Risk Factors Of Occult Cervical Lymph Node Metastasis In Papillary Thyroid Microcarcinoma

Objective:To investigate the risk factors of occult cervical lymph node metastasis in papillary thyroid microcarcinoma?PTMC?,so as to explore which clinicopathological features explored to cause PTMC patients to be prone to occult cervical lymph node metastasis,with a view to guiding the selection of clinical treatment options.The BRAF^V600E mutation is the major oncogene of papillary thyroid cancer?PTC?.In this study,we detected BRAF^V600E mutation in PTMC lesions,and explored the role of BRAF^V600E mutation in the occurrence of occult cervical lymph node metastasis in PTMC patients.Method:This study is divided into two parts.Part ?:Clinical records of 1524 PTMC patients diagnosed in the Affiliated Hospital of Qingdao University from 2013 to 2017 were reviewed.All patients underwent lymph node dissection in the corresponding region.According to their preoperative examination and postoperative pathology,lymph node metastasis was divided into three groups:dominant lymph node metastasis,occult lymph node metastasis,and no lymph node metastasis.The pathological and clinical characteristics were analyzed of three groups,including gender?male?,age,tumor size,multifocality,capsular invasion,bilateral involvement,with Hashimoto's disease,preoperative TSH levels.To explore the relationship between clinical characteristics and PTMC cervical lymph node metastasis.Part ?:A total of 273 cases of parathyroid-embedded tissue diagnosed as PTMC were collected from 2016 to 2017 in thyroid surgery at the Affiliated Hospital of Qingdao University.Tissue-extracted DNA was detected for gene mutations.To observe the mutation of BRAF^V600E in the tissue,combined the relevant clinical data,and to analyze the correlation between BRAF^V600E mutation and occult lymph node metastasis of PTMC.Results:Part ?:In the univariate analysis,the pairwise comparison refected that as the patients without lymph node metastasis,age,bilateral involvement,multifocality had statistic difference?P<0.05?.And the age of the occult lymph node metastasis group is lower?P<0.05?,there was no significant difference in the ratio of Hashimoto's disease?P>0.05?.Occult lymph node metastasis compared with dominant lymph node metastases,the former is lower than the latter,with the size of the tumor,multifocality and the pathological Hashimoto's dise ase?P<0.05?.Multivariate analysis showed that,as the patients without lymph node metastasis,gender,age and multifocality were risk factors for occult lymph node metastasis?OR=1.905,1.033,1.178?.Compared with occult lymph node metastasis,patients with Hashimoto's disease had a higher risk of dominant cervical lymph node metastasis,and the age of onset was larger than that of the former?OR=2.700,0.979?.Part ?:Univariate analysis showed that BRAF^V600E mutation was associated with tumor size,capsular invasion,Hashimoto's disease and occult lymph node metastasis?P<0.05?.Compared with BRAF^V600E negative group,BRAF^V600E mutation-positive PTMC tumors were larger in diameter,more prone to external invasion and occult lymph node metastasis in the neck?P<0.05?,and PTMC with Hashimoto's disease had a lower BRAF^V600E mutation rate?P<0.05?.Multivariate analysis showed that tumor size?OR=11.231?and occult cervical lymph node metastasis?OR=1.902?were significantly associated with BRAF^V600E mutation,while Hashimoto's disease was negatively correlated with BRAF^V600E mutation?OR=0.385?.The mutation rate of BRAF^V600E in occult cervical lymph node metastasis group was significantly higher than that in the control group?P<0.05?.After multifactorial correction,BRAF^V600E600E mutation was still significantly associated with occult lymph node metastasis?OR=1.957,95%CI:1.070-3.581,P=0.029?.Conclusion:Part ?:The risk factors for early lymph node metastasis of PTMC were male,the younger and tumor involving multifocality.The risk of dominant cervical lymph node metastasis was higher in patients with Hashimoto's disease.Part ?:BRAF^V600E mutation is closely related to occult lymph node metastasis of PTMC,and it can be used as a risk factor for predicting preoperative risk of PTMC.