Primary prevention reduces the likelihood that a disease or disorder will develop.25 The aim of primary prevention is to limit the incidence of disease by controlling specific causes and risk factors.26 Preventive steps to reduce risk factors for cancer, such as tobacco use, alcohol use, poor diet, physical inactivity, and overweight and obesity, also contribute to reducing risk of other chronic diseases, including cardiovascular diseases, type 2 diabetes and chronic respiratory diseases.4 The Royal Australian College of General Practitioners (RACGP) Guidelines for preventive activities in general practice(the red book) provides recommendations for general practitioners, based on current, evidence-based guidelines for preventive activities.27
Recommendations by the WCRF and AICR on food, nutrition and physical activity8 to reduce risk of cancer have recently been assessed through analysis of participants in the large European Prospective Investigation into Cancer (EPIC) study. Concordance with the WCRF and AICR recommendations was significantly associated with decreased risk of cancer, risk of death, and risk of death from cancer, circulatory disease and respiratory disease.28,29
WHO estimates that at least one third of all cancer cases are preventable.1 Other estimates suggest that more than half of all cancers could be prevented through a combination of healthy lifestyle and regular screening.2,3
Changes in lifestyle have the potential to reduce the number of cancer cases. The WCRF and AICR estimate that 21-24% of cancers in high-income countries could be prevented through changes to food, nutrition, physical activity and body fatness.30 Using WCRF and AICR estimates, improvements in diet and physical activity, and their impact on obesity, could prevent an estimated 43,000 cancers in Australia in 2025.31
Estimates on the percentage of cancers caused by modifiable risk factors vary depending on the population and the approach used to estimate the magnitude of association of individual risk factors.3 This position statement includes estimates from Australia and, when Australian estimates are not available, estimates from other developed regions, such as the United States and Europe, to indicate the proportion of preventable or avoidable cancer attributable to specific risk factors.