Kidneys are a pair of organs located on either side of the spine in the mid-back region. They function to remove water, excess salt and waste products in the form of urine from the body. Urine that is produced by the kidneys is transported to the urinary bladder via tubes called ureters. It is common for cysts to form within kidneys. By the age of 50, over half of all people have such cysts. These cysts are fluid-filled and are usually benign (noncancerous) and do not need treatment.
Solid tumors of the kidney are rare - approximately three-fourths of these tumors are cancerous with the potential to spread. The most common types of kidney cancer include:
- Renal cell carcinoma (adenocarcinoma)
- Wilm's tumor (nephroblastoma)
- Urothelial cancer (transitional cell carcinoma)
Signs of kidney cancer include:
- Blood in urine
- Pain in the flank (side of the body)
- High blood pressure
These symptoms do not absolutely indicate that kidney cancer is present and these signs may occur in the face of other noncancerous conditions. It is also important to note that many patients who develop kidney cancer experience none of these symptoms and their tumors are found incidentally on imaging studies.
Causes and Risk Factors
There is no known absolute cause for the development of kidney cancer. The cancer can occur at any age but most occur after the age of 50. Twice as many men as women develop kidney cancer.
The risk factors for kidney cancer may include:
- Family history of kidney cancer
- High-fat diet
- Exposure to asbestos, solvents and cadmium
The following methods are generally used to diagnose kidney cancer:
The best chance for cure, particularly if the cancer has not spread to other parts of the body, is to surgically remove the tumor. This may involve removing part of the involved kidney or it may require that the entire kidney and its immediate surrounding tissue be removed. Newly developed medications may be used in addition to surgery, depending on the final diagnosis.