title: Prognosis of invasive intraductal papillary mucinous neoplasm depends on histological and precursor epithelial subtypes.
abstract: OBJECTIVE
  Invasive cancers arising from intraductal papillary mucinous neoplasm (IPMN) are recognised as a morphologically and biologically heterogeneous group of neoplasms. Less is known about the epithelial subtypes of the precursor IPMN from which these lesions arise. The authors investigate the clinicopathological characteristics and the impact on survival of both the invasive component and its background IPMN.
  
  
  METHODS
  The study cohort comprised 61 patients with invasive IPMN (study group) and 570 patients with pancreatic ductal adenocarcinoma (PDAC, control group) resected at a single institution. Multivariate analyses were performed using a stage-matched Cox proportional hazard model.
  
  
  RESULTS
  The histology of invasive components of the IPMN cohort was tubular in 38 (62%), colloid in 16 (26%), and oncocytic in seven (12%). Compared with PDAC, invasive IPMNs were associated with a lower incidence of adverse pathological features and improved mortality by multivariate analysis (HR 0.58; 95% CI 0.39 to 0.86). In subtype analysis, this favourable outcome remained only for colloid and oncocytic carcinomas, while tubular adenocarcinoma was associated with worse overall survival, not significantly different from that of PDAC (HR 0.85; 95% CI 0.53 to 1.36). Colloid and oncocytic carcinomas arose only from intestinal- and oncocytic-type IPMNs, respectively, and were mostly of the main-duct type, whereas tubular adenocarcinomas primarily originated in the gastric background, which was often associated with branch-duct IPMN. Overall survival of patients with invasive adenocarcinomas arising from gastric-type IPMN was significantly worse than that of patients with non-gastric-type IPMN (p=0.016).
  
  
  CONCLUSIONS
  Tubular, colloid and oncocytic invasive IPMNs have varying prognosis, and arise from different epithelial subtypes. Colloid and oncocytic types have markedly improved biology, whereas the tubular type has a course that resembles PDAC. Analysis of these subtypes indicates that the background epithelium plays an equally, if not more, important role in defining the biology and prognosis of invasive IPMNs.
authors.affiliation: Department of Pathology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA. mminokenudson@partners.org
authors.forename: Mari
authors.initials: M
authors.lastname: Mino-Kenudson
authors.forename: Carlos
authors.initials: C
authors.lastname: Fernández-del Castillo
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Baba
authors.forename: Nakul P
authors.initials: NP
authors.lastname: Valsangkar
authors.forename: Andrew S
authors.initials: AS
authors.lastname: Liss
authors.forename: Maylee
authors.initials: M
authors.lastname: Hsu
authors.forename: Camilo
authors.initials: C
authors.lastname: Correa-Gallego
authors.forename: Thun
authors.initials: T
authors.lastname: Ingkakul
authors.forename: Rocio
authors.initials: R
authors.lastname: Perez Johnston
authors.forename: Brian G
authors.initials: BG
authors.lastname: Turner
authors.forename: Vasiliki
authors.initials: V
authors.lastname: Androutsopoulos
authors.forename: Vikram
authors.initials: V
authors.lastname: Deshpande
authors.forename: Deborah
authors.initials: D
authors.lastname: McGrath
authors.forename: Dushyant V
authors.initials: DV
authors.lastname: Sahani
authors.forename: William R
authors.initials: WR
authors.lastname: Brugge
authors.forename: Shuji
authors.initials: S
authors.lastname: Ogino
authors.forename: Martha B
authors.initials: MB
authors.lastname: Pitman
authors.forename: Andrew L
authors.initials: AL
authors.lastname: Warshaw
authors.forename: Sarah P
authors.initials: SP
authors.lastname: Thayer
mesh_terms: D002288:Adenocarcinoma, Mucinous / Q000175:diagnosis* / Q000473:pathology; D000368:Aged; D021441:Carcinoma, Pancreatic Ductal / Q000175:diagnosis* / Q000473:pathology; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009361:Neoplasm Invasiveness / Q000473:pathology; D010179:Pancreas / Q000473:pathology; D010190:Pancreatic Neoplasms / Q000175:diagnosis* / Q000473:pathology; D011379:Prognosis; D016016:Proportional Hazards Models