Risk Factors Of Skip And Bilateral Lateral Lymph Node Metastasis In Papillary Thyroid Carcinoma

Purpose This study was performed to investigate the risk factors of skip and bilateral lateral lymph node metastasis by analyzing the medical records of patients with thyroid papillary carcinoma and lateral lymph node metastasis,which provided a reference for the development of surgical procedures.Methods We reviewed the medical records of 259 patients with papillary thyroid carcinoma who met inclusion and exclusion criteria at the department of Vascular and Thyroid Surgery of the Fujian Medical University Union Hospital between July 2015 and November 2018.Statistical analysis was performed on the following clinicopathological data: patient age,gender,body mass index,tumor size,tumor location,Hashimoto’s thyroiditis,capsule invasion,extrathyroid extension,multifocality,bilobar involvement,bilateral central lymph node metastasis,tumor extension,lateral lymph node metastasis cases(level II-IV),central lymph node number(metastatic/harvested)and lateral lymph node number(metastatic/harvested).Statistical analysis of the count data was performed using the χ2 test,and the measurement data was analyzed by the t test.Multivariate analysis was performed using binary logistic regression analysis.Results 1.The frequency of skip lymph node metastasis in this study was approximately 9.3%(24/259).Univariate analysis showed that there were no significant differences in age,sex,body mass index,Hashimoto’s thyroiditis,capsule invasion,extrathyroid extension,multifocality,tumor extension,bilobar involvement and lymph node metastasis cases in II-IV between the two groups(P>0.05)and skip metastasis was significantly associated with a primary tumor size of <1 cm(P<0.001)and a tumor location in the upper portion of the thyroid(P=0.012).The skip metastasis group showed a lower harvested central lymph node number(P=0.031).Multivariate analysis showed that a primary tumor size of <1 cm(OR 5.934,P<0.001)and a tumor location in the upper portion of the thyroid(OR 2.812,P=0.023)were the independent risk factors of skip metastasis.2.The frequency of bilateral lateral lymph node metastasis in this study was about 15.8%(41/259).Univariate analysis showed that there were no significant differences in age,sex,body mass index,Hashimoto’s thyroiditis,capsule invasion,extrathyroid extension,and lymph node metastasis cases in II and III between the two groups(P>0.05)and a primary tumor size of ≥4 cm(P=0.003),multifocality(P=0.013),T4(P=0.001),bilobar involvement(P=0.001),bilateral central lymph node metastasis(P=0.001)and lymph node metastasis in level IV(P=0.030)were associated with bilateral lateral lymph node metastasis.The bilateral lateral lymph node metastasis group showed a higher central and lateral lymph node metastasis number(P<0.001).Multivariate analysis showed that a primary tumor size of ≥4 cm(OR 5.522,P=0.007),T4(OR 2.820,P=0.014),bilobar involvement(OR 3.470,P=0.025)and bilateral central lymph node metastasis(OR 4.102,P=0.002)were the independent risk factors of bilateral lateral lymph node metastasis.Conclusion Skip metastasis in papillary thyroid carcinoma is more likely in patients with a tumor size of <1 cm and a tumor location in the upper portion of the thyroid.Patients with a primary tumor size of ≥4 cm,bilobar involvement,bilateral central lymph node metastasis and clinical T4 are more likely to have bilateral lateral lymph node metastasis.In the presence of the above factors,the lateral compartment should be more meticulously evaluated.