A large international survey for the International Union Against Cancer (UICC) has revealed that many people have misconceptions about what causes cancer.
The survey involving 29,925 people from 29 countries, has found that many people have in their minds an exaggerated idea of the threat from environmental factors that have relatively little impact and minimize the hazards of behaviours which are well established as cancer risk factors.
The survey has identified important areas where misconceptions can be addressed and lives saved, and is the first study to provide internationally comparable data on perceptions about cancer risk factors between high, middle and low income countries.
The survey found that people in high-income countries were the least likely to believe that drinking alcohol was a greater risk factor for cancer than not eating enough fruits and vegetables, even though the scientific evidence for the protective effect of fruit and vegetables is weaker than the evidence that alcohol intake is harmful.
Those in rich countries also rated stress and air pollution as higher perceived risk factors for cancer than alcohol intake, even though stress is not recognized as a cause of cancer and air pollution is a minor contributor compared with alcohol consumption.
In low and middle-income countries it appears people have more pessimistic beliefs about cancer treatment than those in high-income countries and many believe cancer to be incurable.
This is a concern say the researchers because it could deter people from participating in cancer screening programmes which save lives.
Most people it seems, accept more readily that things outside of their control might cause cancer such as air pollution, than things that are within their own control such as overweight, which is a well-established cancer risk factor.
In low income countries a surprising number prefer their doctor to make all the treatment decisions, very few in fact favoured joint decisions being made between doctor and patient and even fewer thought the patient should decide.
In richer countries a more equitable decision-making style is favoured where the decision is made together with the doctor or rests with the patient alone.
Dr. David Hill, President-Elect of UICC and director of the Cancer Council Victoria in Melbourne, Australia, whose team analyzed the survey data, says the survey reveals there are some unheard messages.