Kidney cancer is a disease in which cancer cells form in the tissues of the kidneys. The kidneys are bean-shaped organs located on either side of the spine, just below the rib cage. They play a crucial role in filtering waste from the blood, forms urine. There are several types of kidney cancer, but the most common type in adults is renal cell carcinoma. Other less common types include transitional cell carcinoma and Wilms tumor, which primarily affect children.