What’s New in Wilms Tumor Research?

Over the past few decades, research into Wilms tumor has led to many advances and much higher cure rates for this type of cancer. Still, not all children are cured, and even those who are cured might still have long-term side effects from treatment, so more research is needed.

In the United States, much of the research on Wilms tumor is coordinated by the Children’s Oncology Group (COG), whose main goal is to improve the treatment and quality of life of children with Wilms tumor and other types of cancer. COG is a large group of doctors, nurses, scientists, and other health professionals whose hard work has already saved the lives of many children with Wilms tumors.

Genetics of Wilms tumors

Research is continuing to unravel how changes in certain genes cause Wilms tumors and affect how aggressive these tumors are likely to be.

As doctors have learned how to treat Wilms tumors more effectively, they have begun to look for ways to determine which children might need more aggressive treatment to be cured, and which children might be spared from more intense treatment (and its possible side effects). For example, studies have shown that Wilms tumors with certain changes on chromosomes 1 or 16 seem to be more likely to come back after treatment. Doctors are now studying whether children with such tumors might benefit from more intense treatment.

Researchers are also studying the gene changes that seem to cause Wilms tumor cells to grow and spread. This may lead to treatments that specifically target these changes.

Treatment of Wilms tumors

Researchers continue to study ways to improve treatment for children with Wilms tumors.

Using less treatment when possible

Earlier studies found treatments that were very effective in curing most Wilms tumors, especially those with favorable histology. Current clinical trials are studying ways to treat these cancers successfully while reducing side effects as much as possible. For example:

• Studies are looking at whether young children who have Wilms tumors with very favorable features need any treatment other than surgery.
• Recent research has suggested that some children with tumors that have spread to only one spot in the lung might not need radiation therapy to the lungs, which can cause long-term side effects.
• Other research is looking at whether some tumors in the lung can be treated with stereotactic body radiation therapy (SBRT). In this type of radiation therapy, a large dose of radiation is focused very tightly on the tumor(s), as opposed to treating the whole lung.

Newer approaches for tumors that are harder to treat

The outlook for some children with Wilms tumors, such as those with anaplastic histology, is not as good, and doctors are looking for better treatments for these children.

Newer chemotherapy drugs such as topotecan and irinotecan are now being tested.

Other studies are looking at stem cell transplants (also known as bone marrow transplants), which let doctors give higher doses of chemo than the body normally could tolerate. This approach might help treat tumors that are not responding to standard treatments or that would otherwise have a poor outlook.

As researchers have learned more about the gene changes in cancer cells, they have started to develop newer drugs that specifically target these changes. Targeted drugs work differently from standard chemotherapy drugs. They sometimes work when chemo drugs don’t, and they often have different (and less severe) side effects. Targeted therapies have already become standard treatments for some kinds of cancers.

For children with Wilms tumors who might not be cured with current treatments, some clinical trials are now testing the tumor cells for certain gene changes. If one of these changes is found, treating the tumor with a drug that can target the change might be helpful. About a dozen different targeted drugs are now being tested in this way.