Oncology is a branch of medicine that deals with the prevention, diagnosis, and treatment of cancer. A medical professional who practices oncology is an oncologist. The name's etymological origin is the Greek word ὄγκος (óngkos), meaning 1. "burden, volume, mass" and 2. "barb", and the Greek word λόγος (logos), meaning "study".
Cancer survival has improved due to three main components: improved prevention efforts to reduce exposure to risk factors (e.g., tobacco smoking and alcohol consumption), improved screening of several cancers (allowing for earlier diagnosis), and improvements in treatment.