Kidney cancer
-
renal cell
carcinoma (renal adenocarcinoma or hypernephroma)
Early diagnosis of kidney cancer is important. As
with most types of cancer, the earlier the tumor is
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
spread (metastasized) through the bloodstream or
lymphatic system to other parts of the body are more
difficult to treat and present an increased risk for
mortality.
Your kidneys are two bean-shaped organs, each
about the size of your fist. They're located behind
your abdomen, one on each side of your spine. 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. Children are more likely to develop a
kind of kidney cancer called Wilms' tumor.
Kidney cancer seldom causes problems in its early
stages. But as a tumor grows, you may notice blood
in your urine or experience unintentional weight
loss or back pain that doesn't go away. Cancer cells
may also spread (metastasize) outside your kidneys
to nearby organs such as your adrenal glands,
pancreas and spine, as well as to more distant sites
in your body.
Yet if kidney cancer is detected and
treated early, the chances for a full recovery are
good.
Signs and symptoms
Kidney cancer rarely causes signs or symptoms in its early stages. In
the later stages, the most common sign of both renal cell and
transitional cell cancers is blood in the urine (hematuria). You may
notice the blood when you urinate, or it may be detected by urinalysis,
a test that specifically checks the contents of your urine.
Other
possible signs and symptoms may include:
-
A pain in your
back just below your ribs that doesn't go away
-
A mass in the area
of your kidneys that's discovered during an examination
-
Weight loss
-
Fatigue
-
Intermittent fever
-
Pain in other
parts of your body if the cancer has metastasized
Wilms' tumor usually has no symptoms. Doctors often discover this
condition when examining a child's abdomen.
Causes
Your kidneys are part of a complex system (urinary system) that removes
waste and excess fluid from your blood, controls the production of red
blood cells and regulates your blood pressure. 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
as well as unneeded minerals and water. This liquid waste urine
drains through two narrow tubes (ureters) into your bladder, where it's
stored until it's eliminated from your body though 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 small tubes (tubules)
that make up a part of each nephron. In most cases, renal cell tumors
grow as a single mass, but you may have more than one tumor in a kidney
or you may develop tumors in both kidneys.
A
far less common type of kidney cancer, transitional cell carcinoma, may
occur inside the kidneys, ureters or bladder, and a rare form of kidney
cancer, renal sarcoma, begins in the connective tissue of the kidney.
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. This type of
kidney cancer occurs most often in people between the ages of 50 and 70.
Men are more than twice as likely as are women to develop renal cell
carcinoma, 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.
A strong link exists between excess weight and renal cell carcinoma
in both men and women. Weighing more than is healthy for you may
cause changes in certain hormones changes that in turn may lead to
cancer.
-
High blood
pressure (hypertension).
Researchers have found a link between high blood pressure and renal
cell carcinoma. Although it appears that your risk decreases when
you're treated for high blood pressure, it's also possible that
diuretic medications used to treat hypertension may play a role in
this type of kidney cancer.
-
Environmental
toxins.
Coal oven workers in steel plants have high rates of kidney cancer.
So do people who are exposed to cadmium, to organic solvents such as
trichloroethylene and 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, possibly because
renal failure depresses the immune system. People who have a kidney
transplant and receive immunosuppressant drugs also are 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 develop benign blood vessel
tumors (hemangioblastomas) in their brain and spinal cord and may
develop tumors of the adrenal glands. They're also at high risk of
kidney cancer.
-
Hereditary
papillary renal cell carcinoma.
Having this inherited condition makes it more likely you'll develop
one or more renal cell carcinomas.
Risk factors for transitional cell carcinoma include:
-
Cigarette
smoking.
This is the leading risk factor for transitional cell carcinomas. A
history of smoking can quadruple your risk of this type of cancer.
-
Exposure to
industrial chemicals.
These include heavy metals, asbestos and aniline dyes.
-
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. By the same token, having
transitional cell kidney cancer makes it more likely you'll develop
bladder cancer.
-
Phenacetin.
Long-term use of this painkiller has led to kidney cancer in some
people.
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, urinary tract infections or glomerulonephritis, a kidney disease that affects your kidneys'
filtering function. In rare cases, you may even notice blood in your
urine after strenuous exercise such as a marathon run.
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 schedule regular checkups. When kidney cancer is
diagnosed early, it's easier to treat and your chances of survival are
good. Once cancer has spread, however, treatment is more difficult and
the prognosis is less positive.
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.
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 those
created by 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 biopsy, your doctor may recommend
removing a tumor right away.
Tests for transitional cell cancer
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 (cystoscopy). In this procedure, a long, narrow tube called a
cystoscope is inserted through your urethra into your bladder. The tube
carries a light source and special lens, which allow your doctor to
inspect both your urethra and bladder. The cystoscope can also be used
to remove a small tissue sample from a tumor. In some cases a
microscopic examination of the sediment in your urine may also help
identify cancer cells.
Tests to determine whether cancer has spread
If your doctor finds signs of kidney cancer, the next step is to
determine whether the cancer has spread. This usually means more tests,
including additional blood tests, an ultrasound of your liver, a CT
scan, 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 taken
up 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 your diseased kidney should be removed, 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.
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 an oncologist who specializes in
treating cancer with radiation (radiation oncologist) 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
kidney along with the adrenal gland that sits atop the kidney, a
border of normal tissue and adjacent lymph nodes. A simple
nephrectomy involves removing the entire kidney, although not the
adrenal gland or lymph nodes. But studies by researchers
show that removing just the tumor (nephron-sparing surgery), rather
than the whole 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 are more likely to enjoy a better quality of life than
do those who have the whole 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 often five 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 your
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.
-
Chemotherapy.
This therapy uses drugs to treat cancer. It works by attacking
rapidly dividing cells, which means it affects not only cancer cells
but also healthy cells, especially those in your bone marrow,
gastrointestinal tract, reproductive system and hair follicles.
Although chemotherapy is an effective treatment for some types of
cancer, it hasn't proven useful for renal cell carcinoma.
Transitional cell cancer
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 need to be removed along with the portion of the bladder that's
connected to the ureter. This helps decrease the risk of cancer cells
spreading to the bladder. Chemotherapy 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 of the tumor followed
by chemotherapy or radiation.
Clinical trials
If
kidney cancer has spread, standard treatments are seldom very effective.
For that reason, you may choose to participate in a clinical trial.
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.
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.
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. Try to include vegetables from
the cabbage family, including broccoli, brussels sprouts and
cauliflower they contain chemicals called indoles that have been
shown to inhibit the growth of cancer cells. Lycopene, a nutrient
found in tomatoes and certain other fruits and vegetables, appears
to lower the risk of some cancers.
-
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
strength-training exercises. Strength training has been found to
reduce stress even more than aerobic exercise does, and it 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.
Exposure to toxins such as heavy metals, organic solvents, asbestos
and aniline dyes increases your risk of kidney cancer.
-
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.
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 also are 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.
Managing stress
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 that require repetitive movements, such as
running and swimming, 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.
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. The
support of friends and family plays a crucial role in 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.
Kidney cancer
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