Breast cancer recurrence, often occurring years after initial treatment, poses a significant challenge to patients and caregivers. Dormant tumor cells, also known as ‘sleeper cells,’ persist in the body after treatment and may reactivate to cause recurrence. Predicting recurrence remains elusive, leaving indefinite treatment as the only option for relapsed patients. However, recent research suggests a promising approach – that is – targeting dormant tumor cells before they can trigger recurrence. We are talking to Dr. Angela DeMichele of the University of Pennsylvania to understand in depth about why breast cancers recur and learn about approaches being investigated to prevent relapse. Dr. DeMichele is leading a project to develop targeted therapies to prevent recurrence.