title: Diffusion-weighted MR imaging of pancreatic cancer and inflammation: Prognostic significance of pancreatic inflammation in pancreatic cancer patients.
abstract: BACKGROUND
  Pancreatic cancer often accompanies chronic obstructive pancreatitis (COP) due to obstruction of the main pancreatic duct, and the inflammatory environment may enhance cancer progression. The purpose of this study is to evaluate COP using the apparent diffusion coefficient (ADC) value measured by diffusion-weighted MR imaging (DWI), and to assess its prognostic significance in pancreatic cancer.
  
  
  METHODS
  Twenty-eight patients (16 men, 12 women; mean age 67.1 years) with pancreatic cancers who underwent DWI followed by curative surgery were evaluated. The ADC value of pancreatic parenchyma upstream to the tumor (upstream pancreas) was measured and compared with the upstream pancreatic duct dilatation to assess whether DWI could reflect COP. The ADC values of tumor and upstream portion were compared with overall survival (OS) using Cox regression and Kaplan-Meier analysis.
  
  
  RESULTS
  The ADC value of upstream pancreas was significantly lower in patients with greater dilated pancreatic duct than those with less (P = 0.03). In univariate Cox regression analysis, the ADC value of upstream pancreas showed a significant association with OS (P = 0.01), but that of tumor did not (P = 0.06). In Kaplan-Meier analysis, patients with lower ADC value of upstream pancreas (<1.36 × 10(-3) mm(2)/s) were significantly associated with poor OS (P = 0.0006). In multivariate analysis, the ADC value of upstream pancreas was identified as an independent prognostic factor (P = 0.01; hazards ratio, 0.05; 95% CI, 0.004-0.59).
  
  
  CONCLUSIONS
  The ADC value of upstream pancreas was an independent prognostic factor for OS in pancreatic cancer patients. Inflammatory environment may play an important role in pancreatic cancer progression.
authors.affiliation: Department of Surgery, Teikyo University School of Medicine, Tokyo, Japan; Department of Frontier Surgery, Chiba University Graduate School of Medicine, Chiba, Japan. Electronic address: hayatin1973@yahoo.co.jp.
authors.forename: Koichi
authors.initials: K
authors.lastname: Hayano
authors.affiliation: Department of Surgery, Teikyo University School of Medicine, Tokyo, Japan.
authors.forename: Fumihiko
authors.initials: F
authors.lastname: Miura
authors.affiliation: Department of Surgery, Teikyo University School of Medicine, Tokyo, Japan.
authors.forename: Keita
authors.initials: K
authors.lastname: Wada
authors.affiliation: Department of Frontier Surgery, Chiba University Graduate School of Medicine, Chiba, Japan.
authors.forename: Kazufumi
authors.initials: K
authors.lastname: Suzuki
authors.affiliation: Department of Radiology, Teikyo University School of Medicine, Tokyo, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Takeshita
authors.affiliation: Department of Surgery, Teikyo University School of Medicine, Tokyo, Japan.
authors.forename: Hodaka
authors.initials: H
authors.lastname: Amano
authors.affiliation: Department of Surgery, Teikyo University School of Medicine, Tokyo, Japan.
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Toyota
authors.affiliation: Department of Surgery, Teikyo University School of Medicine, Tokyo, Japan.
authors.forename: Keiji
authors.initials: K
authors.lastname: Sano
authors.affiliation: Department of Surgery, Teikyo University School of Medicine, Tokyo, Japan.
authors.forename: Takehide
authors.initials: T
authors.lastname: Asano
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D007249:Inflammation / Q000000981:diagnostic imaging* / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D012189:Retrospective Studies
keywords: Apparent diffusion coefficient; Diffusion-weighted imaging; Inflammation; Pancreatic cancer; Pancreatitis; Survival