A retrospective study of factors affecting contralateral central-neck lymph node metastasis in unilateral papillary thyroid carcinoma

Background: In 30-40% of papillary thyroid cancer patients, central neck lymph node metastasis occurs. As a result, prophylactic central neck lymph node dissection is performed. The extent of lymph node dissection and prophylactic central neck lymph node dissection is still debatable. The incidence of central neck lymph node metastasis and related factors were investigated in this study, and also the necessity of both central neck lymph node dissections.Methods: Between December 2017 and December 2019, 482 patients had thyroidectomy at Pusan National University Yangsan Hospital. A retrospective study of 186 patients who had a thyroidectomy with bilateral central neck lymph node dissection for unilateral thyroid carcinoma was done.Results: Ipsilateral and contralateral central neck lymph node metastasis were identified in 40.9% (76/ 186) and 19.3% (36/186), respectively. Male (p < 0.001), tumor size >1 cm (p = 0.047), extrathyroidal extension (p = 0.002), central neck lymph node metastases >5 (p < 0.001), lateral neck lymph node metastasis (p = 0.012), and ipsilateral central neck lymph node metastasis (p < 0.001) were associated with the contralateral central neck lymph node metastasis in univariate analysis. In a multivariate analysis, extrathyroidal extension (OR, 3.664), more than 5 central neck lymph node metastases (OR, 29.667), ipsilateral central neck lymph node metastasis (OR, 3.911), and male (OR, 5.890) were related to contralateral central neck lymph node metastasis.Conclusion: Male, extrathyroidal extension, and ipsilateral central neck lymph node metastasis may be considered for contralateral prophylactic central neck lymph node dissection. In the future, it is thought that more research on the recurrence rate will be required.