The impact of statin use on colorectal cancer prognosis: a systematic review and meta-analysis

BACKGROUND: The evidence considering the potential protective impact of statins on the mortality rate caused by colorectal cancer (CRC) is controversial. This study aimed to systematically assess the effect of statins on the survival rate of CRC patients. METHODS: A comprehensive search was conducted in Scopus, PubMed, and Web of Science to assess the relationship between statin consumption and cancer-specific mortality (CSM), all-cause mortality (ACM), disease-free survival (DFS), and recurrence-free survival (RFS). Subgroup analyses were performed to assess data stratified by country, study design, disease stage, time to use, CRC, and treatment type due to high heterogeneity. RESULTS: Thirty-two studies were included; the data of 24 articles composed the meta-analysis. Statins improved prognosis of CRC, particularly in lower ACM (HR: 0.80; 95% CI: 0.74–0.87) with I²=90%, P-value < 0.01, and lower CSM (HR: 0.74; 95% CI: 0.67–0.82) with I²=88%, P-value < 0.01 when compared to non-users. Both pre- and post-diagnostic statin use were linked to lower ACM and CSM, though high heterogeneity was observed across studies. However, the results for statin use on RFS indicated an HR of 1.01 with 95% CI of 0.94 to 1.09 (I² = 0% and P-value = 0.93). Additionally, for DFS, the HR was 0.93 (95% CI: 0.85–1.01) with I² = 47%, suggesting no meaningful effect of statin use on DFS. No significant publication bias was found. CONCLUSION: Statin use was associated with a reduction in ACM and CSM in CRC patients. However, the variances in RFS and DFS were not statistically significant. However, these findings should be interpreted cautiously due to substantial heterogeneity among some included studies.