Chang JS, et al. - Researchers assessed acute coronary events (ACE) among the general population vs women with breast cancer after adjuvant RT, and if RT-related cardiac toxicity could be prevented by a healthy lifestyle was investigated in a secondary analysis. Among 1,015 women with breast cancer and 8,120 women without cancer who were matched according to age, comorbidities, and smoking history, ACE risks were compared. The cohort used was the National Health Insurance Service-Health Screening Cohort (2002–2013). They assessed the ACE risk over time while accounting for competing risks from other causes of mortality. They reported 5.5% and 11.3% of 5- and 10-year cumulative incidences of ACE, respectively, during 6.1 ± 3.0 years of follow-up. Findings revealed an increase in cardiac risk after adjuvant RT in association with decreasing physical activity. The long-term effect of physical activity on ACE remained uncertain.