Common medications and survival in women with ovarian cancer: A systematic review and meta-analysis

Abstract

Objectives: Ovarian cancer is usually diagnosed at an advanced stage when five-year relative survival is <50%. Therefore, strategies to improve survival are required. Studies suggest associations between common chronic disease medications such as metformin, statins, beta-blockers, aspirin and non-aspirin non-steroidal anti-inflammatory drugs (NA-NSAIDs) and improved cancer survival. We aimed to review the evidence for a possible relation between these medications and survival among women with ovarian cancer.

Methods: We conducted four systematic reviews and evaluated the risk of bias in the included studies. Where possible, we calculated pooled hazard ratios (pHR) and 95% confidence intervals (CI), excluding studies considered to have the potential for immortal time bias (ITB) which, in practice, was the major source of bias.

Results: We identified 36 studies evaluating one or more of the medications (metformin n = 8, statins n = 12, beta-blockers n = 11, aspirin and/or NA-NSAIDs n = 9). We rated 21 studies as ITB-free. The meta-analysis of the ITB-free studies suggested improved survival in statin users compared to non-users (pHR: 0.76, 95%CI: 0.68-0.85), but no overall survival benefit associated with use of metformin, beta-blockers, aspirin or NA-NSAIDs. The pooled result of two studies did, however, suggest a possible association between perioperative beta-blocker use and improved survival. Studies considered to have potential ITB were more likely to report survival benefits associated with these medications.

Conclusion: Statin use is associated with better ovarian cancer survival but further study, preferably a clinical trial, is required. There are insufficient data to draw conclusions regarding metformin, beta-blockers, aspirin and NA-NSAIDs.

Keywords: Aspirin; Beta-blocker; Metformin; NSAID; Ovarian cancer survival; Statin.