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Wilms Tumor: What Parents Should Know About This Pediatric Cancer

There’s probably nothing more frightening for a parent than hearing your child has cancer. Fortunately, thanks to advancements in treatment therapies, most children with Wilms tumor, a rare kidney cancer, survive and go on to live normal, healthy lives.

“Wilms tumor most often affects children ages 3 to 4 and becomes much less common after age 6,” said Joseph Torkildson, MD, a pediatric hematologist and oncologist with Banner Children's. “It typically involves just one kidney, but in rare cases it can involve both kidneys at the same time.

Over the years, advancements in the diagnosis and treatment of Wilms tumor have greatly improved the outlook for children with the disease. Dr. Torkildson helps answer five common questions parents may have about the disease.

What causes Wilms tumor?

It’s not clear what causes Wilms tumor, but in some rare cases, heredity may play a role. Defects in genes may affect the growth of kidney cells.

“Like many childhood cancers, its appearance under the microscope is that of an immature kidney like that seen in utero, suggesting that it represents a failure of maturation or persistence of fetal tissue due to a genetic abnormality,” Dr. Torkildson said.

Our kidneys develop very early in the womb. Sometimes some of the cells that are supposed to develop into mature cells don’t. Instead, these cells may develop errors in the DNA, allowing them to grow and divide uncontrollably and to go on living when other cells would die. These accumulating cells form a tumor. In rare cases, these errors are passed down from parent to the child. But most often there is no known connection between parent and child. “Most often we don’t know what causes Wilms tumor,” Dr. Torkildson said.

What symptoms should I look out for?

Many children with Wilms tumor may have no symptoms or symptoms may be confused with a variety of other childhood ailments.

“Parents may notice a firm mass or fullness in their child’s abdomen while bathing or dressing them,” Dr. Torkildson said. “Some children have abdominal pain, and other symptoms include fever, nausea and vomiting, blood in the urine, constipation and loss of appetite.”

How is Wilms tumor typically diagnosed?

Because symptoms can be confused with symptoms for other medical issues, it’s best to have your child’s healthcare provider evaluate them.

When a mass is suspected in the abdomen, your child’s doctor will typically order an ultrasound. If this confirms there is a tumor, your child will undergo a CT scan of the chest, abdomen and pelvis to determine the size of the tumor and whether it has spread to other areas.

An accurate diagnosis depends on a pathologist looking at the tumor’s tissue under a microscope. “This is obtained either by surgical removal of the entire kidney with the tumor or a biopsy of the tumor if removal is felt to be too risky due to the size of the tumor,” Dr. Torkildson said.

What treatment options are available?

Treatment involves a combination of surgery and chemotherapy and may also involve radiation therapy, depending on the extent of the disease both before and after the tumor is removed.

“Children with a tumor confined to one kidney typically undergo surgical removal of the kidney containing the tumor,” Dr. Torkildson said. “Decisions about further treatment depend on the size and extent of the tumor and whether it has spread to nearby lymph nodes or more distant locations.”

Will my child have a normal life?

“The outlook for children with Wilms tumor is excellent,” Dr. Torkildson said. “Children with Stage 1 disease – a tumor entirely confined to the kidney – are cured with surgery and a brief course of chemotherapy. Children with more advanced diseases are cured over 90% of the time with intensified therapy.”

What other things should I keep in mind when it comes to the diagnosis and treatment of my child’s cancer?

An important thing for parents to understand is that in order to treat a cancer successfully, it is necessary to be certain what it is. Sometimes this can take time—which can be especially hard when it comes to your child and a potential cancer diagnosis.

“Parents get understandably upset when it sometimes takes several days to determine what type of tumor their child has,” Dr. Torkildson said. “However, trying to move forward too quickly, before the actual diagnosis is confirmed, can lead to inappropriate treatment being given. This could well be ineffective or expose the child to unnecessary side effects.”

If your child has recently been diagnosed with Wilms tumor or you have specific questions or concerns, don’t hesitate to reach out to one of our pediatric cancer experts. To find a specialist near you, visit bannerhealth.com.

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