Late effects of treatments for Wilms tumour

Cancer treatment may cause side effects in the years after the treatment has ended. These side effects of treatment are called late effects. The benefits of treating Wilms tumour far outweigh the risk of late effects.

The risk of late effects depends on many factors, including:

• the types of treatment used
• the amount of treatment
• the childʼs age at the time of treatment
• the stage of the cancer

Your child will have long-term follow-up care after treatment, so the healthcare team can find late effects early and start treating of them right away. Your childʼs healthcare team will tell you what they are watching for and why.

The following are possible late effects after treatment for Wilms tumour.

Children with Wilms tumour are usually very young when they are diagnosed and treated, so they have a risk of developing kidney problems as they get older. These problems include:

• increased levels of protein in the urine (proteinuria)
• high blood pressure (hypertension)
• kidney failure if Wilms tumour is in both kidneys

Kidney problems can develop 10 to 20 years after a nephrectomy, radiation therapy or chemotherapy to treat Wilms tumour. Radiation therapy can cause kidney damage (called radiation nephritis).

Children with Denys-Drash syndrome or WAGR syndrome have a higher risk for kidney problems after treatment for Wilms tumour.

Children with only one kidney should avoid medicines that are harmful to the kidneys. They also need to stay well hydrated especially when it's hot outside, when they are sick, or during and after physical activity.

Find out more about kidney problems.

Radiation therapy to the chest can cause heart problems.

Certain chemotherapy drugs used to treat Wilms tumour, such as doxorubicin, may cause weakening of the heart muscles (called cardiomyopathy). Chemotherapy for Wilms tumour can also lead to an abnormal heart rhythm (called arrhythmia).

The following can increase the risk of heart problems after treatment for Wilms tumour:

• receiving doxorubicin at a younger age
• receiving a larger total (cumulative) dose of doxorubicin
• radiation therapy to the chest
• radiation to the left side of the abdomen

The healthcare team will carefully monitor children receiving chemotherapy for any signs of heart damage. They will do regular physical exams and may consider additional tests, such as echocardiograms (an ultrasound of the heart), electrocardiograms (ECG or EKG) and blood pressure monitoring. These tests help doctors find heart problems early and determine if treatment is necessary.

People who have been treated with doxorubicin for Wilms tumour should avoid smoking because it will further damage the heart.

Find out more about heart problems.

Lung problems, such as pneumonitis, can develop after treatment with certain chemotherapy drugs (doxorubicin and dactinomycin) or radiation therapy to the chest. Pneumonitis is inflammation of the lungs. It can lead to pulmonary fibrosis, which is the formation of scar tissue in the lungs.

Find out more about lung problems.

Certain chemotherapy drugs used to treat Wilms tumour can affect the ovaries or testicles and cause reproductive problems for children as they get older. These problems include puberty starting earlier or later than average and infertility. The higher the total dose of chemotherapy, the greater the risk of damage.

Radiation therapy to the abdomen can affect a personʼs ability to get pregnant and increase the risk of complications during pregnancy. It can also cause early menopause.

Your child will be closely monitored during puberty. They may need to be referred to a fertility specialist.

Find out more about male reproductive system problems, female reproductive system problems and fertility problems.

Children treated for Wilms tumour may grow and develop slower or less than other children. Radiation therapy to the abdomen can cause problems with the bones and muscles (called musculoskeletal problems). These problems may include a curved spine (called scoliosis) or underdeveloped or weak muscles.

Find out more about bone and muscle problems.

Chemotherapy and radiation therapy can cause oral and dental problems. These problems may include a higher risk for cavities and white or discoloured patches on the teeth. Chemotherapy and radiation therapy can also affect the roots of teeth so they are shorter or thinner than usual, or sometimes teeth or roots don’t grow at all. The younger the child is when they receive these treatments, the higher the risk of dental problems as they get older.

Find out more about dental problems.

Cognitive function refers to your thinking abilities. This includes communication, reasoning, perception, judgment, learning, attention, memory, organization and problem-solving.

Radiation therapy and chemotherapy can affect cognitive function. Children with WAGR syndrome are also at risk for cognitive problems. Cognitive problems can impact emotional well-being and overall quality of life. Your child may have difficulty at school, at work or in carrying out daily activities. Cognitive problems may also affect the ability to understand or make decisions.

Because their brains are still developing, children have a higher risk for cognitive problems after cancer treatment. Having cognitive problems can affect a childʼs development in many ways and cause learning difficulties, such as problems with writing and math. Chemotherapy may cause problems with attention, memory or problem-solving. High doses of chemotherapy and chemotherapy given for a long time are more likely to cause cognitive problems.

Find out more about cognitive problems.

People who have had Wilms tumour have a higher risk of developing a second cancer. This risk may be due to inherited conditions, or it may be due to treatments such as chemotherapy and radiation therapy.

The most common second cancers that occur in people who have had Wilms tumour are:

• colorectal cancer and other cancers in the gastrointestinal (GI) tract
• breast cancer
• lung cancer
• thyroid cancer
• soft tissue sarcoma
• non-Hodgkin lymphoma
• non-melanoma skin cancer
• melanoma skin cancer
• acute lymphoblastic leukemia
• acute myeloid leukemia

Second cancers donʼt usually develop for 10 to 20 years after treatment. Itʼs important for healthcare professionals who see your child regularly through their life to know about any previous cancer treatments so that cancer screening can be done earlier.

As your child gets older, they should be aware of the risk of developing a second cancer. Itʼs important they do things to reduce their risk of developing a second cancer, such as being sun safe and living smoke-free. They may also have to start cancer screening earlier than usual. Talk to the doctor about their personal plan for cancer screening.

Find out more about second cancers.

Children who have had abdominal surgery can develop scar tissue that increases the risk of a bowel obstruction later in life.

Symptoms of a bowel obstruction include abdominal pain and vomiting. Itʼs important to see a doctor right away if these symptoms are severe.

Find out more about a bowel obstruction.

Certain chemotherapy drugs, such as dactinomycin and vincristine, can cause liver problems. Radiation therapy to the abdomen can also damage the liver. The liver may become enlarged, which is called hepatomegaly. A severe but uncommon complication of treatment is a problem called sinusoidal obstruction syndrome or veno-occlusive disease of the liver. This problem usually occurs while the child is still having treatment.

If damage to the liver continues to get worse over time, the liver may become hard (called fibrosis) and scarred (called cirrhosis).

Find out more about liver problems.

To make the decisions that are right for your child, find out more about late effects of childhood cancer and talk to the healthcare team about long-term survivorship.