title: Circulating levels of inflammatory markers and cancer risk in the health aging and body composition cohort.
abstract: BACKGROUND
  Chronic inflammation is associated with processes that contribute to the onset or progression of cancer. This study examined the relationships between circulating levels of the inflammatory markers interleukin-6 (IL-6), C-reactive protein (CRP), and tumor necrosis factor-alpha (TNF-alpha) and total as well as site-specific cancer incidence.
  
  
  METHODS
  Study subjects (n = 2,438) were older adults (ages 70-79 years) participating in the Health Aging and Body Composition study, who did not report a previous cancer diagnosis (except for nonmelanoma skin cancer) at baseline. Incident cancer events (n = 296) were ascertained during an average follow-up of 5.5 years. Inflammatory markers were measured in stored baseline fasting blood samples.
  
  
  RESULTS
  The adjusted hazard ratios (95% confidence intervals) for incident cancer associated with a 1-unit increase on the natural log-scale were 1.13 (0.94-1.37), 1.25 (1.09-1.43), and 1.28 (0.96-1.70) for IL-6, CRP, and TNF-alpha, respectively. Markers were more strongly associated with cancer death: hazard ratios were 1.63 (1.19-2.23) for IL-6, 1.64 (1.20-2.24) for CRP, and 1.82 (1.14-2.92) for TNF-alpha. Although precision was low for site-specific analyses, our results suggest that all three markers were associated with lung cancer, that IL-6 and CRP were associated with colorectal cancer, and that CRP was associated with breast cancer. Prostate cancer was not associated with any of these markers.
  
  
  CONCLUSIONS
  These findings suggest that (a) the associations between IL-6, CRP, and TNF-alpha and the risk of cancer may be site specific and (b) increased levels of inflammatory markers are more strongly associated with the risk of cancer death than cancer incidence.
authors.affiliation: Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA. dora.ilyasova@duke.edu
authors.forename: Dora
authors.initials: D
authors.lastname: Il'yasova
authors.forename: Lisa H
authors.initials: LH
authors.lastname: Colbert
authors.forename: Tamara B
authors.initials: TB
authors.lastname: Harris
authors.forename: Anne B
authors.initials: AB
authors.lastname: Newman
authors.forename: Douglas C
authors.initials: DC
authors.lastname: Bauer
authors.forename: Suzanne
authors.initials: S
authors.lastname: Satterfield
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Kritchevsky
mesh_terms: D000368:Aged; D000375:Aging / Q000097:blood*; D014408:Biomarkers, Tumor / Q000097:blood*; D001823:Body Composition; D002097:C-Reactive Protein / Q000378:metabolism*; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000097:blood*; D008297:Male; D009369:Neoplasms / Q000097:blood*; D012016:Reference Values; D012307:Risk Factors; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
chemical_list: D014408:Biomarkers, Tumor; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D002097:C-Reactive Protein