Cancer epidemiology Flashcards
What does a rapid change in cancer risk following migration imply?
Lifestyle/environment factors act late in carcinogenesis.
What does a slow change in cancer risk following migration suggest?
Exposures early in life are the most relevant.
What does persistence of cancer rates between generations suggest?
Genetic susceptibility is important in determining risk.
Why is the total burden of cancer increasing?
Demographic changes (ageing populations, increasing size) and Westernisation of lifestyles.
How is incidence of common cancer sites changing?
Increasing in both high and low income countries, perhaps due to effects of earlier diagnosis, screening and changes in risk factors.
How is mortality due to common cancers changing?
Decreasing in most high income countries, but not in low income countries.
What are the main risk factors for cancer?
Smoking Diet Alcohol Infection Occupation Reproductive hormone
What is the percentage population attributable risk of cancer due to occupation?
2-4%
What percentage of cancers in men and women could have been prevented if risk factors had been reduced or eliminated?
45% in men
40% in women
What percentage of lung cancer deaths are caused by smoking in men and women?
90% in men
80% in women
What percentage of all cancer deaths does smoking account for?
At least 30%
What are the World Cancer Research Fund guidelines for dietary prevention of cancer?
Be as lean as possible without becoming underweight.
Be physically active for at least 30 minutes every day.
Avoid sugary drinks.
Limit consumption of energy-dense foods (particularly processed foods high in added sugar, or low in fibre, or high in fat).
Eat more of a variety of vegetables, fruits, wholegrains, and pulses such as beans.
Basing our diets on plant foods, which contain fibre and other nutrients, can reduce our risk of cancer.
Limit consumption of red meats (such as beef, pork and lamb) and avoid processed meats.
To reduce your cancer risk, eat no more that 500g cooked weight (700-750g uncooked) per week of red meats, like beef, pork and lamb, and avoid processed meat such as ham, bacon, salami, hot dogs and some sausages.
If consumed at all, limit alcoholic drinks to 2 for men and 1 for women a day.
Limit consumption of salty foods and foods processed with salt (sodium).
Don’t use supplements to protect against cancer.
To reduce your risk of cancer, choose a balanced diet with a variety of foods rather than taking supplements.
What are the features of a ‘Western’ lifestyle?
Energy dense diet, rich in fat, refined carbohydrates and animal protein.
Low physical activity.
Smoking and drinking.
What may be the consequences of a ‘Western’ lifestyle?
Greater adult body height Early menarche Obesity Diabetes Cardiovascular disease Hypertension Cancer
What percentage of cancer cases are likely caused by infectious agents worldwide?
Around 16%
