RISK FACTORS FOR LYMPH NODE METASTASIS IN CENTRAL ZONE OF PAPILLARY THYROID MICROCARCINOMA

Purpose: To identify risk factors for lymph node metastasis in central zone of papillary thyroid microcarcinoma (PTMC) in patients so as to provide a clinical basis for selective lymph node dissection surgery in central zone. Methods: Clinical data of 210 PTMC patients with surgical treatment in he First Affiliated Hospital of Bengbu Medical College from March, 2012 to December, 2017 were analyzed retrospectively for independent risk factors for lymph node metastasis in central zone. Results: Total metastasis of PTMC in central zone was 37.62 % (79/210). Single factors analysis showed that tumor size, envelope invasion, and clinical typing cN1 patients had close relations with lymph node metastasis in central zone (p < 0.05). Multiple factors analysis showed that size of tumor (OR = 2.418, 95 % CI = 1.186 - 4.731, p = 0.008); envelope invasion (OR = 1.981 95 % CI = 1.976 - 3.307, p = 0.006); and clinical typing (OR = 2.961 95 % CI= 1.163 - 3.162, p = 0.001) were independent risk factors of lymph node metastasis in central zone. Lymph node metastasis in central zone of patients without the three independent factors was 18.03 % (11/61), which was significantly lower than metastasis in patients with any of the risk factors (45.64 %, 681149; chi(2) = 14.054, p < 0.001). Conclusion: Tumor size, tumor envelope invasion and clinical typing cN1 are independent risk factors for lymph node metastasis in central zone. Patients who present with these risk factors should be given lymph node dissection in central zone.