cancer 11 Flashcards
what are the leading causes of death in the world?
- Ischaemic heart disease and stroke lend to the highest global causes of death
- not cancer
how have CVS death numbers changed?
how have cancer death numbers changed?
- Death rates from CVS disease have dropped over the years
- Death rates from cancer have remained stable/increased-slightly over the years.
compare cancer in developed and undeveloped countries?
Developed countries have a greater incidence of cancer than undeveloped countries.
most common male cancers?
- prostate and lung cancers are the most common cancers
most common female cancers?
- breast and cervical cancers are the most common cancers
why might cancer incidence show geographical variation?
- Melanoma is most common in Australia and stomach cancer is most common in Japan.
- Australia might have high melanomas due to exposure to the sunlight and Australian people often have fair skin as they were originally from the UK
- Japan has high rates of stomach cancer due to infection with Helicobacter pylori bacteria as well as a diet factor
why has colorectal cancer increased in japan?
- there has been a shift in diet from fish and vegetables to red meat
- this is reflected in an increase in colorectal cancer in japan
why are migrant studies useful to look at cancer incidence in different countries?
- it is useful to look at migrants and see if their risk for developing cancer changes when they move to a new country eg. when the Japanese moved to Hawaii their risk for stomach cancer decreased down to American levels
- genetic susceptibility is important
- the environment also makes a difference
how is the incidence of cancer changing in the world?
- increasing in both low and high-income countries
- increase in high-income countries may be due to the introduction of screening programs
- increase in low income countries may be due to increasing ageing
how is mortality changing in high and low income countries?
- Mortality is decreasing in high-income countries but NOT low-income
- mortality is decreasing in high income countries due to better treatment and earlier diagnosis
what percentage of cancer is genetic?
- 5-10% , very few
give examples of when a hereditary condition predisposes to cancer :
what are the common risk factors of cancer?
- Smoking
- diet
- infection
- reproductive hormone
- alcohol
- occupation
ranked highest risk to lowest risk
what percentage of cancers are preventable?
45% (men) and 40% (women) of cancers could have been prevented by reducing risk from environmental factors
how much does smoking increase the risk of cancer?
- smoking contributes towards 30% of cancer death
- increases risk for >15 cancers
- 90% (men) and 80% (women) of lung cancer causes.
how does diet increase the risk of cancer?
- colorectal cancer chance increased with low fibrous diet.
- red processed meat increases risk of colorectal cancer
how does alcohol increase the risk of cancer?
- synergistic with alcohol intake
- the mechanism is poorly understood
- it is associated with liver, oral cavity, pharynx, larynx and oesophageal cancer
what are the recommendations for dietary prevention of cancer?
- Be lean without being underweight.
- Be physically active for at least 30 minutes a day.
- Avoid sugary drinks.
- Eat a variety of fruit/veg.
- Limit consumption of red meat (<500g/week) and avoid processed meat.
- Limit alcoholic drinks.
- Limit consumption of salty foods.
what might increase the risk of breast cancer?
- Sex steroids can increase cancer risk.
what percentage of cancer is caused by infectious causes?
16% of cancer is from an infectious cause (25% in Africa and <10% in EU).
for example :
- HPV (cervix cancer)
- EBV (Hodgkin’s/Burkett’s Lymphoma)
- HCV/HBV (liver cancer)
- H. pylori (stomach cancer).
read through the ibook key points:
