Surgery for Wilms tumour

Surgery is a medical procedure to examine, remove or repair tissue. Surgery, as a treatment for cancer, means removing the tumour or cancerous tissue from the body.

Most children with Wilms tumour have surgery. The type of surgery used depends mainly on whether the tumour can be removed with surgery and whether there are tumours in both kidneys at the time of diagnosis. When planning surgery, your childʼs healthcare team will also consider other factors, such as your child’s overall health, if your child has 1 or 2 kidneys and how well the kidneys are working.

Surgery may be used to:

• completely remove the tumour
• diagnose and stage the cancer

There are different types of surgery used to treat Wilms tumour. Your child may also have other treatments before or after surgery.

Before surgery, doctors will use imaging tests such as an ultrasound, a CT scan or an MRI to find out where the tumour is in the kidney and if it has spread outside the kidney. They use this information to decide whether the cancer can be removed with surgery.

In Canada, most tumours are removed before any chemotherapy is given. In some cases, chemotherapy is given for 6 or more weeks before surgery to shrink the tumour making it easier to remove with surgery. A sample of the tumour may also be taken for a biopsy. Other treatments may also be used before surgery in the following situations:

• There are tumours in both kidneys.
• The child has only one kidney.
• The child has a genetic condition that puts them at risk for kidney failure or developing more Wilms tumours.
• The tumour is very large and has grown beyond the midline (the line that divides the body into right and left halves).
• The tumour has grown deep into the veins of the liver or heart.
• The tumour has spread to nearby vital tissues, blood vessels or organs and these would also have to be removed.
• Surgery to remove the entire tumour would cause significant or unnecessary damage.
• The child is too sick to have surgery.

Find out more about the diagnosis of Wilms tumour, including ultrasounds, CT scans and MRIs.

The most common surgery for Wilms tumour is a radical nephrectomy. A radical nephrectomy removes the entire kidney, including the ureter and surrounding fat. Sometimes the adrenal gland is also removed. If the tumour is large, the surgeon may also remove the renal vein.

When cancer is in both kidneys and they are not working well, both kidneys may need to be removed. If both kidneys are removed, your child will need to have dialysis. Dialysis uses a machine to filter waste and excess water from the blood. Once your child is healthy enough and their doctor is certain the cancer will not come back (recur), a kidney transplant may be an option. This usually happens 1 to 2 years after treatment.

A partial nephrectomy removes the tumour along with a small amount of tissue around it (called a surgical margin). The rest of the kidney remains in place. A partial nephrectomy is also called a nephron-sparing surgery or a renal-sparing surgery.

The goal of a partial nephrectomy is to keep as much of kidney as possible. A partial nephrectomy is used only in certain situations, such as when the child has only one kidney or has a genetic condition that puts them at risk for kidney failure or developing more Wilms tumours. When there are tumours in both kidneys, a partial nephrectomy may be used to try to save some normal kidney tissue in both kidneys. Or, a radical nephrectomy may be done to remove the kidney that has more cancer in it, while a partial nephrectomy may be done on the other kidney.

Surgery is often used to stage the cancer. Knowing if Wilms tumour has spread to the lymph nodes or nearby organs can help the healthcare team determine the stage and what other treatment may be needed.

During surgery, the surgeon usually makes a surgical cut (incision) in the abdomen and checks the entire area, including the peritoneum. The surgeon feels the renal vein, ureter and inferior vena cava (a large vein that receives blood from lower limbs and organs of the pelvis and abdomen, and empties into the right atrium of the heart). The surgeon also examines nearby organs such as the liver. A sample (called a biopsy) may be taken from any suspicious areas outside of the kidney.

The following types of surgery may also be used to help stage Wilms tumour.

A lymph node dissection is done to remove lymph nodes near the kidney. It is often done at the same time as surgery to remove the tumour.

Samples from the lymph nodes are examined under a microscope to determine the stage of the cancer. A lymph node dissection is important because sometimes cancer has spread to the lymph nodes without enlarging them.

Find out more about a lymph node dissection.

During a biopsy, the doctor removes tissues or cells from the body so they can be tested in a lab.

In most cases of Wilms tumour, it is best to remove the primary tumour without doing a biopsy first. This is because Wilms tumours can be fragile, and cutting into them may spread cancer cells throughout the abdomen.

But during surgery, the surgeon may find that the tumour can’t be completely removed because it is large and has grown into surrounding tissues and vital blood vessels. The surgeon may take a sample of the tumour for a biopsy rather than try to remove the whole kidney at that time. A biopsy may also be done if your child has only one kidney, or if the diagnosis of Wilms tumour is uncertain.

If there is cancer in both kidneys, chemotherapy is usually given for 6 or more weeks to shrink the tumour before a biopsy or nephrectomy is done.

Find out more about biopsies.

Surgery may be used to remove cancer that has spread (metastasized) to the liver or lungs, or to biopsy an area on the lungs or liver if it showed a spot on an imaging scan.

Chemotherapy and radiation therapy are usually given before surgery for metastases. If tumours remain in the liver or lung after these treatments, your child may have another surgery to remove the remaining tumours.

Side effects of surgery will depend mainly on the type of surgery, the side effects of other cancer treatments and your child’s overall health. Tell the healthcare team if your child has side effects that you think are from surgery. The sooner you tell them of any problems, the sooner they can suggest ways to help your child deal with them.

Surgery for Wilms tumour may cause these side effects:

• scarring
• pain
• nausea and vomiting
• constipation
• trouble urinating (peeing)
• bleeding
• infection
• bowel obstruction
• lung problems
• kidney problems, including kidney failure

Other side effects can develop months or years after treatment for Wilms tumour. Find out more about late effects of treatments for Wilms tumour.

Find out more about surgery and side effects of surgery. To make the decisions that are right for your child, ask the healthcare team questions about surgery.