Renal cell carcinoma, a form of kidney cancer that involves cancerous changes in the cells of the renal tubule, is the most common type of kidney cancer in adults.

Causes

Renal cell carcinoma affects about three in 10,000 people, resulting in about 31,000 new cases in the US per year. Every year, about 12,000 people in the US die from renal cell carcinoma. It is more common in men than women, usually affecting men older than 55.

Why the cells become cancerous is not known. A history of smoking greatly increases the risk for developing renal cell carcinoma. Some people may also have inherited an increased risk to develop renal cell carcinoma, and a family history of kidney cancer increases the risk.

People with von Hippel-Lindau disease, a hereditary disease that affects the capillaries of the brain, commonly also develop renal cell carcinoma. Kidney disorders that require dialysis for treatment also increase the risk for developing renal cell carcinoma.

The first symptom is usually blood in the urine. Sometimes both kidneys are involved. The cancer metastasizes (spreads) easily, most often to the lungs and other organs, and about one-third of patients have metastasis at the time of diagnosis.

Symptoms

• Blood in the urine
• Abnormal urine color (dark, rusty, or brown)
• Flank pain
• Back pain
• Abdominal pain
• Weight loss, more than 5% of body weight
• Emaciated, thin, malnourished appearance
• Enlargement of one testicle
• Swelling or enlargement of the abdomen
• Additional symptoms that may be associated with this disease:
  • Vision abnormalities
  • Paleness
  • Excessive hair grown (females)
  • Constipation
  • Cold intolerance

Treatment

Surgical removal of all or part of the kidney (nephrectomy) is recommended. This may include removal of the bladder or surrounding tissues or lymph nodes.

Radiation therapy is not commonly used for treatment of renal cell carcinoma because it is usually not successful. Hormone treatments may reduce the growth of the tumor in some cases.

Medications such as alpha-interferon and interleukin-2 (IL-2) have been successful in reducing the growth of some renal cell carcinomas, including some with metastasis. IL-2 (Proleukin®) is presently the only therapy FDA-approved for the treatment of metastatic renal cell carcinoma (kidney cancer). Studies have demonstrated that IL-2 offers the possibility of a complete and long-lasting remission in these diseases.

Chemotherapy may be used in some cases, but cure is unlikely unless all the cancer can be removed with surgery.

Expectations (prognosis)

The outcome varies depending on the amount of metastasis. The five-year survival rate is around 60 percent to 75 percent if the tumor is in the early stages and has not spread outside the kidney. If it has metastasized to the lymph nodes, the 5-year survival is around 5 percent to 15 percent. If it has spread to other organs, the 5-year survival at less than 5 percent.

Complications

• Hypertension
• Metastasis (spread) of the cancer

External link

• NIH site on kidney Cancer (http://www.nlm.nih.gov/medlineplus/ency/article/000516.htm)