Kidney Cancer: The Facts

What is it?

Kidney Cancer, as the name implies, occurs when the cells of the kidneys become cancerous. The kidneys are two reddish-brown, bean-shaped organs. They are located at the back of the body, one on each side of the spine, just above the waist. The kidneys are part of the urinary system. They filter waste products and water from the blood, producing urine, which is stored in the bladder and then exits the body through the urethra.

The Kidneys also produce substances that control blood pressure and the formation of red blood cells (the blood cells that carry oxygen). There are three types of Kidney Cancer:

• Renal Cell Cancer - This is the most common type of Kidney Cancer. It affects the small tubes in the lining of the kidney, which filter the blood and produce urine.
• Transitional Cell Cancer - This less common type of Kidney Cancer is very similar to Bladder Cancer, and affects the regions of the Kidney known as the renal pelvis. Treatment for Transitional Cell Kidney Cancer usually resembles the treatments used for Bladder Cancer.
  
• Wilms' Tumor - Wilms' Tumor is the most common type of Kidney Cancer found in children.
  

This fact sheet will discuss renal cell cancer for the most part, since it is the most common type of Kidney Cancer.

Besides type, a particular instance of Kidney Cancer is also identified by stage. The stage a physician assigns to cancer depends on the tumor's size and the degree to which the cancer has spread (metastasized) at the time of diagnosis. Kidney Cancer is identified by four stages:

• Stage I: The cancer is only in the kidneys.
  
• Stage II: The cancer is in the kidneys and the surrounding fatty tissue.
  
• Stage III: The cancer has spread to the renal vein (main blood vessel carrying cleaned blood from the kidney toward the heart) and may or may not be in the lymph nodes or to the inferior vena cava (the blood vessel carrying blood from the lower part of the body below the diaphragm back to the heart).
  
• Stage IV: The cancer has spread to other organs such as the pancreas or lungs.
  

Who Gets it?

There are approximately 28,000 people a year that are diagnosed with Kidney Cancer in the United States and 11,000 associated deaths. Kidney cancer is the 10th most common cancer among women and the 8th most common cancer among men. The incidence rate (number of cases diagnosed in a particular period of time) of Kidney Cancer for men is twice that for women. In Rhode Island, in 2001, there were approximately 140 people diagnosed with Kidney Cancer.

Certain circumstances have been found to put people at a higher risk for Kidney Cancer. Some of these risk factors are out of our own personal control and some can be avoided or changed to help decrease the risk:

• Smoking
  
• High fat diet/obesity
  
• Job exposure to asbestos or chemical cadmium
  
• Radiation exposure, especially to the abdomen or lower back - Radiation therapy is often used to treat other types of cancer. While these treatments do constitute a risk factor for Kidney Cancer, the benefits of the treatments far outweigh this risk.
  
• Long-term dialysis - As with radiation cancer treatments, dialysis is a medical treatment often absolutely necessary to sustain life, and its benefits greatly outweigh the potential risk of Kidney Cancer.
  
• Von-Hippel Lindau (VHL) Disease - Genetic disease including multiple tumors of the kidneys, brain, spine, eyes, pancreas, inner ear and adrenal glands. It usually occurs in 1 out of every 36,000 births and symptoms appear early in life.
  
• Age - Kidney Cancer most often occurs in people ages 50-70.
  

How is it detected?

There is no universal screening process for Kidney Cancer that is recommended for the general population. Kidney Cancer is most often detected in routine blood and urine tests or when symptoms begin to appear. Besides blood and urine screenings, the following diagnostic tests have been used to detect kidney cancer:

• Physical Exams - During this exam, a doctor will feel the abdomen for abnormal masses or changes in size, shape or position of the kidneys and other organs; however, the kidneys are difficult to detect in an abdominal exam because they are set back in the body, under many other organs. Kidney Cancers detected by physical exam are usually in the more advanced stages.
  
  
• Intravenous Pyelogram (IVP) - For an IVP test, special dyes are injected into the body through a needle or a catheter. An X-ray is taken of the kidneys, ureters and bladder. The dye helps the organs to be more visible on the X-ray film.
  
  
• Arteriography - Arteriography is an x-ray image of the blood vessels in and around the kidneys. A dye is injected to enhance the image. Tumor growth typically results in a greater number and density of blood vessels.
  
  
• CT Scan - A CT scan of the abdomen often finds a tumor while looking for something else. It can detect unhealthy tissue and swollen lymph nodes.
  
  
• Magnetic Resonance Imaging (MRI) - An MRI uses magnetism and radio waves to create an image of the inside of the body, similar to a CT Scan. However, the MRI images are easier to read and show more detail.
  
  
• Ultrasound - An ultrasound uses sound waves to create an image of the inner organs of the body that can be used to detect abnormal masses of tissue.
  

Symptoms

Unfortunately, the early stages of kidney cancer usually do not show any symptoms. Most instances of Kidney Cancer are, therefore, diagnosed in the later stages when symptoms prompt the patient to see a doctor, and cancers at these stages are more difficult to treat. Many are picked up accidentally on an abdominal CT scan or MRI.

The most common symptoms of Kidney Cancer are blood in the urine and an abnormal lump or mass in the kidney area. Blood in the urine may be visible or it may be microscopic, in which case it can only be found through urinalysis (examining a urine sample in a pathology lab). Abnormal masses of tissue in the kidney area may be detected through manual examination or using ultrasound, MRI or CT Scanning. Some of the other symptoms of Kidney Cancer include:

• Fatigue
  
• Loss of appetite
  
• Weight loss
  
• Recurrent fever
  
• Side pain that won't go away
  
• A general feeling of poor health
  
• High blood pressure
  
• Anemia- A lower than normal number of red blood cells in the body
  

All of these symptoms do not necessarily mean you have Kidney Cancer, or any other type of cancer, but you should be examined by a doctor as they may indicate a number of other health problems that require treatment.

Is it curable?

Like other cancers, the rate of survival dramatically increases with early detection. If found early, over 79% of patients survive for more than 1 year. Today, in the United States, there are more than 100,000 survivors of Kidney Cancer.

In the United States, 70% of patients diagnosed with Stage I Kidney Cancer survive for more than 5 years. Fifty percent of patients diagnosed with Stage II and 35% of patients diagnosed with Stage III survive for more than 5 years.

Certain lifestyle changes and habits can help to reduce your chances of getting Kidney Cancer (as well as other types of cancer):

• Eat a well balanced diet.
  
• See your physician for a regular physical examination, including blood and urine tests.
  
• Avoid unnecessary exposure to radiation, asbestos, and chemical cadmium whenever possible.
  
• Don't smoke.
  

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