Wilms' Tumor and Other Childhood Kidney Tumors

Wilms tumor (or nephroblastoma) and other childhood kidney tumors are diseases in which malignant (cancer) cells form in the tissues of the kidney. Wilms tumor is the most common solid tumor of the kidney (or renal tumor) of childhood. It also accounts for 5% of all childhood cancers. Between 450 and 500 new cases are reported each year. The peak age a child will present with the tumor is during the third year of life. There is usually a single tumor mass either in one or both kidneys. Approximately 10% of patients will have a malformation associated with the tumor recognized from birth. A syndrome called Beckwith-Wiedemann syndrom involves trisomy 18 and aniridia. Abnormalities seen with the genitourinary tract would be hypospadias (displacement of urethral opening in male boys), cryptorchidism (nondescent of the testicle) at birth, and fusion of the kidneys.

Overview

Wilms tumor may spread to the lungs, liver, or nearby lymph nodes.

Diffuse hyperplastic perilobar nephroblastomatosis (DHPLN) is a condition in which abnormal tissue grows on the outer part of one or both kidneys. Children with DHPLN are at risk for developing a type of Wilms tumor that grows quickly. Frequent follow-up testing is important for at least 7 years after the child is diagnosed with DHPLN.

Other kidney tumors

The following are also tumors of the kidney not related to Wilms tumor:

• Clear cell sarcoma of the kidney is a type of kidney tumor that may spread to the lung, bone, brain, and soft tissue.
• Rhabdoid tumor of the kidney is a type of cancer that occurs mostly in children under age 2. It grows and spreads quickly, often to the lungs and brain.
• Neuroepithelial tumors of the kidney are rare and usually occur in young adults. They grow and spread quickly.
• Renal cell carcinoma occurs rarely in children. The tumor can spread to the lungs, bones, liver, and lymph nodes.
• Mesoblastic nephroma is a tumor of the kidney that is usually diagnosed within the first 3 months of life. It may also be found during an ultrasound before birth. Mesoblastic nephroma occurs more often in males than females.

Chances of Developing Wilms' Tumor and Other Childhood Kidney Tumors

Having certain genetic syndromes or birth defects can increase the risk of developing Wilms tumor.

A risk factor is anything that may increase your risk of developing a disease. Wilms tumor may be part of a genetic syndrome that affects growth or development. A genetic syndrome is a set of symptoms or conditions that occur together and is usually caused by abnormal genes. Certain birth defects can also increase a child's risk for developing Wilms tumor. The following genetic syndromes and birth defects have been linked to Wilms tumor:

• WAGR (Wilms tumor, aniridia, ambiguous genitalia, and mental retardation) syndrome.
• Beckwith-Wiedemann syndrome.
• Hemihypertrophy.
• Denys-Drash syndrome.
• Cryptorchidism.
• Hypospadias.

Children with these genetic syndromes and birth defects should be screened for Wilms tumor every three months until age 8. An ultrasound test may be used for screening.

Related Problems

Renal cell carcinoma may be related to the following conditions:

• Von Hippel-Lindau disease (an inherited condition that causes abnormal growth of blood vessels).
• Tuberous sclerosis (an inherited disease marked by noncancerous fatty cysts in the kidney).
• Neuroblastoma and/or sickle cell disease.

Signs and Symptoms

Possible signs of Wilms tumor and other childhood kidney tumors include a lump or mass in the abdomen and blood in the urine (hematuria).

These and other symptoms may be caused by kidney tumors. Other conditions may cause the same symptoms. A doctor should be consulted if any of the following problems occur in the child:

• A lump, swelling, or pain in the abdomen.
• Blood in the urine.
• Fever for no known reason.

Diagnosis

Tests that examine the kidney and the blood are used to detect (find) Wilms tumor and other childhood kidney tumors.

Exams and tests

• Physical exam and history: An exam of the patient is always performed to check general signs of health, including checking for signs of disease, such as masses or anything suspicious. A history of the patient's health habits and past illnesses and treatments will also be taken.
• Complete blood count (CBC): A procedure in which a sample of blood is drawn and checked for the following:
  • The number of red blood cells, white blood cells, and platelets.
  • The amount of hemoglobin (the protein that carries oxygen) in the red blood cells.
• Blood chemistry studies: A procedure in which a blood sample is checked to measure the amounts of certain substances released into the blood by organs and tissues in the body. An unusual (higher or lower than normal) amount of a substance can be a sign of disease in the organ or tissue that makes it.
• Liver function test: A procedure in which a blood sample is checked to measure the amounts of certain substances released into the blood by the liver. A higher than normal amount of a substance can be a sign that the liver is not working as it should.
• Renal function test: A procedure in which blood or urine samples are checked to measure the amounts of certain substances cleared by the kidneys. These values are related to how well the kidneys are functioning.
• Urinalysis: A test to check the color of urine and its contents, such as sugar, protein, blood, and bacteria.
• Ultrasound exam: A procedure in which high-energy sound waves (ultrasound) are bounced off internal tissues or organs and make echoes. The echoes form a picture of body tissues called a sonogram. An ultrasound of the abdomen and kidney can differentiate between normal and abnormal tissue. It is the current initial study of choice in patients with an abdominal mass.
• CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography. In Wilms tumor, it can show how extensive the disease is.
• Abdominal x-ray: An x-ray of the organs within the abdomen. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body.
• Biopsy: The removal of cells or tissues so they can be viewed under a microscope by a pathologist to check for signs of cancer.

Once a kidney tumor is found, surgery is done to determine whether the tumor is cancerous. If the tumor is only in the kidney, the surgeon will remove the entire kidney (nephrectomy). If there are tumors in both kidneys or if the tumor has spread outside the kidney, a piece of the tumor will be removed. In any case, a sample of tissue from the tumor is sent to a pathologist, who looks at it under a microscope to evaluate for cancer.

Expected Outcome

The prognosis (chance of recovery) and treatment options depend on the following:

• The stage of the cancer.
• The type and size of the tumor.
• The age of the child.
• Ability to completely remove the tumor surgically.
• Newly-diagnosed or recurrent tumor (a tumor that has returned after successful treatment).
• The genetics related to the tumor (if the patient inherited the tumor)
• Level of experience of the pediatric department in treating childhood renal tumors.

Stages of Wilms Tumor and Other Childhood Kidney Tumors

Wilms tumors and other childhood kidney tumors are staged during surgery and with imaging tests.

The process used to find out if cancer has spread outside of the kidney to other parts of the body is called staging. The information gathered from the staging process determines the stage of the disease. It is important to know the stage in order to plan treatment.

For Wilms tumor, the stage is determined during the initial surgery and with the results from imaging tests. The following imaging tests may be done to see if cancer has spread to other places in the body:

• CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, such as the chest or brain, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.
• X-ray of the chest and bones: An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body.
• MRI (magnetic resonance imaging): A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body, such as the brain. This procedure is also called nuclear magnetic resonance imaging (NMRI).
• Bone scan: A procedure to check if there are rapidly dividing cells, such as cancer cells, in the bone. A very small amount of radioactive material is injected into a vein and travels through the bloodstream. The radioactive material collects in the bones and is detected by a scanner.
• Ultrasound exam: A procedure in which high-energy sound waves (ultrasound) are bounced off internal tissues or organs and make echoes. The echoes form a picture of body tissues called a sonogram. An ultrasound of the major heart vessels is done to stage Wilms tumor.

Pathology of Tumor and Staging

In addition to the stages, Wilms tumors are described by their histology.

The histology (how the cells appear under a microscope) of the tumor affects the prognosis and the treatment of Wilms tumor. The histology may be favorable or anaplastic (malignant). Tumors with a favorable histology have a better prognosis and respond better to chemotherapy than those with anaplastic histology. Tumor cells that are anaplastic divide rapidly and have a different appearance from normal renal tissue. Anaplastic tumors are harder to treat with chemotherapy than other Wilms tumors at the same stage.

The following stages are used for both favorable histology and anaplastic Wilms tumors:

• Stage I

In stage I, the tumor is completely removed by surgery and all of the following:

• Cancer is confined to the kidney and has not spread to the blood vessels of the kidney.
• The outer layer of the kidney is intact - not broken open.
• The tumor is intact - not break open.
• A biopsy of the tumor has not been performed.
• No cancerous cells are left behind during surgery or complete removal of the tumor is accomplished.

• Stage II

In stage II, complete nephrectomy performed successfully. Before the tumor was removed, one of the following was true:

• Cancer had spread out of the kidney to nearby soft tissue.
• Cancer had spread to blood vessels of the kidney.

• Stage III

In stage III, cancer remains in the abdomen after surgery and at least one of the following is true:

• Cancer spread to lymph nodes in the abdomen or pelvis (the part of the body between the hips).
• Cancer spread to or through the surface of the peritoneum (the layer of tissue that lines the abdominal cavity and covers most organs in the abdomen).
• A biopsy of the tumor was done during surgery to remove it.
• The tumor broke open before or during surgery to remove it.
• The tumor was removed in more than one piece.

• Stage IV

In stage IV, cancer has spread through the blood to organs such as the lungs, liver, bone, or brain, or to lymph nodes outside of the abdomen and pelvis.

• Stage V

In stage V, cancer cells are found in both kidneys when the disease is first diagnosed. Each kidney will be staged separately as I, II, III, or IV.

Recurrent Wilms Tumor and Other Childhood Kidney Tumors

Recurrent cancer is cancer that has recurred (come back) after it has been successfully treated.

Treatment Option Overview

There are different types of treatment for patients with Wilms tumor and other childhood kidney tumors.

Different types of treatment are available for children with Wilms and other childhood kidney tumors. Some treatments are standard (the currently used treatment), and some are being tested in clinical trials. A treatment clinical trial is a research study meant to help improve current treatments or obtain information on new treatments for patients with cancer. When clinical trials show that a new treatment is better than the standard treatment, the new treatment may become the standard treatment.

Because cancer in children is rare, taking part in a clinical trial should be considered. Clinical trials are taking place in many parts of the country. Information about ongoing clinical trials is available from the NCI Web site. Choosing the most appropriate cancer treatment is a decision that ideally involves the patient, family, and health care team.

Children with Wilms tumor or other childhood kidney tumors should have their treatment planned by a team of doctors with expertise in treating cancer in children.

Your child's treatment will be overseen by a pediatric oncologist, a doctor who specializes in treating children with cancer. The pediatric oncologist may refer you to other doctors who have experience and expertise in treating children with Wilms tumor or other childhood kidney tumors and who specialize in certain areas of medicine. These may include the following specialists:

• Pediatric surgeon or urologist.
• Radiation oncologist.
• Rehabilitation specialist.
• Pediatric nurse specialist.
• Social worker.

Four types of standard treatment are used:

Surgery

Wilms tumor and other childhood kidney tumors are usually treated with nephrectomy (surgery to remove the whole kidney). Nearby lymph nodes may also be removed.

If cancer is found in both kidneys, surgery may include a partial nephrectomy (removal of the cancer in the kidney and a small amount of normal tissue around it). Partial nephrectomy is done to keep the kidney working.

Even if the doctor removes all the cancer that can be seen at the time of the surgery, some patients may be given chemotherapy or radiation therapy after surgery to kill any cancer cells that are left. Treatment given after the surgery, to increase the chances of a cure, is called adjuvant therapy. Sometimes, a second-look surgery is done to see if cancer remains after chemotherapy or radiation therapy.

Radiation therapy

Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells or keep them from growing. There are two types of radiation therapy. External radiation therapy uses a machine outside the body to send radiation toward the cancer. Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer. The way the radiation therapy is given depends on the type and stage of the cancer being treated.

Chemotherapy

Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping them from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). When chemotherapy is placed directly into the spinal column, an organ, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy). The way the chemotherapy is given depends on the type and stage of the cancer being treated.

Combination chemotherapy is treatment using two or more anticancer drugs.

Biologic therapy

Biologic therapy is a treatment that uses the patient's immune system to fight cancer. Substances made by the body or made in a laboratory are used to boost, direct, or restore the body's natural defenses against cancer. This type of cancer treatment is also called biotherapy or immunotherapy.

New types of treatment are being tested in clinical trials. These include the following:

High-dose chemotherapy with stem cell transplant

High-dose chemotherapy with stem cell transplant is a method of giving high doses of chemotherapy and replacing blood -forming cells destroyed by the cancer treatment. Stem cells (immature blood cells) are removed from the blood or bone marrow of the patient or a donor and are frozen and stored. After the chemotherapy is completed, the stored stem cells are thawed and given back to the patient through an infusion. These re-infused stem cells grow into (and restore) the body's blood cells.

This summary section refers to specific treatments under study in clinical trials, but it may not mention every new treatment being studied. Information about ongoing clinical trials is available from the NCI Web site.

Late effects may be caused by cancer treatment.

Some cancer treatments cause side effects that continue or appear months or years after cancer treatment has ended. These are called late effects. (See the PDQ summary on [/cancertopics/pdq/treatment/lateeffects/Patient Late Effects of Treatment for Childhood Cancer] for more information.) It is important that parents of children who are treated for cancer know about the possible late effects caused by certain treatments. After several years, some patients develop another form of cancer as a result of their treatment with chemotherapy and radiation. Clinical trials are ongoing to find out if lower doses of chemotherapy and radiation can be used.

Treatment Options for Wilms Tumor and Other Childhood Kidney Tumors

Stage I Wilms Tumor

Treatment of stage I Wilms tumor with favorable histology may include the following:

• Nephrectomy with lymph node removal followed by combination chemotherapy.
• A clinical trial of nephrectomy with lymph node removal, followed by observation or new combinations of chemotherapy.

Treatment of stage I anaplastic Wilms tumor may include the following:

• Nephrectomy with lymph node removal followed by combination chemotherapy.
• A clinical trial of nephrectomy with lymph node removal, followed by combination chemotherapy and radiation therapy.

This summary section refers to specific treatments under study in clinical trials, but it may not mention every new treatment being studied. Information about ongoing clinical trials is available from the NCI Web site.

Check for clinical trials from NCI's PDQ Cancer Clinical Trials Registry that are now accepting patients with stage I Wilms tumor.

Stage II Wilms Tumor

Treatment of stage II Wilms tumor with favorable histology may include the following:

• Nephrectomy with removal of lymph nodes, followed by combination chemotherapy.
• A clinical trial of nephrectomy with removal of lymph nodes, followed by new combinations of chemotherapy.

Treatment of stage II anaplastic Wilms tumor may include the following:

• Nephrectomy with removal of lymph nodes, followed by radiation therapy to the abdomen and combination chemotherapy.
• A clinical trial of nephrectomy with removal of lymph nodes, followed by new combinations of chemotherapy and radiation therapy.

This summary section refers to specific treatments under study in clinical trials, but it may not mention every new treatment being studied. Information about ongoing clinical trials is available from the NCI Web site.

Check for clinical trials from NCI's PDQ Cancer Clinical Trials Registry that are now accepting patients with stage II Wilms tumor.

Stage III Wilms Tumor

Treatment of stage III Wilms tumor with favorable histology may include the following:

• Nephrectomy with removal of lymph nodes, followed by radiation therapy to the abdomen and combination chemotherapy.
• A clinical trial of nephrectomy with removal of lymph nodes, followed by radiation therapy to the abdomen and new combinations of chemotherapy.

Treatment of stage III anaplastic Wilms tumor may include the following:

• Nephrectomy with removal of lymph nodes, followed by radiation therapy to the abdomen and combination chemotherapy.
• A clinical trial of nephrectomy with removal of lymph nodes, followed by new combinations of chemotherapy and radiation therapy.

This summary section refers to specific treatments under study in clinical trials, but it may not mention every new treatment being studied. Information about ongoing clinical trials is available from the NCI Web site.

Check for clinical trials from NCI's PDQ Cancer Clinical Trials Registry that are now accepting patients with stage III Wilms tumor.

Stage IV Wilms Tumor

Treatment of stage IV Wilms tumor with favorable histology may include the following:

• Nephrectomy with removal of lymph nodes, followed by radiation therapy to the abdomen and combination chemotherapy. If cancer has spread to the lungs, patients will also receive radiation therapy to the lungs.
• A clinical trial of chemotherapy for cancer that has spread only to the lungs. If tumors remain after chemotherapy, radiation therapy may be given.
• A clinical trial of chemotherapy and radiation therapy to places where cancer has spread.

Treatment of stage IV anaplastic Wilms tumor may include nephrectomy with removal of lymph nodes, followed by new combinations of chemotherapy and radiation therapy.

This summary section refers to specific treatments under study in clinical trials, but it may not mention every new treatment being studied. Information about ongoing clinical trials is available from the NCI Web site.

Check for clinical trials from NCI's PDQ Cancer Clinical Trials Registry that are now accepting patients with stage IV Wilms tumor.

Stage V Wilms Tumor

Treatment of stage V Wilms tumor may be different for each patient. Treatment is usually chemotherapy to shrink the tumor, followed by surgery to remove as much of the cancer as possible. This may be followed by more chemotherapy and/or radiation therapy if cancer remains after surgery.

Check for clinical trials from NCI's PDQ Cancer Clinical Trials Registry that are now accepting patients with stage V Wilms tumor.

Inoperable Tumors

Sometimes the tumor is inoperable (cannot be removed by surgery) because it is too close to important organs or blood vessels or because it is too large to remove. In this case, chemotherapy may be given to reduce the size of the tumor so it may be removed in surgery. If the tumor does not shrink enough after chemotherapy, radiation therapy may be given to shrink it further so that surgery may be done. This may be followed by more chemotherapy and/or more radiation therapy.

Clear Cell Sarcoma of the Kidney

There is no standard treatment for clear cell sarcoma of the kidney. Treatment is usually within a clinical trial and may include nephrectomy with lymph node removal, with or without radiation therapy to the abdomen, and new combinations of chemotherapy.

This summary section refers to specific treatments under study in clinical trials, but it may not mention every new treatment being studied. Information about ongoing clinical trials is available from the NCI Web site.

Check for clinical trials from NCI's PDQ Cancer Clinical Trials Registry that are now accepting patients with clear cell sarcoma of the kidney.

Rhabdoid Tumor of the Kidney

There is no standard treatment for rhabdoid tumor of the kidney. Treatment may be within a clinical trial and may include new combinations of chemotherapy and radiation therapy.

This summary section refers to specific treatments under study in clinical trials, but it may not mention every new treatment being studied. Information about ongoing clinical trials is available from the NCI Web site.

Check for clinical trials from NCI's PDQ Cancer Clinical Trials Registry that are now accepting patients with rhabdoid tumor of the kidney.

Neuroepithelial Tumor of the Kidney

There is no standard treatment for neuroepithelial tumor of the kidney. Treatment is usually within a clinical trial. It may be treated in the same way that Ewing family of tumors or primitive neuroectodermal tumors are treated. See the PDQ summary on [/cancertopics/pdq/treatment/ewings/Patient Ewing Family of Tumors Treatment] for more information.

Information about ongoing clinical trials is available from the NCI Web site.

Check for clinical trials from NCI's PDQ Cancer Clinical Trials Registry that are now accepting patients with peripheral primitive neuroectodermal tumor of the kidney.

Mesoblastic Nephroma

Treatment for mesoblastic nephroma is usually surgery with or without chemotherapy.

This summary section refers to specific treatments under study in clinical trials, but it may not mention every new treatment being studied. Information about ongoing clinical trials is available from the NCI Web site.

Check for clinical trials from NCI's PDQ Cancer Clinical Trials Registry that are now accepting patients with congenital mesoblastic nephroma.

Renal Cell Cancer

Treatment of renal cell cancer is usually nephrectomy with removal of lymph nodes. If cancer has spread, treatment may include biologic therapy or surgery to remove the primary tumor. See the PDQ summary on [/cancertopics/pdq/treatment/renalcell/Patient Renal Cell Cancer Treatment] for more information.

Check for clinical trials from NCI's PDQ Cancer Clinical Trials Registry that are now accepting patients with childhood renal cell carcinoma.

Diffuse Hyperplastic Perilobar Nephroblastomatosis

Treatment of diffuse hyperplastic perilobar nephroblastomatosis (DHPLN) may include nephrectomy with lymph node removal followed by combination chemotherapy. A partial nephrectomy may be done to keep as much kidney function as possible.

Check for clinical trials from NCI's PDQ Cancer Clinical Trials Registry that are now accepting patients with diffuse hyperplastic perilobar nephroblastomatosis.

Recurrent Wilms Tumor and Other Childhood Kidney Tumors

Treatment of recurrent Wilms tumor may be within a clinical trial of combination chemotherapy, surgery, and radiation therapy, with or without stem cell transplant, using the child's own blood stem cells.

Treatment of recurrent clear cell sarcoma, rhabdoid tumor, and neuroepithelial tumor of the kidney is usually within a clinical trial.

This summary section refers to specific treatments under study in clinical trials, but it may not mention every new treatment being studied. Information about ongoing clinical trials is available from the NCI Web site.

Check for clinical trials from NCI's PDQ Cancer Clinical Trials Registry that are now accepting patients with recurrent Wilms tumor and other childhood kidney tumors.

Other Resources

The NCI Web site provides online access to information on cancer, clinical trials, and other Web sites and organizations that offer support and resources for cancer patients and their families.