Your kidneys are 2 bean-shaped organs that produce urine. They’re about the size of your fist and are in the back of your abdomen, near your spine. Kidneys balance your body’s water and mineral levels and filter waste out of your blood.
Cancer is the out-of-control growth of cells in your body. Cells are the tiny building blocks of your body. Cells specialize in what they do. Different organs are made of different kinds of cells. Almost any kind of cell can become cancerous.