What is Kidney Cancer?

Cancer is caused by malignant (cancerous) cells that grow and multiply without control. When cancer begins in the tissues of a kidney, it is called kidney cancer (or renal cancer).

The kidneys are two large, bean-shaped organs.  One is located to the left of the backbone, the other is to the right. They have many important roles, including filtering blood to create urine, maintaining the balance of water and vital salts needed by the body, and helping control blood pressure.

The American Cancer Society (ACS) estimates that more than 81,000 new cases of kidney cancer will be diagnosed in the United States in 2023, and that the disease would cause about 14,000 deaths.

According to the ACS, renal cell carcinoma (also known as renal cell cancer) is "by far the most common type of kidney cancer. About 9 out of 10 kidney cancers are renal cell carcinomas." Other types of kidney cancer include transitional cell carcinoma of the renal pelvis and Wilms tumor.

Please note: The information on this page refers to renal cell carcinoma. 

Kidney Cancer Symptoms

The symptoms of kidney cancer may look like symptoms of other medical conditions. Talk to your doctor if you notice any of the following: 

  • Blood in the urine
  • Weight loss for no clear reason
  • Low back pain not caused by an injury
  • Loss of appetite
  • Swelling of ankles and legs
  • Mass or lump on the side or lower back
  • Fatigue
  • Recurrent fever not caused by a cold or the flu
  • Unrelieved pain in the side
  • High blood pressure (not as often)
  • Anemia, or low red blood cell count (not as often)

Diagnosing Kidney Cancer

The first step in diagnosing any disease is to complete a medical history and physical exam. To diagnose kidney cancer, your doctor may also order tests and procedures including:

  • Blood and urine laboratory tests
  • Intravenous pyelogram (IVP): First, a contrast dye is injected into a vein.  Then, X-rays are taken of the kidney, bladder and ureters (tubes running from each kidney to the bladder). The procedure enables kidney tumors (abnormal growths), kidney stones, and any other abnormalities or blockages to be detected
  • Imaging tests: Magnetic resonance imaging (MRI) and computerized tomography (CT) scans are advanced imaging technologies that can show the difference between diseased and healthy tissues
  • Ultrasound: High-frequency sound waves are used to create images of the kidneys and locate lumps in the tissue
  • Biopsy: A sample of a kidney tumor is removed during surgery and then viewed under a microscope to check for cancer

Treating Kidney Cancer

If you are diagnosed with kidney cancer, your care team will work with you to develop a treatment plan that is right for you. This plan will depend on factors such as type and stage (extent) of kidney cancer, your general health, and your treatment preferences.

The most common treatment for kidney cancer is a surgical procedure called a nephrectomy. (The remaining kidney is generally able to perform the work of both kidneys.) The types of nephrectomies include:

  • Partial nephrectomy: The part of the kidney that contains the tumor is removed
  • Radical nephrectomy: The whole kidney is removed

A nephrectomy may be traditional (open) or minimally invasive in nature. Laparoscopic nephrectomy is a minimally invasive approach that takes out all or part of the kidney using instruments.  These instruments are inserted through small incisions in the abdomen.

Another type of surgery is called ablation, which uses radiofrequency waves or freezing with cryoprobes to destroy tumors. This is an outpatient surgery, usually done with local anesthesia and light sedation; it offers the same benefits as partial nephrectomy.

Nonsurgical treatment options for kidney cancer include:

  • Radiation therapy uses high-energy radiation beams to kill or shrink tumors while saving healthy tissue. It may also be used to relieve pain when kidney cancer has spread to the bone
  • Targeted therapy uses drugs that attack specific parts of cancer cells. These drugs work differently from standard chemotherapy drugs and often have less-severe side effects
  • Biological therapy uses the body's own immune system to fight cancer
  • Arterial embolization involves the injection of a special gelatin sponge through a catheter to clog the main blood vessel in the kidney. The procedure shrinks the tumor by blocking the passage of oxygen-carrying blood and other substances it needs to grow
  • Active surveillance recognizes that some patients with kidney cancer may not need treatment right away, and may be followed – sometimes for many years – with close observation until such time as treatment is needed

Some hospitals also offer clinical trials that may provide access to new and promising therapies for kidney cancer.