Data from a new study presented this week at The Liver Meeting®—held by the American Association for the Study of Liver Diseases—found that taking a regular aspirin is associated with a dose-dependent reduction in the risk of hepatocellular carcinoma (HCC), one of the most common liver cancers. The cancer risk reduction is apparent after at least 5 years of aspirin use, the study showed.

Evidence suggests that aspirin may prevent HCC, but it’s still unclear what dose and duration of aspirin is needed to prevent this liver cancer. To examine aspirin’s influence on HCC incidence and risk, a group of researchers from Massachusetts General Hospital and Harvard Medical School in Boston conducted two nationwide, prospective cohort studies of men and women in the United States.

“Given the limitations of existing therapies and the growing mortality [due to] HCC in the US, there is an urgent and growing need to identify effective strategies for primary prevention,” says Tracey G. Simon, MD, a research fellow at Massachusetts General Hospital and the study’s coauthor. “Previous studies have suggested that aspirin is associated with a lower risk for developing incident HCC, but the optimal dose and duration of aspirin use to achieve clinical benefit was unknown. Understanding the optimal dose and duration of aspirin use to effectively reduce the risk for developing HCC may inform future clinical guidelines and facilitate the planning of clinical trials. We know that HCC has a very long latency, and that the impact of a preventive therapy, such as aspirin, will likely require long-term use.”

The study included 133,371 individuals from both the Nurses’ Health Study and the Health Professionals Follow-Up Study who reported aspirin use, dosage, and duration every 2 years from 1980 (for the NHS) and 1986 (for the HPFS) until 2012. The study defined regular aspirin use as two or more standard (325-mg) aspirin tablets per week. The researchers updated all data prospectively at each biennial follow-up. Cases of incident HCC were reported by study participants (or their next of kin or through death certificates) and were subsequently confirmed by physician review of the individuals’ medical records.

In over 4.2 million person-years of follow-up, the study found 108 incident cases of HCC in 65 women and 43 men. Compared to non-regular aspirin use, regular aspirin use was associated with significantly lower HCC risk in this population. The relationship appeared to be closely related to the dose of aspirin a person was taking: compared to non-use, the multivariable adjusted hazard ratio (HR) was 0.87 for 1.5 or less standard aspirin tablets a week, 0.51 for more than 1.5 up to five tablets a week, and 0.49 for more than five tablets a week.

This inverse association also appeared to be duration-dependent, the study found. Among former aspirin users, an increase in time since the discontinuation of aspirin was associated with progressively increased risk of HCC. When both dose and duration were analyzed together, significant HCC risk reduction was found when patients took 1.5 or more standard aspirin tablets per week for 5 or more years, compared to non-use. Importantly, non-aspirin NSAID (nonsteroidal anti-inflammatory drug) use was not associated with HCC risk compared to non-NSAID use—suggesting the apparent benefit was specific to aspirin.

“We still need to define the impact of aspirin use in various types of chronic liver disease, including nonalcoholic fatty liver disease, which is now the leading cause of chronic liver disease in the US,” explains Dr. Simon of next steps. “We also need to understand the impact of aspirin in various stages of liver disease, since there is some data to suggest that aspirin may be most effective if it is taken before the development of cirrhosis. Finally, we need to carefully understand the risks of using aspirin for the primary prevention of HCC, including the risk of bleeding. We need to understand which patients stand to achieve the greatest benefit from aspirin use, with the lowest possible bleeding risks.”

—Newswise