causes of cancer Flashcards
what sort of things can cause cancer?
ionizing radiation
genetics
asbestos
viruses
diet
parasites
cigarettes
the sun
hormones
is smoking associated with cancer?
yes 15% of cancers are associated with smoking
what ways does alcohol cause damage?
–Acetaldehyde: damages cells
–Hormone changes: oestrogen, insulin
–Increased absorption (of harmful chemicals)
how does UV light cause damage?
UV-B causes sunburn and directly damages DNA
*UV-A does not cause sunburn although it is still thought to contribute to skin
cancer through free radical formation
*Less concerned with UV-C as it is [hopefully] blocked out by the ozone layer
what are the types of non-melanoma skin cancers?
basal cell carcinoma
squamous cell carcinoma
where does basal cell carcinoma start?
starts in the cells lining the bottom of the epidermis
where does squamous cell carcinoma start?
starts in the cell lining the top of the epidermis
what is thought to be the cause of malignant melanoma?
*UV-A and UV-B radiation are both thought to be
responsible for malignant melanoma
what is the usual treatment for malignant melanoma?
surgery
how does whole foods affect cancer, based on observation?
Associated with reductions in cancer and CVD mortality
how does red meat affect cancer?
–Excessive consumption increases incidence of colon cancer and
ER+ve breast cancer
what is the benefit of taking vitamin D?
–High intake and high plasma levels of vitamin D associated with
a decreased risk of several cancers
–Supplementation may be beneficial in areas with limited sun
exposure
how does physical activity prevent cancer?
*Recommended for the primary prevention of
cancer
*Can lower hormone levels e.g. insulin
*Correlation between physical activity and a
reduction in:
–Colon, breast and endometrial cancer
*Also beneficial during cancer treatment and
in cancer survivors
how does hormones affect cell behaviour?
Hormones can enter cells and cause the cell to make
proteins, which might change cell behaviour
*Overstimulation of hormone receptors can lead to
excessive cell multiplication
do all cells have hormone receptors?
no
what are the hormone driven cancers?
Breast and gynaecological cancers, prostate cancers
how can hormonal cancers be stimulated?
Can be stimulated by endogenous or exogenous
hormones
when is hormonal intervention important ?
Hormonal intervention important in cancer treatment and prevention
how do cancers develop due to genetics?
Could be caused by a
change in a gene as a result
of age or a carcinogen
*Some faulty genes can be
inherited from parents
how does geography influence development of different cancers?
–Chinese high levels stomach cancer
–Cannot be explained by genetic differences between races
give an example of how viruses can cause cancer?
HPV- cervical cancer
how does your immune system influence your chances of developing cancer?
Immunosuppression increases incidence of
some cancers
*40% patients with AIDS syndrome develop
malignancy
what are chemical factors that increase your risk of developing cancer?
*Cigarette Smoking
*Asbestos
*Alcohol
*Naphthylamine and azo dyes
*Wood dust
*Soot
*Tar
*Arsenic
what are the screening options available?
*Bowel: 60 years+ invited to collect a small
sample of faeces and post to lab to test for
blood (every 2 years)
*Breast: patients 50 – 70 years who have
breasts invited for mammogram where breasts
are X-rayed (every 3 years)
*Cervical: patients with a cervix 25 to 64 years
invited for cervical screen – small sample of
cells removed and tested for HPV and
abnormal changes (3 years until 49 and then 5
years)
