Increased Blood Lipid Level is Associated with Cancer-Specific Mortality and All-Cause Mortality in Patients with Colorectal Cancer (≥65 Years): A Population-Based Prospective Cohort Study

BACKGROUND: Hyperlipidaemia is related to the development of many cancers. The aim of this study was to explore whether blood lipid levels were associated with increased rates of cancer-specific mortality and all-cause mortality in patients with colorectal cancer (CRC). METHODS: Data on 8504 participants from The Irish Longitudinal Study on Ageing (TILDA) were analysed. A total of 304 participants with CRC who had experienced curative surgery were included. Logistic regression analysis was performed to analyse the relationship between blood lipid levels and CRC severity. Cox regression analysis was performed to assess the association between blood lipid levels and cancer-specific mortality and all-cause mortality in patients with CRC. RESULTS: In 304 patients with CRC, the average age was 67.8±5.4 years. The logistic regression analysis indicated that elevated levels of total cholesterol (2.104 [1.358–3.650]; P-trend<0.001), triglycerides (1.665 [1.337–2.076]; P-trend=0.005) and LDL (2.127 [1.446–4.099]; P-trend<0.001) but not HDL (0.688 [0.409–1.252]; P-trend=0.124) were associated with an increased risk of higher CRC stage after adjustments were made for age, sex, marital status, BMI, drinking status, smoking status, education, physical activity, antilipidaemic medications and self-reported CVDs (≥2). Cox proportional hazard analysis showed that higher blood lipid levels of total cholesterol, triglycerides and LDL were independently associated with higher rates of cancer-specific mortality and all-cause mortality. Similar results persisted in the sensitivity analysis using antilipidaemic medications as an additional covariate and the stratification analysis using antilipidaemic medications as a stratified variable. CONCLUSION: Increased blood lipid levels were associated with an increased risk of cancer-specific mortality and all-cause mortality in patients with CRC after adjusting for potential confounding factors. Clinicians should pay more attention to the prognostic value of increased blood lipids in patients with CRC for the risk of death.