Kidney cancer, also known as renal cancer, occurs when malignant cells grow uncontrollably in the tissues of the kidneys. The kidneys, two bean-shaped organs located on either side of the spine, play a crucial role in filtering blood and removing waste through urine. The most common type of kidney cancer is renal cell carcinoma (RCC), which accounts for about 90% of cases. Kidney cancer is typically detected early, but in advanced stages, it can spread to other parts of the body.