Cancer Epidemiology Flashcards
Describe the differences in death rate from cancer and heart disease in <85 and 85>
Higher rates in <85
Describe the temporal trend in death rate from cancer
Little change from 1975
Which countries have the highest cancer incidence rates (top 5)
Ireland Belgium France USA UK
What does a rapid change in risk following migration suggest
Lifestyle/environment factors act late in carcinogenesis
What does a slow change in risk following migration suggest
Suggests that exposures early in life are the most relevant
What does persistence of rates between generations suggest
Genetic susceptibility is important in determining risk
Describe the trend in mortality of cancer
Decreasing in most high-income countries
Not decreasing in low income countries
Describe the trend in incidence for common cancer sites
Incidence is increasing for common cancer sites in both high-income (now with plateauing and even decreases) and low-income countries (e.g. breast, colorectum, prostate)
What is thought to be the cause of the increase in incidence of common cancer sites
effects of earlier diagnosis, screening, changes in risk factors
Why is total burden of cancer increasing
Demographic changes (ageing populations, increasing size) Westernization of lifestyles
What proportion of cancer has its risks increased by inherited conditions
5-10%
Give examples of inherited conditions that can increase risk of cancer
Paget’s - bone
Fanconi’s - leukaemia, liver, skin
Familial adenomatous polyposis - colon, rectum
Hereditary retimoblastoma - retinoblastoma
What are the main risk factors for cancer
Smoking Diet Alcohol Infection Occupation Reproductive
What percentage of cancers in men and women could be prevented if risk factors had been reduced to the optimal levels or eliminated
men - 45%
women - 40%
Other than reducing cancer risk, what are the advantages of reduction/elimination of risk factors
Substantial reduction also of cases of: Cardiovascular disease Renal disease Hepatic disease Diabetes Possibly some neurological diseases.
What proportion of cancer deaths does smoking account for + lung cancer deaths in mean and women
30%
men - 90%
women - 80%
What types of cancers are promoted by alcohol
Oral cavity Pharynx Larynx Oesophagus Liver
Describe the effect of alcohol on cancer
all types of alcohol
mechanisms poorly understood
synergism with tobacco
balance with preventive effect for CHD
What are the 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.
- Limit red and processed meats
- Drinks limited to 2(M) or 1(F)
- Limit salty foods
- Supplements do not work
Describe the western lifestyle
Energy dense diet, rich in
- fat,
- refined carbohydrates
- animal protein
Low physical activity
Smoking and drinkingWhat are the consequences of the western diet
Greater adult body height Early menarche Obesity Diabetes Cardiovascular disease Hypertension
What proportion of cases of cancer are caused by infectious agents
16%
Wha is cancer incidence related to
Age
Common environmental causes
Geographical variation and secular trends
There are several well defined risk factors for cancer
