Could low-dose aspirin protect against liver cancer?
New research suggests that for adults with chronic viral hepatitis B or C, at high risk of developing liver cancer, long-term, low-dose aspirin use may be associated with reduced risks of disease development and liver-related mortality.
Results from a Swedish nationwide registry study, conducted by researchers from the Karolinska Institutet (Solna, Sweden) and Massachusetts General Hospital (MA, USA), suggest that amongst adults at high risk of developing liver cancer, with chronic viral hepatitis B or C, long-term, low-dose aspirin use may be associated with reduced risks of disease development and liver-related mortality.
Diagnosis with chronic viral hepatitis, which results from hepatitis B or C viral infection, is the most common risk factor for the development of liver cancer. Despite rising prevalence of hepatocellular carcinoma in the USA, there are currently no established interventions for the prevention of liver cancer or reduction in risk of liver-related mortality.
In this study, investigators employed data from nationwide Swedish registries, identifying all adults with a positive confirmed diagnosis of chronic hepatitis B or C between 2005 and 2015 who did not have prior histories of aspirin use. Researchers defined a subset of study participants as ‘new aspirin users’ from their first prescriptions filled for at least 90 consecutive doses of low-dose (less than 163mg) aspirin.
Investigators constructed a propensity score and applied inverse probability of treatment weighting to balance baseline characteristics between a subset of 14,205 individuals identified as new aspirin users, and the remaining 50,275 study participants. Cox proportional-hazards regression modeling was used to estimate the relative risks of liver cancer development and liver-related mortality incidence between the two cohorts, accounting for competing events.
Over the course of a median 7.9-year follow-up period, incidence rates of liver cancer were observed to be 4% and 8.3% amongst low-dose aspirin users and non-users respectively.
The protective benefit of low-dose aspirin appeared to be related to the length of time individuals took aspirin; compared with individuals who took low-dose aspirin for 3 months–1 year, the relative risk of liver cancer was 34% lower for individuals who took aspirin for 3–5 years and 43% lower for those who took aspirin for more than 5 years.
In this study, the observed benefits were independent of participants sex or the severity of their diagnosed hepatitis. Importantly, risk of internal bleeding – a common, sometimes concerning, consequence of long-term aspirin use – was not significantly different between long-term aspirin users and non-users.
Senior study author Jonas Ludvigsson (Karolinska Institutet) concluded: “This is the first large-scale, nationwide study to demonstrate that the use of aspirin is associated with a significantly reduced long-term risk of liver cancer and liver-related mortality.”
Simon TG, Duberg A-S, Aleman S et al. Association of aspirin with hepatocellular carcinoma and liver-related mortality. N Engl J Med. 382: 1018–1028 (2020); https://news.ki.se/low-dose-aspirin-linked-to-reduced-liver-cancer-risk