VIA&VIB Lymph Node Metastasis Characteristics Of Papillary Thyroid Carcinoma

Background:Thyroid cancer is the most common malignant tumor of the endocrine system.Most of them are papillary thyroid carcinomas.The prognosis is good,but the local lymph node metastasis rate is as high as 20-90%.level VI is often considered the most common metastatic part of papillary thyroid carcinoma(PTC).Due to its special anatomical relationship with the recurrent laryngeal nerve and parathyroid glands,surgery may lead to a higher incidence of complications.Therefore,exploring the characteristics of level VIA and VIB lymph node metastasis seems to be very important.Objective:To investigate the risk factors of lymph node metastasis in level VIA and VIB,and guide the level VI lymph nodes dissection in papillary thyroid carcinoma.Methods:The clinical data of 91 right PTC patients,diagnosed in China-Japan Union Hospital Attached to Jilin University were analyzed.All the level VIA and VIB dissections were did by the same associate chief physician.Level VIA and VIB lymph nodes removed were sent for pathological examinations separately.Results:(1)The total lymph node metastasis rate in level VIA was 45.1%;the total lymph node metastasis rate in level VIB was 19.8%;the simultaneous lymph node metastasis rate in level VIA and VIB was 16.5%.(2)Univariate analysis showed that younger age(<45 years),male,calcification,larger tumor(?1 cm),and lateral lymph node metastasis(LLNM)were related to level VIA metastasis;Male,larger tumor(?1 cm),calcification,LLNM and level VIA metastasis were related to level VIB metastasis(3)Multivariate logistic regression analysis showed that younger age(<45 years),male,and calcification were independent risk factors of level VIA metastasis(P<0.05);Male and LLNM were independent risk factors of level VIB metastasis(P<0.05).(4)ROC curve showed that when the number of metastatic lymph nodes in level VIA was?1.5(AUC = 0.829,P=0.001<0.05),metastatic lymph nodes were likely to exist in level VIB(5)When the foci were located in the lower pole of the thyroid gland,the upper pole and the middle,the rates of lymph node metastasis in level VIA and VIB both decreased.(P>0.05)Conclusion:(1)Some patients had level VIA lymph node metastasis,but no VIB lymph node metastasis.Only level VIA lymph nodes dissection without level VIB could cause residual level VIB metastatic lymph nodes.(2)younger age(<45 years),male,calcification,larger tumor(?1 cm),and LLNM were all significantly related with level VIA metastasis;Male,larger tumor(?1 cm),calcification,LLNM and level VIA metastasis were all significantly related with level VIB metastasis(3)This study revealed that younger age(<45 years),male,and calcification were independent factors of PRRLN-LN(level VIA).Male and LLNM were independent factors of PRRLN-LN(level VIB).(4)We recommend level VIA and VIB both to be thoroughly cleaned when the number of metastatic lymph nodes is>?2 in the level VIA.(5)As for the thyroid papillary carcinoma VI regional lymph node drainage rules,When the lesion was located in the lower pole of the thyroid gland,the cancer cells metastasized to level VIA and VIB first more easily.