Study Of Risk Factors For Mediastinal Lymph Node Metastasis In Peripheral Pulmonary Adenocarcinoma Patients With CN0

ObjectiveTo analyze the risk factors of mediastinal lymph node metastasis in patients with cN0 peripheral pulmonary adenocarcinoma,and provide a better evaluation to both the mediastinal lymph node staging and lymph node dissection.MethodsThese data were collected from 458 patients with cN0 peripheral pulmonary adenocarcinoma who underwent surgical treatment in the Department of Thoracic Surgery in the First Hospital of Jilin University between 2017-09-01 to 2019-09-01.The correlation between the following factors and the mediastinal lymph node metastasis were analyzed by SPSS19.0 software.The factors include gender,age,the ratio of solid part area in tumor,location and size of the tumor,preoperative serum CEA level,pathological subtype,Ki-67 expression,infiltration of visceral pleural,vascularan,nerve and small bronchi wall.Results76 of 458 cN0 patients were found to be unexpected lymph node metastasis,30 patients were pN1(6.6%),28 patients were pN1+pN2(6.1%)and 18 patients were pN2 only(3.9%).Univariate analysis of 458 patients showed tumor size,preoperative serum CEA>5.0ng/ml,mGGN(solid part more than 50%)-pSN,solid predominant adenocarcinoma,micropapillary predominant adenocarcinoma,high Ki-67 expression,infiltration of visceral pleural,vascular,nerve and small bronchial wall were risk factors for N2 patients(P<0.05).Multivariate logistic regression analysis showed that tumor size,preoperative serum CEA> 5.0ng/ml,mGGN(solid part more than 50%)-pSN,solid predominant adenocarcinoma,infiltration of visceral pleural,vascular were independent risk factors for N2 patients(P<0.05).We did not find LN metastasis case in pGGN,AIS or MIA group.Univariate analysis of 76 patients with lymph node metastasis showed that preoperative serum CEA>5 ng/ml and pleural infiltration of pN2 patients were significantly different from pN1 patients(P< 0.05).Multivariate logistic regression analysis showed that preoperative serum CEA>5 ng/ml and visceral pleural infiltration were risk factors for N2 patients(P<0.05).Conclusionstumor diamete(r especially more than 2cm),preoperative serum CEA >5.0ng/ml,mGGN(solid part more than 50%)-pSN,solid predominant adenocarcinoma,infiltration of visceral pleural,vascular and nerve are independent risk factors for N2 patients.Patients with these risk factors should receive systemic lymph node dissection.We found pGGN,AIS or MIA did not occur lymph node metastasis,so we can perform systemic mediastinal lymphnode sampling or lobe-specific lymphnode dissection.tumor diameter>2cm,preoperative serum CEA>5ng/ml,mGGN(solid part more than 50%)-pSN,suspicious visceral pleural infiltration are risk factors of N2.We suggest patients with these risk factors should receive PET-CT examination.