title: Comparison of Clinical Characteristics between Occupational and Sporadic Young-Onset Cholangiocarcinoma.
abstract: BACKGROUND
  Since seventeen employees of an offset printing company in Osaka, Japan developed cholangiocarcinoma it has become recognized as an occupational cancer. This study investigated the differences of clinical features between occupational cholangiocarcinoma and sporadic young-onset cholangiocarcinoma.
  
  
  METHODS
  Thirty-four young adults (<50 years old) with sporadic cholangiocarcinoma were extracted from the Rosai Hospital Group database (sporadic group) and their clinical features were compared with those of 17 patients with occupational cholangiocarcinoma (occupational group).
  
  
  RESULTS
  The 34 patients in the sporadic group were treated for cholangiocarcinoma at 16 different Rosai hospitals. There were significant differences of age (p<0.01), gender (p<0.01), abnormal laboratory tests (p<0.01), and tumor location (p<0.01) between the two groups. The percentage of patients with abnormal laboratory tests was significantly higher in the occupational group than in the sporadic group (p<0.001). Regional dilation of bile ducts, which is a characteristic of occupational cholangiocarcinoma, was not observed in the sporadic group.
  
  
  CONCLUSIONS
  No cluster of cholangiocarcinoma cases was identified in the Rosai Hospital database. There were differences of clinical features between occupational and sporadic cholangiocarcinoma, which might be helpful for diagnosing occupational cholangiocarcinoma in the future.
authors.affiliation: Department of Gastroenterology, Japan Labour Health and Welfare Organization Kanto Rosai Hospital, Osaka, Japan E-mail : rena@kantoh.rofuku.go.jp.
authors.forename: Rena
authors.initials: R
authors.lastname: Kaneko
authors.forename: Shoji
authors.initials: S
authors.lastname: Kubo
authors.forename: Yuzuru
authors.initials: Y
authors.lastname: Sato
mesh_terms: D000328:Adult; D017668:Age of Onset; D001650:Bile Duct Neoplasms / Q000453:epidemiology / Q000209:etiology / Q000473:pathology*; D001653:Bile Ducts, Intrahepatic / Q000473:pathology*; D018281:Cholangiocarcinoma / Q000453:epidemiology / Q000209:etiology / Q000473:pathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009784:Occupational Diseases / Q000453:epidemiology / Q000209:etiology / Q000473:pathology*; D016273:Occupational Exposure / Q000009:adverse effects*; D011379:Prognosis