Risk Factors For Lymph Node Metastasis In Patients With Papillary Thyroid Carcinoma

ObjectiveWe aimed to analyze the risk factors of cervical lymph node metastasis in patients with papillary thyroid cancer(PTC)and to determine the risk factors of tumor recurrence in patients with PTCMethodsA total of 418 patients who underwent the first surgical treatment and confirmed to be PTC by postoperative pathology in the Third Affiliated Hospital of Soochow University from January 2010 to October 2018 were taken as the research subjects.The clinical and pathological data of patients with PTC were retrospectively collected.Univariate and multivariate analyses were performed to determine the risk factors associated with central lymph node metastasis(CLNM),lateral lymph node metastasis(LLNM),and skip metastasis Cox proportional hazards model was used to analyze the risk factors for recurrence.Kaplan-Meier method was used to draw the recurrence-free survival(RFS)curveResults(1)CLNM was detected in 213(51.0%)patients.Multivariate analysis showed that patients<45 years of age(OR:1.893,P=0.003),tumor diameter>1 cm(OR:4.781,P=0.024),extrathyroidal invasion(OR:5.195,P<0.001),LLNM(OR:12.087,P=0.001),and the number of removed lymph nodes in the central compartment(OR:1.201,P=0.043)were independent predictors for high prevalence of CLNM(2)LLNM was detected in 64(15.3%)patients.Multivariate analysis showed that tumor diameter>1 cm(OR:3.742,P<0.001),CLNM(OR:4.404,P<0.001),the number of metastatic lymph nodes in the central compartment(OR:2.266,P=0.003),and the number of removed lymph nodes in the lateral compartment(OR:1.129,P=0.034)were independent predictors for high prevalence of LLNM(3)Skip metastasis was detected in 10(2.4%)patients.Multivariate analysis showed that tumor diameter<1 cm(OR:6.600,P=0.010)was the independent predictor for high prevalence of skip metastasis.(4)According to the multivariate Cox proportional hazards model,obesity,vascular invasion,the presence of skip metastases,and CLNM were independent risk factors for recurrence(all P<0.05),Kaplan-Meier curves showed that patients with CLNM had significantly lower RFS than patients without CLNM(P=0.006),and patients with skip metastasis had significantly lower RFS than patients without skip metastasis(P=0.008)Conclusion(1)CLNM is the risk factor for recurrence.Hence,for cN0 patients with risk factors for CLNM,prophylactic central neck dissection is recommended(2)For patients diagnosed with CLNM,especially those with the tumor diameter>1 cm preoperatively,a detailed preoperative examination of the lateral compartment should be performed to rule out LLNM.(3)Considering that microcarcinomas(tumor diameter ≤lcm)are more likely to develop the skip metastases,detailed preoperative examination of these of patients is necessary.