Serum lipid levels may help predict colorectal cancer: BMJ

China: There is a correlation between lipid profile and the risk of colorectal cancer (CRC). High levels of serum triglyceride (TG) and total cholesterol (TC) are associated with an increased risk of CRC, states the study results published in The BMJ Open.

High levels of serum high-density lipoprotein cholesterol (HDL-C) are negatively correlated with the incidence rate of colorectal cancer and no association was found between LDL-C and the risk of developing CRC. 

Colorectal (also known as bowel) cancer is the 3rd most common cancer worldwide. It poses a significant threat to public health as it is associated with a high incidence rate, a high mortality rate, rapid progress, and uncomplicated metastasis. Evidence has shown that lipid imbalance is one of the main risk factors for CRC through associations with inflammation, oxidative stress, and insulin resistance. Thus, exploring the relationship between the lipid profile and the risk of CRC is the key to understanding the occurrence of CRC. As lipid profiling is convenient, it carries an advantage in studying its relationship to CRC. The lipid profile includes triglyceride(TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C). Previous studies have reported contradictory results on the relationship between serum lipid levels and the risk of CRC.

Yang Z, Capital Medical University Affiliated Beijing Shijitan Hospital, China, and colleagues conducted a meta-analysis of prospective published studies to explore the relationship between serum lipid and CRC risk.

Reviewers searched PubMed and Embase databases for all literature from inception until December 2020. They considered prospective cohort and case-control studies that evaluated differences in serum lipid levels with the risk of developing CRC. Twenty-four prospective studies, including 4 224 317 individuals with 29 499 CRC cases, were included in the meta-analysis.

Key findings of the analysis,

• The total pooled risk ratio (RR) for high vs low concentrations of triglyceride (TG), total cholesterol(TC), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) was reported at 1.21, 1.15, 0.86 and 1.03, respectively.

Investigators conclude that high levels of serum TG and TC are positively correlated and high levels of serum HDL-C are negatively correlated with the incidence rate of CRC. Furthermore, no association was found between LDL-C and the risk of developing CRC. The study suggests that dyslipidemia may be a risk factor to consider when making clinical decisions on CRC screening and monitoring.

The effectiveness of the present study is limited by the heterogeneity brought about by comparative methods, demographic differences, and pathological differences between the research subjects. In the future, a high-quality, large-scale, multicentre prospective study is needed to confirm the role of serum lipids in the risk of CRC and to verify whether intervention in the concentration of lipid components would reduce the CRC incidence rate, the authors wrote.

Reference:

Yang Z, Tang H, Lu S, Sun X, Rao B. Relationship between serum lipid level and colorectal cancer: a systemic review and meta-analysis. BMJ Open. 2022 Jun 22;12(6):e052373. doi: 10.1136/bmjopen-2021-052373. PMID: 35732386.