Correlation Study Between Preoperative Ultrasonic Features of Medullary Thyroid Carcinoma and Postoperative Recurrence

Background: To investigate factors that affects postoperative recurrence in medullary thyroid carcinoma (MTC) patients in terms of preoperative ultrasonic characteristics and so on. Method: A retrospective analysis of 74 MTC patients who underwent the first thyroid surgery from 2009 to 2018 at hospital and had complete follow-up information. According to the follow-up results, these patients were divided into recurrence group (17 cases) and non-recurrence group (57 cases). The preoperative ultrasound characteristics, preoperative and postoperative calcitonin level, and general information of the two groups were recorded separately. Univariate and multivariate analysis was performed. Results: Single factor KM analysis showed that: ①Preoperative ultrasonic characteristic of tumor size> 40.0 mm, capsular invasion, and abnormal cervical lymph node ,as well as preoperative calcitonin level > 565.8pg / ml, postoperative calcitonin (within one week) level > 45.0pg / ml are the factors that affect postoperative recurrence of MTC (P <0.05); ②There is no evidence shows that gender and age have statistical significance with postoperative recurrence of MTC patients (P> 0.05). Multi-factor COX regression analysis showed that abnormal cervical lymph node （HR=5.368,95%CI1.063-27.104，P=0.042）is an independent risk factor affecting postoperative recurrence of MTC patients. Conclusions: MTC patients with abnormal cervical lymph nodes prone to postoperative recurrence. In addition, MTC patients with tumor> 40.0mm, capsular invasion, preoperative calcitonin level > 565.8pg / ml, postoperative calcitonin level > 45.0pg / ml are more likely to have postoperative recurrence.