Statin and aspirin for prevention of hepatocellular carcinoma: what are the levels of evidence?

Recent analyses of large cohorts suggest that statins or aspirin may reduce the risk of hepatocellular carcinoma (HCC). Due to their observational nature, these studies may have been flawed by confounding by indication or immortal time bias. Reviews of clinical trials conducted in the metabolic or cardiovascular domain showed no effect of statins on cancer of any type, but identified a 20% reduction of cancer with aspirin use. The effect of aspirin was concentrated to adenocarcinomas. More convincing evidence is needed to support the potential preventive effect of aspirin on HCC, but a clinical trial would be achievable in patients who are at high risk.