Is there sufficient evidence to recommend women diagnosed with endometrial cancer take a statin: Results from an Australian record-linkage study.

OBJECTIVE

A recent paper suggested all women with endometrial cancer should take statins but it is unclear whether there is sufficient evidence to justify this recommendation.

METHODS

We identified all women diagnosed with uterine cancer in Australia between July 2003 and December 2013 (2012 in New South Wales) through the Australian Cancer Database (N = 16,501) and linked these to the national prescription database and National Death Index to identify statin use and survival outcomes to December 2015. We used Cox proportional hazards regression to estimate hazard ratios (HR) and 95% confidence intervals (CI) for the associations between statin use and survival.

RESULTS

Among the 15,703 women with endometrial cancer, pre-diagnosis statin use was not associated with survival. Endometrial cancer-specific mortality was lower among women who used statins after diagnosis (time-varying models: HR = 0.92; 95%CI 0.82-1.03) but the association was only seen among women with type 1 cancers (0.87; 0.76-1.00), for hydrophilic statins (0.84; 0.68-1.03) and for new use of statins after diagnosis (0.75; 0.59-0.95). There was a weak dose-response with increasing number of statin prescriptions. Sensitivity analyses using inverse probability of treatment weights were similar.

CONCLUSION

Women with endometrial cancer who take statins after diagnosis may have better survival than those who do not use statins. However, it is impossible to completely rule out bias, particularly reverse causation where disease status may affect statin use. We believe it is too early to recommend all women with endometrial cancer take statins, but there is sufficient evidence to justify a randomized trial.