Kidney cancer, which most often occurs in men 50 to 70 years old, rarely produces symptoms in its early stages. Eventually, though, a tumor in one of the kidneys may trigger one or more of the following: blood in the urine (most common symptom), persistent pain in the back, a lump in the abdomen and general symptoms such as persistent fatigue, unexplained weight loss, recurrent fevers, high blood pressure, and swelling in the ankles.
Being aware of these signs can help patients catch their condition and begin treatment as soon as possible.