Wilms tumours factsheet


Wilms tumours are cancers that grow on one or both kidneys. 

The kidneys are two organs below the ribs, on either side of the spine. 

The kidneys: 

  • filter waste from the blood and turn it into urine or wee
  • control blood pressure, the force needed to push blood through the body.

Wilms tumours are more common in children under five years. They have a high cure rate when treated by a doctor.

Signs and symptoms

Symptoms of a Wilms tumour will depend on how advanced the cancer is. 

They can include: 

  • a lump, swelling, and pain in the belly 
  • abnormal or blood-coloured urine or wee 
  • constipation - hard poo that is difficult to pass
  • loss of appetite 
  • fever  
  • high blood pressure 
  • sweating at nighttime 
  • nausea and vomiting.

See your local doctor as soon as possible if you are concerned your child is showing signs of a Wilms tumour.


Your child’s local doctor will try to rule out any other illnesses first. They will:

  • take a blood test
  • take a medical and family history
  • do a physical check and feel the kidneys

Your child will be referred to a cancer specialist, called an oncologist.

The oncologist will be able to check symptoms and diagnose a Wilms tumour using the results from:

  • blood tests
  • urine tests
  • scans to see the kidneys more clearly, including X-ray, ultrasound, CT and MRI 
  • biopsy - a procedure where a sample of the tumour is taken out and tested.


Treatment for a Wilms tumour will usually involve: 

  • chemotherapy – where a mixture of medications is given to kill cancer cells or stop them from growing
  • radiotherapy -    where high-energy X-rays are used to kill cancer cells or stop them from growing, used for Wilms tumours that are advanced
  • surgery – to remove the tumour or the affected kidney.

The type of surgery used will depend on how advanced the cancer is. The surgeon will try to only remove the tumour.

Sometimes, the entire kidney needs to be removed. However, it is possible to live with just one kidney.

When the cancer is in both kidneys, the surgeon will try to take out as much of the cancer as possible and keep as much healthy kidney tissue as they can. This is to try and avoid your child needing a kidney transplant.

A kidney transplant is when a damaged or sick kidney is removed and replaced with a healthy kidney donated by another person.

Speak to your child’s doctor if you have any questions about kidney surgery and transplants.


Cure rate

The cure rate of a Wilms tumour can depend on:

  • your child’s age
  • the type of tumour
  • how much it has spread. 

Children who have their Wilms tumour found and treated early have a cure rate of 85-90%, depending on the stage of their cancer.

More advanced tumours can have a cure rate of around 70-80%, depending on their stage and whether they have spread to other body parts.

Support for families

A cancer diagnosis can leave families and children feeling overwhelmed, scared, anxious, and upset. Practical and emotional support during and after treatment is essential and can come from: 

  • family
  • friends
  • healthcare professionals
  • specialised support services.

Speak to your child’s treatment team for information about support services.

Last updated Monday 25th March 2024


This factsheet is provided for general information only. It does not constitute health advice and should not be used to diagnose or treat any health condition.

Please consult with your doctor or other health professional to make sure this information is right for you and/or your child.

The Sydney Children’s Hospitals Network does not accept responsibility for inaccuracies or omissions, the interpretation of the information, or for success or appropriateness of any treatment described in the factsheet.

© Sydney Children’s Hospitals Network 2024