic MTC according to the use of systematic preoperative calcitonin screening. Methods: Retrospective analysis of 178 sporadic MTC patients operated between 1980 and 2017 was performed. The impact of prognostic factors on cure and survival following the introduction of routine preoperative calcitonin screening in 2001 was evaluated according to the year of surgery. Results: Since 2001, a significant decline of node-positive tumors (from 56.1 to 34.7%) and advanced stage at diagnosis (stage III/IV from 56.1 to 34.7%) occurred, with a concomitant significant increase in cure rate (64.5% vs 38.6%; p = 0.0012) and survival (p < 0.05). At univariate analysis, the cure was achieved more frequently in more recently operated patients (64.5% vs 38.6%; p = 0.0012), in disease staging I/II (86.5% vs 13.5%; p < 0.0001), in patients undergoing preoperative calcitonin screening (63.8% vs 23.5%; p < 0.0001) and in the absence of lymph node metastases (86.5% vs 13.5%; p < 0.0001). At multivariate analysis, only preoperative calcitonin screening and stage at diagnosis turned out to be significant independent prognostic factors for cure and survival. Conclusion: The outcome of sporadic MTC improved in the new millennium; diagnosis was achieved earlier, at a less advanced stage. Routine preoperative calcitonin screening may have contributed to improve cure and survival rates.