Prior studies have suggested aspirin lowers long-term cancer risk, especially colorectal cancer, but the ASPREE trial (Australia & US-based) in older adults found no reduction in cancer incidence and an unexpected rise in late-stage cancers and cancer mortality¹. This study examined 10-year outcomes in more than 19,000 adults aged 70 and older from ASPREE and its observational extension.
Participants received either low-dose aspirin (100mg) or a placebo.
Over a median of 8.6 years, aspirin did not reduce overall cancer incidence, cancer stage, or colorectal cancer specifically. However, aspirin was linked to higher cancer-related mortality. In post-trial follow-up of nearly 15,000 cancer-free participants, prior aspirin use showed no association with cancer incidence or mortality, indicating no legacy effect.
Overall, long-term low-dose aspirin did not prevent cancer in older adults and was associated with increased cancer mortality during treatment.
