title: Relationship between autoimmune pancreatitis and pancreatic cancer: a single-center experience.
abstract: OBJECTIVE
  Ordinary chronic pancreatitis (CP), such as alcoholic CP, is well established to have the increased risk for pancreatic cancer (PaC), nevertheless an association between autoimmune pancreatitis (AIP) and PaC is still unknown. The aims of this study are to examine the frequency of patients who developed PaC during follow-up after being diagnosed with type 1 AIP and to compare the incidence rate of PaC between patients with type 1 AIP and CP.
  
  
  METHODS
  Sixty-three patients with type 1 AIP and 41 patients with CP were enrolled. We examined development of PaC during follow-up from their clinical records.
  
  
  RESULTS
  The mean follow-up period was 62.4 months in AIP group and 49.2 months in CP group. The occurrence of PaC was observed in 3 patients with AIP during the mean follow-up period of 94.7 months (range, 31-186), whereas a single CP patient developed PaC 38 months after CP diagnosis. The incident rate of PaC during follow-up was comparable between the 2 groups [4.8% (3/63) in type 1 AIP group vs. 2.4% (1/41) in CP group]. In all of 3 AIP patients who developed accompanying PaC, the clinical remission of AIP was achieved with maintenance steroid therapy, when tumors were discovered. In the histological examination of one surgical patient with PaC, lymphoplasmacytic infiltration in storiform fibrosis with abundant IgG4-positive cell infiltration was observed around the PaC area.
  
  
  CONCLUSIONS
  Similar to patients with ordinary CP, surveillance for development of PaC is needed at regular interval during follow-up in AIP patients.
authors.affiliation: The Third Department of Internal Medicine, Kansai Medical University, Osaka, Japan. Electronic address: ikeurat@takii.kmu.ac.jp.
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Ikeura
authors.affiliation: The Third Department of Internal Medicine, Kansai Medical University, Osaka, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Miyoshi
authors.affiliation: The Third Department of Internal Medicine, Kansai Medical University, Osaka, Japan.
authors.forename: Kazushige
authors.initials: K
authors.lastname: Uchida
authors.affiliation: The Third Department of Internal Medicine, Kansai Medical University, Osaka, Japan.
authors.forename: Toshiro
authors.initials: T
authors.lastname: Fukui
authors.affiliation: The Third Department of Internal Medicine, Kansai Medical University, Osaka, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Shimatani
authors.affiliation: The Third Department of Internal Medicine, Kansai Medical University, Osaka, Japan.
authors.forename: Yuri
authors.initials: Y
authors.lastname: Fukui
authors.affiliation: The Third Department of Internal Medicine, Kansai Medical University, Osaka, Japan.
authors.forename: Kimi
authors.initials: K
authors.lastname: Sumimoto
authors.affiliation: The Third Department of Internal Medicine, Kansai Medical University, Osaka, Japan.
authors.forename: Mitsunobu
authors.initials: M
authors.lastname: Matsushita
authors.affiliation: The Third Department of Internal Medicine, Kansai Medical University, Osaka, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Takaoka
authors.affiliation: The Third Department of Internal Medicine, Kansai Medical University, Osaka, Japan.
authors.forename: Kazuichi
authors.initials: K
authors.lastname: Okazaki
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001327:Autoimmune Diseases / Q000150:complications*; D016022:Case-Control Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D010195:Pancreatitis / Q000150:complications* / Q000276:immunology; D050500:Pancreatitis, Chronic / Q000150:complications; D012307:Risk Factors
keywords: Autoimmune pancreatitis; Carcinogenesis; Chronic pancreatitis; Diagnosis; IgG4; Pancreatic cancer