Staging, risk groups and treatment plans for Wilms tumour

About staging

The tests and scans your child had to diagnose the cancer give some information about the stage. It is not usually possible to be certain about the stage of a Wilms tumour until after surgery.

Doctors use a number system to stage Wilms tumours. The International Society of Paediatric Oncology (SIOP) has designed the staging system for the UK and the rest of Europe.

Outside of Europe, the Children’s Oncology Group (COG) uses a similar but slightly different staging system.

Most children have 4 weeks of chemotherapy before surgery unless there are special circumstances.

Risk groups

Doctors group Wilms tumours in terms of risk of the cancer coming back after treatment. There are 3 risk groups:

• low

• medium ((intermediate)

• high

Doctors decide on a risk group based on what the ​pathologist​ sees down the microscope when the tumour is looked at after surgery.

Staging for Wilms tumour

Staging for Wilms tumour can seem complicated. Ask your child's specialist as many questions as you need and in as much detail as you find helpful.

Stage 1

Stage 1 means the tumour is only affecting the kidney. The tumour has not spread and it was completely removed during surgery.

Treatment

Treatment for stage 1 Wilms tumour is usually chemotherapy for 4 weeks. The chemotherapy drugs used are usually dactinomycin (also known as actinomycin D) and vincristine. This is called the AV regime. They then have surgery to remove the kidney.

Low and medium risk

Your child won’t need any treatment after surgery if they have a low risk tumour. If your child has a medium risk tumour, they will have a further 4 weeks of chemotherapy.

High risk

For a high risk Wilms tumour your child has 27 weeks of chemotherapy. High risk stage 1 tumours are usually treated with AV chemotherapy and another chemotherapy drug called doxorubicin.

Stage 2

Stage 2 means the tumour has spread beyond the kidney to the nearby structures. There are no cancer cells in distant organs, such as the lungs. The cancer is completely removed during surgery.

Treatment

Treatment for stage 2 Wilms tumour is usually chemotherapy for 4 weeks. Then surgery to remove the kidney.   

After surgery, your child usually has more chemotherapy.

Low risk

If your child is low risk they usually have chemotherapy for 27 weeks. Using dactinomycin and vincristine (AV regimen).

Medium risk

Some children with medium risk Wilms tumours have chemotherapy for 27 weeks with dactinomycin and vincristine (AV). Other children have AV chemotherapy with another chemotherapy drug called doxorubicin. This depends on what the cells look like under the microscope.

High risk

Treatment for high risk stage 2 Wilms tumours after surgery is usually more intensive chemotherapy for 34 weeks. The chemotherapy drugs they have are usually:

• etoposide

• carboplatin

• cyclophosphamide

• doxorubicin

They may or may not have radiotherapy. This depends on what the cells look like under a microscope.

Stage 3

Stage 3 means one of the following. The tumour has

• not been completely removed during surgery

• spread to the ​lymph nodes​ in the tummy area (abdomen)

• burst, before or during, the surgery

• spread to the lining of the abdomen (the peritoneum), ​ureter​ or blood vessels

If your child needed a sample of tissue (biopsy) before starting treatment with chemotherapy, this could mean that the tumour becomes stage 3. Having a biopsy taken through an operation is called an open biopsy.

Treatment

Treatment for stage 3 Wilms tumour is usually chemotherapy for 4 weeks. Then surgery to remove the kidney. 

After surgery, your child will usually have chemotherapy.   

Low risk

For low risk stage 3 tumours they have 27 weeks of chemotherapy with dactinomycin and vincristine.

Medium risk

For medium risk stage 3  tumours they have chemotherapy for 27 weeks with dactinomycin and vincristine. Or chemotherapy for 27 weeks with dactinomycin, vincristine, and another chemotherapy drug called doxorubicin. This depends on what the cells look like under a microscope.

High risk

For high risk stage 3 Wilms tumour your child usually has the following chemotherapy drugs for 34 weeks:

• etoposide

• carboplatin

• cyclophosphamide

• doxorubicin

Your child usually also has radiotherapy for medium or high risk tumours.

Stage 4

Stage 4 means that the tumour has spread to a distant part of the body. This is most commonly the lungs. But Wilms tumours can also spread to other parts of the body such as the liver, the bones, or the brain. Or lymph nodes in an area outside the tummy (abdominal) or pelvic area.

Treatment

Treatment for stage 4 Wilms tumour is usually chemotherapy for 6 weeks. Using dactinomycin, vincristine, and doxorubicin. Then surgery to remove the kidney. 

After surgery, your child is likely to have more chemotherapy. This may be up to 34 weeks. The treatment schedule depends on:

• your child’s risk group

• how well treatment is working

Your specialist will explain what chemotherapy drugs your child will have and for how long. The chemotherapy drugs your child has may include:

• dactinomycin

• vincristine

• doxorubicin

• etoposide

• carboplatin

• cyclophosphamide 

Your child may also have radiotherapy.

Stage 5

Stage 5 means there are tumours in both kidneys. This is called bilateral Wilms tumour. Doctors stage each of the tumours separately.

Treatment

Treatment is usually chemotherapy first. This may be up to 12 weeks. Then surgery to remove as much of the cancer as possible from each kidney. Your child’s surgeon will aim to keep as much healthy kidney tissue as possible.

It’s likely your child will have more chemotherapy after surgery. They might also have radiotherapy.

Treating children younger than 6 months

In most situations, children 6 months and older usually have chemotherapy before their surgery. Children younger than 6 months usually have surgery first then have chemotherapy. Your specialist will explain your child's treatment to you in more detail.

Treatment

Read more information about the different treatments for Wilms tumours