A great deal of progress has been made in treating Wilms tumor over the last 25 years. Nine out of ten children are successfully treated with surgery, chemotherapy and sometimes radiation therapy. Many improvements in treatments have resulted from the work of the National Wilms Tumor Study Group. Today, most children with Wilms tumor are enrolled and treated in a clinical trial, so that the best treatments available can be improved even further.
Wilms tumors are relatively rare, therefore it is important to seek care at an experienced children’s cancer center. A team approach that includes the child’s pediatrician as well as specialists at the children’s cancer center where the treatment will be provided is recommended. Once a Wilms tumor is discovered, children should begin treatment quickly. Wilms tumors are often quite large by the time they are discovered, and these tumors tend to grow rapidly.
The first goal is to remove the tumor from the involved kidney or major site, even if the cancer has spread (metastasized) to other parts of the body. Sometimes, the tumor can be too large to remove immediately and may have spread into nearby blood vessels, other vital structures, or may be found in both kidneys. For these patients, doctors sometimes use chemotherapy to shrink the tumor before removing it later in the course of therapy.
Surgery is the main treatment for Wilms tumor. The most common operation for Wilms tumor is called a radical nephrectomy. In this procedure, a surgeon removes the cancer along with the entire kidney, the ureter (the tube that carries urine from the kidney to the bladder), and fatty tissue that surrounds the kidney.
At the time of the radical nephrectomy, a regional lymph node sampling is performed. In this procedure, the surgeon removes the lymph nodes next to the kidney. Lymph nodes are bean-sized glands that are part of the immune system and help to fight infections. Many cancers spread to the lymph nodes. Sampling the lymph nodes helps assess the degree of spread within the abdomen.
During surgery, the liver and the other kidney will also be examined. Any suspicious areas may be biopsied, meaning that tissue samples are removed for examination under a microscope.
If imaging tests such as a chest x-ray or CT scan suggest that the Wilms tumor has spread to the lungs, the surgeon may also take a tissue sample or remove the nodule completely. This may be done through a separate incision in the chest wall.
Knowing whether or not a Wilms tumor has spread to the lymph nodes, liver or the other kidney is important in determining the stage of the disease, as well as in choosing treatment.