What is Wilms' Tumor?

Wilms' tumor is a very rare form of kidney cancer that occurs in young children, usually between the ages of two and five. The kidneys are two fist-sized, bean-shaped organs located in the back of the torso, just above the waist. They filter waste and excess water from the blood and turn it into urine.

The kidneys begin developing in the fetus before birth. After birth, immature cells in the kidneys continue to mature and develop during the first few years of life. In children with Wilms' tumor, these immature cells mutate and begin to grow rapidly and uncontrollably.

Wilms' tumor usually develops in a single kidney, but some children may have multiple tumors in the same kidney or tumors in both kidneys. Although Wilms' tumor can be fairly aggressive and grow very large very quickly, doctors are able to cure about 90% of cases.

A study from St. Jude Children's Research Hospital – ALSAC found that stromal-predominant Wilms' tumors have a very favorable outcome, even when resistant to chemotherapy, suggesting a potential shift in treatment approaches for this subtype.

Click here to learn more about Wilms' Tumor, including risk factors, diagnosis, and treatment.