Daily Aspirin May Up Growth, Spread of Cancers in Older Adults

A study published in the Journal of the National Cancer Institute found daily, low doses of aspirin may elevate the risk for progression and metastasis and death related to later-stage disease in cancer patients 65 and older, reports Medical Xpress . Australian researchers studied daily use of 100 milligrams of aspirin in 16,703 Australians (70 and older) and 2,411 U.S. participants (65 and older) for an average of 4.7 years in a randomized, placebo-controlled, double-blind trial. A total of 981 cancer events occurred in the aspirin cohort and 952 occurred in the placebo group. An association between daily aspirin intake and the occurrence of metastasis or progression to a stage 4 diagnosis was seen in those with incident cancers. Moreover, subjects had an increased mortality risk if their presenting cancer stage was at 3 or 4. No significant differences were observed in the occurrence of all incident cancers, hematological cancer, or all solid cancers. "Possible explanations for this finding include aspirin suppressing (or 'blunting') antitumor inflammatory or immune responses critical to controlling later-stage growth and spread," the investigators explained. "Such an effect may be particularly evident among an older population for which underlying antitumor immunity may already be compromised."