Preventive therapy for cancer.

Therapeutic cancer prevention is a developing area that can gain a lot from the successes in the prevention of cardiovascular diseases. Although weight control and physical activity are important in the prevention of both diseases, several other preventive measures exist. Low-dose aspirin for cancer prevention is often cited as the most important approach in terms of population benefit, and should be offered to those older than 50 years of age without hypertension or risk factors for gastrointestinal bleeding. Universal vaccination against the human papillomavirus, ideally with the nine-valent vaccine, also offers substantial benefits for the whole population if given before infection occurs (ie, typically at age 12-14 years). Other therapies, such as anti-oestrogen drugs for breast cancer prevention, should be targeted to high-risk groups to maintain a favourable benefit-risk ratio. Better algorithms for identification and improved platforms to reach these groups, such as during a screening visit, remain a key priority to allow existing knowledge to inform public health. Many other promising compounds have been identified, often as components of food, but results suggesting increased disease incidence with β carotene and vitamin E administration indicate that such treatments need rigorous evaluation before acceptance.