Cancer is when abnormal cells divide in an uncontrolled way. Some cancers may eventually spread into other tissues.
There are more than 200 different types of cancer.
1 in 2 people in the UK will get cancer in their lifetime. Thanks to research many people are cured.
Cancer grows as cells multiply over and over
Cancer starts when gene changes make one cell or a few cells begin to grow and multiply too much. This may cause a growth called a tumour.
Is cancer genetic?
Most cancers start due to gene changes that happen over a person’s lifetime. More rarely cancers start due to inherited faulty genes passed down in families.
The main types of cancer
Our bodies are made up of billions of cells. The cells are so small that we can only see them under a microscope.
Cells group together to make up the tissues and organs of our bodies. They are very similar but vary in some ways because body organs do very different things. For example, nerves and muscles do different things, so the cells have different structures.
We can group cancer according to the type of cell they start in. There are 5 main types:
- carcinoma – cancer that begins in the skin or in tissues that line or cover internal organs. There are different subtypes, including adenocarcinoma, basal cell carcinoma, squamous cell carcinoma and transitional cell carcinoma
- sarcoma – cancer that begins in the connective or supportive tissues such as bone, cartilage, fat, muscle or blood vessels
- leukaemia – cancer that starts in blood forming tissue such as the bone marrow and causes abnormal blood cells to be produced and go into the blood
- lymphoma and myeloma – cancers that begin in the cells of the immune system
- brain and spinal cord cancers – these are known as central nervous system cancers
We can also classify cancers according to where they start in the body, such as breast cancer or lung cancer.