What is cancer?

The body's basic building blocks are cells, and cancer is a disease of these cells. Our bodies are constantly producing new cells, to help us grow whilst replacing worn-out tissue and healing any injuries.


There's a pattern to how how cells increase and die, with each new cell replacing a lost one. Sometimes, the pattern becomes disrupted as some cells keep growing and are then known as abnormal because they have stopped doing what they normally do.


With some cancers, these abnormal cells form a mass or lump called a tumour. These cancers are solid cancers, such as breast or bowel cancer. In other cases, with cancer such as leukaemia, the cells build up in the blood instead.


How cancer starts.How cancer starts.

And with tumours, they can again be different, being either benign or malignant:

  • Benign tumours are cells that stay in one area and do not tend to spread. They generally grow slowly as well. However, some benign tumours do have the ability to precancerous and may later develop into cancer.
  • Malignant tumours are cancerous cells that can spread by travelling via the bloodstream or the lymphatic system.

The cancer that develops first, is called the primary cancer and is generally named after the organ or type of cell affected.


A malignant tumour that hasn't spread to other areas in the body, is called localised cancer. This tumour may embed itself further into the surrounding tissue and can also grow it's own blood vesses in a process known as angiogeneis.


When cancerous cells grow and form a new tumour elsewhere in the body, this is known as a secondary cancer or a mestasis. For example: cervical cancer that has spread to the kidneys is called metastatic cervical cancer, even though the person might be experiencing issues caused by the cancer existing in the kidneys.

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September 2020
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