Clinical Characteristics And Programmed Cell Death Ligand-1 Expression In Lung Adenocarcinoma In Situ And Minimally Invasive Adenocarcinoma Of Lung

Objectives:According to the IASLC/ATS/ERS 2011 classification,there are two new conceptions of lung adenocarcinoma,adenocarcinoma in situ(AIS),minimally invasive adenocarcinoma(MIA),which are very early stages of lung adenocarcinoma.This study aimed to analyze clinical features of AIS and MIA and determine the expression profile of PD-L1 in AIS and MIA.Materials and Methods:We analyzed some clinical features of 274 patients like age,sex,smoking history,family history,surgery,EGFR mutation,ALK,ROS-1,serum CEA level et al.The expression of PD-L1 was evaluated by immunohistochemical analysis in 37 specimens of MIA and 17 specimens of AIS.Tumors with staining in over 5%of tumor cells were scored as positive for PD-L1 expression.Results:In all 274 patients,77 were diagnosed as AIS and 197 as MIA.We accidentally found 4 patients with recurrence,which were all MIA.The median age of the patients at diagnosis was both 52 years.71.4%were female in AIS as while as 71.1%in MIA.36.4%patients were observed with ever symptoms in AIS and 28.9%in MIA.As for smoking,12.9%and 8.6%had smoking history respectively in AIS an MIA.All MIA cases were PD-L1 negative,and only one case of AIS was weak positive.There was mild progress of pulmonary nodules in 16.7%(5/30)AIS and 27.5%(14/51)MIA.There was significant association between symptoms and progression in chest CT before surgery.No lymph node metastasis was found in any cases.Conclusions:There is no significance between AIS and MIA.In patients with AIS or MIA,female patients are much more than male,especially female without smoking.AIS and MIA almost do not express PD-L1 protein and without any lymph node metastasis.