what is cancer?
Cancer is a disease caused by an uncontrolled division of abnormal cells in the body
Metastases are secondary tumours – these are formed when cells from malignant tumours when they break off and spread to other parts of the body via blood or lymphatic system (metastasis)
what causes cancer?
Radiation – radiation that are high in energy can damage the bonds in DNA- this leads to mutations, ultraviolent radiation can cause skin cancer.
Carcinogens – carcinogens cause changes in DNA, DNA can be repaired by cells – it often takes lots of carcinogens before cancer is triggered. Carcinogens in cigarettes causes cancer, carcinogens in alcohol can cause cancer.
Ageing – older people have been exposed to more factor that cause cancers, they have also more time to accumulate damage DNA.
Heredity – some people inherit genes which make them more likely to develop cancer.
Viruses – some viruses cause cancer, viruses infect cells by inserting new genetic materials into cells – cause changes in cell’s DNA.
how cancer is detected?
X-rays - X-rays use high energy rays to take pictures of the inside of your body; they can show changes in tissues and organs.
Mammography – type of x-ray used to detect small tumours in breast
CT scans/CAT scans – tunnel shaped machine – that takes x-ray pictures from different angles – a computer builds up 3D images of the body; making it easier to see tumours
Thermography – digital infrared images – warmer parts of body give off more infrared radiation; cancer tumours are warmer as they respire more.
Ultrasound - use sound waves to build up a picture of the inside of the body, the radiographer can see if there are any abnormalities
MRI scans - scan uses magnetism to build up a picture of the inside of the body, taking measurements of different parts of body. A computer makes these measurements into 3D images (more detailed than CT scans but more expensive)
PET scans – patient is injected with radioactive substance that breaks down and releases gamma rays; the gamma rays emit a pattern which is used to build up an image of body, these can be used to see abnormalities
how cancer is treated?
Chemotherapy – a chemical that is toxic to dividing cells, cancer cells divide more rapidly than normal cells.
Radiotherapy – ionising radiation destroy the cancer cells, ionising radiation destroy actively growing cells
Surgery – where the tumour is removed
Lumpectomy - removal of the tumour a in breast and a border of breast tissue