In the United States, surgery is the main treatment for Wilms tumor. It should be done by a doctor who is an expert in operating on children and has experience treating these cancers.
Removing the tumor
The main goal of surgery is to remove the Wilms tumor. If the surgeon finds that the whole tumor can’t be removed safely, other treatments may be used first. If these treatments shrink the tumor enough, surgery can then be done more safely. Different operations may be used to remove the tumor.
Radical nephrectomy: This is the most common operation for a Wilms tumor that is only in one kidney. The cancer and the whole kidney are removed as well as the ureter, the adrenal gland, and some fatty tissue around the kidney. Most children can live very well with only one kidney.
Partial nephrectomy (nephron-sparing surgery): In the small number of children who have Wilms tumors in both kidneys, the surgeon will try to save some normal kidney tissue, if possible. The kidney containing the most tumor is often removed. In the other kidney the surgeon may try to take out just the tumor and a rim (margin) of normal tissue, which is known as a partial nephrectomy. Another option may be to remove just the tumors in both kidneys.
In some cases, both kidneys may need to be removed. This means the child will need to be on dialysis, which involves using a machine to filter waste products out of the blood several times a week. Once the child is healthy enough and a donor kidney becomes available, a kidney transplant might be done.
Finding out the extent of the disease
Another main goal of the operation is to figure out the extent of the cancer and whether or not it can all be removed. During surgery the doctor will look at the liver and the other kidney and may take samples of any areas of concern. These samples will be looked at under a microscope to see if they contain cancer cells. Lymph nodes near the kidney may also be removed at this time. (Lymph nodes are bean-shaped collections of immune cells that normally fight infection. Cancer often spreads to lymph nodes.) Knowing whether or not a Wilms tumor has spread is important in finding its stage and choosing further treatments.
Putting in a port (central venous access line)
If chemotherapy is to be given, the surgeon may talk to you about putting a small plastic tube (called a venous access device or port) into a large blood vessel. The end of the tube may be just under the skin or sticking out of the skin of the chest area or upper arm. This port is left in place for several months to take blood samples and to give chemo and other medicines, as well as blood transfusions. It cuts down on the number of needle sticks needed. Someone on your cancer care team will teach you how to care for your child's port.
Risks and side effects of surgery
Problems during surgery such as bleeding, damage to major blood vessels or other organs, or reactions to the drugs (anesthesia) used are rare, but they can happen.
Problems after surgery are rare, too. They can include bleeding inside the body (internal bleeding), infections, or problems with food moving through the intestines. Almost all children will have some pain for a while after the operation, although this can often be helped with medicines. If there are tumors in both kidneys, another concern is the loss of kidney function. In these cases, doctors must strike a balance between making sure the tumors are removed completely and removing only as much tissue as is needed. Children who have all or parts of both kidneys removed may need dialysis, and may need a kidney transplant at some point.
For more information on surgery as a treatment for cancer, see our separate document, Understanding Cancer Surgery: A Guide for Patients and Families
Last Revised: 08/01/2012