Cancer is a disease of the cells in the body.
Changes to our genes can make cells grow and reproduce abnormally. Sometimes they grow into a lump called a tumour. Not all tumours are cancerous. Non-cancerous tumours are called benign and cancerous tumours are called malignant.
Malignant tumours are made up of cancer cells. Cancer cells have the ability to spread beyond an organ and around the body. When cancer cells spread to other parts of the body, it is called metastatic cancer.
The beginning of cancer