title: Low efficacy of serum levels of CA 19-9 in prediction of malignant diseases in asymptomatic population in Taiwan.
abstract: OBJECTIVE
  Serum levels of carbohydrate antigen (CA) 19-9 have long been employed as a biomarker in diagnosing pancreatic cancer in symptomatic patients. We assessed the clinical usefulness of serum CA 19-9 in screening pancreatic cancer and other malignancies in individuals without symptoms.
  
  
  METHODS
  The study enrolled 5,343 consecutive asymptomatic individuals who completed a health check-up comprising serum CA 19-9, chest film, abdominal ultrasonography, esophagogastroduodenoscopy, and colonoscopy or sigmoidoscopy. The sensitivity, specificity and positive predictive rate of CA 19-9 in detecting cancers were analyzed.
  
  
  RESULTS
  There were 385 patients (7.2%) with CA 19-9 higher than 37 U/mL. Two patients diagnosed with pancreatic cancer had CA 19-9 levels of 46,885 U/mL and 88.4 U/mL, respectively. Thirteen among 58 patients with other cancers had CA 19-9 levels higher than 37 U/mL. If the cut-off value of CA 19-9 was set at 37 U/mL, the sensitivity and specificity for pancreatic cancer and other cancers were 100% and 92.8%, as well as 22.4% and 92.9%, respectively. However, the positive predictive rates for pancreatic cancer and other cancers were as low as 0.5% and 3.4%, respectively.
  
  
  CONCLUSIONS
  Efficacy of CA 19-9 in predicting either pancreatic cancer or other cancers in the asymptomatic population is low.
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital, Taipei.
authors.forename: Chi-Yang
authors.initials: CY
authors.lastname: Chang
authors.forename: Shih-Pei
authors.initials: SP
authors.lastname: Huang
authors.forename: Han-Mo
authors.initials: HM
authors.lastname: Chiu
authors.forename: Yi-Chia
authors.initials: YC
authors.lastname: Lee
authors.forename: Min-Fong
authors.initials: MF
authors.lastname: Chen
authors.forename: Jaw-Town
authors.initials: JT
authors.lastname: Lin
mesh_terms: D000328:Adult; D000368:Aged; D018395:CA-19-9 Antigen / Q000097:blood*; D004067:Digestive System Neoplasms / Q000097:blood* / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D013624:Taiwan
chemical_list: D018395:CA-19-9 Antigen