Kidney cancer occurs most often in children and one type is Wilms tumor, which typically strikes children between ages 3-8. Risk factors include smoking, obesity, high blood pressure, family history, and certain medicines or jobs. Symptoms can include abdominal pain, loss of appetite, and swelling. Treatment options depend on the cancer type and stage but may include surgery, radiation, chemotherapy, or hormone therapy. Preventative measures include not smoking and maintaining a healthy weight.