Abstract
Objective:To investigate the detection rate and metastasis rate of delphain lymph node （DLN）in thyroid papillary adenocarcinoma（PTC） and to analyze the risk factors for DLN metastasis. Methods:The clinicopathological data of 200 PTC patients admitted to the from January 2018 to June 2020 were retrospectively analyzed, and the detection of DLN was clearly recorded in the pathological reports of all patients. The number of DLN detected, the number of metastasis, the detection rate and the metastasis rate were counted. The clinicopathological factors that might affect DLN metastasis were analyzed by univariate analysis and multivariate Logistic regression analysis, including gender, age, tumor size and tumor location. Results:DLN was detected in 121 of 200 PTC patients, with a detection rate of 60.50% （121/200）. DLN metastasis was found in 46 of the 121 patients with a metastasis rate of 38.02% （46/121）.Univariate analysis showed that tumor diameter, multiple foci, capsular invasion, extradandular invasion, lymphatic vascular invasion, lymph node metastasis in central region （excluding DLN）, and lateral cervical lymph node metastasis were the risk factors for DLN metastasis of PTC （P<0.05）. Gender, age, tumor location, bilateral tumors, Hashimoto's thyroiditis and BRAFV600E mutation were not significantly correlated with DLN metastasis of PTC（P>0.05）. The 7 variables with statistically significant differences in univariate analysis were incorporated into Logistic regression model for multivariate analysis, and the results showed that, Tumor diameter ≥1.0 cm, capsule invasion, lymphatic vascular invasion, lymph node metastasis in central region （excluding DLN）, and lateral cervical lymph node metastasis were independent risk factors for DLN metastasis of PTC （OR= 3.386-9.186, P<0.05）. The sensitivity and specificity of DLN metastasis in predicting central lymph node （excluding DLN） metastasis in PTC patients were 36.79% and 92.55%, respectively, while the sensitivity and specificity of DLN metastasis in predicting lateral cervical lymph node metastasis were 41.03% and 81.37%, respectively.The incidence of central lymph node metastasis （excluding DLN） in DLN-positive patients were was 4.94 times higher than that in DLN-negative patients, and the incidence of lateral neck lymph node metastasis in DLN-positive patients were 2.20 times higher than that in DLN-negative patients. Conclusion:The detection rate and metastasis rate of DLN in PTC patients were higher, DLN metastasis predicts more extensive lymph node metastasis, and DLN metastasis was related to multiple factors,among which tumor diameter ≥ 1.0 cm, capsule invasion, lymphatic vascular infiltration, lymph node metastasis in the central region （excluding DLN）, and lateral cervical lymph node metastasis were independent risk factors for DLN metastasis of PTC. Therefore, PTC patients with the above characteristics should actively explore DLN and formulate appropriate surgical strategies.