The Association between Genetically Predicted C-Reactive Protein Levels and Risk of Colorectal Cancer in an East...

C-reactive protein (CRP) is a widely used inflammatory biomarker that has been related to colorectal cancer risk. However, observational studies are prone to confounding and reverse causality.

We conducted a two-sample Mendelian randomization using CRP genome-wide association study (GWAS) data from 59,605 Korean individuals and colorectal cancer GWAS data from 23,572 cases and 48,700 controls from an East Asia population. The analysis had 80% power to detect an OR of 1.12 for colorectal cancer risk per twofold increase in CRP levels.

Genetically predicted serum CRP levels (per twofold increase) were not significantly associated with colorectal cancer risk (inverse-variance weighted OR, 0.995; 95% confidence interval, 0.893-1.109; P value, 0.929). Null findings remained consistent in sensitivity analyses excluding the horizontally pleiotropic effect.

Despite sufficient statistical power, little evidence supported a causal association between CRP and colorectal cancer risk in East Asians.

Our findings suggest that CRP is unlikely to be a key determinant of colorectal carcinogenesis, aligning with prior studies in European populations.