A predictive role of C-reactive protein in colorectal cancer risk: an updated meta-analysis from 780,985 participants and 11,289 cancer cases

Purpose This meta-analysis is aimed at understanding the potential role of circulating C-reactive protein (CRP) in the prediction of colorectal cancer (CRC) risk and the potential effect of relevant variables, with specific concern to determine the incorporation of CRP into a CRC risk prediction model. Methods Relevant articles on the association between circulating CRP and CRC risk were searched from PubMed, Embase, Web of Science, and Cochrane Database of Systematic Reviews through August 2022. Random-effects models were used to estimate the pooled relative risk (RR) for the highest versus lowest CRP categories. Linear and non-linear trend analyses were conducted to explore the dose–response associations between CRP and CRC risk. Results Twenty-three articles including 780,985 participants and 11,289 cancer cases met the selection criteria. The overall result demonstrated a remarkable association between elevated CRP levels and CRC risk (RR, 1.259; 95% CI, 1.060–1.457), but not in dose–response analysis (RR, 1.002 (95% CI, 0.964–1.041) per natural log unit change in CRP). Subgroup analyses indicated a significant difference when grouped by study location, the length of follow-up, and gender composition. No evidence of publication bias was observed. Conclusion The predictive role of CRP in CRC incidence is limited to colon cancer and a period of 10 years after the initial discovery of CRP elevation. The result did not support the etiological role of CRP in CRC and the inclusion of CRP into the CRC risk prediction model.