title: Clinical significance of subepithelial growth patterns in non-muscle invasive bladder cancer.
abstract: BACKGROUND
  We evaluated the clinical significance and prognostic value of histopathological features of bladder cancer, such as subepithelial growth patterns and tumor growth pattern at the invasion front.
  
  
  METHODS
  In total, 130 patients newly diagnosed with non-muscle invasive bladder cancer and underwent transurethral resection between 1998 and 2009 were enrolled. Subepithelial growth patterns consisting of endophytic growth pattern (EGP) and von Brunn's nest involvement (VBNI) were investigated using hematoxylin and eosin-stained slides, and their frequency of occurrence, prognostic value, and correlation with other clinicopathological features was evaluated.
  
  
  RESULTS
  EGP and VBNI were found in 40 (30.8%) and 5 (3.9%) of the 130 cases, respectively. Of the 26 pT1 tumors, the growth pattern at the invasion front was trabecular in 17 (65.4%) and infiltrative in 9 (34.6%). Although 8 (47.1%) of 17 trabecular tumors coexisted with EGP, no cases with infiltrative tumors had EGP (p = 0.023). VBNI correlated with high tumor grades (p = 0.006) and lymphovascular involvement (p = 0.026). The multivariate Cox proportional hazards analysis revealed that tumor diameter less than 3 cm (p = 0.04) and intravesical bacillus Calmette-Guérin therapy (p = 0.004) were independent favorable prognostic factors for recurrence-free survival, whereas tumor stage was an independent poor prognostic factor for disease progression (p = 0.006).
  
  
  CONCLUSIONS
  Subepithelial growth patterns were not a significant prognostic factor in this study. Additionally, no tumors with an infiltrative growth pattern coexisted with EGP, suggesting that determining the presence of EGP might be helpful for managing non-muscle invasive bladder cancers.
authors.affiliation: Department of Urology, Hirao Hospital, 6-28 Hyobu-cho, Kashihara-shi, Nara, Japan. mm-ulo@naramed-u.ac.jp
authors.forename: Makito
authors.initials: M
authors.lastname: Miyake
authors.forename: Shuya
authors.initials: S
authors.lastname: Hirao
authors.forename: Hisakazu
authors.initials: H
authors.lastname: Mibu
authors.forename: Masahiro
authors.initials: M
authors.lastname: Tanaka
authors.forename: Kenji
authors.initials: K
authors.lastname: Takashima
authors.forename: Keiji
authors.initials: K
authors.lastname: Shimada
authors.forename: Kazuya
authors.initials: K
authors.lastname: Hirao
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D012189:Retrospective Studies; D001749:Urinary Bladder Neoplasms / Q000473:pathology*; D019459:Urothelium / Q000473:pathology*