Analysis Of Risk Factors For Lateral Lymph Node Skip Metastasis In Papillary Thyroid Carcinoma

Background:An increasing number of people suffer from thyroid carcinoma globally,and papillary thyroid carcinoma is the most common subtype.Papillary thyroid carcinoma tends to spread through the lymphatic system.Lymph node metastasis is a significant risk factor for local recurrence and distant metastasis of thyroid carcinoma.Traditionally,it is believed that thyroid carcinoma first metastases to the central lymph nodes compartment and subsequently invades the ipsilateral cervical lymph nodes compartment.However,sometimes skip metastasis happens.Skip metastasis of papillary thyroid carcinoma is defined as suffering lateral lymphatic metastasis without central compartment metastasis.At present,the relationship between skip metastasis in patients with papillary thyroid carcinoma and clinicopathological characteristics remains uncertain.The objective of our study was to explore the predictive factors for lymphatic skip metastasis in papillary thyroid carcinoma,in order to help clinicians build an individualized strategy towards such patients.Methods:A total of 408 patients who were diagnosed of papillary thyroid carcinoma with lateral lymphatic metastasis in the Department of Thyroid and Hernia Surgery at Guangdong Provincial People’s Hospital between October 2015 to June 2020 were assessed retrospectively.According to whether developed skip metastasis,patients were divided into skip metastasis group and control group.Basic data and clinicopathological characteristics of patients in both groups were collected.Univariate analysis was performed byΧ~2 test,Fisher’s exact test or Mann-Whitney U test,while multivariate analysis was performed by binary logistic regression analysis to explore the predictive factors for lymphatic skip metastasis of papillary thyroid carcinoma.P values<0.05 was defined as statistically significant.Results:There were 66 patients developed lymph node skip metastasis among all 408 patients and the incidence of skip metastasis was 16.2%.In the univariate analyses,we found age,tumor diameter,tumor location and preoperative serum Tg were risk factors for skip metastasis of papillary thyroid carcer.And multivariate analysis showed that skip metastasis of papillary thyroid carcinoma was significantly associated with age≥55(P=0.049,OR=2.423),tumor located in the upper lobe(P<0.001,OR=5.435)and preoperative serum Tg≤77 ng/ml(P=0.006,OR=5.802).Conclusions:16.2% of patients with papillary thyroid carcinoma developed skip metastasis.Age,tumor diameter,tumor location and preoperative serum Tg were risk factors for lymphatic skip metastasis of papillary thyroid carcinoma.Age≥55,tumor located in the upper lobe and preoperative serum Tg≤77 ng/ml were independent predictors of skip metastasis.Therefore,clinicians should give sufficient consideration of the influence of the above risk factors when evaluating the risk of lateral cervical lymph node metastasis in papillary thyroid carcinoma.