title: Lymph node involvement influenced by lung adenocarcinoma subtypes in tumor size ≤3 cm disease: A study of 2268 cases.
abstract: OBJECTIVE
  Whether lung adenocarcinoma subtype has influence on lymph node involvement in small-sized lung cancer is still unclear. If it has, we want to clarify the extent of the impact.
  
  
  METHODS
  We identified 2268 operable lung adenocarcinoma patients with tumor size ≤ 3 cm who had undergone a lobectomy and systematic nodal dissection at Shanghai Chest Hospital between July 2012 and December 2014. The histologic subtypes of all patients were classified according to the IALSC/ATS/ERS classification. The relationship between lymph node involvement and clinicopathologic characteristics was evaluated.
  
  
  RESULTS
  Lymph node involvement (pN1+ pN2) was found in 7 of 220 (3.2%) patients with tumor size ≤ 1.0 cm, 173 of 1196 (14.5%) patients with tumor size >1.0, ≤2.0 cm, and 265 of 852 (31.1%) patients with tumor size > 2.0, ≤3.0 cm. Among all 2268 patients, the percentages of lymph node involvement (pN1+ pN2) were: 47.6%, 47.2%, 24.0%, 18.9%, 18.1%, 0%, 0%, and 0% for solid predominant (Sol), micropapillary predominant (MIP), variants of invasive adenocarcinoma (VIA), papillary predominant (Pap), acinar predominant (Aci), lepidic predominant (Lep), minimally invasive adenocarcinoma (MIA), adenocarcinoma in situ (AIS), respectively. For Sol and MIP, the percentages of lymph node involvement were significantly higher than other subtypes, 50.0% and 66.7% in tumor size ≤ 1.0 cm, 42.0% and 38.6% in tumor size > 1.0, ≤2.0 cm, 52.2% and 55.7% in tumor size > 2.0, ≤3.0 cm.
  
  
  CONCLUSIONS
  Our study revealed that lung adenocarcinoma subtypes had important role in lymph node involvement for the patients with small-sized lung cancer.
authors.affiliation: Shanghai Lung Cancer Center, Shanghai Chest Hospital, Shanghai Jiao Tong University, 241 West Huaihai Road, Xuhui District, Shanghai 200030, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Yu
authors.affiliation: Shanghai Lung Cancer Center, Shanghai Chest Hospital, Shanghai Jiao Tong University, 241 West Huaihai Road, Xuhui District, Shanghai 200030, China.
authors.forename: H
authors.initials: H
authors.lastname: Jian
authors.affiliation: Shanghai Lung Cancer Center, Shanghai Chest Hospital, Shanghai Jiao Tong University, 241 West Huaihai Road, Xuhui District, Shanghai 200030, China.
authors.forename: L
authors.initials: L
authors.lastname: Shen
authors.affiliation: Department of Pathology, Shanghai Chest Hospital, Shanghai Jiao Tong University, 241 West Huaihai Road, Xuhui District, Shanghai 200030, China.
authors.forename: L
authors.initials: L
authors.lastname: Zhu
authors.affiliation: Shanghai Lung Cancer Center, Shanghai Chest Hospital, Shanghai Jiao Tong University, 241 West Huaihai Road, Xuhui District, Shanghai 200030, China. Electronic address: lushun1964@126.com.
authors.forename: S
authors.initials: S
authors.lastname: Lu
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics / Q000473:pathology*; D000077192:Adenocarcinoma of Lung; D000328:Adult; D000368:Aged; D066246:ErbB Receptors / Q000235:genetics; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics / Q000473:pathology*; D008198:Lymph Nodes / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009154:Mutation
chemical_list: D066246:ErbB Receptors
keywords: Histologic classification; Lung adenocarcinoma; Lymph node involvement