The regularity and clinical significance of intrapulmonary lobar and segmental lymph nodes metastasis in patients with cT1N0M0 stage lung adenocarcinoma / 中华胸心血管外科杂志

ABSTRACT

Objective To investigate the regularity of intrapulnonary lobar and segmental lymph nodes metastasis in patients with cT1N0M0 stage lung adenocarcinoma.To provide a basis for more accurate determination of N stage and indication for pulmonary segmental resection.Methods A prospective study was performed from March 2014 to December 2015.103 cases of cT1 N0M0 stage lung adenocarcinoma received lobectomy and mediastinal lymph node dissection in the thoracic surgery department of China-Japan Friendship Hospital.Intrapulmonary lobar and segmental lymph nodes were dissected and sorted carefully then sent to the pathological department with the corresponding lung specimen and other lymph nodes.Statistical analysis was carried out considering size of the lesion,imaging features,serum CEA levels,pathological subtypes and so on.Results In total 103 cases,pN0 was confirmed in 82 cases,pN1 in 15 cases,pN1 + N2 in 5 cases,and skipping-pN2 in 1 case.14 cases(93.3％) in pN1 group were detected with station 12-14 lymph node metastasis,while only 5 cases (33.3％) were detected with station 12-14 LSNs metastasis.4 cases(66.7％) in pN2 group were detected with station 12-14 lymph node metastasis,while only 1 case(16.7％) with station 13 and station 7 lymph node metastasis.If LSNs were not detected,the false negative rate of N staging could be as high as 6.1％ (5/82),The rate of missed diagnosis of lymph node metastasis might be 30％ (6/20) to N1 stations alone.41.2％ (7/17)cases with metastasis to the adjacent LSNs had been proved with metastasis to the isolated LSNs.The metastasis rate of the isolated LSNs was significantly lower(P =0.049) in pure GGNs compared with those part-solid/solid nodules.Invasive adenocarcinoma had higher metastasis rate of isolated LSNs,compared with preinvasive lesions or minimally invasive adenocarcinomas,with no statistical difference between groups (P =0.055).No significant difference in isolated LSNs metastasis rate was found between groups with different serum CEA levels(P =0.251) or tumor size(P =0.197).Conclusion Dissection of intrapulmonary lobar and segmental lymph nodes might facilitate a more accurate N stage,reduce the false negative rate of lymph node metastasis,and provide basis for more accurate assessment of prognosis and postoperative adjuvant treatment.The sampling area of lymph nodes during segmental resection should include the adjacent LSNs of the target segment.The isolated LSNs metastasis rate of cT1N0M0 stage lung adenocarcinoma with pureGGN as imaging feature is relative low,which might be suitable for segmentectomy when meeting other criteria.