title: Risk factors for postoperative recurrence of intraductal papillary mucinous neoplasms of the pancreas based on a long-term follow-up study: proposals for follow-up strategies.
abstract: BACKGROUND
  The aim of this study was to examine the associations between postoperative clinicopathological features of intraductal papillary mucinous neoplasm (IPMN) and recurrence over a long follow-up period.
  
  
  METHODS
  We retrospectively assessed 153 IPMN patients who underwent resection.
  
  
  RESULTS
  The resected tumors showed low/intermediate-grade dysplasia (LGD/IGD), high-grade dysplasia (HGD), T1a (stromal invasion ≤5 mm), and invasive intraductal papillary mucinous carcinoma (IPMC), in 54.9%, 22.2%, 4.6%, and 18.3% of patients, respectively. The median follow-up period after surgery was 46.4 (6.0-216.3) months, with an overall recurrence rate of 17.0%; the recurrence rates by histological type were 6.0%, 5.9%, 42.9%, and 57.1% for LGD/IGD, HGD, T1a, and invasive IPMC, respectively. Multivariate analysis revealed that recurrences related with tumor location, mural nodule size, presence of invasive cancer, lymph node metastasis, IPMN in the remnant pancreas, and main pancreatic duct dilatation after surgery. Recurrence occurred within the remnant pancreas in all LGD-T1a patients and as extrapancreatic metastasis in all patients with invasive IPMC. Of the total recurrences, 15.4% occurred over 5 years postoperatively.
  
  
  CONCLUSIONS
  The postoperative follow-up protocol for patients with LGD-T1a should be similar to non-resected IPMN, and that for invasive IPMC should be the same as for pancreatic ductal adenocarcinoma patients.
authors.affiliation: Department of Gastroenterology, Aichi Cancer Center Hospital, Nagoya, Japan.|Department of Infectious, Respiratory, and Digestive Medicine, Control and Prevention of Infectious Diseases (First Department of Internal Medicine), Faculty of Medicine, University of the Ryukyus, Okinawa, Japan.
authors.forename: Tatsuji
authors.initials: T
authors.lastname: Yogi
authors.affiliation: Department of Gastroenterology, Aichi Cancer Center Hospital, Nagoya, Japan.
authors.forename: Susumu
authors.initials: S
authors.lastname: Hijioka
authors.affiliation: Department of Gastroenterology, Aichi Cancer Center Hospital, Nagoya, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Imaoka
authors.affiliation: Department of Gastroenterology, Aichi Cancer Center Hospital, Nagoya, Japan.
authors.forename: Nobumasa
authors.initials: N
authors.lastname: Mizuno
authors.affiliation: Department of Gastroenterology, Aichi Cancer Center Hospital, Nagoya, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Hara
authors.affiliation: Department of Endoscopy, Aichi Cancer Center Hospital, Nagoya, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Tajika
authors.affiliation: Department of Endoscopy, Aichi Cancer Center Hospital, Nagoya, Japan.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Tanaka
authors.affiliation: Department of Endoscopy, Aichi Cancer Center Hospital, Nagoya, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Ishihara
authors.affiliation: Department of Gastrointestinal Surgery, Aichi Cancer Center Hospital, Nagoya, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Shimizu
authors.affiliation: Department of Pathology and Molecular Diagnostics, Aichi Cancer Center Hospital, Nagoya, Japan.
authors.forename: Waki
authors.initials: W
authors.lastname: Hosoda
authors.affiliation: Department of Pathology and Molecular Diagnostics, Aichi Cancer Center Hospital, Nagoya, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Yatabe
authors.affiliation: Department of Endoscopy, Aichi Cancer Center Hospital, Nagoya, Japan.
authors.forename: Yasumasa
authors.initials: Y
authors.lastname: Niwa
authors.affiliation: Innovative Clinical Research Center, Kanazawa University, Kanazawa, Japan.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Yoshimura
authors.affiliation: Department of Hepatology, Institute of Liver and Biliary Sciences, Delhi, India.
authors.forename: Vikram
authors.initials: V
authors.lastname: Bhatia
authors.affiliation: Department of Infectious, Respiratory, and Digestive Medicine, Control and Prevention of Infectious Diseases (First Department of Internal Medicine), Faculty of Medicine, University of the Ryukyus, Okinawa, Japan.
authors.forename: Jiro
authors.initials: J
authors.lastname: Fujita
authors.affiliation: Department of Gastroenterology, Aichi Cancer Center Hospital, Nagoya, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Yamao
mesh_terms: D002288:Adenocarcinoma, Mucinous / Q000401:mortality / Q000473:pathology* / Q000601:surgery*; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D021441:Carcinoma, Pancreatic Ductal / Q000401:mortality / Q000473:pathology* / Q000601:surgery*; D002291:Carcinoma, Papillary / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D015331:Cohort Studies; D016208:Databases, Factual; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007564:Japan; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009364:Neoplasm Recurrence, Local / Q000401:mortality / Q000473:pathology*; D010180:Pancreatectomy / Q000009:adverse effects / Q000379:methods; D011183:Postoperative Complications / Q000473:pathology / Q000601:surgery; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D018570:Risk Assessment; D012737:Sex Factors; D016019:Survival Analysis; D013997:Time Factors; D016896:Treatment Outcome
keywords: Follow-up; Intraductal papillary mucinous neoplasm; Pancreas; Prognosis; Recurrence