Several types of cancer can start in the
kidney. The most common type of kidney cancer
in adults is renal cell cancer, which is also called renal
adenocarcinoma or hypernephroma. Another type
of cancer, transitional cell carcinoma, affects the renal
pelvis. It is similar to bladder cancer
and is often treated like bladder cancer. Wilms' tumor
is the most common type of childhood kidney cancer. It is different from
adult kidney cancer and requires different treatment.
|The kidneys are a pair of organs on either side of
the spine in the lower abdomen. Each
kidney is about the size of a fist. Attached to the top of each kidney
is an adrenal gland. A mass
of fatty tissue and an outer layer of fibrous tissue (Gerota's fascia)
enclose the kidneys and adrenal glands. The kidneys are part of the
urinary system. They make urine
by removing wastes and extra water from the blood.
Urine collects in a hollow space (renal pelvis) in the middle of each
kidney. It passes from the renal pelvis into the bladder
through a tube called a ureter. Urine
leaves the body through another tube (the urethra).
The kidneys also make substances that help control blood
pressure and the production of red
|Stages of renal cell carcinoma. Stage I:
Cancer is in the kidney only and the size of the tumor is less than
or equal to 7 cm in diameter. Stage II: Cancer is
in the kidney only but the size of the tumor is greater than 7 cm
in diameter. Stage III: The tumor in the kidney may
be any size, but it extends beyond the layer of tissue (Gerota's fascia)
that encapsulates the kidney and adrenal gland. Additionally, cancer
may have spread to blood vessels that carry blood away from the kidney,
or to the adjacent adrenal gland. Stage IV: Tumor
in the kidney extends beyond Gerota's fascia and/or cancer has spread
to one or more lymph node near the kidney. In addition, there may
be evidence that cancer has spread to other organs in the body, such
as the lungs, liver, brain, or bones.
Source: Kidney Science Program, Oregon Health & Science University
What follows applies specifically to renal cell cancer.
factors for kidney cancer
Kidney cancer develops most often in people over 40, but no one knows the
exact causes of this disease. Doctors can seldom explain why one person
develops kidney cancer and another does not. However, it is clear that kidney
cancer is not contagious. No one can "catch" the disease from another person.
Research has shown that people with certain risk factors are more likely
than others to develop kidney cancer. A risk factor is anything that increases
a person's chance of developing a disease.
Studies have found the following risk factors for kidney cancer:
Most people who have these risk factors do not get kidney cancer. On the
other hand, most people who do get the disease have no known risk factors.
- Smoking: Cigarette smoking is a major risk factor. Cigarette
smokers are twice as likely as nonsmokers to develop kidney cancer.
Cigar smoking also may increase the risk of this disease.
- Obesity: People who are obese have an increased risk of kidney
- High blood pressure:
High blood pressure increases the risk of kidney cancer.
- Long-term dialysis: Renal
dialysis is a treatment for people whose kidneys do not work well.
It removes wastes from the blood. Being on dialysis for many years is
a risk factor for kidney cancer.
- Von Hippel-Lindau (VHL) syndrome: VHL is a rare disease that
runs in some families. It is caused by changes in the VHL gene. An abnormal
VHL gene increases the risk of kidney cancer. It also can cause cysts
or tumors in the eyes, brain, and other parts of the body. Family members
of those with this syndrome can have a test to check for the abnormal
VHL gene. For people with the abnormal VHL gene, doctors may suggest
ways to improve the detection of kidney cancer and other diseases before
- Occupation: Some people have a higher risk of getting kidney
cancer because they come in contact with certain chemicals or substances
in their workplace. Coke oven workers in the iron and steel industry
are at risk. Workers exposed to asbestos
or cadmium also may be at risk.
- Gender: Males are more likely than females to be diagnosed
with kidney cancer. Each year in the United States, about 20,000 men
and 12,000 women learn they have kidney cancer.
Symptoms of kidney cancer
Common symptoms of kidney cancer include:
Most often, these symptoms do not mean cancer. An infection, a cyst, or
another problem also can cause the same symptoms. A person with any of these
symptoms should see a doctor so that any problem can be diagnosed and treated
as early as possible.
- Blood in the urine (making the urine slightly rusty to deep red)
- Pain in the side that does not go away
- A lump or mass in the side or the abdomen
- Weight loss
- Feeling very tired or having a general feeling of poor health
Diagnosis of kidney cancer
If a patient has symptoms that suggest kidney cancer, the doctor may perform
one or more of the following procedures:
- Physical exam: The doctor checks general signs of health and
tests for fever and high blood pressure. The doctor also feels the abdomen
and side for tumors.
- Urine tests: Urine is checked for blood and other signs of
- Blood tests: The lab checks
the blood to see how well the kidneys are working. The lab may check
the level of several substances, such as creatinine. A high level of
creatinine may mean the kidneys are not doing their job.
- Intravenous pyelogram (IVP): The doctor injects dye into a
vein in the arm. The dye travels through the body and collects in the
kidneys. The dye makes them show up on X-rays.
A series of X-rays then tracks the dye as it moves through the kidneys
to the ureters and bladder. The X-rays can show a kidney tumor or other
- CT scan (CAT scan):
An X-ray machine linked to a computer takes a series of detailed pictures
of the kidneys. The patient may receive an injection of dye so the kidneys
show up clearly in the pictures. A CT scan can show a kidney tumor.
- Ultrasound test:
The ultrasound device uses sound waves that people cannot hear. The
waves bounce off the kidneys, and a computer uses the echoes to create
a picture called a sonogram. A solid tumor or cyst shows up on a sonogram.
- Biopsy: In some cases, the doctor
may do a biopsy. A biopsy is the removal of tissue to look for cancer
cells. The doctor inserts a thin needle through the skin into the kidney
to remove a small amount of tissue. The doctor may use ultrasound or
X-rays to guide the needle. A pathologist uses a microscope to look
for cancer cells in the tissue.
- Surgery: In most cases, based on the results of the CT scan,
ultrasound, and X-rays, the doctor has enough information to recommend
surgery to remove part or all of the kidney. A pathologist makes the
final diagnosis by examining the tissue under a microscope.
To plan the best treatment, the doctor needs to know the stage (extent)
of the disease. The stage is based on the size of the tumor, whether the
cancer has spread and, if so, to what parts of the body (see illustration
Staging may involve imaging tests such as an ultrasound or a CT scan. The
doctor also may use an MRI. For this test, a powerful magnet linked to a
computer makes detailed pictures of organs and blood vessels.
Doctors describe kidney cancer by the following stages:
- Stage I is an early stage of kidney cancer. The tumor measures
up to 2¾ inches (7 cm). It is no bigger than a tennis ball. The
cancer cells are found only in the kidney.
- Stage II is also an early stage of kidney cancer, but the tumor
measures more than 2¾ inches. The cancer cells are found only in
- Stage III is one of the following:
- The tumor does not extend beyond the kidney, but cancer cells
have spread through the lymphatic
system to one nearby lymph node;
- The tumor has invaded the adrenal
gland or the layers of fat and fibrous tissue that surround
the kidney, but cancer cells have not spread beyond the fibrous
tissue. Cancer cells may be found in one nearby lymph node; or
- The cancer cells have spread from the kidney to a nearby large
blood vessel. Cancer cells may be found in one nearby lymph node.
- Stage IV is one of the following:
- The tumor extends beyond the fibrous tissue that surrounds the
- Cancer cells are found in more than one nearby lymph node; or
- The cancer has spread to other places in the body such as the
- Recurrent cancer is cancer that has come back (recurred) after
treatment. It may come back in the kidney or in another part of the
Treatment for kidney cancer
Treatment depends mainly on the stage of disease and the patient's general
health and age. People with kidney cancer may have surgery, arterial embolization,
radiation therapy, biological therapy, or chemotherapy. Some may have a
combination of treatments.
At any stage of disease, people with kidney cancer may have treatment to
control pain and other symptoms, to relieve the side effects of therapy,
and to ease emotional and practical problems. This kind of treatment is
called supportive care, symptom management, or palliative care.
Because treatment may damage healthy cells and tissues, unwanted side effects
are common. These side effects depend mainly on the type and extent of the
treatment. Side effects may not be the same for each person, and they may
change from one treatment session to the next. Before treatment starts,
the health care team will explain possible side effects and suggest ways
to help the patient manage them.
Surgery is the most common treatment for kidney cancer. It is a type of
local therapy. It treats cancer in the kidney and the area close to the
An operation to remove the kidney is called a nephrectomy. There are several
types of nephrectomies. The type depends mainly on the stage of the tumor.
The doctor can explain each operation and discuss which is most suitable
for the patient:
It takes time to heal after surgery, and the time needed to recover is different
for each person. Patients are often uncomfortable during the first few days.
However, medicine can usually control their pain. Before surgery, patients
should discuss the plan for pain relief with the doctor or nurse. After
surgery, the doctor can adjust the plan if more pain relief is needed.
- Radical nephrectomy: Kidney cancer is usually treated with
radical nephrectomy. The surgeon removes the entire kidney along with
the adrenal gland and some tissue around the kidney. Some lymph nodes
in the area also may be removed.
- Simple nephrectomy: The surgeon removes only the kidney. Some
people with Stage I kidney cancer may have a simple nephrectomy.
- Partial nephrectomy: The surgeon removes only the part of the
kidney that contains the tumor. This type of surgery may be used when
the person has only one kidney, or when the cancer affects both kidneys.
Also, a person with a small kidney tumor (less than 4 centimeters) may
have this type of surgery.
It is common to feel tired or weak for a while. The health care team watches
the patient for signs of kidney problems by monitoring the amount of fluid
the patient takes in and the amount of urine produced. They also watch for
signs of bleeding, infection, or other problems requiring immediate treatment.
Lab tests help the health care team monitor for signs of problems.
If one kidney is removed, the remaining kidney generally is able to perform
the work of both kidneys. However, if the remaining kidney is not working
well or if both kidneys are removed, dialysis is needed to clean the blood.
For a few patients, kidney transplantation may be an option. For this procedure,
the transplant surgeon replaces the patient's kidney with a healthy kidney
from a donor.
Arterial embolization is a type of local therapy that shrinks the tumor.
Sometimes it is done before an operation to make surgery easier. When surgery
is not possible, embolization may be used to help relieve the symptoms of
The doctor inserts a narrow tube (catheter)
into a blood vessel in the leg. The tube is passed up to the main blood
vessel (renal artery) that supplies blood to the kidney. The doctor injects
a substance into the blood vessel to block the flow of blood into the kidney.
The blockage prevents the tumor from getting oxygen and other substances
it needs to grow.
After arterial embolization, some patients have back pain or develop a fever.
Other side effects are nausea and vomiting.
These problems soon go away.
Radiation therapy (also called radiotherapy) is another type of local therapy.
It uses high-energy rays to kill cancer cells. It affects cancer cells only
in the treated area. A large machine directs radiation at the body. The
patient has treatment at the hospital or clinic, 5 days a week for several
A small number of patients have radiation therapy before surgery to shrink
the tumor. Some have it after surgery to kill cancer cells that may remain
in the area. People who cannot have surgery may have radiation therapy to
relieve pain and other problems caused by the cancer.
The side effects of radiation therapy depend mainly on the amount of radiation
given and the part of the body that is treated. Patients are likely to become
very tired during radiation therapy, especially in the later weeks of treatment.
Resting is important, but doctors usually advise patients to try to stay
as active as they can.
Radiation therapy to the kidney and nearby areas may cause nausea, vomiting,
diarrhea, or urinary discomfort. Radiation
therapy also may cause a decrease in the number of healthy white blood cells,
which help protect the body against infection. In addition, the skin in
the treated area may sometimes become red, dry, and tender. Although the
side effects of radiation therapy can be distressing, the doctor can usually
treat or control them.
Biological therapy is a type of systemic therapy. It uses substances that
travel through the bloodstream, reaching and affecting cells all over the
body. Biological therapy uses the body's natural ability (immune system)
to fight cancer.
For patients with metastatic kidney cancer, the doctor may suggest interferon
alpha or interleukin-2 (also called IL-2 or aldesleukin). The body normally
produces these substances in small amounts in response to infections and
other diseases. For cancer treatment, they are made in the laboratory in
Biological therapy may cause flu-like symptoms, such as chills, fever, muscle
aches, weakness, loss of appetite, nausea, vomiting, and diarrhea. Patients
also may get a skin rash. These problems can be severe, but they go away
after treatment stops.
Chemotherapy is also a type of systemic therapy. Anticancer drugs enter
the bloodstream and travel throughout the body. Although useful for many
other cancers, anticancer drugs have shown limited use against kidney cancer.
However, many doctors are studying new drugs and new combinations that may
prove more helpful.
The side effects of chemotherapy depend mainly on the specific drugs and
the amount received at one time. In general, anticancer drugs affect cells
that divide rapidly, especially:
- Blood cells: These cells fight infection, help the blood to clot,
and carry oxygen to all parts of the body. When drugs affect blood cells,
patients are more likely to get infections, may bruise or bleed easily,
and may feel very weak and tired.
- Cells in hair roots: Chemotherapy can cause hair loss. The hair grows
back, but sometimes the new hair is somewhat different in color and
- Cells that line the digestive tract: Chemotherapy can cause poor appetite,
nausea and vomiting, diarrhea, or mouth and lip sores. Many of these
side effects can be controlled with drugs.
Follow-up care after treatment for kidney cancer is important. Even when
the cancer seems to have been completely removed or destroyed, the disease
sometimes returns because cancer cells can remain in the body after treatment.
The doctor monitors the recovery of the person treated for kidney cancer
and checks for recurrence of cancer. Checkups help ensure that any changes
in health are noted. The patient may have lab tests, chest X-rays, CT scans,
or other tests.
Source: National Cancer
Institute, US National Institutes of Health