Positive association between apolipoprotein B and colorectal cancer risk: Findings from a 14-year follow-up cohort...

The effects of lipid traits on colorectal cancer (CRC) risk and the extent to which obesity may modify these effects remain unclear.

To examine the associations between lipid traits and CRC risk using an observational study and Mendelian randomization (MR) analyses, and the role of weight status in the potential associations.

In the Guangzhou Biobank Cohort Study (GBCS), lipid profiles were measured during 2003-2008, and CRC events were identified through record linkage with the cancer registry. MR analyses assessed the causal effects of lipid traits on CRC using a genome-wide association study meta-analysis of 185,616 Europeans.

Among 28,576 GBCS participants followed until 2020, 599 CRC events occurred. Participants in the highest quartile of apolipoprotein B (apoB) had a higher CRC risk (hazard ratio [HR] 1.43, 95% CI 1.02-2.01). This association remained in those with overweight/obesity (HR 2.21, 95% CI 1.28-3.83). MR analyses supported a detrimental effect of apoB on CRC (odds ratio 1.12 per 1 SD, 95% CI 1.02-1.22). MR analyses also showed positive associations for total cholesterol and the apoB/apolipoprotein A-I ratio, which were not significant in the observational study.

Higher apoB levels were associated with an increased CRC risk in both observational and MR analyses, suggesting a potential role of apoB in CRC prevention, especially among participants with overweight/obesity. However, the limitations of single-time lipid measurements and the use of different ancestries across study designs indicate the need for further research to confirm the robustness and generalizability of the findings.