title: Relevance of EGFR mutation with micropapillary pattern according to the novel IASLC/ATS/ERS lung adenocarcinoma classification and correlation with prognosis in Chinese patients.
abstract: BACKGROUND
  A new histological classification by the International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society (IASLC/ATS/ERS) for lung adenocarcinoma (LAC) was proposed recently, in which a micropapillary pattern (MPP) was described.
  
  
  OBJECTIVE
  This study aimed to evaluate the clinicopathological characteristics of LAC with MPP (LAC-MPP) and to investigate the correlation between LAC-MPP and epidermal growth factor receptor (EGFR) mutation status with the prognosis in Chinese patients.
  
  
  METHODS
  From May 2007 and February 2012, two hundred and forty-eight patients underwent resection and pathologically confirmed LAC. We classified all cases histologically according to the IASLC/ATS/ERS classification; an MPP ratio ≥5% was considered MPP-positive. Used Pearson's chi-square test to evaluate the relationships between EGFR mutation status and MPP status with patient clinicopathological characteristics.
  
  
  RESULTS
  There were MPP-positive tumors (MPP ratio ≥5%) in 31.9% of cases (79/248); the MPP ratio correlated with TNM stage (p=0.001) and lymph node metastasis (p=0.03). EGFR mutation (EGFR-mut) was detected in 87 cases (34.3%); 161 cases had wild-type EGFR (EGFR-wt). EGFR mutation was present in 65% of the MPP-positive subtype. Patients with EGFR-mut tumors had significantly longer overall survival (OS) (p=0.002). OS was also significantly longer in MPP-negative EGFR-mut or EGFR-wt patients (p<0.001).
  
  
  CONCLUSIONS
  These findings indicate that EGFR-mut tumors are likelier to be MPP-positive subtypes and that MPP may be a novel potential pathological marker of poor prognosis in Chinese LAC patients.
authors.affiliation: Department of Pathology and Laboratory Medicine, Guangdong General Hospital & Guangdong Academy of Medical Sciences, Guangzhou 510080, China.
authors.forename: Liu
authors.initials: L
authors.lastname: Chao
authors.affiliation: Guangdong Lung Cancer Institute, Guangdong General Hospital & Guangdong Academy of Medical Sciences, Guangzhou 510080, China.
authors.forename: Huang
authors.initials: H
authors.lastname: Yi-Sheng
authors.affiliation: Department of Pathology and Laboratory Medicine, Guangdong General Hospital & Guangdong Academy of Medical Sciences, Guangzhou 510080, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Yu
authors.affiliation: Department of Pathology and Laboratory Medicine, Guangdong General Hospital & Guangdong Academy of Medical Sciences, Guangzhou 510080, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Li-Xu
authors.affiliation: Department of Pathology and Laboratory Medicine, Guangdong General Hospital & Guangdong Academy of Medical Sciences, Guangzhou 510080, China.
authors.forename: Luo
authors.initials: L
authors.lastname: Xin-Lan
authors.affiliation: Department of Pathology and Laboratory Medicine, Guangdong General Hospital & Guangdong Academy of Medical Sciences, Guangzhou 510080, China.
authors.forename: Luo
authors.initials: L
authors.lastname: Dong-Lan
authors.affiliation: Department of Pathology and Laboratory Medicine, Guangdong General Hospital & Guangdong Academy of Medical Sciences, Guangzhou 510080, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Jie
authors.affiliation: Guangdong Lung Cancer Institute, Guangdong General Hospital & Guangdong Academy of Medical Sciences, Guangzhou 510080, China. Electronic address: syylwu@live.cn.
authors.forename: Wu
authors.initials: W
authors.lastname: Yi-Lon
authors.affiliation: Department of Pathology and Laboratory Medicine, Guangdong General Hospital & Guangdong Academy of Medical Sciences, Guangzhou 510080, China. Electronic address: chao830122@126.com.
authors.forename: Liu Yan
authors.initials: LY
authors.lastname: Hui
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis / Q000235:genetics* / Q000401:mortality / Q000473:pathology*; D000077192:Adenocarcinoma of Lung; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People / Q000235:genetics*; D002681:China; D004252:DNA Mutational Analysis; D066246:ErbB Receptors / Q000235:genetics*; D005091:Exons; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis / Q000235:genetics* / Q000401:mortality / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D011379:Prognosis; D012307:Risk Factors; D047368:Tumor Burden; D055815:Young Adult
chemical_list: D066246:ErbB Receptors
keywords: Classification; Epidermal growth factor receptor (EGFR); Micropapillary pattern (MPP); Mutation; Non-small cell lung cancer; Survival