| What is kidney cancer? |
Your kidneys are two bean-shaped organs, each about the size of your fist, located behind your abdomen on either side of your spine. Their main function is to remove excess water and waste from your blood. But they also produce hormones that help control blood pressure, regulate the production of red blood cells and form bone.
Like other major organs in your body, your kidneys can sometimes develop cancer. In adults, the most common type of kidney cancer is renal cell carcinoma (renal adenocarcinoma or hypernephroma), which begins in the cells that line small tubes (tubules) within your kidneys.
Transitional cell carcinoma, which makes up about 10 percent of kidney cancers, may occur in the kidneys, the bladder or the tubes leading from the kidneys to your bladder (ureters). Another type of kidney cancer, Wilms' tumor, occurs primarily in children and accounts for 5 percent of kidney cancers.
Cancer that begins in the kidneys can grow and spread, invading nearby organs, such as the adrenal glands or pancreas and even the spine. Cancer cells may also spread (metastasize) to other parts of the body, especially the lungs, liver and bones. Unfortunately, kidney cancer often gives no warning signs in its early stages. As the tumor grows, there may be blood in the urine or a mass in the kidney that usually causes no symptoms.
Every year, kidney cancer is diagnosed in more than 31,000 Americans, and nearly 12,000 die of the disease. Yet if kidney cancer is detected and treated early, the chances for a full recovery are good.
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| Signs and symptoms |
- A pain in the back just below the ribs that doesn't go away
- A mass in the area of the kidneys that's discovered during an examination
- Weight loss
- Fatigue
- Intermittent fever
- Pain in other parts of the body if the cancer has metastasized
| Causes |
Your kidneys are part of a complex system (urinary system) that removes waste and excess fluid from your blood. Inside each kidney are more than a million small filtering units known as nephrons. As blood circulates through your kidneys, the nephrons filter out waste products and unneeded water. This liquid waste — urine —drains through two narrow tubes (ureters) into your bladder, where it's stored until it passes from your body through another tube, the urethra.
Renal cell carcinoma, which accounts for almost 90 percent of all kidney cancers, usually begins in the cells that line the tubules — small tubes that make up a part of each nephron. Transitional cell cancer, which makes up 10 percent of kidney cancers, may occur inside the kidneys, ureters or bladder.
Normally, cells in the urinary system grow and divide in an elegant and orderly way. But sometimes the cells may start to divide without control or order, producing new cells even when your body doesn't need them. This forms a mass of extra tissue known as a tumor.
Not all tumors are cancerous. Those that are cancerous are called malignant tumors. Cells from these tumors may invade and destroy surrounding tissue. They may also break away from the original tumor and enter your bloodstream or lymph system, where they're carried to other parts of your body — a process known as metastasis.
Just what causes kidney cells to become cancerous isn't clear. But researchers have identified certain factors that appear to increase the risk of developing both renal and transitional cell kidney cancers.
| Risk factors |
The risk of renal cell carcinoma increases as you age, occurring most often in people between the ages of 50 and 70. Men are more than twice as likely as women are to develop this type of kidney cancer, and black men have a slightly higher risk than white men do. Other risk factors for renal cell carcinoma include:
- Smoking. Smokers, especially those who smoke pipes or cigars, are at greater risk than are
nonsmokers. The risk increases the longer you smoke and decreases after you quit.
- Obesity. Some studies have shown a link between excess weight and kidney cancer in both men
and women.
- High blood pressure (hypertension). Researchers have found a clear link between high blood
pressure and renal cell carcinoma in men.
- Environmental toxins. Coal oven workers in steel plants have high rates of kidney cancer.
So do people who are exposed to asbestos, a fireproofing material that has also been linked to lung
cancer.
- Dialysis. People who receive long-term dialysis to treat chronic renal failure are at
greater risk of developing kidney cancer primarily because renal failure depresses the immune system.
People who have a kidney transplant and receive immunosuppressant drugs are also more likely to
develop kidney cancer.
- Radiation. In some cases exposure to radiation may increase your risk of kidney cancer.
- Von Hippel-Lindau (VHL) disease. People with this inherited disorder also are at risk of developing kidney cancer.
- Bladder cancer. People who have bladder cancer are at increased risk of developing
transitional cell carcinoma of the ureter or kidney as well as developing additional bladder cancers.
- Phenacetin. Long-term use of this painkiller has lead to kidney cancer in some people. The drug is no longer available in the United States.
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| When to seek medical advice |
See your doctor right away if you notice blood in your urine. In most cases, this doesn't mean you have kidney cancer. Blood in the urine may be a sign of many conditions, including a renal cyst — a noncancerous lesion of the kidney that's common in people older than 50 — bladder or kidney stones, prostate problems, or urinary tract infections.
If you think you may be at risk of developing kidney cancer, discuss your concerns with your doctor. He or she may suggest ways to reduce your risk and can help schedule regular checkups. When kidney cancer is diagnosed early, it's easier to treat and your chances of survival are good.
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| Screening and diagnosis |
In addition to taking a complete medical history and performing a physical exam, your doctor will likely recommend blood and urine tests. If he or she suspects kidney cancer, you may also have one or more of these tests to check for growths or tumors:
- Intravenous pyelogram (IVP). In this test, a contrast dye is injected into a vein in your
arm. A series of X-rays are taken as the dye moves through your kidneys, ureters and bladder.
- Ultrasound examination. An ultrasound isn't an X-ray. Instead, it uses high-frequency sound
waves to generate images of your internal organs, such as your kidneys and bladder, on a computer
screen.
- Computerized tomography (CT) or magnetic resonance imaging (MRI) scan. CT scans use
computers to create more detailed images than conventional X-rays. MRI scans use magnetic fields and
radio waves to generate cross-sectional pictures of your body.
- Biopsy. In this test, a sample of tissue is removed and examined under a microscope. It's the only way to confirm the presence of cancer. Depending on the results of the scans, your doctor may recommend removing a tumor right away.
If the results of an IVP suggest transitional cell cancer, your doctor will likely recommend a test that examines your bladder for signs of cancer (cytoscopy). In this procedure, your doctor inserts a long, narrow tube called a cystoscope through your urethra into your bladder. The tube carries a light source and special lens, which allow your doctor to inspect both the urethra and bladder. The cystoscope can also be used to remove a small tissue sample from a tumor (biopsy). In some cases a microscopic examination of the sediment in your urine (cytology) may also help identify cancer cells.
Tests to determine if cancer has spread
If your doctor finds signs of kidney cancer, he or she will use certain tests to determine whether the cancer has spread. These tests may include more blood tests, an ultrasound of your liver, CT scans, a chest X-ray or a bone scan. A bone scan is a test in which you're given a small amount of a radioactive material that's then absorbed by your bones. Tumors absorb even more of this material and show up as a black area when a special camera scans your body.
If your doctor decides to remove your diseased kidney, he or she will also want to make sure your other kidney is healthy. In almost all cases, you can function well with one normal kidney.
Second opinions
If you've received a diagnosis of kidney cancer, you may want to seek a second opinion. Sometimes your insurance company may even require you to do so. In that case your current doctor may be able to recommend other specialists. In addition, the Cancer Information Service at 800-4-CANCER (800-422-6237) can provide information on treatment centers. You can also get a list of doctors from your local hospital or a nearby medical school.
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| Treatment |
Together, you and your treatment team — which may include a surgeon, a doctor who specializes in disorders of the urinary organs (urologist), a cancer specialist (oncologist) and a radiation oncologist, who specializes in treating cancer with radiation — will discuss all of your options. The best approach for you may depend on a number of factors, including your general health, the kind of kidney cancer you have and whether the cancer has spread.
Renal cell carcinoma
Treatments for renal cell carcinoma include:
- Surgical removal. Until recently, the standard treatment for cancer that was confined to
the kidney was surgical removal of the entire kidney (radical or simple nephrectomy). In a radical
nephrectomy, surgeons remove the entire kidney along with the adrenal gland that sits atop the kidney,
the tissue adjacent to the kidney and some lymph nodes. A simple nephrectomy involves removing the
entire kidney but not the adrenal gland or lymph nodes. But studies by Mayo Clinic researchers show
that removing just the tumor (nephron-sparing surgery), rather than the entire kidney, results in
survival rates similar to those of more radical procedures. In addition, people who have
nephron-sparing surgery appear less likely to develop chronic kidney failure and more likely to enjoy
a better quality of life than those who have their entire kidney removed.
Sometimes surgeons may choose to remove the entire kidney because of the extent and the location of the tumor. In that case, laparoscopic nephrectomy may offer advantages over traditional open surgery because it typically results in less postoperative pain, faster recovery time and less scarring. In a laparoscopic procedure, a tiny camera is inserted into your body through a small incision. The camera transmits video images that allow your surgeon to see the kidney in great detail. Your surgeon then inserts surgical instruments through two or three other small incisions and performs the operation. The recovery time and side effects of any type of kidney surgery will vary, but it's likely you'll feel tired and weak for a time, even with laparoscopic nephrectomy. - Arterial embolization. In this procedure, a radiologist injects a special material into the
main blood vessel leading to the kidney. By clogging this vessel, the tumor is deprived of oxygen and
other nutrients. Arterial embolization may be used before an operation or to relieve pain and bleeding
when surgery isn't possible. Side effects may include temporary nausea, vomiting or pain.
- Radiation therapy. This therapy uses radiation to kill cancer cells. It's usually used to
relieve pain when kidney cancer has spread to the bones. In general, you'll receive radiation
treatment at a clinic or hospital on an outpatient basis — usually 5 days a week for several weeks.
The effects of radiation are cumulative, and you may become very tired in the last few weeks of
treatment. The skin in the treated area may become red, tender or itchy. You may also have other side
effects, such as nausea and vomiting, depending on the part of the body being treated.
- Immunotherapy. This treatment uses your body's immune system to fight cancer. An oncologist may administer a substance known as a biological response modifier — such as interferon or interleukin-2. Normally produced by the body, these substances are also made in laboratories to help treat disease. Studies show that people may do better when they're treated with both interferon and surgery, rather than with interferon alone. Biological response modifiers can have serious side effects, including chills, fever, nausea, vomiting and loss of appetite. You may bruise easily after treatment and feel extremely tired. Interleukin and interferon therapies can also affect liver and kidney function. These side effects usually disappear once treatment is stopped.
To treat transitional cell cancer in its early stages, surgeons remove an area surrounding the tumor while trying to save the kidney itself. If the tumor is too large or too centrally located, the kidney and ureter may be removed along with the portion of the bladder that is connected to the ureter. This helps decrease the risk of bladder cancer. Chemotherapy — a type of therapy that uses drugs to kill cancer cells — is often used to treat transitional cell cancer that has spread.
Wilms' tumor
Treatment for children with Wilms' tumor depends on the child's age, overall health, the type of tumor and whether the cancer has spread. In many cases, treatment may include surgical removal followed by chemotherapy or radiation.
Clinical trials
If kidney cancer has spread, standard treatments may not always be effective. In that cases you may choose to participate in clinical trials. These trials test the effectiveness and side effects of new treatments. Those who take part have a chance to receive a treatment that may be promising but not yet widely available. If you're interested in clinical trials, talk to your doctor. You can also contact the National Cancer Institute for detailed information, or visit the clinical trials page on their Web site.
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| Prevention |
Currently, no proven methods exist to prevent kidney cancer. But the following steps may reduce your risk and help you stay healthy:
- Quit smoking. Smokers are twice as likely to develop kidney cancer as are nonsmokers. Talk
to your doctor about the best ways to stop smoking.
- Limit fat in your diet. No clear link exists between dietary fat intake and kidney cancer.
But reducing the amount of fat in your diet decreases your risk of some other cancers as well as
diabetes, heart disease and stroke. A low-fat diet also helps you maintain a healthy weight, which
does reduce your risk of kidney cancer. It's a good idea to limit your fat intake to less than 30
percent of your daily calories, with no more than 10 percent of your calorie intake coming from
saturated fats. Saturated fats are found in animal sources such as red meat, whole milk, cheese and
ice cream. Other saturated fats include palm and coconut oils. Try substituting lean chicken and fish
for red meat and using low- or reduced-fat dairy products. For salads, cooking and baking, choose oils
such as olive and canola.
- Eat foods high in fiber. Try to increase the amount of fiber you eat to between 20 and 30
grams daily — about twice the amount in an average American diet. Foods high in fiber include fruits,
vegetables and whole grains.
- Eat plenty of fruits and vegetables. Fruits and vegetables contain sulfides, antioxidants
and tannins, which have anticancer effects. Try to eat five or more servings of fruits and vegetables
every day. Look for deep green and dark yellow or orange fruits and vegetables, such as Swiss chard,
bok choy, spinach, cantaloupe, mango, acorn or butternut squash, and sweet potatoes. Also try to eat
vegetables from the cabbage family, including broccoli, brussels sprouts and cauliflower. Lycopene, a
nutrient found in tomatoes and other red fruits and vegetables such as strawberries and red bell
peppers, may be a particularly powerful anticancer chemical.
- Include soy foods in your diet. Substances in soy may inhibit the development and growth of
cancer cells.
- Stay physically active. In addition to all of its other benefits, exercise can help lower
high blood pressure and help you maintain a healthy weight — both of which reduce your risk factors
for kidney cancer. Aim for at least 30 minutes of exercise on most days. If you haven't been active
before, start out slowly and gradually increase the amount of time you exercise. Try to include
weight-bearing exercises, such as walking, jogging or dancing, in your routine as well as some
weight-training exercises. Strength training has been found to reduce stress even more than aerobic
exercise and has the added benefit of helping keep your bones strong.
- Maintain a healthy weight. There is a clear link between weighing more than is healthy for
you and kidney cancer.
- Avoid exposure to environmental toxins.
- Reduce high blood pressure. If you have, or think you may have, high blood pressure — which has been linked to renal cell carcinoma in men — talk to your doctor. Diet and exercise can control high blood pressure in many cases
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| Self-care |
Eating well, managing stress and exercising are ways to promote your overall health and cope with any form of cancer.
Eating well
Good nutrition is especially important for people undergoing cancer treatment. But eating well can be difficult, especially if your treatment includes chemotherapy or radiation treatment. You may feel nauseated or lose your appetite, and foods may seem tasteless. You may find that the last thing you want to do is plan meals.
Even so, eating well during cancer treatment can help you maintain your stamina and your ability to cope with the side effects of treatments. Good nutrition may also help you prevent infections and remain more active.
Remember these strategies for eating well when you don't feel well:
- Eat protein-rich foods. Foods high in protein can help build and repair body tissues. Choices include eggs, yogurt, cottage cheese, peanut butter, poultry and fish. Kidney beans, chickpeas and black-eyed peas are also good sources of protein, especially when combined with rice, corn or bread.
- Keep an open mind about the foods you might eat. Foods that are unappealing today might taste better to you next week.
- When you do feel well, make the most of it. Eat as many healthy foods as you can. Prepare meals that you can easily freeze and reheat. Also look for low-fat frozen dinners and other prepared foods.
- Give meals a pleasant atmosphere. Whenever possible, eat at a table set with attractive dishes and flowers.
- Pack calories into the foods you eat. For example, spread butter, jam or honey on bread. Sprinkle foods with chopped nuts.
- Eat smaller amounts of food more frequently. If you can't face the thought of a large meal, try eating small amounts of food more often. Keep fruits and vegetables handy for snacking.
Methods for reducing physical tension can help you manage stress. One simple and powerful technique is to simply close your eyes and notice your breathing. Pay attention to each inhalation and exhalation. Your breathing will become slower and deeper, promoting relaxation. Another technique is to lie down, close your eyes and mentally scan your entire body for any points of tension.
In addition, activities such as running and swimming that require repetitive movements can produce a mental state similar to meditation. So can yoga and other stretching exercises.
Your doctor may have more specific suggestions about how to best care for yourself before, during and after treatment for kidney cancer.
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| Coping skills |
Even if you care for yourself well, you might feel overwhelmed or helpless at times. But you don't have to deal with cancer alone. In fact, studies show that the support of friends and family is crucial for surviving cancer. If that's not an option for you, a counselor, a psychologist, a psychiatrist or a clergy member may be able to help.
You may also want to consider joining a support group for people with cancer. Although support groups aren't for everyone, members often provide helpful information about new treatments. And being with people who understand what you're going through may make you feel less alone.
— April 17, 2002 —