Wilms Tumor: Childhood Kidney Cancer, Treatment, and the Road After
Last updated September 4, 2026.
Wilms tumor, also called nephroblastoma, is a kidney cancer that almost always affects young children, most often between the ages of two and five. It is the most common kidney cancer of childhood, and it carries one of the best outlooks in pediatric cancer: with modern treatment, the large majority of children are cured.
How it shows up
The usual story is a parent noticing a firm, painless swelling in the child's belly, sometimes discovered at bath time or while dressing. Other children have belly pain, blood in the urine, fever, or high blood pressure. Because the swelling is often painless and the child otherwise well, the diagnosis can land like a bolt from a clear sky. Scans confirm the tumor and map its extent, and further tests check the lungs, where this cancer most often travels.
Wilms tumor is one of the most curable childhood cancers. Surgery plus chemotherapy is the path, one kidney does the work of two, and the first two years of scans matter most.
Start a free AI doctor consult →How it is treated
Treatment is built around surgery to remove the affected kidney, followed by chemotherapy. Radiation is added for higher-stage disease. In some cases chemotherapy comes first to shrink the tumor before surgery. Children can live completely normal lives with one kidney, and surgeons preserve kidney tissue whenever the situation allows. Treatment is delivered through specialist children's cancer centers, most often on national protocols that have steadily improved cure rates over decades.
The road after treatment
Follow-up scans continue for years, because most recurrences happen within two years of diagnosis and the schedule is built to catch them early. Longer term, the team monitors kidney function, growth, and the specific late effects of the chemotherapy drugs used, including heart and hearing checks for certain regimens. Children who had both kidneys involved or a genetic predisposition get a tailored plan, and families are offered genetic counseling when the pattern suggests one.
- Cure is the expectation, not the hope. The overall cure rates for Wilms tumor are among the highest of any childhood cancer, and your team can give you the numbers for your child's exact stage.
- The other kidney usually takes over completely. One healthy kidney grows and does the work of two. Kidney precautions in later life are about protecting it from injury, not about limits on ordinary childhood.
- Keep every follow-up appointment. Recurrence is most likely in the first two years, and the scan schedule is designed around that window.
If you are weighing the risks and benefits of any treatment mentioned here, our overview of how treatments are tested and monitored for safety explains what those conversations are built on.
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Common questions
What causes Wilms tumor?
In most children there is no identifiable cause and nothing the parents did or could have done. A small number of cases are linked to genetic syndromes or run in families, and the team will say if your child's pattern suggests one of those.
Is Wilms tumor curable?
Yes, in the large majority of children. Cure rates are among the highest of any childhood cancer, though the exact numbers depend on the stage and the tumor's features under the microscope. Your child's team can give you the figures for her specific situation.
Can my child live normally with one kidney?
Yes. The remaining kidney grows and takes over the full workload. Children with one kidney eat normally, play sports, and live unrestricted lives, with sensible protection of the remaining kidney from direct injury in contact sports.
Will the cancer come back?
Most recurrences happen within the first two years, which is why follow-up scans cluster in that window. If recurrence does happen, further treatment exists and cures a meaningful share of those children too.
Does she need genetic testing?
Some children do. Tumors in both kidneys, certain birth features, or a family history prompt genetic assessment, and the team will raise it if it applies. Most Wilms tumors are not inherited, so siblings are usually at no increased risk.
What late effects should we watch for?
It depends on her exact treatment. The follow-up program monitors kidney function, growth, and the specific effects of her chemotherapy drugs, with heart and hearing checks for certain regimens. Ask the team which late-effect checks apply to her plan.