As cardiologists, we tend to consider the potential benefit of aspirin therapy in preventing cardiovascular disease (CVD), balanced against the risk of bleedings events. However, alternate day aspirin also may have a role in primary prevention of cancer and the combined benefit of cancer and CVD prevention is a more relevant metric than either outcome alone. To address the risk-benefit of primary prevention with aspirin in women, Dr. Visseren and colleagues (see page 369) developed a competing risks model based on outcomes in over 27 thousand healthy women in the Women's Health Study (WHS) randomized to 100 mg aspirin or placebo on alternate days. Overall, aspirin therapy had a negative effect on outcomes with an increased risk of gastrointestinal bleeding, despite a modest reduction in CVD and colorectal cancer over 15 years of followup. However, selective treatment of women 65 years of age and older may provide net benefit with an estimated number needed to treat of 29 (95% CI 12 to 102) to prevent one event over 15 years (figure 1).