Circulating C-peptide Level Is a Predictive Factor for Colorectal Neoplasia: Evidence From the Meta-Analysis of Prospective Studies

Cancer Causes Control. 2013 Oct;24(10):1837-47. doi: 10.1007/s10552-013-0261-6. Epub 2013 Jul 12.


Purpose: C-peptide, a hormone secreted by the pancreas, is a marker for insulin production and hyperinsulinemia. Epidemiological studies have suggested an association between circulating C-peptide level and colorectal neoplasia risk; however, the results were not always consistent. Herein, we conducted a systematic review and meta-analysis study to evaluate the association between circulating C-peptide level and the colorectal neoplasia risk.

Methods: The PubMed database was searched for the eligibility studies updated to May 2013, which prospectively evaluated the association between circulating C-peptide level and colorectal neoplasia risk. The summary estimates and 95 % confidential intervals (95 % CIs) for those with the highest quantile C-peptide level in contrast to the lowest quantile were estimated with the random-effects model. Heterogeneity between the studies was assessed with the Q test and the I (2) statistic. Potential publication bias was evaluated with the Egger's test.

Results: We identified 9 nested case-control studies that have recruited a total of 3,109 cases and 4,285 controls met the criteria. From the meta-analysis, we found that subjects with high circulating C-peptide were associated with a 37 % increased colorectal neoplasia risk [pooled odds ratios (OR) 1.37, 95 % CI 1.09-1.72] under the random-effects model. In the stratification studies, we found the association was more prominent in the men (pooled OR 2.34, 95 % CI 1.36-4.04) compared to women (pooled OR 1.41, 95 % CI 0.89-2.25). Significant association between circulating C-peptide level and colon cancer risk was found (pooled OR 1.72, 95 % CI 1.26-2.36), but not for rectal cancer (pooled OR 1.14, 95 % CI 0.75-1.73). No significant publication bias was found for any meta-analysis study.

Conclusion: In conclusion, the results of the meta-analysis studies suggested that higher circulating C-peptide could be a predictive factor for higher colorectal neoplasia susceptibility.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't
  • Review
  • Systematic Review

MeSH terms

  • Biomarkers, Tumor / blood*
  • C-Peptide / metabolism*
  • Colonic Neoplasms / blood*
  • Female
  • Humans
  • Male
  • Prospective Studies


  • Biomarkers, Tumor
  • C-Peptide