Epidemiology of cancer Flashcards
How many people die every day as result of cancer in US?
1500
What percentage of deaths a year does cancer account for in the US?
23%- 2nd highest cause of death
Why is the incidence of cancer expected to increase?
Increasing population, ageing population and increasing number of new diagnoses
What is the global prevalence of cancer?
24.6 million (many are mild so have good survival rates)
What effect does increasing prevalence have on health services?
Increased cost
What are the differences in incidence between high income and low income countries?
Gap between incidence and mortality is greater in high income countries (better access to treatment?)
Cancer resulting from infection disease is greater in low-income countries
Prostate, breast and lung cancer incidence is higher in high-income countries (better screening?)
What are the leading cancer types in terms of incidence worldwide and in the UK?
Worldwide- lung (male) and breast (female)
UK- Prostate (male) and breast (female)
What are the leading cancer types in terms of mortality worldwide and in the UK?
Worldwide- lung (male) and breast (female)
UK- lung (male) and lung (female)
What does geographical variation show in terms of individual cancers?
It is useful in identifying causes for example, highest incidence of melanoma is in Australi/NZ (highest UV exposure= environmental), where there are many migrants from England and europe (fair skin= genetic predisposition
How does geographical variation help work out if cancer is environmental or geographical?
If risk of cancer doesn’t change with migration this suggests a genetic cause and if it changes to the new population, this suggests environmental
How are migrant studies considering the extent and rate of change in cancer incidence informative?
A rapid change in risk following migration implies that lifestyle/envrionmental factors act late in carcinogenesis
A slow change suggests that exposures early in life are most relevant
What common reasons are there for secular trends in cancer rates?
Changes in completeness of the sources of data
Changes in diagnostic abilities
Changes of practice in data classification
Demographic changes
Changes in screening practices
Changes in treatment practices
Change in risk factor distribution
What affects 5 year survival rates?
Race
Stage at diagnosis
Geographical variation
What known causes of cancer are there?
HPC- cervical cancer
H pylori- stomach cancer
Smoking- lung cancer
What risk factors are attributable to cancer?
Smoking Diet Alcohol Infection Occupation Reproductive hormone
