title: International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society classification predicts occult lymph node metastasis in clinically mediastinal node-negative lung adenocarcinoma.
abstract: OBJECTIVE
  We investigated the role of the 2011 International Association for the Study of Lung Cancer, American Thoracic Society, and European Respiratory Society (IASLC/ATS/ERS) classification in predicting occult lymph node metastasis in clinically mediastinal node-negative lung adenocarcinoma.
  
  
  METHODS
  We reviewed lung adenocarcinoma patients who had clinically N2-negative status, were evaluated by preoperative positron emission tomography combined with computed tomography (PET/CT) and had undergone lobectomy or pneumonectomy at Memorial Sloan Kettering Cancer Center (n = 297). Tumours were classified according to the 2011 IASLC/ATS/ERS classification. The associations between occult lymph node metastasis and clinicopathological variables were analysed using Fisher's exact test and logistic regression analysis.
  
  
  RESULTS
  Thirty-two (11%) cN0-1 patients had occult mediastinal lymph node metastasis (pN2) whereas 25% of cN1 patients had pN2 disease. Increased micropapillary pattern was associated with increased risk of pN2 disease (P = 0.001). On univariate analysis, high maximum standard uptake value of the primary tumour on PET/CT (P = 0.019) and the presence of micropapillary (P = 0.014) and solid pattern (P = 0.014) were associated with occult pN2 disease. On multivariable analysis, micropapillary pattern was positively associated with risk of pN2 disease (odds ratio = 3.41; 95% confidence intervals = 1.42-8.19; P = 0.006).
  
  
  CONCLUSIONS
  The presence of micropapillary pattern is an independent predictor of occult mediastinal lymph node metastasis. Our observations have potential therapeutic implications for management of early-stage lung adenocarcinoma.
authors.affiliation: Thoracic Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, USA Department of Pathology and Laboratory Medicine, Taipei Veterans General Hospital, Taipei, Taiwan Institute of Clinical Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Yi-Chen
authors.initials: YC
authors.lastname: Yeh
authors.affiliation: Thoracic Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, USA Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
authors.forename: Kyuichi
authors.initials: K
authors.lastname: Kadota
authors.affiliation: Thoracic Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, USA Department of Thoracic Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Nitadori
authors.affiliation: Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
authors.forename: Camelia S
authors.initials: CS
authors.lastname: Sima
authors.affiliation: Thoracic Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
authors.forename: Nabil P
authors.initials: NP
authors.lastname: Rizk
authors.affiliation: Thoracic Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
authors.forename: David R
authors.initials: DR
authors.lastname: Jones
authors.affiliation: Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
authors.forename: William D
authors.initials: WD
authors.lastname: Travis
authors.affiliation: Thoracic Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, USA Center for Cell Engineering, Memorial Sloan Kettering Cancer Center, New York, NY, USA adusumip@mskcc.org.
authors.forename: Prasad S
authors.initials: PS
authors.lastname: Adusumilli
mesh_terms: D000046:Academic Medical Centers; D000230:Adenocarcinoma / Q000145:classification* / Q000401:mortality* / Q000473:pathology / Q000601:surgery; D000077192:Adenocarcinoma of Lung; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D002173:Cancer Care Facilities; D018572:Disease-Free Survival; D005060:Europe; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D038622:Internationality; D016015:Logistic Models; D008175:Lung Neoplasms / Q000145:classification* / Q000401:mortality* / Q000473:pathology / Q000601:surgery; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009361:Neoplasm Invasiveness / Q000473:pathology; D009367:Neoplasm Staging; D011013:Pneumonectomy / Q000379:methods / Q000401:mortality; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D018570:Risk Assessment; D012955:Societies, Medical / Q000592:standards; D015996:Survival Rate; D013997:Time Factors; D016896:Treatment Outcome; D014481:United States
keywords: Early stage; Lung cancer; Metastasis; Micropapillary; Non-small cell lung cancer