Traditionally, discussions about harm in healthcare focus on clinical error, and its direct impacts on the affected patient. While a focus on 'direct error harm' is vital to patient safety, the scope of our vigilance in harm prevention must extend much wider. This presentation will use patient stories and research evidence to illuminate ethical theory, and cast a broader net over the true diversity of both the types of harm that can occur in cancer treatment, and the people, entities and interests that can be harmed. It will explore the ways in which the fine distinction between help and harm can turn on what were once thought of as incidental factors - such as manner, communication and assumptions. It will also explore the way in which harm impacts not only patients and their families, but practitioners, social groups, and even society at large. This presentation will equip you to think differently about harm prevention, and the plethora of ways in which you can act to improve safety for all whom you encounter in practice, and many who you don't.