title: Pancreatic ductal adenocarcinomas in long-term follow-up patients with branch duct intraductal papillary mucinous neoplasms.
abstract: OBJECTIVE
  Although branch duct intraductal papillary mucinous neoplasms (BD-IPMNs) are slow-growing tumors with a favorable prognosis, the synchronous occurrence of pancreatic ductal adenocarcinomas (PDAs) in patients with BD-IPMNs has been reported. This study was aimed to elucidate the development of PDAs in long-term follow-up patients with BD-IPMNs.
  
  
  METHODS
  We investigated 89 BD-IPMN patients who had no mural nodules and followed them up conservatively at least 2 years (median follow-up, 64 months; range, 25-158 months). All subjects underwent examinations by imaging modalities including endoscopic retrograde pancreatography. We calculated the standardized incidence ratio (SIR) from the vital statistics compiled by the Ministry of Health, Labor, and Welfare of Japan.
  
  
  RESULTS
  Among the 89 patients, 4 cases of PDAs distant from BD-IPMN were observed in 552 patient-years of follow-up (7.2 per 1000 patient-years). The expected number was 0.25, and the SIR of PDAs was 15.8 (95% confidence interval [CI], 4.3-40.4; P = 0.00014). Subgroup analyses showed that the incidence of PDAs was significantly increased in patients 70 years or older (SIR 16.7; 95% CI, 3.4-48.7; P = 0.0008) and in women (SIR 22.5; 95% CI, 2.7-81.1; P = 0.0037).
  
  
  CONCLUSIONS
  Patients with BD-IPMNs are at a high risk for PDAs. During the follow-up, careful examination is required to detect the development of PDAs in patients with BD-IPMNs.
authors.affiliation: Department of General Medicine, Asahikawa Medical College, Asahikawa, Japan. tanno1se@asahikawa-med.ac.jp
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tanno
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Nakano
authors.forename: Kazuya
authors.initials: K
authors.lastname: Koizumi
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Sugiyama
authors.forename: Kazumasa
authors.initials: K
authors.lastname: Nakamura
authors.forename: Junpei
authors.initials: J
authors.lastname: Sasajima
authors.forename: Tomoya
authors.initials: T
authors.lastname: Nishikawa
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Mizukami
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Yanagawa
authors.forename: Tsuneshi
authors.initials: T
authors.lastname: Fujii
authors.forename: Toshikatsu
authors.initials: T
authors.lastname: Okumura
authors.forename: Takeshi
authors.initials: T
authors.lastname: Obara
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Kohgo
mesh_terms: D002288:Adenocarcinoma, Mucinous / Q000473:pathology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D021441:Carcinoma, Pancreatic Ductal / Q000473:pathology*; D002291:Carcinoma, Papillary / Q000473:pathology*; D049448:Cholangiopancreatography, Magnetic Resonance; D018450:Disease Progression; D019160:Endosonography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000473:pathology*; D011379:Prognosis; D013997:Time Factors; D014057:Tomography, X-Ray Computed