title: The Frequency and Prognostic Impact of Pathological Microscopic Vascular Invasion According to Tumor Size in Non-Small Cell Lung Cancer.
abstract: BACKGROUND
  Microscopic vascular invasion (MVI) in patients with non-small cell lung cancer (NSCLC) has been reported to be a strong predictor of poor outcomes but it has not been a descriptor of the TNM classification. The purposes of this study were to determine whether the presence of MVI is related to a predictor of poor outcomes and to explore the degree of MVI according to tumor size.
  
  
  METHODS
  A total of 1,884 patients with stage pT1-4N0-2 NSCLC who underwent complete resection comprised the study sample. Overall survival (OS) and recurrence-free proportion were estimated using the Kaplan-Meier method. The Cox proportional hazards model was used to assess independent predictors of poor outcomes.
  
  
  RESULTS
  Of 1,884 patients, 1,097 (58.2%) had MVI. Multivariate analysis showed MVI was a significant independent predictor of unfavorable OS (hazard ratio, 1.666; P < .001) and recurrence (hazard ratio, 2.268; P < .001). The frequency of MVI varied according to tumor size, and in each cohort of tumor sizes ≤ 2 cm, > 2 to 3 cm, and > 3 to 5 cm, there were significant differences in survival outcome by MVI status. The proportions of patients with a 5-year recurrence-free period with tumor sizes ≤ 2 cm, > 2 to 3 cm, and > 3 to 5 cm between MVI (+) and MVI (-) were 93.0% and 72.5% (P < .001), 90.8% and 63.3% (P < .001), and 86.4% and 59.9% (P < .001), respectively.
  
  
  CONCLUSIONS
  This study demonstrated that MVI was a strong predictor of poor outcomes and that the effect is more prominent in patients with tumor sizes ≤ 5 cm. Further analysis of survival and MVI should be collected for future revision of the TNM system.
authors.affiliation: Department of Thoracic Surgery, Tokyo Medical University Hospital, Tokyo, Japan. Electronic address: zenkyu@za3.so-net.ne.jp.
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Shimada
authors.affiliation: Department of Chest Surgery, St Marianna University School of Medicine, Kanagawa, Japan.
authors.forename: Hisashi
authors.initials: H
authors.lastname: Saji
authors.affiliation: Department of Thoracic Surgery, Tokyo Medical University Hospital, Tokyo, Japan.
authors.forename: Yasufumi
authors.initials: Y
authors.lastname: Kato
authors.affiliation: Department of Thoracic Surgery, Tokyo Medical University Hospital, Tokyo, Japan.
authors.forename: Yujin
authors.initials: Y
authors.lastname: Kudo
authors.affiliation: Department of Thoracic Surgery, Tokyo Medical University Hospital, Tokyo, Japan.
authors.forename: Junichi
authors.initials: J
authors.lastname: Maeda
authors.affiliation: Department of Thoracic Surgery, Tokyo Medical University Hospital, Tokyo, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Yoshida
authors.affiliation: Department of Thoracic Surgery, Tokyo Medical University Hospital, Tokyo, Japan.
authors.forename: Masaru
authors.initials: M
authors.lastname: Hagiwara
authors.affiliation: Department of Anatomic Pathology, Tokyo Medical University Hospital, Tokyo, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Matsubayashi
authors.affiliation: Department of Thoracic Surgery, Tokyo Medical University Hospital, Tokyo, Japan.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Kakihana
authors.affiliation: Department of Thoracic Surgery, Tokyo Medical University Hospital, Tokyo, Japan.
authors.forename: Naohiro
authors.initials: N
authors.lastname: Kajiwara
authors.affiliation: Department of Thoracic Surgery, Tokyo Medical University Hospital, Tokyo, Japan.
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Ohira
authors.affiliation: Department of Thoracic Surgery, Tokyo Medical University Hospital, Tokyo, Japan.
authors.forename: Norihiko
authors.initials: N
authors.lastname: Ikeda
mesh_terms: D000230:Adenocarcinoma / Q000401:mortality / Q000473:pathology*; D000367:Age Factors; D000368:Aged; D018287:Carcinoma, Large Cell / Q000401:mortality / Q000473:pathology*; D002289:Carcinoma, Non-Small-Cell Lung / Q000401:mortality / Q000473:pathology*; D002294:Carcinoma, Squamous Cell / Q000401:mortality / Q000473:pathology*; D015331:Cohort Studies; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008175:Lung Neoplasms / Q000401:mortality / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology*; D009367:Neoplasm Staging; D011379:Prognosis; D016016:Proportional Hazards Models; D011651:Pulmonary Artery / Q000473:pathology*; D011667:Pulmonary Veins / Q000473:pathology*; D012189:Retrospective Studies; D012737:Sex Factors; D012907:Smoking / Q000453:epidemiology; D047368:Tumor Burden
keywords: microscopic vascular invasion; non-small cell lung cancer; overall survival; pathology lung cancer; recurrence-free proportion; tumor size