C-reactive protein and cancer risk: a pan-cancer study of prospective cohort and Mendelian randomization analysis

BMC Med. 2022 Sep 19;20(1):301. doi: 10.1186/s12916-022-02506-x.

Abstract

Background: Although observational studies have reported associations between serum C-reactive protein (CRP) concentration and risks of lung, breast, and colorectal cancer, inconsistent or absent evidences were showed for other cancers. We conducted a pan-cancer analysis to comprehensively assess the role of CRP, including linearity and non-linearity associations.

Methods: We analyzed 420,964 cancer-free participants from UK Biobank cohort. Multivariable-adjusted Cox proportional hazards model was conducted to evaluate the observed correlation of CRP with overall cancer and 21 site-specific cancer risks. Furthermore, we performed linear and non-linear Mendelian randomization analyses to explore the potential causal relation between them.

Results: During a median follow-up period of 7.1 years (interquartile range: 6.3, 7.7), 34,979 incident cancer cases were observed. Observational analyses showed higher CRP concentration was associated with increased risk of overall cancer (hazard ratio (HR) = 1.02, 95% CI: 1.01, 1.02 per 1mg/L increase, P < 0.001). There was a non-linear association between CRP and overall cancer risk with inflection point at 3mg/L (false-discovery rate adjust (FDR-adjusted) Poverall < 0.001 and FDR-adjusted Pnon-linear < 0.001). For site-specific cancer, we observed positive linear associations for cancers of esophagus and stomach (FDR-adjusted Poverall < 0.050 and FDR-adjusted Pnon-linear > 0.050). In addition, we also observed three different patterns of non-linear associations, including "fast-to-low increase" (head and neck, colorectal, liver, lung, kidney cancer, and non-Hodgkin lymphoma), "increase-to-decrease" (breast cancer), and "decrease-to-platform" (chronic lymphocytic leukemia). Furthermore, the inflection points of non-linear association patterns were consistently at around 3mg/L. By contrast, there was no evidence for linear or non-linear associations between genetically predicted CRP and risks of overall cancer or site-specific cancers.

Conclusions: Our results indicated that CRP was a potential biomarker to assess risks of overall cancer and 12 site-specific cancers, while no association were observed for genetically-predicted CRP and cancer risks.

Keywords: C-reactive protein; Cancer risk; Cohort study; Mendelian randomization analysis; Non-linear Mendelian randomization.

MeSH terms

  • Biomarkers
  • Breast Neoplasms*
  • C-Reactive Protein* / genetics
  • C-Reactive Protein* / metabolism
  • Female
  • Humans
  • Mendelian Randomization Analysis*
  • Neoplasms* / genetics
  • Neoplasms* / metabolism
  • Prospective Studies

Substances

  • Biomarkers
  • C-Reactive Protein