Low-Dose Aspirin Not Linked to Increased Cancer Risk in Older Adults: JAMA
Australia: A new study has found that, over a median follow-up of 8.6 years, the use of low-dose aspirin in older adults was not associated with an increased incidence of cancer. However, cancer-related mortality was significantly higher among aspirin users during the randomized clinical trial (RCT) period. Importantly, this elevated cancer mortality did not continue after the RCT ended, indicating no long-term (legacy) effect of aspirin on cancer mortality in the post-trial observation period.
The findings are from a follow-up analysis of the Aspirin in Reducing Events in the Elderly (ASPREE) trial, published in JAMA Oncology. The study was led by Suzanne G. Orchard from the School of Public Health and Preventive Medicine at Monash University, Melbourne, Australia, along with an international team of researchers. The ASPREE trial was originally designed to evaluate whether daily low-dose aspirin could extend healthy lifespan in older adults, but unexpected cancer-related outcomes prompted further investigation.
Earlier research, largely conducted in middle-aged populations, suggested that prolonged aspirin use may reduce cancer risk, particularly colorectal cancer, after a decade of use. In contrast, the original ASPREE trial reported that a median of 4.7 years of low-dose aspirin did not reduce overall cancer incidence in older adults and was associated with a higher risk of advanced-stage cancer and cancer-related death. The current study aimed to determine whether these effects persisted over a longer follow-up period and whether aspirin exposure had any delayed or long-term effects after treatment cessation.
The community-based, binational cohort study included 19,114 older adults from Australia and the United States. Participants were aged 70 years or older (or 65 years or older for Black and Latino individuals in the US) and were free of cardiovascular disease, dementia, and significant physical disability at enrollment. During the randomized phase of the trial, participants received either 100 mg of aspirin daily or a placebo. Long-term outcomes were assessed using data from both the ASPREE trial and its observational extension, ASPREE-XT.
Key Findings:
- Over a median follow-up of 8.6 years, the study recorded 3,448 incident cancer cases and 1,173 cancer-related deaths.
- Long-term analyses found no association between low-dose aspirin use and overall cancer incidence.
- Aspirin use was not linked to differences in colorectal cancer risk or cancer stage at diagnosis.
- During the randomized trial phase, aspirin use was associated with an increased risk of cancer-related mortality.
- Participants who were cancer-free at the end of the trial were followed during the observational phase to assess potential legacy effects.
- In the post-trial follow-up period, the original aspirin assignment showed no association with cancer incidence.
- Cancer-related mortality did not differ between the original aspirin and placebo groups after trial completion.
- These findings indicate that the elevated cancer mortality seen during the trial did not persist after aspirin discontinuation.
The authors conclude that initiating a multiyear low-dose aspirin strategy solely for cancer prevention is not supported in older adults. These findings reinforce current recommendations to carefully individualize aspirin use in this age group, weighing potential risks and benefits rather than assuming long-term cancer protection.
Reference:
Orchard SG, Polekhina G, Zalcberg J, et al. Cancer Incidence and Mortality With Aspirin in Older Adults: Follow-Up of the ASPREE Trial. JAMA Oncol. Published online January 29, 2026. doi:10.1001/jamaoncol.2025.6196
Next Story