FACT
Carcinogens can
cause aDNA
mutationthat
occurs in one of
severalgenesthat
normally function to
control growth. E.g
theBRCA1, or
”Breast Cancer
Gene”. TheBRCA1
gene normally
functions to
suppress tumour
formation; but if a
genetic mutation
occurs it does not
work properly, and
tumour formation
can begin.
Mutations in this
gene does not mean
that a person will
develop breast
cancer, but they
have an increased
risk for breast
cancer.Causes of cancer DUMMY
Canceris caused by agents calledcarcinogens. Carcinogens cause cancer by damaging
DNA which can no longer code for the important regulatory functions of the cell cycle.
Some viruses can also increase the likelihood of getting certain types of cancer. Human
papillomavirus (HPV), the disease that causes genital warts, can increase a woman’s risk of
cervical cancer, and infection with hepatitis B or C increases the risk of liver cancer. In
addition, some people are born with genetic mutations that they have inherited from their
parents that increase their chances of getting cancer. However a genetic predisposition to
cancer does not mean that you will get cancer. If you have a family history of cancer it simply
means it is more important for you to limit your exposure to carcinogens. Examples of some
carcinogens include:
- cigarette smoke
- radiation
- x-rays
- UV light
- food additives
- several dangerous chemicals
Beliefs and attitudes concerning cancer DUMMY
There are some common misconceptions about cancer
- It is people’s fault if they get cancer: although there are ways to try and decrease your
risk of getting cancer, it is not always possible. Cancer is caused by random mutations
in DNA, and sometimes people get cancer purely by chance. - Cancer is a death sentence: sometimes when the cancer is very advanced there is not
much to be done to save a person, but there are many cancers that respond well to
treatment when detected early. Depending on the type and the stage of the cancer,
people can survive cancer and go on to live healthy happy lives. - If someone in your family has cancer you might get it too: although there are some
cancers that are more common in certain families due to an inherited genetic mutation,
a family history of cancer does not mean than you will also get cancer. However, if
a certain type of cancer runs in your family it is good to see a doctor for regular
screenings. - Cancer is contagious and you can catch it from others: cancer cannot be spread from
one person to another. - A positive attitude can cure cancer: there is plenty of evidence that a positive attitude
can help a person with cancer feel better and stay healthier for longer, however it is
not the only factor that determines whether someone will recover or not. - Only old people get cancer: although cancer is more common in older people, chil-
dren and babies can also get cancer. Leukaemia is a common childhood cancer. - Only females get breast cancer: although breast cancer is more common in females,
males can also get breast cancer. - Only pale people get skin cancer: although skin cancer is more common in people
with light skin (melanin, the pigment that makes your skin dark is also protective),
people with dark skin can also get skin cancer.
Chapter 4. Cell division 105