Statin use and survival in colorectal cancer: results from a population-based cohort study and an updated systematic review and meta-analysis.

Authors

Gray RT, Coleman HG, Hughes C, Murray LJ, Cardwell CR.

Departments / Institutions

Cancer Epidemiology and Health Services Research Group, Centre for Public Health, Queen’s University Belfast, Royal Victoria Hospital, Belfast BT12 6BA, Northern Ireland.

Publication Date

Autumn 2016

Introduction

Statins may have anti-cancer properties and possibly improve survival in colorectal cancer (CRC). In this study the association between statin use and survival in a population-based CRC cohort was assessed and an updated meta-analysis was performed.

Methods

A cohort of 8,391 patients with newly diagnosed Dukes’ A-C CRC (2009-2012) was identified from the Scottish Cancer Registry. This cohort was linked to the Prescribing Information System and the National Records of Scotland Death Records (until January 2015) to identify 1,064 colorectal cancerspecific deaths. Adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for cancer-specific mortality by statin use were calculated using time dependent Cox regression models. The systematic review included relevant studies published before January 2016. Meta-analysis techniques were used to derive combined HRs for associations between statin use and cancer-specific and overall mortality.

Results

In the Scottish cohort, statin use before diagnosis (HR=0.84, 95%CI 0.75-0.94), but not after (HR=0.90, 95% CI 0.77-1.05), was associated with significantly improved cancerspecific mortality. The systematic review identified 15 relevant studies. In the meta-analysis, there was consistent (I2=0%) evidence of a reduction in cancer-specific mortality with statin use before diagnosis (n=86,622, pooled HR=0.82, 95% CI 0.79- 0.86) but this association was less apparent and more heterogeneous (I2=67%) with statin use after diagnosis (n=19,152, pooled HR=0.84, 95% CI 0.68-1.04).

Conclusion

In a Scottish CRC cohort and updated metaanalysis there was some evidence that statin use was associated with improved survival. However, these associations were weak in magnitude and, particularly for post-diagnosis use, varied markedly between studies.