C-reactive protein, interleukin 6 and lung cancer risk: a meta-analysis

PLoS One. 2012;7(8):e43075. doi: 10.1371/journal.pone.0043075. Epub 2012 Aug 17.

Abstract

Purpose: Epidemiologic findings are inconsistent concerning the associations between C-reactive protein (CRP), interleukin 6 (IL-6) and lung cancer risk. We conducted a meta-analysis of epidemiologic studies to examine these associations.

Methods: A systematic literature search up to October 2011 was performed in MEDLINE and EMBASE. Study-specific risk estimates were pooled using a random-effects model.

Results: The 10 studies on CRP involved a total of 1918 lung cancer cases. The pooled RR of lung cancer for one unit change in natural logarithm (ln) CRP was 1.28 (95% CI 1.17-1.41). There was no statistically significant heterogeneity among studies (P = 0.116; I(2) = 36.6%). We also found that CRP was significantly associated with increased risk of lung cancer among men (RR 1.18, 95% CI 1.09-1.28) but not among women. The 5 studies on IL-6 involved a total of 924 lung cancer cases. The pooled RR of lung cancer for one unit change in ln IL-6 was 1.28 (95% CI 0.92-1.79), however, statistically significant heterogeneity was found. After excluding the study contributing most to the heterogeneity, the summary estimate was essentially unchanged.

Conclusion: CRP was associated with increased risk of lung cancer, especially among men. There was no significant association between IL-6 and lung cancer risk.

Publication types

  • Meta-Analysis

MeSH terms

  • C-Reactive Protein / metabolism*
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Genetic Association Studies
  • Humans
  • Interleukin-6 / metabolism*
  • Lung Neoplasms / epidemiology*
  • Male
  • Risk Factors
  • Sex Factors

Substances

  • Interleukin-6
  • C-Reactive Protein

Grant support

The authors have no support or funding to report.