Predictors for central lymph node metastases in CN0 papillary thyroid microcarcinoma (mPTC): A retrospective analysis of 1304 cases

Abstract

Background: Presence of lymph node metastases increases the risk of recurrence, but prophylactic central neck node dissection for patients with micropapillary thyroid cancer (mPTC) is controversial. We aim to find the clinical predictors of central lymph node metastases (CLNM) in patients with cN0 mPTC.

Methods: We retrospectively reviewed the clinicopathological and molecular genetic characteristics of 1304 patients with cN0 mPTC operated at the First Hospital of Jilin University between January 1, 2013 and May 31, 2016, all underwent thyroid lobectomy or total thyroidectomy with unilateral or bilateral prophylactic central neck dissection. Univariate and multivariate analysis were used to identify the predictors of CLNM.

Results: 30.7% of cN0 mPTC patients had CLNM. Univariate analysis found CLNM to be associated with younger age (≤45), male gender, larger tumor (>0.5 cm), multifocality, bilaterality, capsular invasion, lymphovascular invasion and extrathyroidal infiltration, but not associated with BRAF mutation, tumor location, preoperative TSH and anti-thyroglobulin antibody level. Multivariate logistic regression showed age ≤45 years (p < 0.001, OR = 2.05), male gender (p < 0.001, OR = 1.94), tumor size >0.5 cm (p < 0.001, OR = 1.87), bilaterality (p = 0.003, OR = 1.86) and capsular invasion (p = 0.013, OR = 1.49) to be independent predictors for CLNM in cN0 mPTC patients.

Conclusions: Prophylactic central neck dissection has higher yield for cN0 mPTC patients with age ≤45 years, male gender, tumor size>0.5 cm, bilaterality and capsular invasion. BRAF mutation is not a predictor for CLNM in cN0 mPTC patients.

Keywords: BRAF; Central lymph node metastases; Papillary thyroid microcarcinoma; cN0; mPTC.