Treatment by type and stage 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, doctors prefer to begin the chemotherapy before surgery. The results seem to be about the same.

In most cases, the stage and histology of the cancer are actually determined when surgery is done to remove the cancer, because the true extent of the tumor often can’t be determined by imaging tests alone. The findings from surgery are then used to guide further treatment. But sometimes it is clear that the cancer has already spread beyond the kidney even before surgery is done, based on imaging tests. This may affect the order in which treatments are given, as well as the extent of surgery.

Stage I

These tumors are only in the kidney. Surgery (radical nephrectomy) has completely removed the tumor along with the entire kidney, nearby structures, and some nearby lymph nodes.

Favorable histology: Children younger than 2 years with small tumors (weighing less than 550 grams) 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 with the drugs actinomycin D (dactinomycin) and vincristine (and possibly more surgery) is very likely to be effective at this point.

For children older than 2 and for those of any age who have larger tumors, surgery is usually followed by chemotherapy with actinomycin D and vincristine. If the tumor cells have certain chromosome changes, the drug doxorubicin (Adriamycin) may be given as well. The chemotherapy is given for several months.

Unfavorable histology: For children of any age who have tumors with unfavorable histology, surgery is usually followed by radiation therapy to the area of the tumor, along with chemotherapy with actinomycin D, vincristine, and doxorubicin (Adriamycin) for several months.

Stage II

These tumors have grown outside the kidney into nearby tissues, but surgery (radical nephrectomy) was able to remove all visible signs of cancer.

Favorable histology: After surgery, standard treatment is chemotherapy with actinomycin D and vincristine. If the tumor cells have certain chromosome changes, the drug doxorubicin (Adriamycin) may be given as well. The chemotherapy is given for several months.

Unfavorable histology with focal (only a little) anaplasia: When the child recovers from surgery, radiation therapy is given to the abdomen for several days. When this is finished, chemotherapy (doxorubicin, actinomycin D, and vincristine) is given for about 6 months.

Unfavorable histology with diffuse (widespread) anaplasia: After surgery, these children get radiation to the abdomen for several days. This is followed by a more intense type of chemotherapy using the drugs vincristine, doxorubicin, etoposide, cyclophosphamide, and carboplatin, along with mesna (a drug that protects the bladder from the effects of cyclophosphamide), which is given for about 6 months.

Stage III

These tumors were not removed completely with surgery because of their size or location or for other reasons. In some cases, surgery to remove the tumor (radical nephrectomy) may be postponed until other treatments are able to shrink the tumor first (see below).

Favorable histology: Treatment is usually surgery if it can be done, 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 if it can be done, 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.

Unfavorable histology with diffuse (widespread) anaplasia: Treatment begins with surgery if it can be done, followed by radiation therapy to the abdomen for several days. This is followed by chemotherapy, usually with the drugs vincristine, doxorubicin, etoposide, cyclophosphamide, and carboplatin, 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 children a small biopsy sample is taken from the tumor to be sure that it is a Wilms tumor and to determine its histology. Then chemotherapy is started. If the tumor doesn’t shrink enough with chemotherapy, then radiation therapy is given. 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.

Stage IV

These tumors have already spread to distant parts of the body at the time of diagnosis. As with stage III tumors, surgery to remove the tumor (radical nephrectomy) may be the first treatment, or it may need to be delayed until other treatments can shrink the tumor (see below).

Favorable histology and unfavorable histology with focal (only a little) anaplasia: Standard treatment is usually surgery, 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, usually with 3 drugs (actinomycin D, vincristine, and doxorubicin) for about 6 months.

Unfavorable histology with diffuse (widespread) anaplasia: Treatment usually begins with surgery, 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, cyclophosphamide, and carboplatin, along with mesna given for about 6 months.

If the tumor is too large or has grown too extensively to be safely treated with surgery first, a small biopsy sample may be taken from the tumor to be sure that it is a Wilms tumor and to determine its histology. Chemotherapy and/or radiation therapy may then be used 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.

Stage V

Treatment for children with tumors in both kidneys is unique for each child, although it typically includes surgery, chemotherapy, and radiation therapy at some point.

Biopsies (tissue samples) of tumors in both kidneys and of nearby lymph nodes may be taken first, although not all doctors feel this is needed because when both kidneys have tumors, the chance that they are Wilms tumors is very high.

Chemotherapy is typically given first to try to shrink the tumors. The drugs used will depend on the extent and histology (if known) of the tumors. After about 6 weeks of chemotherapy, surgery (partial nephrectomy) may be done to remove the tumors if enough normal kidney tissue can be left behind. If the tumors haven’t shrunk enough, treatment may include more chemotherapy or radiation therapy for about another 6 weeks. Surgery (either partial or radical nephrectomy) may then be done. This is followed by more chemotherapy, possibly along with radiation therapy if it hasn’t been given already.

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, the cancer's histology (favorable or unfavorable), and where it recurs. 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 (if not already given to the area), 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.