Treatment by Type and Stages of Wilms Tumor
Below are some of the most common treatment approaches for patients with Wilms tumors. Most children with this type of cancer are treated in clinical trials developed by the Children's Oncology Group. The goal of these studies is to cure as many children as possible while limiting side effects by giving as little treatment as is necessary. This is done by comparing the current best treatment with one the doctors think might be better. Because of this, treatment may differ slightly from those described below in some cases.
Treatment for Wilms tumor is based mainly on the stage of the cancer and whether its histology (appearance under the microscope) is favorable or unfavorable. In the United States, doctors prefer to use surgery as the first treatment in most cases, and then give chemotherapy (and possibly radiation therapy) afterward. In Europe, experts prefer to begin the chemotherapy before surgery. The results seem to be the same.
Stage I (favorable or unfavorable histology)
These tumors are still only in the kidney. Standard treatment starts with surgery to remove the kidney containing the tumor (an operation called radical nephrectomy).
Children younger than 2 years with small tumors (weighing less than 550 grams) with favorable histology may not need further treatment, such as chemotherapy. But they need to be watched closely because the chance the cancer will come back is slightly higher than if they had chemotherapy. If the cancer does come back, chemotherapy (actinomycin D and vincristine) is very likely to be effective at this point.
For children older than 2 and for those of any age with larger tumors or unfavorable histology, surgery is usually followed by chemotherapy with actinomycin D (dactinomycin) and vincristine, which is given for 18 weeks. Children who have unfavorable histology tumors may also get radiation therapy.
These tumors have grown outside the kidney into nearby tissues, but surgery can remove all visible signs of cancer.
Favorable histology: Standard treatment is surgery (radical nephrectomy), followed by chemotherapy with actinomycin D and vincristine. The chemotherapy is given for 18 weeks.
Unfavorable histology with focal (only a little) anaplasia: Treatment begins with surgery (radical nephrectomy). When the child recovers, radiation therapy is given to the abdomen for 6 or 7 days. When this is finished, chemotherapy (doxorubicin, actinomycin D, and vincristine) is given for about 6 months.
Unfavorable histology with diffuse (widespread) anaplasia: These children also get surgery (radical nephrectomy) and radiation to the abdomen for several days. This is followed by more intense chemotherapy using the drugs vincristine, doxorubicin, etoposide, and cyclophosphamide along with mesna (a drug that protects the bladder from the effects of cyclophosphamide), which is given for about 6 months.
Favorable histology: Treatment is usually surgery (radical nephrectomy) followed by radiation therapy to the abdomen over several days. This is followed by chemotherapy with 3 drugs (actinomycin D, vincristine, and doxorubicin) for about 6 months.
Unfavorable histology with focal (only a little) anaplasia: Treatment begins with surgery (radical nephrectomy) followed by radiation therapy to the abdomen for several days. This is followed by chemotherapy, usually with 3 drugs (actinomycin D, vincristine, and doxorubicin) for about 6 months.
In rare instances the tumor may be very large or may have grown into nearby blood vessels or other structures so that it cannot be removed safely. In these cases a small tissue sample is taken from the tumor for testing to be sure that it is a Wilms tumor and then chemotherapy is started. If there is no response or not enough response to chemotherapy, then radiation therapy is given to shrink the tumor. Usually the tumor will shrink within several weeks so that a radical nephrectomy can be done. Chemotherapy starts again after surgery. If radiation was not given before surgery, it is given after surgery.
Unfavorable histology with diffuse (widespread) anaplasia: Treatment begins with surgery (radical nephrectomy) followed by radiation therapy to the abdomen for several days. This is followed by chemotherapy, usually with the drugs vincristine, doxorubicin, etoposide, and cyclophosphamide along with mesna (a drug that protects the bladder from the effects of cyclophosphamide). Chemotherapy lasts about 6 months.
In some instances the tumor may be very large or may have grown into nearby blood vessels or other structures so that it cannot be removed safely. In these patients a small tissue sample is taken from the tumor for testing to be sure that it is a Wilms tumor and then chemotherapy is started. If there is no response or not enough response to chemotherapy, then radiation therapy is given to shrink the tumor. Usually the tumor will shrink enough within several weeks so that a radical nephrectomy can be done. Chemotherapy will be started again after surgery. If radiation was not given before surgery, it is given after surgery.
These tumors have already spread to distant parts of the body at the time of diagnosis.
Favorable histology and unfavorable histology with focal (only a little) anaplasia: Standard treatment is surgery (radical nephrectomy), followed by radiation therapy to the abdomen. The entire abdomen will be treated if there is still some cancer in the abdomen. If the cancer has spread to the lungs, low doses of radiation will also be given to that area. This is followed by chemotherapy with 3 drugs (actinomycin D, vincristine, and doxorubicin) for about 6 months.
Unfavorable histology with diffuse (widespread) anaplasia: Treatment begins with surgery (radical nephrectomy) followed by radiation therapy to the abdomen. The entire abdomen will be treated if there is still some cancer in the abdomen. Low doses of radiation will also be given to both lungs if there is spread to the lungs. This is followed by chemotherapy with the drugs vincristine, doxorubicin, etoposide, and cyclophosphamide along with mesna given for about 6 months.
In cases where the tumor is too large or has grown too extensively to be safely treated with surgery, chemotherapy and/or radiation therapy may be used first to shrink the tumor. Surgery may be an option at this point. This would be followed by more chemotherapy (and radiation therapy if it wasn't given already).
For stage IV cancers that have spread to the liver, surgery may be an option to remove any liver tumors that still remain after chemotherapy and radiation therapy.
Treatment for children with tumors in both kidneys is unique for each child, although it typically involves surgery, chemotherapy, and radiation therapy at some point.
Usually biopsies (tissue samples) of tumors in both kidneys and of lymph nodes are taken first. Chemotherapy is then given to try to shrink the tumors. The drugs used will depend on the extent and histology of the tumors. After about 6 weeks of chemotherapy, a second operation may be done. The tumors may be removed at this point if enough normal kidney tissue can be left behind. If the cancer is still present, treatment may include more chemotherapy, radiation therapy, and/or surgery to try to remove the tumors but not the entire kidneys.
If not enough functioning kidney tissue is left after surgery, a child may need to be placed on dialysis, a procedure where a special machine filters waste products out of the blood several times a week. If there is no evidence of any cancer after a year or two, a donor kidney transplant may be done.
Recurrent Wilms tumor
The prognosis and treatment for children with Wilms tumor that recurs (comes back after treatment) depends on their prior treatment and the cancer's histology (favorable or unfavorable). The outlook is generally better for recurrent Wilms tumor with the following features:
- Favorable histology
- Initial stage of I or II
- Initial chemotherapy with vincristine and actinomycin D only
- No previous radiation therapy
- Recurrence at least 12 months after initial diagnosis
The usual treatment for these children is surgery to remove the recurrent cancer (if possible), radiation therapy, and chemotherapy, often with drugs different from those used during first treatment.
Recurrent Wilms tumors that do not have the features listed above are much harder to treat. These children are usually treated with aggressive chemotherapy, such as the ICE regimen (ifosfamide, carboplatin, and etoposide) or others being studied in clinical trials. Very high-dose chemotherapy followed by a stem cell transplant (sometimes called a bone marrow transplant) may also be an option in this situation.
The treatment of Wilms tumor depends on the size and location of the tumor, whether the cancer has spread, and the child’s overall health. The main treatments for Wilms tumor are surgery, chemotherapy, and radiation therapy. Descriptions of these treatment options are listed below.
Surgery is a common treatment for all stages of Wilms tumor. A surgical oncologist is a doctor who specializes in treating cancer using surgery. The types of surgery used include the following:
Radical nephrectomy. A radical nephrectomy is the removal of the whole kidney and some surrounding tissue and nearby lymph nodes (called a lymph node dissection).
Partial nephrectomy. A partial nephrectomy is the removal of the tumor and some of the surrounding kidney, leaving as much of the kidney as possible.
When one kidney is removed, the other kidney takes over the full job of filtering wastes from the body. A partial nephrectomy is performed when the other kidney is damaged, also contains a tumor, or has already been removed; dialysis, a mechanized filtering process, may also be used if this is not possible.
Learn more about surgery.
Chemotherapy is the use of drugs to kill cancer cells. Systemic chemotherapy is delivered through the bloodstream, targeting cancer cells throughout the body. Chemotherapy for Wilms tumor is given by a pediatric oncologist. Some people may receive chemotherapy in their doctor’s office; others may go to the hospital. A chemotherapy regimen (schedule) usually consists of a specific number of cycles given over a specific time. Chemotherapy given after surgery to kill any remaining cancer cells, called adjuvant chemotherapy, may be used. Sometimes, chemotherapy is given before surgery to shrink a tumor if it is too large to remove, or if it is growing into blood vessels or other organs that make it too risky to remove.
Chemotherapy for Wilms tumor is usually injected into a vein, called intravenous (IV) chemotherapy. The main drugs used for Wilms tumor with a favorable histology include vincristine (Vincasar PFS), dactinomycin (Cosmegen, Lyovac Cosmegen), and doxorubicin (Adriamycin). Other drugs being used to treat Wilms tumor include cyclophosphamide (Cytoxan, Clafen, Neosar), etoposide (VePesid, Toposar), and irinotecan (Camptosar).
The side effects of chemotherapy depend on the individual and the dose use, but can include fatigue, risk of infection, nausea and vomiting, loss of appetite, hair loss, and diarrhea. These side effects usually go away once treatment is finished.
Learn more about chemotherapy and preparing for treatment. The medications used to treat cancer are continually being evaluated. Talking with your child’s doctor is often the best way to learn about the medications prescribed for your child, their purpose, and their potential side effects or interactions with other medications. Learn more about your child’s prescriptions by using searchable drug databases.
Radiation therapy is the use of high-energy x-rays or other particles to kill cancer cells. A doctor who specializes in giving radiation therapy to treat cancer is called a radiation oncologist. The most common type of radiation treatment is called external-beam radiation therapy, which is radiation therapy given from a machine outside the body. When radiation treatment is given using implants, it is called internal radiation therapy or brachytherapy.
Radiation therapy may be used to treat a large tumor or a tumor that has spread to other parts of the body. It may also be used to shrink a tumor before surgery or kill cancer cells that remain after surgery. Radiation therapy is generally part of the treatment plan for children with stage III or IV Wilms tumor.
Side effects from radiation therapy depend on the part of the body treated. For example, side effects from radiation therapy to the abdomen can include fatigue, mild skin reactions, upset stomach, and loose bowel movements. Most side effects go away soon after treatment is finished.
Learn more about radiation therapy.
Recurrent Wilms tumor
If the tumor returns after the original therapy, the treatment plan depends on four factors:
- Where in the body the cancer has returned
- The type of treatment the child received for the original tumor
- How long it has been since the original cancer was treated
- Whether the new growth has a favorable or anaplastic histology
Treatment for recurrent cancer may include surgery, radiation therapy, and chemotherapy.