About Kidney Cancer

Types of Kidney Cancers
Renal cell carcinoma, which accounts for 85 percent of kidney tumors, arises in the lining of the tiny tubules inside the kidney that filter the blood and make urine.

There are five types of renal cell kidney cancer:

• clear cell
• chromophilicchromophobic
• oncocytic
• papillary
• collecting duct
• sarcomatoid.

Clear cell cancer is the most common form of renal cell cancer. Cancer that arises in the renal pelvis, the part of the kidney that collects urine and drains it into the ureters is called transitional-cell carcinoma. A type of kidney cancer that affects children is called Wilm's Tumor.

Risk Factors
Kidney cancer usually affects people over the age of 50. Men are more likely to get the disease then women, and smokers are twice as likely to get kidney cancer as nonsmokers. Being overweight, and having a high-fat diet also increases the risk of getting kidney cancer.

Sometimes, substances in the workplace, such as asbestos, cadmium (a trace metal), and organic solvents (especially trichloroethylene), may also be risk factors for kidney cancer. Occupations that have been linked to asbestos exposure include builders, car mechanics, and shipyard workers. Other occupations linked to kidney cancer include leather tanners and shoe workers.

Other risk factors include long-term kidney dialysis, a faulty gene that makes a person more susceptible to kidney cancer, and four inherited diseases: Von Hippel Lindau syndrome, Birt-Hogg-Dube syndrome, Hereditary non-VHL clear cell renal cell cancer, and Hereditary papillary renal cell cancer. People with tuberous sclerosis--a disease associated with several bumps on the skin, seizures, mental retardation, and cysts in the kidneys, liver, and pancreas is also at a greater risk.

Symptoms
Kidney cancer is often undiscovered until the later stages. Symptoms may include blood in the urine, a lump in the abdomen, fatigue, loss of appetite, weight loss, recurrent fevers not associated with colds or flu, and a pain in the side that doesn't go away.

Diagnosis
To detect kidney cancer, a doctor may feel the abdomen for lumps, and may perform blood and urine tests. The doctor usually orders tests that produce pictures of the kidneys and nearby organs to show changes in the kidney and surrounding tissues. For example, an intravenous pyelogram is a series of X-rays of the kidneys, ureters, and bladder, taken after the injection of a dye. The dye in the pictures show changes in the shape of these organs and nearby lymph nodes.

Another test, arteriography, is a series of X-rays of the blood vessels after dye is injected into a large blood vessel through a catheter. The X-rays show the dye as it moves through the network of smaller blood vessels in and around the kidney.

Other tests, such as magnetic resonance imaging (MRI), computed tomography (CT), and ultrasonagraphy, can also show the difference between diseased and healthy tissues.

February 2007