Wilms Tumor - Childhood: Statistics

Approved by the Cancer.Net Editorial Board, 07/2023

ON THIS PAGE: You will find information about the estimated number of children who will be diagnosed with a Wilms tumor each year. You will also read general information on surviving the disease. Remember, survival rates depend on several factors, and no 2 people with a tumor are the same. Use the menu to see other pages.

Every person is different, with different factors influencing their risk of being diagnosed with this tumor and the chance of recovery after a diagnosis. It is important to talk with your doctor about any questions you have around the general statistics provided below and what they may mean for your child individually. The original sources for these statistics are provided at the bottom of this page.

How many children are diagnosed with a Wilms tumor?

In the United States, about 500 to 600 children are diagnosed with a Wilms tumor each year. The disease accounts for about 4% of all cancers in children younger than 15 and is the most common kind of kidney cancer in children.

A Wilms tumor occurs most often in young children, usually between the ages of 3 and 4. In fact, two-thirds of Wilms tumors are diagnosed before age 5, and nearly all cases are diagnosed before age 10. As children get older, these tumors are less common, but they can still occur in people of any age. Wilms tumors are slightly more common in girls than in boys, and the risk is slightly higher in Black children than White children. Asian American children have the lowest risk.

What is the survival rate for children with a Wilms tumor?

There are different types of statistics that can help doctors evaluate a person’s chance of recovery from a Wilms tumor. These are called survival statistics. A specific type of survival statistic is called the relative survival rate. It is often used to predict how having a tumor may affect life expectancy. Relative survival rate looks at how likely people with a Wilms tumor are to survive for a certain amount of time after their initial diagnosis or start of treatment compared to the expected survival of similar people without this tumor.

Example: Here is an example to help explain what a relative survival rate means. Please note this is only an example and not specific to this type of cancer. Let’s assume that the 5-year relative survival rate for a specific type of cancer is 90%. “Percent” means how many out of 100. Imagine there are 1,000 people without cancer, and based on their age and other characteristics, you expect 900 of the 1,000 to be alive in 5 years. Also imagine there are another 1,000 people similar in age and other characteristics as the first 1,000, but they all have the specific type of cancer that has a 5-year survival rate of 90%. This means it is expected that 810 of the people with the specific cancer (90% of 900) will be alive in 5 years.

It is important to remember that statistics on the survival rates for children with a Wilms tumor are only an estimate. They cannot tell an individual person if the tumor will or will not shorten their life. Instead, these statistics describe trends in groups of people previously diagnosed with the same disease, including specific stages of the disease.

The 5-year relative survival rate for children with a Wilms tumor is 93%.

The survival rates for children with a Wilms tumor vary based on several factors. These include the stage of tumor, a person’s age and general health, and how well the treatment plan works. The risk that a Wilms tumor will come back after treatment is between 15% and 50%, and it is most likely to come back within the first 2 years following treatment.

Stage I, II, and III tumors with a favorable histology have a 4-year relative survival rate that ranges from 95% to 100%. The histology of a tumor is how its cells look under a microscope. Stage IV and V tumors with a favorable histology have a 4-year relative survival rate that ranges from 85% to 100%. Survival rates for tumors with a focal anaplastic histology are generally lower in each category and range from 70% to 100% survival rates. For tumors with a diffuse anaplastic histology, the survival rates range from 30% to 85% in different stage categories.

Survival rates for children with a Wilms tumor are based on a small number of patients due to Wilms tumors being generally uncommon. Experts measure relative survival rate statistics for children with a Wilms tumor every 4 or 5 years. This means the estimate may not reflect the results of advancements in how children with a Wilms tumor are diagnosed or treated from the last 4 or 5 years. Talk with your child’s doctor if you have any questions about this information. Learn more about understanding statistics.

Statistics adapted from the American Cancer Society and National Institutes of Health MedlinePlus websites. Additional source was: Seigel R, et al.: Cancer Statistics 2023. CA: A Cancer Journal for Clinicians. 2023 Jan; 73(1):17–48. doi/full/10.3322/caac.21763. (All sources accessed March 2023.)

The next section in this guide is Medical Illustrations. It offers a drawing of a kidney, which is where a Wilms tumor occurs. Use the menu to choose a different section to read in this guide.