Nephroblastoma, also known as Wilms' tumor, is the most common kidney cancer in children. The tumor usually appears in children less than five years of age (the median age is three), although it may develop in adolescence. Wilms' tumor is about 90 percent curable. Even if the cancer has spread to distant organs, more than half of all patients survive.

WHAT CAUSES WILMS' TUMOR?
The tumor sometimes runs in families, indicating a genetic influence yet to be defined. One of six children who develop the malignancy has congenital deformities of the urinary tract of the genitals (such as a malformation of the urethra or an undescended testicle). Other associated abnormalities include structural deformities of the heart and absence of the iris from the eye. Wilms' tumor sometimes develops in a child who has relatives with these congenital abnormalities.

WHEN SHOULD I SUSPECT WILMS' TUMOR?
Parents are usually the first to detect the tumor, often while bathing or dressing the child. The first sign is usually a firm or solid lump in the abdomen or side. Abdominal pain and swelling, fever, appetite and weight loss, and blood in the urine also may occur.

HOW CAN THE DOCTOR TELL IF MY CHILD HAS WILMS' TUMOR?
After examining the child and feeling the abdominal mass, the doctor will order blood tests and an X ray of the kidneys. Other tests, including ultrasound, may also be needed.

IS MEDICAL TREATMENT NECESSARY?
Yes. Without treatment, Wilms' tumor can spread to the liver, lungs and other sites.

WHAT TREATMENTS ARE AVAILABLE?
Treatment involves surgery to remove the kidney, along with any cancerous tissue that has spread to other parts of the abdomen. Despite extensive surgery, children usually recover quickly. Chemotherapy also will be used. A combination of two or three anticancer drugs has proven most effective in killing off remaining cancer cells.

In advanced cases, surgery is followed by 15 months of radiation and combined chemotherapy with three or four drugs. If the tumor is very large or widespread, or if it affects both kidneys, chemotherapy or radiation therapy will be ordered before surgery to shrink the tumor so that the surgeon can remove only cancerous tissue, not the entire kidney.

FOLLOW-UP CARE
Wilms' tumor may recur, most commonly in the lungs. Lung symptoms, such as coughing and shortness of breath, signal such a relapse, but they are not always present. The physician will therefore schedule regular checkups for several years after treatment to ensure that the child remains free of disease. The examinations will involve kidney and liver tests, bone scans and chest X rays. Chest X rays are ordered every three months during the first year of treatment, then routinely but less frequently for five years thereafter.

GETTING HELP
Call your doctor if:

• Your child has any unexplained lump or growth in any part of the body

Excerpt from THE DISNEY ENCYCLOPEDIA OF BABY & CHILD CARE, © 1995 DSH Communications, Inc. This material is based on current medical research and, to the best of the editors' knowledge and understanding, is accurate and valid. However the reader should not use information contained in this material to alter a medically prescribed regimen or as a form of self-treatment, without seeking the advice of a licensed physician.