Wilms’ tumor is a disease in which cancer (malignant) cells are found in certain parts of the kidney. The kidneys are a “matched” pair of organs found on either side of the backbone. The kidneys are shaped like a kidney bean. Inside each kidney are tiny tubes that filter and clean the blood, taking out unneeded products, and making urine. The urine made by the kidneys passes through a tube called a ureter into the bladder where it is held until it is passed from the body.
Wilms’ tumor is curable in the majority of affected children. If your child has symptoms, your child’s doctor will usually feel your child's abdomen for lumps and run blood and urine tests. The doctor may order a special x-ray called an intravenous pyelogram. During this test, a dye containing iodine is injected into your child's bloodstream. This allows your child's doctor to see the kidney more clearly on the x-ray. Your child's doctor may also do an ultrasound, which uses sound waves to make a picture, or a special x-ray called a computed tomographic scan to look for lumps in the kidney. A special scan called magnetic resonance imaging, which uses magnetic waves to make a picture, may also be done. Chest and bone x-rays may also be taken.
If abnormal tissue is found, your child's doctor will need to cut out a small piece and look at it under the microscope to see if there are any cancer cells. This is called a biopsy.
Your child's chance of recovery (prognosis) and choice of treatment depend on the stage of your child's cancer (whether it is just in the kidney only or has spread to other places in the body), how the cancer cells look under a microscope (histology), and your child's age and general health.
Clear cell sarcoma of the kidney, rhabdoid tumor of the kidney, and neuroepithelial tumor of the kidney are childhood kidney tumors unrelated to Wilms' tumor. The treatment of these tumors is different from that of Wilms' tumor but because of their location near the kidneys, they have been treated on clinical trials developed by the National Wilms' Tumor Study Group.
Once Wilms' tumor has been found, more tests will be done to find out if cancer cells have spread from the kidney to other parts of the body. This is called staging. Your child's doctor needs to know the stage of the disease to plan treatment. For Wilms' tumors, the stage is based on the amount of tumor that remains after the patient has had surgery to look at or remove the tumor. The following stages are used for Wilms' tumor:
The tumor was completely removed by surgery and all of the following are true:
Cancer has spread deeper into other parts of the kidney and to nearby blood vessels, but was completely removed by surgery. No cancer cells are found at the edges of the area where the tumor was removed.
Cancer remains in the abdomen after surgery to remove the tumor but no cancer remains in or on the blood vessels. Any 1 of the following may be true:
Cancer has spread through the blood to the lungs, liver, bone, or brain, or to lymph nodes outside of the abdomen and pelvis.
Cancer cells are found in both kidneys when the disease is first diagnosed. The cancer in each kidney will be staged as I, II, III, or IV.
Recurrent disease means that the cancer has come back (recurred) after it has been treated. It may come back where it started or in another part of the body.
In Wilms’ tumor, how the cancer cells look under a microscope (histology) is also very important for describing stage and determining treatment options. The cancer cells can be of favorable histology or anaplastic histology. Anaplastic means the cancer cells divide rapidly and look very different from normal cells. Anaplastic tumors may be focal (in one area) or diffuse (spread widely throughout an area).
There are treatments for patients with Wilms' tumor. Three kinds of treatment are used:
Surgery is a common treatment for Wilms' tumor. Your doctor may take out the cancer using one of the following:
Chemotherapy uses drugs to kill cancer cells. Chemotherapy may be taken by pill, or it may be put into the body by a needle in a vein or muscle. Chemotherapy is called a systemic treatment because the drugs enter the bloodstream, travel through the body, and can kill cancer cells throughout the body. Chemotherapy given after an operation to remove the tumor is called adjuvant therapy.
When very high doses of chemotherapy are used to kill cancer cells, these high doses can destroy the blood-forming tissue in the bones (the bone marrow). If very high doses of chemotherapy are needed to treat the cancer, bone marrow may be taken from the bones before therapy and frozen until it is needed. Following chemotherapy, the bone marrow is given back through a needle in a vein. This is called autologous bone marrow reinfusion.
Radiation therapy uses x-rays or other high-energy rays to kill cancer cells and shrink tumors. Radiation for Wilms' tumor usually comes from a machine outside the body (external radiation therapy). Radiation may be used before or after surgery and/or chemotherapy.
Some cancer treatments cause side effects that continue or appear years after cancer treatment has ended. These are called late effects. 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. Refer to the PDQ summary on Late Effects of Treatment for Childhood Cancer for more information. Clinical trials are ongoing to determine if lower doses of chemotherapy and radiation can be used.
Treatments for Wilms' tumor depend on the stage of your child's disease, the histology (cell type), and your child's age and general health.
Your child may receive treatment that is considered standard based on its effectiveness in a number of patients in past studies, or you may choose to have your child take part in a clinical trial. Not all patients are cured with standard therapy and some standard treatments may have unwanted side effects. For these reasons, clinical trials are designed to test new treatments and to find better ways to treat cancer patients. Clinical trials are ongoing in most parts of the country for most stages of Wilms' tumor. If you want more information, call the Cancer Information Service at 1-800-4- CANCER (1-800-422-6237); TTY at 1-800-332-8615.
Treatment for stage I Wilms' tumor with either favorable or anaplastic histology will probably be surgery to remove the kidney and some of the lymph nodes near the kidney, followed by chemotherapy.
Treatment for stage II Wilms' tumor depends on the histology of the cancer.
If your child has a favorable histology tumor, treatment will probably be surgery to remove the kidney and some of the lymph nodes near the kidney, followed by chemotherapy.
If your child has an anaplastic histology tumor, treatment will probably be surgery to remove the kidney followed by radiation therapy plus chemotherapy.
Treatment of both favorable and anaplastic stage III Wilms' tumors will probably be surgery to remove the kidney and some of the lymph nodes near the kidney, followed by radiation therapy to the abdomen, and chemotherapy.
Treatment of both favorable and anaplastic stage IV Wilms' tumors will probably be surgery to remove the kidney and some of the lymph nodes near the kidney, followed by radiation therapy to the abdomen, and chemotherapy. Patients whose cancer has spread to the lungs will also receive radiation therapy to the lungs.
Your child's doctor will probably do a biopsy of the cancer by taking out a piece of the cancer in both kidneys and removing some of the lymph nodes around the kidney to see whether they contain cancer. Following the biopsy, chemotherapy will be given to shrink the cancer. A second surgery will remove as much of the cancer as possible, while leaving as much of the kidneys as possible. Surgery may be followed by more chemotherapy and/or radiation therapy.
Sometimes the cancer is inoperable (cannot be removed during surgery) because it is too close to important organs or blood vessels or because it is too large to remove. In this case, the doctor may perform a biopsy only and then give chemotherapy with or without radiation therapy. Once the cancer has become smaller, surgery to remove part or all of the tumor may be done, followed by more chemotherapy and radiation therapy.
Clear cell sarcoma of the kidney is a primary kidney tumor. It is not a type of Wilms' tumor. This tumor can spread to the lung, bone, brain, and soft tissue. If your child has clear cell sarcoma of the kidney, he or she may be treated with surgery to remove the kidney followed by radiation therapy to the abdomen and lung (if cancer has spread to the lung) followed by chemotherapy.
Rhabdoid tumor of the kidney is a type of cancer that grows and spreads quickly. At diagnosis, children are usually younger than 1 year and may have fever, blood in the urine, and advanced cancer. This tumor type tends to spread to the lungs and the brain. Treatment is usually a clinical trial.
Neuroepithelial tumors of the kidney are tumors that grow and spread quickly. At diagnosis, these tumors have often spread to the outer layer of the kidney, the veins of the kidney, and to other parts of the body. If your child has neuroepithelial tumors of the kidney, treatment on an Ewing's/primitive neuroectodermal tumors (PNET) clinical trial should be considered.
If your child's cancer comes back (recurs), treatment depends on the treatment he or she received before, how much time has passed since the first cancer was treated, the histology of the cancer, and where the cancer came back.
Clinical trials are evaluating new treatments, such as new chemotherapy drugs and combinations, and very high doses of chemotherapy followed by bone marrow reinfusion.
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In the United States, about two-thirds of children with cancer are treated in a clinical trial at some point in their illness. A clinical trial is a study to answer a scientific question, such as whether one treatment is better than another. Trials are based on past studies and what has been learned in the laboratory. Each trial answers certain scientific questions in order to find new and better ways to help cancer patients. During treatment clinical trials, information is collected about new treatments, the risks involved, and how well they do or do not work. If a clinical trial shows that a new treatment is better than one currently being used, the new treatment may become "standard."
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Because cancer in children and adolescents is rare, the majority of children with cancer are treated by health professionals specializing in childhood cancers, at hospitals or cancer centers with special facilities to treat them. The PDQ database contains listings of health professionals who specialize in childhood cancer and listings of hospitals with cancer programs. For help locating childhood cancer health professionals or a hospital with cancer programs, call the Cancer Information Service at 1-800-4-CANCER (1-800-422-6237), TTY at 1-800-332-8615.Physicians version: CDR0000062789