A secondary analysis of the ASPREE randomized clinical trial found no overall cancer prevention effect of daily low-dose aspirin in older adults. However, an effect score model identified subgroups with different outcomes: patients who were older, nonsmokers, had lower body mass index, family history of cancer, or clonal hematopoiesis at ≥10% variant allele frequency showed reduced cancer risk, while current smokers and those with higher body mass index did not benefit. Clonal hematopoiesis was the strongest predictor of aspirin benefit, and smoking was the strongest predictor of harm. The model improved 5-year cancer risk reduction by about 2% compared with treating all participants. Study limitations included the largely White, Australian population, aspirin initiation only at age 70 or older, and biospecimen timing. Findings are exploratory and require external validation.

Source: JAMA Oncology