title: Serum interleukin-6 levels reflect disease status of gastric cancer.
abstract: OBJECTIVE
  Interleukin-6 (IL-6) has been shown to be associated with cancer development. However, its role in gastric cancer patients has never been investigated. Our intent was to investigate this role.
  
  
  METHODS
  Using enzyme-linked immunosorbent assay, we determined the IL-6 levels in sera of patients with gastric cancer (n = 218), benign gastric lesions (n = 9), and hepatitis B (n = 9), and in normal subjects (n = 85). C-reactive protein (CRP) levels and Helicobacter pylori antibodies were simultaneously determined in 150 and 133 gastric cancer patients, respectively. Serial serum IL-6 levels were also measured in 14 gastric cancer patients. Six gastric cancer cell lines were examined for IL-6 secretion. For comparison, serum carcinoembryonic antigen levels in all gastric cancer patients were also determined.
  
  
  RESULTS
  Mean IL-6 levels were significantly higher in patients with gastric cancer (10.0 +/- 9.5 pg/ml) than in patients with benign gastric lesions (2.6 +/- 0.5 pg/ml), in hepatitis B carriers (2.8 +/- 0.9 pg/ml), and in normal subjects (2.5 +/- 0.3 pg/ml). Gastric cancer patients with IL-6 > 10 pg/ml increased in a stage-related manner (p = 0.0001). Serum IL-6 levels increased when four patients had recurrence, whereas IL-6 levels decreased in 10 patients with a disease-free status after gastric resection. Serum IL-6 levels correlated moderately with serum CRP levels (r = 0.5, p < 0.01), but not with H. pylori antibody titers (p = 0.23). Serum IL-6 levels correlated with survival, but not as an independent prognostic indicator. Conversely, patients with CEA > 5 ng/ml increased in a stage-related manner, but this is not an effective reflection of disease progression. Five of six gastric cancer cell lines secrete IL-6.
  
  
  CONCLUSIONS
  Serum IL-6 levels correlate with disease status of gastric cancer and may be used as a new tumor marker for monitoring treatment and response of gastric cancer patients.
authors.affiliation: Department of Surgery, Veterans, General Hospital-Taipei, Taiwan.
authors.forename: C W
authors.initials: CW
authors.lastname: Wu
authors.forename: S R
authors.initials: SR
authors.lastname: Wang
authors.forename: M F
authors.initials: MF
authors.lastname: Chao
authors.forename: T C
authors.initials: TC
authors.lastname: Wu
authors.forename: W Y
authors.initials: WY
authors.lastname: Lui
authors.forename: F K
authors.initials: FK
authors.lastname: P'eng
authors.forename: C W
authors.initials: CW
authors.lastname: Chi
mesh_terms: D000230:Adenocarcinoma / Q000097:blood* / Q000276:immunology / Q000401:mortality; D000368:Aged; D000907:Antibodies, Bacterial / Q000097:blood; D014408:Biomarkers, Tumor / Q000097:blood*; D002272:Carcinoembryonic Antigen / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D016481:Helicobacter Infections / Q000097:blood / Q000276:immunology; D016480:Helicobacter pylori / Q000276:immunology; D006801:Humans; D015850:Interleukin-6 / Q000096:biosynthesis / Q000097:blood*; D008297:Male; D008875:Middle Aged; D011127:Polyps / Q000097:blood / Q000276:immunology; D013274:Stomach Neoplasms / Q000097:blood* / Q000276:immunology / Q000401:mortality; D013276:Stomach Ulcer / Q000097:blood / Q000276:immunology; D014407:Tumor Cells, Cultured
chemical_list: D000907:Antibodies, Bacterial; D014408:Biomarkers, Tumor; D002272:Carcinoembryonic Antigen; D015850:Interleukin-6