title: Tumor markers are elevated in patients with rheumatoid arthritis and do not indicate presence of cancer.
abstract: OBJECTIVE
  To investigate serum levels of tumor markers in patients with rheumatoid arthritis (RA) and their association with disease activity or the presence of cancer.
  
  
  METHODS
  We performed an observational cohort study including 100 patients with RA and control subjects. Serum levels of tumor markers carcinoembryonic antigen (CEA), cancer antigen (CA) 125, CA 19-9 and CA 15-3 were evaluated along with clinical and laboratorial RA data. Association tests between tumor markers levels and RA disease activity parameters were performed. Patients with abnormal tests were submitted to further investigation, including chest X-ray, colonoscopy, abdominal ultrasonography, upper gastrointestinal endoscopy and mammography, depending on the type of tumor marker that was elevated.
  
  
  RESULTS
  Patients with RA had high levels of CEA and CA 19-9 more frequently than controls (P < 0.05). No correlation was found between tumor markers and RA disease activity assessed by the Disease Activity Score 28. Two neoplasms were found, but only one was related to high tumor marker (an ovarian carcinoma with high CA 125 levels).
  
  
  CONCLUSIONS
  High tumor markers were frequently found in RA patients, even with controlled disease and were not related to actual cancer. Therefore, small increases of these markers in RA cases probably do not warrant a search for an occult neoplasm.
authors.affiliation: Medicine, Universidade Federal de Santa Catarina, Florianopolis, SC, Brazil.
authors.forename: Samuel
authors.initials: S
authors.lastname: Bergamaschi
authors.forename: Edelton
authors.initials: E
authors.lastname: Morato
authors.forename: Maria
authors.initials: M
authors.lastname: Bazzo
authors.forename: Fabricio
authors.initials: F
authors.lastname: Neves
authors.forename: Sonia
authors.initials: S
authors.lastname: Fialho
authors.forename: Glaucio
authors.initials: G
authors.lastname: Castro
authors.forename: Adriana
authors.initials: A
authors.lastname: Zimmermann
authors.forename: Ivanio
authors.initials: I
authors.lastname: Pereira
mesh_terms: D001172:Arthritis, Rheumatoid / Q000097:blood* / Q000150:complications / Q000503:physiopathology; D014408:Biomarkers, Tumor / Q000097:blood*; D018395:CA-19-9 Antigen / Q000097:blood; D002272:Carcinoembryonic Antigen / Q000097:blood; D015331:Cohort Studies; D005260:Female; D006304:Health Status; D006801:Humans; D007596:Joints / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000097:blood* / Q000175:diagnosis; D012720:Severity of Illness Index
chemical_list: D014408:Biomarkers, Tumor; D018395:CA-19-9 Antigen; D002272:Carcinoembryonic Antigen