title: Impact of tumor spread to the cystic duct on the prognosis of patients with gallbladder carcinoma.
abstract: BACKGROUND
  The importance of gallbladder carcinoma spread to the cystic duct has not yet been described. Although the cystic duct is contiguous with the gallbladder, it is located in the hepatoduodenal ligament and differs in structure from the gallbladder. The incidence and prognostic significance of cancer spread to the cystic duct in patients with gallbladder cancer is unclear.
  
  
  METHODS
  Surgical specimens from 42 patients who underwent resection for advanced gallbladder carcinoma were examined retrospectively.
  
  
  RESULTS
  Altogether, 13 (31%) of the patients had cancer spread to the cystic duct. The incidences of perineural invasion, lymph node metastasis, and venous invasion were significantly higher in these patients than in the other 29 patients without cancer spread to the cystic duct (P = 0.027, 0.034, and 0.034, respectively). The 3- and 5-year survival rates of these 13 patients were significantly lower than those of the other 29 patients (15.4% vs. 51.0% and 7.7% vs. 46.6%, respectively, P < 0.0001 each). Multivariate analysis using the Cox proportional hazard model identified positive cancer spread to the cystic duct and depth of invasion (beyond serosa) as significant independent indicators of a poor prognosis.
  
  
  CONCLUSIONS
  Cancer spread to the cystic duct is an indicator of poor prognosis in patients with gallbladder carcinoma. This may be due to the high incidence of concomitant perineural invasion and lymph node metastasis associated with cancer spread.
authors.affiliation: Department of Surgery, Shinshu University School of Medicine, Asahi 3-1-1, Matsumoto, Nagano, 390-8621, Japan.
authors.forename: Takenari
authors.initials: T
authors.lastname: Nakata
authors.forename: Akira
authors.initials: A
authors.lastname: Kobayashi
authors.forename: Shiro
authors.initials: S
authors.lastname: Miwa
authors.forename: Junpei
authors.initials: J
authors.lastname: Soeda
authors.forename: Shinichi
authors.initials: S
authors.lastname: Miyagawa
mesh_terms: D000230:Adenocarcinoma / Q000401:mortality* / Q000473:pathology*; D000328:Adult; D000368:Aged; D002760:Cholangiopancreatography, Endoscopic Retrograde; D003549:Cystic Duct / Q000473:pathology*; D004386:Duodenum / Q000294:innervation; D005260:Female; D005706:Gallbladder Neoplasms / Q000401:mortality* / Q000473:pathology*; D006801:Humans; D008022:Ligaments / Q000294:innervation; D008099:Liver / Q000294:innervation; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009415:Nerve Net; D011379:Prognosis; D016016:Proportional Hazards Models; D016019:Survival Analysis