title: Factors influencing the concordance of histological subtype diagnosis from biopsy and resected specimens of lung adenocarcinoma.
abstract: OBJECTIVE
  Lung adenocarcinoma is heterogeneous, characterized by various histological subtypes. Determination of the predominant histological subtype (lepidic, papillary, acinar or solid-predominant) has been shown to correlate with genetic abnormalities and clinicopathological features. Although subtyping using small biopsy samples is important for tailored approaches to clinical management, limited data exist on the concordance of predominant subtype between resected specimens and biopsy specimens.
  
  
  METHODS
  We compared the diagnosed predominant subtypes in resected specimens and matched biopsy specimens in a series of 327 lung adenocarcinomas. The accuracy of preoperative diagnosis by biopsy and the factors that influence concordance with resected specimen analysis were examined.
  
  
  RESULTS
  In 211 of the 326 patients (66.0%), the predominant adenocarcinoma subtype diagnosed from biopsy matched the findings of resection analysis. Overall, the concordance rate in biopsy samples with larger tumor areas (≥ 0.7 mm(2)) was significantly higher than in those with smaller tumor area (<0.7 mm(2); 71.2% vs 60.7%, respectively; p=0.015). In the biopsy samples with smaller tumor areas, the concordance rate was 77% in lepidic subtype, 71% in papillary subtype, 60% in solid subtype, and 40% in acinar subtype. Concordance rate in the biopsy samples with larger tumor area was higher in papillary and solid subtypes (88% and 76%, respectively), but remained low in acinar subtype (37%).
  
  
  CONCLUSIONS
  The current results indicate that accuracy of adenocarcinoma subtyping based on small biopsy samples is influenced by tumor area. Our study also suggests that subtyping of acinar histology using biopsy specimen is particularly error-prone.
authors.affiliation: Division of Pathology, Exploratory Oncology Research & Clinical Trial Center, National Cancer Center, Japan; Department of Thoracic Oncology, National Cancer Center Hospital East, Japan.
authors.forename: Reiko
authors.initials: R
authors.lastname: Matsuzawa
authors.affiliation: Department of Thoracic Oncology, National Cancer Center Hospital East, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Kirita
authors.affiliation: Division of Pathology, Exploratory Oncology Research & Clinical Trial Center, National Cancer Center, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kuwata
authors.affiliation: Department of Thoracic Oncology, National Cancer Center Hospital East, Japan.
authors.forename: Shigeki
authors.initials: S
authors.lastname: Umemura
authors.affiliation: Department of Thoracic Oncology, National Cancer Center Hospital East, Japan.
authors.forename: Shingo
authors.initials: S
authors.lastname: Matsumoto
authors.affiliation: Division of Pathology, Exploratory Oncology Research & Clinical Trial Center, National Cancer Center, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Fujii
authors.affiliation: Department of Thoracic Oncology, National Cancer Center Hospital East, Japan.
authors.forename: Kiyotaka
authors.initials: K
authors.lastname: Yoh
authors.affiliation: Division of Pathology, Exploratory Oncology Research & Clinical Trial Center, National Cancer Center, Japan.
authors.forename: Motohiro
authors.initials: M
authors.lastname: Kojima
authors.affiliation: Department of Thoracic Oncology, National Cancer Center Hospital East, Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Niho
authors.affiliation: Department of Thoracic Oncology, National Cancer Center Hospital East, Japan.
authors.forename: Hironobu
authors.initials: H
authors.lastname: Ohmatsu
authors.affiliation: Division of Pathology, Exploratory Oncology Research & Clinical Trial Center, National Cancer Center, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Ochiai
authors.affiliation: Department of Thoracic Surgery, National Cancer Center Hospital East, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Tsuboi
authors.affiliation: Department of Thoracic Oncology, National Cancer Center Hospital East, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Goto
authors.affiliation: Division of Pathology, Exploratory Oncology Research & Clinical Trial Center, National Cancer Center, Japan. Electronic address: gishii@east.ncc.go.jp.
authors.forename: Genichiro
authors.initials: G
authors.lastname: Ishii
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis* / Q000601:surgery; D000077192:Adenocarcinoma of Lung; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011184:Postoperative Period; D057234:Preoperative Period; D047368:Tumor Burden
keywords: Biopsy specimen; IASLC/ATS/ERS classification; Predominant subtype; Resected specimen