A major study shows aspirin raises gastrointestinal bleeding risk in seniors with cancer and may speed disease progression. Experts urge caution before starting treatment.
Previous research has suggested daily aspirin use can lower the risk of developing cancer, particularly colorectal cancer, but most studies focused on middle-aged adults. To address this gap, researchers from Monash University's Faculty of Medicine in Australia conducted the ASPREE trial, with results published in BMJ Journals on August 2, 2020. They examined effects specifically in older adults.
The randomized trial followed 19,114 participants aged over 70 in Australia and the U.S. for about five years. Half received a daily 100 mg dose of aspirin, while the other half took a placebo. Overall cancer incidence was similar: 981 cases in the aspirin group and 952 in the placebo group, showing no significant difference.
However, a troubling pattern emerged. Aspirin users faced a 19% higher risk of metastasized cancer at diagnosis and a 22% increased risk of advanced cancer, including stage 4.
Lead researchers noted higher mortality rates among aspirin users diagnosed with advanced cancer, suggesting aspirin might promote cancer growth in the elderly once disease is present. This calls for greater caution when prescribing aspirin to older patients at risk.
Importantly, the study does not advise those already on long-term aspirin to stop without consulting a doctor. Further research is needed, but the team hypothesizes aspirin may interact differently at the cellular level in older adults.
For context, in 2019, U.S. researchers shared promising early data on a colorectal cancer vaccine that trains the immune system to recognize cancer cells.
