title: Study of an elevated carbohydrate antigen 19-9 concentration in a large health check-up cohort in China.
abstract: BACKGROUND
  Carbohydrate antigen 19-9 (CA19-9) is frequently tested in cancer patients. However, elevated CA19-9 can be found in many benign diseases. We investigated the relationship between elevated CA19-9 and diseases, and presented suggestions for its utility in a health check-up cohort.
  
  
  METHODS
  From June 2008 to December 2008, we enrolled consecutive health check-up individuals with elevated CA19-9 (>37 U/mL). They were divided into three groups: group A (malignant diseases), group B (decreasing concentrations), and group C (increasing concentrations) according to the following criteria: (i) CA19-9 was rechecked monthly in the first 3 months; (ii) follow-up was completed if malignancy was found or if CA19-9 concentration dropped to normal; (iii) if CA19-9 kept increasing, it was monitored every 3 months; (4) total duration was 1 year.
  
  
  RESULTS
  Among 33,867 individuals, 572 (1.7%) individuals showed elevated CA19-9 concentration. A total of 509 (90.0%) individuals finished at 1-year follow-up. In total, nine (1.8%) individuals were diagnosed with malignancies. For 336 (66.0%) individuals CA19-9 concentrations dropped to normal, whereas for 164 (32.2%) individuals it kept rising. Interestingly, we did not find any differences in concentration levels between group A and group C. The main associated benign diseases included fatty liver (25.3%), cholecystolithiasis (13.9%), and chronic hepatitis B (13.9%).
  
  
  CONCLUSIONS
  Dynamic monitoring of CA19-9 is recommended in asymptomatic populations with elevated CA19-9 concentrations.
authors.affiliation: Department of Gastroenterology and Hepatology, Hangzhou Binjiang Hospital, the Second Affiliated Hospital (Binjiang Branch) of Zhejiang University, Zhejiang Province, PR China.
authors.forename: Yuling
authors.initials: Y
authors.lastname: Tong
authors.forename: Zhenya
authors.initials: Z
authors.lastname: Song
authors.forename: Weihua
authors.initials: W
authors.lastname: Zhu
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood*; D018395:CA-19-9 Antigen / Q000097:blood*; D002681:China; D041761:Cholecystolithiasis / Q000097:blood* / Q000175:diagnosis; D005234:Fatty Liver / Q000097:blood* / Q000175:diagnosis; D005260:Female; D005500:Follow-Up Studies; D019694:Hepatitis B, Chronic / Q000097:blood* / Q000175:diagnosis; D006801:Humans; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D009369:Neoplasms / Q000097:blood* / Q000175:diagnosis; D065626:Non-alcoholic Fatty Liver Disease
chemical_list: D014408:Biomarkers, Tumor; D018395:CA-19-9 Antigen