Kidney tumors in children are rare, comprising less then 5% of all childhood malignancies. The most common type of kidney tumor, known as Wilm’s tumor, or nephroblastoma, grows from immature cells in the kidney. As with any tumor, the prognosis for Wilm’s tumor can vary greatly from child to child, however most children with Wilm’s tumor can be cured of their disease. Approximately 500 children in the United States are diagnosed with Wilm’s tumor each year. At Ochsner for Children, our Pediatric Oncologists work with a multidisciplinary team to provide state-of–the-art care to children and young adults diagnosed with Wilm’s. This includes pediatric oncologists, pediatric surgeons, radiation oncologists and pediatric urologists. We are very active in research and clinical trials designed to increase cure rates, decrease treatment-related side effects and improve care for long-term survivors.
What are kidney tumors/Wilm’s tumor?
There are several different types of tumors that can arise from the kidney in children, however by far the most common is known at Wilm’s tumor, or nephroblastoma. Wilm’s tumor is very different than kidney cancer in adults. It usually occurs in young children, almost always younger than 8 years old. Most children with Wilm’s tumor can be successfully treated by surgical removal of the affected kidney. Some children will also require chemotherapy and/or radiation, depending on characteristics of the tumor.
What are the symptoms of kidney tumors/Wilm’s tumor?
The symptoms of Wilm’s tumor are often subtle, but can include:
- Swelling or fullness of the abdomen
- Blood in the urine
- Abdominal pain
- Constipation or difficulty urinating
- High blood pressure
- Weakness, fatigue or fever
How common are kidney tumors/Wilm’s tumor?
Approximately 500 children in the United States are diagnosed with Wilm’s tumor each year. Overall, kidney tumors account for ~5% of childhood cancers. 1-2 % of children with Wilm’s tumor will have another family member with Wilm’s (known as familial Wilm’s tumor), and ~10% of children with Wilm’s will present with tumors in both kidneys, known as bilateral Wilm’s. There are several genetic syndromes associated with Wilm’s tumor as well, such as Beckwith-Wiedemann syndrome or WAGR syndrome. Wilm’s tumor is slightly more common in African Americans than in Caucasians and Asians.
How are kidney tumors/Wilm’s tumors diagnosed?
A variety of techniques may be used to diagnose and stage kidney tumors. These include:
- Biopsy, in which a pediatric surgeon performs a procedure to take a sample of the tumor in order to determine what type of tissue it is and to run special molecular tests.
- Nephrectomy, in which the pediatric surgeon removes the entire affected kidney with the tumor inside of it. This is often done if the tumor has not spread outside of the kidney.
- Computed tomography (CT) scan, which uses a combination of X-rays and computer to produce images of the body, is useful for evaluating both bones and soft tissues.
How are kidney tumors/Wilm’s tumor staged?
In the United States, the Children’s Oncology Group staging system is used most often to describe the extent of spread of Wilm’s tumors.
- Stage I - The tumor was contained within one kidney and was completely removed by surgery. The tumor was not biopsied before surgery to remove it. ~40% of all Wilm’s tumors are stage I.
- Stage II - The tumor has grown beyond the kidney, either into nearby fatty tissue or into blood vessels in or near the kidney, but it was completely removed by surgery without any apparent cancer left behind. Lymph nodes do not contain cancer. The tumor was not biopsied before surgery. ~20% of all Wilm’s tumors are stage II.
- Stage III - This stage refers to Wilm’s tumors that may not have been completely removed. The cancer remaining after surgery is limited to the abdomen (belly). ~25% of Wilm’s tumors are stage III. One or more of the following features may be present:
- The cancer has spread to lymph nodes in the abdomen or pelvis
- The cancer has invaded nearby vital structures so the surgeon could not remove it completely.
- Deposits of tumor (tumor implants) are found along the inner lining of the abdominal space.
- Cancer cells are found at the edge of the sample (the margins) removed by surgery, indicating that some of the cancer still remains after surgery.
- Cancer cells “spilled” into the abdominal space before or during surgery.
- A biopsy of the tumor was done before it was removed with surgery.
- Stage IV - The cancer has spread to organs away from the kidneys such as the lungs, liver, brain, or bone, or to lymph nodes far away from the kidneys. ~10% of all Wilm’s tumors are stage IV.
- Stage V - Tumors are found in both kidneys at diagnosis. ~5% of all Wilms tumors are stage V.
How are kidney tumors/Wilm’s tumor treated?
Treatment for kidney tumors may involve a combination of therapies including surgery, radiation and/or chemotherapy. Treatment options may vary greatly, depending on your child's situation. Our pediatric oncologists work closely with a multidisciplinary team to create a personalized treatment plan that is best for your child.
- Surgery - Surgery is usually the first step in treating children with kidney tumors. In some cases, only a biopsy is done. This is often necessary when the tumor is too close to critical structures in the brain, or when the surgeon does not feel the tumor can be safely removed. In other cases, the tumor can be removed completely. This may require the entire kidney to be removed, a procedure known as a nephrectomy.
- Chemotherapy - To decrease the size of the tumor, kill tumor that has spread and prevent further tumor spread, your child may receive chemotherapy. This can be done before or after surgery, depending on your child’s unique circumstances.
- Radiation therapy - High-energy X-rays or other types of radiation can kill cancer cells or stop them from growing. Radiation therapy is used in certain types of tumors to either shrink the tumor prior to surgery, or to try to prevent the tumor from coming back after surgery.
What clinical trials does Ochsner Hospital for Children offer for kidney tumors/Wilm’s tumor?
As part of the Children’s Oncology Group, Ochsner Hospital for Children is an active participant in children’s cancer research. We currently have multiple clinical trials available to treat children and young adults with various types of kidney tumors.