Prevention of cancer through lifestyle change and screening

Cancer is the leading cause of death worldwide. Evidence shows that about 40% of all cancers are preventable. This article looks at the evidence base for primary prevention measures focusing on lifestyle risk factors of tobacco exposure, overweight and obesity, dietary factors, alcohol and physical activity. Some basic principles of screening and screening programmes are discussed with emphasis on the importance of doing more benefits than harms, at a reasonable cost. We look at the evidence for effectiveness of cancer screening programmes, including randomized controlled trials and touch briefly on the ongoing debates for and against the effectiveness of organized screening programmes. Sufficient evidence exists to demonstrate the effectiveness of screening for breast, colorectal and cervical cancer. Ongoing studies in prostate screening will provide valuable evidence in due course.peer-reviewe