title: Systematic review and meta-analysis of the spectrum and outcomes of different histologic subtypes of noninvasive and invasive intraductal papillary mucinous neoplasms.
abstract: BACKGROUND
  Our aim was to review the available evidence to determine the clinical importance of the histologic subtypes of noninvasive and invasive intraductal papillary mucinous neoplasms (IPMNs) on disease characteristics and overall survival.
  
  
  METHODS
  We reviewed systematically 14 comparative studies that reported clinicopathologic characteristics and survival of 1,617 patients with IPMN (900 noninvasive and 717 invasive).
  
  
  RESULTS
  The pancreatobiliary subtype was associated with the greatest likelihood of tumor invasion (67.9%; odds ratio [OR], 2.87; 95% CI, 1.90-4.35), harboring an associated mural nodule (56.6%; OR, 2.92; 95% CI, 1.21-7.04), demonstrating tumor recurrence (46.3%; OR, 3.28; 95% CI, 1.41-7.66) and transformation to tubular adenocarcinoma (81.8%; OR, 92.96; 95% CI, 20.76-416.28) among all subtypes. The gastric subtype was associated with the least likelihood of tumor invasion (10.2%; OR, 0.18; 95% CI, 0.13-0.26), association with main duct IPMN (19.2%; OR, 0.12; 95% CI, 0.06-0.26), and tumor recurrence (9.4%; OR, 0.47; 95% CI, 0.26-0.83) among all subtypes. The intestinal subtype had the greatest likelihood of progressing to colloid carcinoma among all subtypes. Tubular adenocarcinoma was associated with an increased risk of vascular invasion (32.9%; OR, 4.86; 95% CI, 1.96-12.01), perineural invasion (54.5%; OR, 2.30; 95% CI, 1.22-4.34), nodal metastasis (52.4%; OR, 3.31; 95% CI, 1.79-6.14), and a positive margin status (17.3%; OR, 8.45; 95% CI, 1.52-46.83). Tubular adenocarcinoma (hazard ratio [HR], 1.90; 95% CI, 1.36-2.67) had a poorer 5-year overall survival compared with colloid carcinoma and was similar to the survival observed in pancreatic ductal adenocarcinoma (HR, 2.00; 95% CI, 1.59-2.52).
  
  
  CONCLUSIONS
  The prognosis of IPMN depends on its pathologic subtype. Subtype identification should be considered an essential component in future guidelines for the management of IPMN.
authors: Department of Hepatopancreatobiliary and Transplantation Surgery, Singapore General Hospital, Singapore.
authors: Ye Xin
authors: YX
authors: Koh
authors: Saw Swee Hock School of Public Health, National University of Singapore, Singapore.
authors: Hui Li
authors: HL
authors: Zheng
authors: Department of Hepatopancreatobiliary and Transplantation Surgery, Singapore General Hospital, Singapore.
authors: Aik-Yong
authors: AY
authors: Chok
authors: Saw Swee Hock School of Public Health, National University of Singapore, Singapore.
authors: Chuen Seng
authors: CS
authors: Tan
authors: Department of Hepatopancreatobiliary and Transplantation Surgery, Singapore General Hospital, Singapore.
authors: Wyiki
authors: W
authors: Wyone
authors: Department of Pathology, Singapore General Hospital, Singapore.
authors: Tony K H
authors: TK
authors: Lim
authors: Department of Gastroenterology and Hepatology, Singapore General Hospital, Singapore.
authors: Damien M Y
authors: DM
authors: Tan
authors: Department of Hepatopancreatobiliary and Transplantation Surgery, Singapore General Hospital, Singapore; Duke-NUS Graduate Medical School, Singapore. Electronic address: bsgkp@hotmail.com.
authors: Brian K P
authors: BK
authors: Goh
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology; D002288:Adenocarcinoma, Mucinous / Q000145:classification / Q000401:mortality / Q000473:pathology*; D021441:Carcinoma, Pancreatic Ductal / Q000145:classification / Q000401:mortality / Q000473:pathology*; D002291:Carcinoma, Papillary / Q000145:classification / Q000401:mortality / Q000473:pathology*; D018450:Disease Progression; D006801:Humans; D009361:Neoplasm Invasiveness; D010190:Pancreatic Neoplasms / Q000145:classification / Q000401:mortality / Q000473:pathology*