The reasons aren’t clear, but it most often affects kids who are 3 to 4 years old. It’s much less common after 5. Because doctors are getting better at spotting and treating this type of cancer, many children who have it will make a full recovery.
What Causes It?
All cancer is caused when cells in your body start to grow out of control. If your child has a Wilms tumor, their kidney cells didn’t mature like they were supposed to. Instead, they turned into cancer cells. Most of the time, this is due to a random change in a gene. It’s rarely inherited from a parent.
What Types Are There?
There are two kinds of Wilms tumors. The cells look different under a microscope.
Favorable histology: More than 9 out of 10 Wilms tumors fall into this group. It means that the cancer cells don’t vary widely. Children who have a “favorable histology” have a good chance of being cured.
Unfavorable histology: This type has a variety of deformed cancer cells. It can be much harder to cure.
Who’s at Risk?
Many things can put a child at risk of having a Wilms tumor.
Age. Most children who get this type of cancer are between 3 and 5 years old.
Gender. Girls are more likely to have it than boys.
African-American. Black children are slightly more likely to get a Wilms tumor than children of other races.
Family history. If someone in your family has had a Wilms tumor, the odds that your child will get it are higher, too.
Another health problem. A Wilms tumor sometimes appears in children who have other rare conditions:
What Are the Symptoms?
Children who have a Wilms tumor may have:
- Pain, swelling, or growth in their belly. Many Wilms tumors get very big before they’re noticed. The average size is 1 pound.
- Fever, nausea, or no interest in eating
- High blood pressure
- Blood in their pee
- Shortness of breath
In some cases, kids won’t have any symptoms.
How Is It Diagnosed?
After a complete exam, your doctor will ask about your child’s symptoms and how long she’s had them. He’ll likely want to know if cancer or urinary tract problems run in your family.
Your doctor will also run some tests. This often includes a blood test, so your doctor can get a general sense of your child’s health. An imaging test will also be done. An ultrasound, MRI, or CT scan all can show a detailed view of your child’s kidneys.
If your doctor finds a kidney tumor, more tests will be needed. These can check to see if the cancer has spread and may include a bone scan or chest X-ray. To make a final diagnosis, your doctor will remove a small piece of the tumor and have it checked at a lab.
What Is the Treatment?
If your doctor operates, he may do a procedure called a radical nephrectomy. It removes the cancerous kidney, the ureter (the tube that carries pee away from the kidney), the adrenal gland on top of the kidney, and nearby tissue.
The doctor will also take out the lymph nodes near your child’s affected kidney. These are glands that help your body fight infection. Tests can be run on them to learn how much the cancer has spread.
The outlook for most kids with a Wilms tumor is good. Up to 90% of children who have a tumor with “favorable histology” can be cured. If the tumor has “unfavorable histology,” the cure rate is lower.