Kidney Cancer: Patient Education
- Cancer Facts
According to the American Cancer Society:
- There will be almost 61,000 new cases of kidney cancer this year (renal cell and renal pelvis & ureter).
- The average of people when they’re diagnosed with kidney cancer is 64. It’s very uncommon in people under age 45.
- The rate of people developing kidney cancer has been rising in recent years, perhaps due to the development of better imaging tests.
Kidney cancer is a malignant tumor that forms in the tissues of the kidneys. There are three main kinds of kidney cancer.
Renal cell carcinoma is a malignant tumor that forms in the lining of the small tubes of the kidney that filter blood, water, salt and waste products. About 90 percent of kidney cancers are renal cell adenocarcinomas.
Renal pelvis and ureter cancer is a malignant tumor that forms in your renal pelvis or ureter. Your renal pelvis is located at the top of your ureter. Your ureter is the long tube connecting your kidney to your bladder. It’s treated differently than renal cell carcinoma.
Wilms tumor is a kind of kidney cancer that generally affects children under the age of 5. It’s evaluated and treated differently than renal cell carcinoma and renal pelvis and ureter cancer. Because it’s a childhood cancer, it’s generally treated by a pediatric urologist.
Information here refers to renal cell carcinoma, commonly referred to as kidney cancer.
You have two kidneys. Each kidney is bean-shaped, about the size of your fist. They’re located in the back portion of your upper abdomen, on either side of your spine.
The outer portion of your kidney is solid tissue, while the central portion contains blood vessels and hollow spaces (called the renal pelvis) that collect urine.
Your kidneys are part of your urinary tract. The primary functions of your kidneys are to:
- Eliminate fluid and nitrogen waste
- Regulate electrolytes, red blood cell production and blood pressure
Urine produced by each kidney travels through a tube called the ureter to the bladder, which stores urine. When you urinate, urine leaves your bladder through a tube called the urethra.
Your kidneys are important but you can live a long time with just one kidney. In fact, many people can live a long time with no kidney at all, surviving with the help of dialysis.
How Kidney Cancer Grows
Renal cell carcinoma begins in the nephrons (the functional units of your kidney), which are located in the solid outer portion of your kidney.
Compared to other cancers, most cases of renal cell carcinoma are slow growing. The average growth rate of renal cell carcinoma is approximately 0.5 cm per year; the doubling time is around 18 months.
In most cases, the growth rate and doubling time are slower for smaller tumors and faster for larger tumors. Larger tumors generally spread to other organs, including the liver, lungs and bones.
Without prompt and effective treatment, renal cell carcinoma typically spreads through the lymph or the bloodstream. In many cases, kidney cancers have no symptoms, so they may be found later at advanced stages.