title: Lung Adenocarcinoma Staging Using the 2011 IASLC/ATS/ERS Classification: A Pooled Analysis of Adenocarcinoma In Situ and Minimally Invasive Adenocarcinoma.
abstract: Lung adenocarcinoma accounts for almost 60% of non-small-cell lung cancer. According to the 2011 International Association for the Study of Lung Cancer (IASLC), American Thoracic Society (ATS), and European Respiratory Society (ERS) classification and 2015 World Health Organization classification of tumors of the lung, lepidic-predominant adenocarcinomas ≤ 3 cm in size can be classified as adenocarcinoma in situ (AIS), minimally invasive adenocarcinoma (MIA), and invasive adenocarcinoma, lepidic predominant. AIS lesions, which are noninvasive, and MIA lesions, which show ≤ 0.5 cm of invasion, have been recommended to be considered stage pTis (adenocarcinoma) and pT1(mi), respectively. We conducted a systematic analysis of the published data to evaluate the prognostic differences between AIS and MIA.
  
  
  
  A comprehensive search of published studies was conducted from the electronic databases using relevant search criteria. Studies that reported outcomes for ≥ 8 cases classified as AIS or MIA using the 2011 IASLC/ATS/ERS criteria were selected for the present analysis. A systematic analysis of the extracted data were performed using Comprehensive Meta-Analysis software, version 2.2.
  
  
  
  Nineteen studies published from 2011 to 2015 were eligible. A total of 972 patients were included (429 with AIS and 294 with MIA; 2 studies reported AIS and MIA together, n = 249). The median age was 65.5 years, 63% were female, and 40% were smokers. The 5-year disease-free survival rate for the whole population was 97.9%. The 5-year disease-free survival rate was 100% for AIS and MIA pooled from the studies that reported the 2 groups separately. The 5-year overall survival rate for the entire group was 97.5%, and the 5-year overall survival rate was 100% for AIS and 98.5% for MIA.
  
  
  
  No significant differences were found in the survival rates between patients with lung adenocarcinoma categorized as MIA or AIS. This finding raises questions regarding the evidence for TNM staging of AIS and MIA as recommended by the 2011 IASLC/ATS/ERS and 2015 World Health Organization classification of tumors of the lung and should be reevaluated with further studies.
authors.affiliation: Department of Hematology and Medical Oncology, Winship Cancer Institute of Emory University, Atlanta, GA.
authors.forename: Madhusmita
authors.initials: M
authors.lastname: Behera
authors.affiliation: Department of Hematology and Medical Oncology, Winship Cancer Institute of Emory University, Atlanta, GA.
authors.forename: Taofeek K
authors.initials: TK
authors.lastname: Owonikoko
authors.affiliation: Department of Pathology and Laboratory Medicine, Winship Cancer Institute of Emory University, Atlanta, GA.
authors.forename: Anthony A
authors.initials: AA
authors.lastname: Gal
authors.affiliation: Department of Hematology and Medical Oncology, Winship Cancer Institute of Emory University, Atlanta, GA.
authors.forename: Conor E
authors.initials: CE
authors.lastname: Steuer
authors.affiliation: Biostatistics and Bioinformatics Research Center, Cedars-Sinai Medical Center, Los Angeles, CA.
authors.forename: Sungjin
authors.initials: S
authors.lastname: Kim
authors.affiliation: Department of Hematology and Medical Oncology, Winship Cancer Institute of Emory University, Atlanta, GA.
authors.forename: Rathi N
authors.initials: RN
authors.lastname: Pillai
authors.affiliation: Department of Hematology and Medical Oncology, Winship Cancer Institute of Emory University, Atlanta, GA.
authors.forename: Fadlo R
authors.initials: FR
authors.lastname: Khuri
authors.affiliation: Department of Hematology and Medical Oncology, Winship Cancer Institute of Emory University, Atlanta, GA.
authors.forename: Suresh S
authors.initials: SS
authors.lastname: Ramalingam
authors.affiliation: Department of Pathology and Laboratory Medicine, Winship Cancer Institute of Emory University, Atlanta, GA. Electronic address: gabriel.sica@emoryhealthcare.org.
authors.forename: Gabriel L
authors.initials: GL
authors.lastname: Sica
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology*; D065311:Adenocarcinoma in Situ / Q000473:pathology*; D000077192:Adenocarcinoma of Lung; D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology*; D008297:Male; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D011379:Prognosis; D012907:Smoking / Q000453:epidemiology; D015996:Survival Rate
keywords: 2011 classification; AIS; MIA; Staging; Survival