Abstract
PURPOSE: The aim of this study was to examine risk factors for nodal recurrence in the lateral neck (NRLN) in patients with papillary thyroid cancer (PTC) who underwent total thyroidectomy with prophylactic central neck dissection (TT + pCND). METHODS: This was a retrospective cohort study of patients with PTC who underwent TT + pCND. Data of all patients treated over a 10-year period (between 1998 and 2007) were analysed. The primary outcome was prevalence of NRLN within the 5-year follow-up after initial surgery. Predictors of NRLN were determined in the univariable and multivariable analysis. RESULTS: Of 760 patients with PTC included in this study, 44 (6.0 %) developed NRLN. In the univariable analysis, the following factors were identified to be associated with an increased risk of NRLN: positive/negative lymph node ratio ≥0.3 (odds ratio (OR) 14.50, 95 % confidence interval (CI) 7.21 to 29.13; p < 0.001), central lymph node metastases (OR 7.47, 95 % CI 3.63 to 15.38; p < 0.001), number of level VI lymph nodes <6 in the specimen (OR 2.88, 95 % CI 1.21 to 6.83; p = 0.016), extension through the thyroid capsule (OR 2.55, 95 % CI 1.21 to 5.37; p = 0.013), localization of the tumour within the upper third of the thyroid lobe (OR 2.35, 95 % CI 1.27 to 4.34; p = 0.006) and multifocal lesions (OR 1.85, 95 % CI 1.01 to 3.41; p = 0.048). CONCLUSIONS: Central lymph node metastases together with positive to negative lymph node ratio ≥0.3 represent the strongest independent prognostic factors for the PTC recurrence in the lateral neck.