Do cholesterol levels and continuity of statin use affect colorectal cancer incidence in older adults under 75 years of age?

INTRODUCTION: Colorectal cancer(CRC) is 3rd most common cancer and has a relatively high mortality rate. Currently, the relationships between CRC and serum cholesterol or statin treatment, especially in older adults under 75 years of age, remain questionable due to a lack of data. The present study evaluated the association between serum cholesterol levels and statin treatment continuity and CRC risk in older adults under 75 years of age. METHODS: This study used senior cohort data obtained from the National Health Insurance Service of South Korea. The selected cohort contains 131,266 participants who were enrolled from 2009 to 2011 and followed for up to 5 years. Serum cholesterol levels were classified as categorical variables, and continuity of statin treatment was evaluated based on dyslipidemia diagnosis and average medication possession ratio. We used Cox regression analysis to evaluate the associations between CRC risk and serum cholesterol level or statin use. RESULTS: A low level of high-density lipoprotein cholesterol(HDL-C) was significantly associated with high CRC risk compared to an HDL-C level in the normal range(hazard ratio [HR]: 1.197, 95% CI: 1.040–1.377). A high level of low-density lipoprotein cholesterol(LDL-C) was associated with increased CRC risk compared to a normal LDL-C level, but not statistically significant. Statin use was associated with decreased CRC risk, and high medication compliance was inversely associated with CRC risk in patients with and without dyslipidemia. CONCLUSIONS: Statin use was associated with decreased CRC risk, and high medication compliance was inversely associated with CRC risk in patients with and without dyslipidemia compared to non-use of medication. Regular health examinations can help identify individuals who are vulnerable to CRC, and continued statin use may be associated with a reduced risk of CRC. This is particularly important in patients with diabetes and dyslipidemia.