Statin use and survival outcomes in colorectal cancer patients with hepatic steatosis evaluated by fatty liver index: a nationwide cohort study

Purpose: Hepatic steatosis influences the hepatic microenvironment, thereby affecting the prognosis of colorectal cancer (CRC). This study aimed to evaluate whether pre-existing hepatic steatosis is associated with survival outcomes in patients with CRC and whether statin use after CRC diagnosis is associated with improved survival in patients with hepatic steatosis.Methods: A nationwide retrospective cohort study was conducted using data from the Korea- Clinical data Utilization network for Research Excellence (K-CURE) Cancer Public Library from 2012 to 2021. Newly diagnosed patients with CRC aged 40 to 80 years with localized or regional disease were included. Hepatic steatosis was defined as a fatty liver index ≥60. The primary analysis evaluated the association between hepatic steatosis, CRC, and all-cause mortality. Secondary analysis was restricted to patients with hepatic steatosis, and statin users and non-users were compared using an active-comparator design. Cox proportional hazards models, Fine–Gray competing risk models, and propensity score matching were applied.Results: In 57,368 patients with CRC, hepatic steatosis was associated with an increased risk of CRC-specific mortality and all-cause mortality. After propensity score matching, the adjusted hazard ratios (aHR) for CRC-specific mortality were 1.283 (95% confidence interval [CI], 1.055 to 1.561) and 1.171 (95% CI, 1.001 to 1.371) for all-cause mortality. In a secondary analysis of patients with hepatic steatosis, statin use after CRC diagnosis was associated with a reduced risk of CRC-specific mortality (aHR, 0.462; 95% CI, 0.232 to 0.920) and all-cause mortality (aHR, 0.504; 95% CI, 0.290 to 0.877).Conclusion: Pre-existing hepatic steatosis is associated with poor survival in patients with CRC. In patients with hepatic steatosis, statin use after CRC diagnosis was associated with improved cancer-specific and overall survival. These findings suggest that hepatic steatosis may be a clinically relevant prognostic factor in CRC and that statins may have potential survival benefits in this subgroup.