title: Histological scoring for small lung adenocarcinomas 2 cm or less in diameter: a reliable prognostic indicator.
abstract: OBJECTIVE
  Lung adenocarcinomas 2 cm or less in diameter were studied to develop histologic criteria predicting the outcome.
  
  
  METHODS
  We reviewed 510 consecutive lung adenocarcinomas 2 cm or less in diameter and assessed three histologic parameters to implement a histologic scoring system: lymphovascular invasion, maximum diameter of the nonbronchioloalveolar carcinoma (BAC) component, and percentage of the solid, cribriform, and/or papillary component in the entire tumor volume (%solid/cribriform/papillary). One point was given to each of lymphovascular invasion-positive, non-BAC >10 mm and %solid/cribriform/papillary > or =30%, and by the sum of these points, a score of 0 to 3 was assigned for each tumor. We also evaluated minimally invasive adenocarcinomas comprising non-BAC < or =5 mm, Sakurai grades 1 and 2.
  
  
  RESULTS
  Five-year disease-free survival rates of 287 patients with a histologic score of 0, 69 with a score of 1, 64 with a score of 2, and 90 with a score of 3 were 98.9%, 92.4%, 78.4%, and 54.0%, respectively. The 510 tumors included 129 noninvasive and 127 minimally invasive adenocarcinomas. None of these tumors recurred. In remaining 254 patients with overtly invasive adenocarcinomas, 5-year disease-free survival rates in 51 with a histologic score of 0, 49 with a score of 1, 64 with a score of 2, and 90 with a score of 3 were 95.9%, 89.2%, 79.4%, and 54.2%, respectively.
  
  
  CONCLUSIONS
  The histologic scoring system comprising lymphovascular invasion-positive, non-BAC >10 mm and %solid/cribriform/papillary > or =30% is able to predict the outcome of lung adenocarcinomas 2 cm or less in diameter not only in all cases but also in overtly invasive adenocarcinomas. Minimally invasive adenocarcinomas did not recur in this large series.
authors.affiliation: Clinical Laboratory Division, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuoku, 104-0045 Tokyo, Japan. akmaeshi@ncc.go.jp
authors.forename: Akiko Miyagi
authors.initials: AM
authors.lastname: Maeshima
authors.forename: Naobumi
authors.initials: N
authors.lastname: Tochigi
authors.forename: Akihiko
authors.initials: A
authors.lastname: Yoshida
authors.forename: Hisao
authors.initials: H
authors.lastname: Asamura
authors.forename: Koji
authors.initials: K
authors.lastname: Tsuta
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Tsuda
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology* / Q000601:surgery; D002282:Adenocarcinoma, Bronchiolo-Alveolar / Q000473:pathology* / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology* / Q000601:surgery; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D011379:Prognosis; D055752:Small Cell Lung Carcinoma / Q000473:pathology* / Q000601:surgery; D015996:Survival Rate; D055815:Young Adult