Childhood cancers

Wilms' tumor (nephroblastoma)

Wilms' tumor is the most common form of childhood kidney cancer, making up about 6 percent of all childhood cancers. About 500 new cases are diagnosed each year in the U.S., most often in children ages two to four. New advances in treatment now allow the vast majority of children with Wilms' tumor to survive.

Risk factors
If there is a family history of Wilms' tumor, or if a child has a birth defect known to occur with Wilms', the child should undergo periodic ultrasound examinations.

Symptoms
Wilms' tumor is usually first recognized when a swelling or lump in the abdomen is noticed. The majority of children have no other symptoms but about a quarter will also have stomach pain, blood in the urine, fever or high blood pressure. Other symptoms may include swelling in the abdomen, loss of appetite or constipation.

Questions to ask your child's doctor

Diagnosis
A physician who specializes in the study of the kidneys is called a nephrologist. Your child's pediatric nephrologist can provide more detailed information about how the two kidneys filter the blood and remove extra salt, water and waste products. During an examination, the physician will feel the child's abdomen for lumps. Sometimes, these lumps are easily felt because the tumors can grow much larger than the kidney in which they developed.

In addition, blood and urine tests may be performed. If more investigation is needed, your child will undergo an ultrasound and perhaps a CT scan. Additional X-rays, ultrasound or magnetic resonance imaging (MRI) and bone scans may also be used. Diagnosing cancer

Most often, with Wilms' tumor, the entire kidney is removed and diagnosis is then made. A pathologist, a physician who specializes in identifying diseases, examines cells from the kidney under a microscope. This is done to determine the histology or type of kidney cancer. Histology describes how the cells and tissue look under a microscope and gives physicians an idea of whether the cancer is likely to spread.

All of these tests can help determine if cancer is present, what type of cancer it is, and, in some cases, if it has spread.

Treatment
Before cancer is treated, it has to be staged. Staging involves finding out where the cancer is located, the extent of the cancer and whether it has spread. Early stage cancers (Stage 1 and 2 that have not spread) are the easiest to treat.

There have been tremendous strides made in treating Wilms' tumors, with five-year survival rates surpassing 92 percent. Treatment depends on the stage of the disease, the cell type or histology and the child's age and overall health.

Treatment usually includes surgery to remove the tumor and all or part of the kidney, in addition to other nearby tissues. (The body can function normally with only one kidney.) If the cancer is confined to one kidney, it is called Stage 1. Cancers that have spread near the kidney are called Stage 2, while cancer that has spread regionally to local lymph nodes is called Stage 3. Stage 4 indicates cancer has spread to other organs.

Depending on the stage and type of cancer, surgery can be followed by radiation therapy and chemotherapy.

Clinical trials, protocols and research

Learn more
• YNHH Health Library: Wilms tumor

Last revised: Jan. 8, 2008 (dh)

Home page URL: http://www.ynhh.org

All information is intended for your general knowledge and is not a substitute for medical advice or treatment for specific medical conditions. You should seek prompt medical care for any specific health issues and consult your physician before starting a new fitness regimen.