Cancer epidemiology Flashcards
What is the definition of cancer epidemiology?
The study of the distribution/patterns and determinants of the likelihood of cancer development. Cancer epidemiology can be used to identify events that increase or decrease cancer incidence in specific populations
What is incidence?
Occurrence of a given medical condition in a specified population within a specified time period
What is prevalence?
The total number of cases of a given disease in a specified population at a designated time
What is mortality?
Measure of the number of deaths in a particular population, scaled to the size of that population, per unit of time
What are risk factors?
Something that increases a person’s chances of developing a disease
What is correlation?
A statistical relationship between two variables
What is causation?
Establishing the cause of a disease
What are co-variates?
An independent variable that can influence the outcome of a given statistical trial, but which is not of direct interest
Why is cancer epidemiology important?
- Provides an overview of cancer burden and its likely future evolution
- Describes national/international differences in cancers over time & possible reasons
- Investigates predictors of survival
- Assesses efficacy of preventive measures
Which gender is more affected by cancer?
Males by 21% compare to females at 18%
What are the 3 most common cancers in the world?
- Lung
- Breast
- Colorectum
What are the major risk factors for cancer?
- Aging
- Lifestyle (tobacco, alcohol, poor diet, lack of physical activity, overweight, etc.)
- Environmental (sunlight, infectious diseases, pollution, etc.)
- Genetics (family history of cancer, sporadic mutations, etc.)
- Occupational carcinogens
- Radiation
What is the biggest risk factor for cancer?
Aging
How to study cancer epidemiology: correlation or causation?
Correlation is not causation!
Ice cream sales can be correlated to shark attacks but it is not the cause!
What is descriptive epidemiology studies?
To describe the difference in occurrence of a particular cancer between different groups (age, gender, country, a period of time for time trend) and to generate hypotheses for increased/decreased incidence for the specific tumour type
What is analytic epidemiology studies?
To study risk factors or potential causes of cancer by a particular study design (case-control study or cohort study)
What is intervention studies?
Applying the knowledge (risk/protective factors) obtained from analytic epidemiological studies to specific population in order to reduce the risk of cancer
What are examples in the study design for descriptive and analytic studies?
Descriptive studies: case series, case report or descriptive statistics
Analytic studies: cohort study, case-control study, before-after study, etc.
What is Randomised Controlled Trials (RCTs), what does it provide and when is it not possible?
- A design with subjects randomly assigned to “treatment” and “comparison” groups
- Provides most convincing evidence of relationship between exposure and effect
- Not possible to use RCTs to test effects of exposures that are expected to be harmful, for ethical reasons
RCT is the “gold standard” of research designs and provides most convincing evidence of relationship between exposure and effect
