More than a third of cancer could be prevented by modifying or avoiding key risk factors, which include:
- tobacco use
- alcohol use
- being overweight or obese
- low fruit and vegetable intake
- physical inactivity
- sexually transmitted human papillomavirus (HPV) infection
- outdoor and indoor air pollution
- occupational exposure to carcinogens.
Tackling these risk factors, plus safeguarding exposure to carcinogens particularly in the workplace, advancing immunization against hepatitis B virus, vaccinating against HPV, and reducing exposure to sunlight play an enormous role in reducing the burden of cancer. Cervical cancer, which is caused by HPV, causes more than 28 000 deaths per year among women of the WHO European Region.
Tobacco
Tobacco is the single largest preventable cause of cancer in the world today. It causes 80% of lung cancer, which accounts for 20% of all cancer deaths in the Region. Other cancers – oral cavity, larynx, oesophagus and stomach – are highly associated with tobacco consumption and account for 10% of all cancer deaths in the Region. Tobacco also significantly increases the risk of kidney, bladder, pancreas and cervical cancers.
Alcohol use
Alcohol use is a risk factor for many cancer types including cancer of the oral cavity, pharynx, larynx, oesophagus, liver, colorectum and breast. The risk of cancer increases with the amount of alcohol consumed. Heavy drinking increases substantially the risk for several cancer types (e.g. oral cavity, pharynx, larynx and oesophagus) particularly if the person is also a smoker. In 2018 alone, around 180 000 cases of cancer and 92 000 cancer deaths were causally linked to alcohol in the Region..
Physical activity and diet
Regular physical activity and the maintenance of a healthy body weight, along with a healthy diet, will considerably reduce cancer risk. The types of cancer linked to overweight and obesity include oesophagus, colorectum, breast, endometrium and kidney. Diets high in fruits and vegetables have a protective effect against many cancers, while excess consumption of preserved meat is associated with an increased risk of cancer.
Infectious diseases
Viral hepatitis B and C cause cancer of the liver; HPV infection causes cervical cancer; the bacterium Helicobacter pylori increases the risk of stomach cancer. Preventive measures include vaccination and prevention of infection and infestation.
Exposure to carcinogens
Exposure to ionizing radiation is known to cause to certain cancers. Excessive solar ultraviolet radiation increases the risk of all types of cancer of the skin. Avoiding excessive exposure and using sunscreen and protective clothing are effective preventive measures.
More than 40 agents, mixtures and exposure circumstances in the working environment are carcinogenic to humans and are classified as occupational carcinogens. Asbestos can cause lung cancer; aniline dyes have been linked to bladder cancer, and benzene can lead to leukaemia. The prevention of certain occupational and environmental exposure to these and other chemicals is another important element in preventing cancer.
The incidence of cancer rises dramatically with age: the overall risk accumulation is combined with the tendency for cellular repair mechanisms to be less effective as a person grows older.