Statin use and mortality in cancer patients: Systematic review and meta-analysis of observational studies.

BACKGROUND

Previous studies have examined the effect of statin use on the mortality in cancer patients, but the results are inconsistent. A meta-analysis was performed to assess the association with all available studies.

METHODS

Relevant studies were identified by searching PubMed and EMBASE to April 2015. We calculated the summary hazard ratios (HRs) and 95% confidence intervals (CIs) using random-effects models. We estimated combined HRs associated with defined increments of statin use, using random-effects meta-analysis and dose-response meta-regression models.

RESULTS

Thirty-nine cohort studies and two case-control studies involving 990,649 participants were included. The results showed that patients who used statins after diagnosis had a HR of 0.81 (95% CI: 0.72-0.91) for all-cause mortality compared to non-users. Those who used statin after diagnosis (vs. non-users) had a HR of 0.77 (95% CI: 0.66-0.88) for cancer-specific mortality. Prediagnostic exposure to statin was associated with both all-cause mortality (HR=0.79, 95% CI: 0.74-0.85) and cancer-specific mortality (HR=0.69, 95% CI: 0.60-0.79). Stratifying by cancer type, the three largest cancer-type subgroups were colorectal, prostate and breast cancer and all showed a benefit from statin use. HRs per 365 defined daily doses increment were 0.80 (95% CI: 0.69-0.92) for all-cause mortality and 0.77 (95% CI: 0.67-0.89) for cancer-specific mortality. A 1year increment in duration only conferred a borderline decreased risk of death.

CONCLUSIONS

In conclusion, the average effect of statin use, both postdiagnosis and prediagnosis, is beneficial for overall survival and cancer-specific survival.