Wilms Tumor

Wilms tumor, also called nephroblastoma, is a cancerous tumor that usually starts in the kidney. It is the most common type of kidney cancer in children and adolescents and accounts for about 4 percent of all childhood cancers. Since the tumor is usually not painful, many children develop very large tumors before they are detected. The disease can occasionally occur in both kidneys. It can also spread to other parts of the body, most commonly the lymph nodes in the abdomen and the lungs.

Our care team includes experts in oncology, surgery, radiation oncology, urology, nephrology, pathology and radiology, all of whom are exclusively focused on caring for children, adolescents and young adults. Our doctors have decades of experience treating Wilms tumor. We will continue to follow your child for many years to ensure that they return to good health and are monitored for post-treatment complications. Our researchers are also working to develop new cancer drugs and identify better treatments for Wilms tumor.

What causes Wilms tumor?

The cause of most cases of Wilms tumor is unknown. It is uncommon for Wilms tumor to run in families. Most cases of Wilms tumor seem to occur by chance and are the result of random genetic mutations that affect how cells in the kidney grow. A small percentage of patients with Wilms tumor have one of three genetic syndromes:

• WAGR syndrome: The acronym WAGR stands for the four conditions present in WAGR syndrome: Wilms tumor, aniridia (absence of the iris, the colored part of the eye), genitourinary malformations (defect of the kidneys, urinary tract, penis, scrotum, clitoris, testicles or ovaries) and intellectual disability. This is caused by a genetic abnormality that causes loss or inactivation of a tumor suppressor gene called WT1 on chromosome 11. Tumor suppressor genes usually suppress the growth of tumors and control cell growth. When altered, they no longer control cell growth and tumors may form.
• Denys–Drash syndrome: This syndrome is characterized by kidney failure in infancy, genitourinary malformations and abnormal development of the reproductive organs. This syndrome is also caused by an abnormality on chromosome 11.
• Beckwith–Wiedemann syndrome: This syndrome is characterized by large birthweight; an enlarged liver, spleen and tongue; low blood sugar in the newborn period; malformations around the ear; asymmetric growth of the body (one side larger than the other); abdominal wall defects near the navel (omphalocele); and tumors of the liver and adrenal glands. This syndrome is thought to be caused by an overactive copy of an oncogene on chromosome 11, called IGF2. Oncogenes control cell growth, but, if mutated, may cause uncontrolled cell growth and tumor formation.

How is Wilms tumor treated?

Surgical removal of the tumor is an important part of treatment. Whenever possible, only a portion of the kidney is removed, but in most cases the entire kidney must be removed. Your child will also likely receive chemotherapy (medicines that kill cancer cells) for four to eight months. If your child’s cancer has spread outside the kidney to other parts of the body, radiation therapy may also be used.