Download Causes of Cancer

Causes
of
Cancer
Ageing
• Most types of cancer become more common
as people age
• Older people have had more time for their
DNA to mutate as a result of carcinogens
• Different mutations to DNA have to occur for
cancer to develop
• It can take years for several mutations to occur
Heredity
• There need to be a lots of genetic mutations
within a cell before it becomes cancerous.
• If a person is born with one of these
mutations it doesn't mean they will definitely
get cancer.
• BRCA1 and BRCA2 can mutate to cause breast
cancer
– 60% lifetime risk of developing breast cancer
– Higher risk of developing ovarian cancer
Viruses
• Viruses can cause some types of cancer
• The virus can cause genetic changes in cells
that make them more likely to become
cancerous.
• Most cervical cancer cases are caused by the
Human Papilloma Virus
Chemical Carcinogens
Hair dye = Bladder
Cancer
In 2008, the World Health
Organisation (WHO) that
they can increase the risk
of bladder cancer for male
hairdressers and barbers
because they are working
with the chemicals all the
time.
Arsenic = lung and
skin cancer
• Drinking
contaminated
water
• Eating
contaminated
food
• irrigation of
food crops
• industrial
processes.
Alcohol =
oesophageal (more
common in men)
and oropharyngeal
cancer
(throat,speaking and
swallowing)
http://www.youtube.com/watch?v=S087WW6RZkI
Evaluating Epidemiological Evidence
EPIC
- a study that collects a lot of data
-Data is assessed
-Correlation is analysed (Factor vs increase risk of cancer)
-In correlation is ‘strong positive’ then the government are inform
-The results are then published
• Epidemiology is the study (or the science of the study) of the patterns,
causes, and effects of health and disease conditions in defined
populations.
Case Study: Processed Meat
• Bowel cancer risk was a third higher in those who ate two 80g portions of
processed meat a day.
•Red meat includes lamb, pork, ham, bacon, sausages, liver plate, salami and
tinned meat.
•Red meat that is preserved by methods other than freezing can increase the
risk of bowel cancer.
No theory has been conclusively
linked to causing cancer, there are
several ideas among scientists
about the health risks associated
with processed (red) meat.
Though no theory has been conclusively linked to causing
cancer, there are several ideas among scientists about the
health risks associated with processed (red) meat.
One theory is that haemoglobin and myoglobin, two
polypeptides found in red meat, trigger a process called
nitrosation in the gut, which can lead the formation of
carcinogens.
Alternatively, scientists believe a particular group of chemicals
(heterocyclic amines), which are formed in the cooking process
can increase the risk of cancer.