Chemotherapy (chemo) is the use of drugs to treat cancer. These drugs enter the blood and reach all areas of the body, which makes this treatment useful for cancer that has spread or might have spread beyond the kidney.
When might chemo be used?
Most children with Wilms tumors will get chemo at some point during their treatment. (Some children with very low risk tumors might not need it.)
In the United States, chemo is usually given after surgery. Sometimes it may be needed before surgery to shrink a tumor to make the operation possible. In Europe, chemo is given before surgery and continued afterward. In both cases, the type and amount of chemo depend on the stage and histology of the cancer.
Chemo drugs used to treat Wilms tumors
A combination of chemo drugs is used to treat children with Wilms tumors. The chemo drugs used most often are:
- Actinomycin D (dactinomycin)
For tumors at more advanced stages, those with anaplastic histology, or tumors that recur (come back) after treatment, other drugs might also be used, such as:
- Doxorubicin (Adriamycin)
How is chemo given?
Chemo drugs for Wilms tumors are injected into the blood, either through a vein (IV) or through a central venous catheter (a thin tube inserted into a large blood vessel during surgery).
Different drugs, doses, and lengths of treatment are used, depending on the type and stage of the Wilms tumor and the child’s age. Most often, the drugs are given once a week for at least several months.
Chemo is usually given by a nurse in the doctor’s office or in the outpatient section of the hospital. Some children with Wilms tumors might need to stay in the hospital while they are getting chemo, but usually this is not needed.
Possible side effects of chemo
Chemo drugs can affect cells other than cancer cells, which can lead to side effects.
The side effects of chemo depend on the types and doses of drugs used, and the length of treatment. Possible short-term side effects can include:
- Hair loss
- Mouth sores
- Loss of appetite
- Nausea and vomiting
- Diarrhea or constipation
- Increased chance of infections (from having too few white blood cells)
- Easy bruising or bleeding (from having too few blood platelets)
- Fatigue or extreme tiredness (from having too few red blood cells)
Your child’s doctor and treating team will watch closely for any side effects that develop. There are often ways to lessen these side effects. For example, drugs can be given to help prevent or reduce nausea and vomiting. Be sure to ask your child’s doctor or nurse about medicines to help reduce side effects, and let them know if your child has side effects so they can be managed.
Along with the effects listed above, some drugs can have specific side effects. For example:
- Vincristine can damage nerves. Some patients may have tingling, numbness, weakness, or pain, particularly in the hands and feet. (This is called peripheral neuropathy.)
- Doxorubicin can damage the heart. The risk of this happening goes up as the total amount of the drug given goes up. Doctors try to limit this risk as much as possible by not giving more than the recommended doses and by checking the heart with a test called an echocardiogram (an ultrasound of the heart) during treatment.
- Cyclophosphamide can damage the bladder, which can cause blood in the urine. The risk of this can be lowered by giving the drug with plenty of fluids and with a drug called mesna, which helps protect the bladder.
Lab tests to check for chemo side effects
Before each chemo session, your child’s doctor will get blood tests to check blood cell levels and to see how well the liver and kidneys are working. If there are problems, chemo might need to be delayed or the doses reduced.
Long-term side effects of chemo
Possible long-term effects of treatment are one of the major challenges children might face after cancer treatment. For example:
- If your child is given doxorubicin (Adriamycin), there is a chance it could damage the heart. Your child’s doctor will carefully watch the doses used and will check your child’s heart function with imaging tests.
- Some chemo drugs can increase the risk of developing a second type of cancer (such as leukemia) years after the Wilms tumor is cured. But this small increase in risk has to be weighed against the importance of chemo in treating Wilms tumor.
- Some drugs might also affect fertility (the ability to have children) years later.
See Living as a Wilms Tumor Survivor for more on the possible long-term effects of treatment.