Renal Cell Carcinoma (RCC)
Several types of cancer can afflict the kidneys. Renal cell carcinoma (RCC),
the most common form, accounts for approximately 85% of all kidney cancers.
In RCC, malignant (cancerous) cells develop in the lining of the kidney's
tubules and typically grow into a mass called a tumor. Single tumors are the
norm, although more than one tumor can develop within one or both kidneys.
Early diagnosis is critically important. As with most cancers, the
earlier kidney tumors are discovered, the better a patient's chances for
survival. Tumors discovered at an early stage often respond well to
treatment. Survival rates in such cases are high. Tumors that have grown
large or metastasized (spread) through the bloodstream or lymphatic system
to other parts of the body are much more difficult to treat and present a
greatly increased risk for mortality.
Incidence and Prevalence
According to the National Cancer Institute, the highest incidence of kidney
cancer occurs in the United States, Canada, Northern Europe, Australia, and
New Zealand. The lowest incidence is found in Thailand, China, and the
In the United States, kidney cancer accounts for approximately 3% of all
adult cancers. According to the American Cancer Society, about 32,000 new
cases are diagnosed and about 12,000 people die from the disease annually.
Kidney cancer occurs most often in people between the ages of 50 and 70, and
affects men almost twice as often as women.
Smokers develop renal cell carcinoma about twice as often as nonsmokers
and develop cancer of the renal pelvis about 4 times as often. Not smoking
is the most effective way to prevent kidney cancer and it is estimated that
the elimination of smoking would reduce the rate of renal pelvis cancer by
one-half and the rate of renal cell carcinoma by one-third.
Wilms’ tumor accounts for about 6% of childhood cancers and it is the
most common type of kidney cancer in children. Incidence of Wilms’ tumor is
higher in girls younger than the age of 5 and in African Americans.
The kidneys are an essential part of the body's urinary system. Each kidney
is composed of about one million microscopic "filtering packets" called
glomeruli. The glomeruli remove uremic waste products from the blood. Each
glomerulus connects to a long tube, called the tubule. Urine made by the
glomerulus moves down the tubule. Together, the glomerulus and the tubule
form a unit called a nephron. Each nephron connects to progressively larger
tubular branches, until it reaches a large collection area called the calyx.
The calices form the funnel-shaped portion of the upper ureter (renal
pelvis). Urine moves from the renal pelvis to the ureters, the large tubes
that connect the kidney to the bladder.
The kidneys produce three important hormones: erythropoietin (EPO), which
triggers the production of red blood cells in bones; renin, which regulates
blood pressure; and vitamin D, which helps regulate the body's metabolism of
calcium necessary for healthy bones.