How does cancer kill people?

Cancer is the general name for a group of diseases in which cells in a part of the body begin to grow out of control. All cancers start because abnormal cells grow out of control. If the immune system does not destroy these cells, they will continue to grow and invade adjacent tissues. Cancer usually kills because abnormal cells impair the function of the organ or tissue they are growing on.

Cancer can cause death by spreading from the primary site to other parts of the body. Usually, this is well tolerated and people can live well for many years without problems. Many treatments can control cancer for a long time even if they can not cure it. Bear in mind that some cancers have survival rates of more than 90 percent and overall, more than 50 percent of people diagnosed with cancer live for more than five years. However, if a cancer continues to grow it can overwhelm the body’s essential functions such as the lungs, liver and digestive system. If this happens the treatment may no longer control the cancer and this might make it difficult to survive such an experience.