Cancer is a disease in which cells grow out of control and invade,
erode, and destroy normal tissue. Damaged genes cause this development
of cancer. These damaged genes are often a factor caused by such
things such as the environment, and can be influenced by inherited
factors. As the very early damaged cells divide they can evolve into a
malignant cell population, and lose the control mechanism that govern
normal cell division. These malignant cells can then go on to form
solid tumours that start to destroy normal tissue. These can then
spread to other parts of the body by releasing these tumour cells.
Once these cancer cells spread, they grow in other parts of the body
and then form new cancers. If this cancer spreads to take over a part
of the body that performs an essential function, this can kill you.
One in three people will be diagnosed with cancer during their
lifetime. However most cancers mainly affect older people. Therefore
as the average life expectancy in the United Kingdom has almost
doubled, the risk of cancer has grown. It is estimated that a third of
all cancers are caused by smoking and another third is caused by the
diet people choose. These are over two hundred different types of
cancer, and all have different causes, different symptoms and require
different types of treatment. Some types of cancer are very common,
such as breast, lung, bowel, and prostate cancer, whereas some types
of blood cancers are very rare.
There are many causes of cancer. However, usually there is more than
one cause, which will cause cancer. This is known as being
Carcinogens are one major cause known to produce cancer. Carcinogens
are dangerous as some are highly reactive molecules that target DNA.
These are known as mutagens. These carcinogens can cause errors,
duplication or rearrangement in DNA sequences that contribute to the
progression of cancer. An example of a carcinogen is tobacco. Tobacco
smoke contains at least twenty carcinogens, which are known to cause
Age can be a factor when asked what causes cancer. This is because
cancer becomes more common as we get older. 85% of cancers are
diagnosed in patients over fifty-five. This is because as we get older
we become more...