kidney cancer

The definitions used in this glossary of terminology either have been provided by the authors of the articles, or have been extracted wholly or in part, or paraphrased from the following sources: The American Medical Association Encyclopedia of Medicine, Charles B. Clayman, MD, Medical Editor, Random House, New York, 1989; Biotechnology from A to Z, 2d Edition, William Bains, Oxford University Press, New York, New York, 2002; A Dictionary of Genetics, 6th Edition, Robert C. King and William D. Stansfield, Oxford University Press, New York, New York, 2002; Dorland's Illustrated Medical Dictionary, 29th and 30th Editions, W. B. Saunders Company, Philadelphia, 2000, 2003; Genes VII, Benjamin Lewin, Oxford University Press, New York, New York, 2000; The Gale Encyclopedia of Genetic Disorders, Volumes I and II, Stacey L. Blachford, Ed., Thomson Learning, New York, New York, 2002; The Merriam-Webster Dictionary, Merriam-Webster, Inc., Springfield, Massachusetts, 1997; Molecular Biology of the Cell, 3rd Edition, Bruce Alberts, et al., Garland Publishing, 1994; The Random House Dictionary of the English Language, Unabridged Edition, 1966; Webster's Ninth New Collegiate Dictionary, 1991.

DEFINITION:

kidney cancer
Cancers that have their origins in the kidneys themselves are not rare. Cancer that starts in other organs rarely spreads to the kidneys.


TYPES

There are three main types of cancer arising in the kidneys.


Renal Cell Carcinoma This is the most common type of kidney cancer, accounting for about 75 percent of all kidney growths. The tumor usually occurs after the age of 40 and affects twice as many men as women. The most common symptom is hematuria (blood in the urine). There may be pain in the loins, a lump in the abdomen, fever, or weight loss. About 25 percent of patients survive five years or more because the tumor often has spread to the lungs, bone, liver, and brain by the time treatment is started.


Nephroblastoma Also called Wilms' tumor, this cancer accounts for about 20 percent of all cancers in children. It is found mainly in children under the age of 4 years and occurs almost twice as often in males. Nephroblastoma grows rapidly and is often felt as a lump in the abdomen. This cancer occasionally causes abdominal pain. Nephroblastoma frequently spreads to the lungs, liver, and brain. If treatment is started early, about 50 to 80 percent of children survive.


Transitional Cell Carcinoma This type arises from cells lining the renal pelvis. It develops in tobacco smokers and in people who have consumed very large quantities of analgesics (painkillers) over the course of many years. Hematuria is a common symptom; hydronephrosis (distention of the kidney with urine) may occur due to blockage of the ureter. Survival rates vary greatly, depending in part on early detection and treatment of the tumor.


DIAGNOSIS AND TREATMENT

Diagnosis is made by intravenous pyelography or by renal angiography. Treatment consists of nephrectomy (removal of the kidney) and sometimes removal of the ureter as well. In the case of a nephroblastoma, nephrectomy is followed by radiation therapy and chemotherapy.