Changes of biochemical factors and the effect on recurrence of medullary thyroid carcinoma after surgery

Objective: Medullary thyroid carcinoma (MTC) is a rare malignancy secreting calcitonin (Ctn). We aimed to analyze the relationship between Ctn levels at different time points in patients with MTC, and evaluate its predictive effect on recurrence. Methods: A retrospective study of patients diagnosed with MTC in a large medical center were conducted in northern China. The interrelationships between preoperative Ctn, normalization of postoperative serum Ctn at the first month (NPS), and long-term biochemical cure as well as their predicting roles on structural recurrence were assessed. Results: A total of 212 patients were included in this study. The median follow-up time was 59.5 months. The 5- and 10-year cumulative disease-free survival rates were 81.5 % and 66.8 %, respectively. NPS (OR: 216.33, 95 % CI: 28.69–1631.09, P