What is cancer?
Our body is made up of billions of tiny living cells. These cells grow and divide naturally, producing more cells as they are needed to keep our body healthy. Old cells die naturally and are replaced by new ones.
Sometimes this orderly process can go wrong. Genes contain instructions that tell a cell what to do. Genes may change, mostly in reaction to external factors in our lifestyle or environment. These changes cause cells start to multiply out of control, forming new and different cells when the body does not need them. These uncontrolled cells that continue to grow are “malignant” or abnormal and the disease they cause is called “cancer”.
There are many types of cancer, usually named after the tissue where they start. The abnormal, unwanted cells may form a lump, called a “tumor” (or solid cancer) or may be dispersed throughout the body, as with blood cancer or cancers of the lymph system (called non-solid cancer).
Even though the success of cancer treatment has greatly improved and about 50% of cancers can now be cured, the burden of cancer is still too high.
Once cancer is diagnosed, doctors conduct a careful classification (staging and grading) describing the nature and development of the cancer. This classification, together with other factors including the health of the patient, determines the choice of treatment.
