Late effects of treatments for childhood bone cancer

Cancer treatment may cause side effects in the years after treatment has ended. These side effects of treatment are called late effects. However, the benefits of treating childhood bone cancer far outweigh the risk of late effects.

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

• the type of treatment used
• the amount of treatment
• your child’s age at the time of treatment

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

The following are possible late effects after treatment for childhood bone cancer.

Children who are treated for bone cancer may have bone problems in the future. Children who are treated before the age of 6 or during a growth spurt have a greater risk for bone problems. The following are the most common bone problems that can develop.

Differences in the length of limbs can occur in children treated for bone cancer. Bones constantly grow throughout childhood and the teen years until the skeleton is mature and adult height is reached. The area on each bone where growth occurs is called the growth plate (epiphyseal plate). Bone cancer often develops near the growth plate, so this area is usually removed during surgery. As a result, the reconstructed bone cannot grow as it normally would. The other limb continues to grow normally, which leads to the limbs being different lengths. Further surgery and other procedures may be needed to help the treated bone grow, or make the limbs the same length.

Problems with an internal prosthesis, such as the prosthesis breaking or becoming loose, can happen as children grow. They can also happen from physical activity. Your child may need to have more surgery to tighten or replace part of the internal prosthesis.

Stiffening of a joint can occur after limb-sparing surgery because the surgery can cause muscles, tendons and ligaments around the joint to shrink or become stiff. Follow-up with physical or occupational therapy and keeping active can help to prevent this late effect.

Infection can be an ongoing or chronic concern in some cases. The bone graft or internal prosthesis can sometimes become infected after limb-sparing surgery. Immune cells called neutrophils help defend the body against bacteria, viruses and types of fungus. Children who have a low neutrophil count (called neutropenia) may be given antibiotics to lessen the chance of infection. Doctors may need to remove and replace an internal prosthesis if it becomes infected. More surgeries may also be needed to adjust a prosthesis as a child grows taller. With any surgery, there is always the risk of infection.

Find out more about bone and muscle problems.

Phantom limb pain can happen after a child has had an arm or leg amputated. Phantom limb pain is a feeling that the amputated limb is still there. It happens because nerves are cut and damaged during surgery, which may cause the body to send abnormal nerve impulses. Symptoms can include pain, burning, throbbing or itching.

Phantom limb pain usually starts 1 to 4 weeks after surgery. For many children, it gets better during the first year, but sometimes phantom limb pain becomes a long-term problem.

A pain specialist may be able to help treat problems caused by long-term phantom limb pain.

Find out more about pain.

Radiation therapy to the chest can cause heart problems.

Certain chemotherapy drugs, such as doxorubicin, may cause weakening of the heart muscles (called cardiomyopathy). Chemotherapy for childhood bone cancer can also lead to abnormal heart rhythm (called arrhythmia).

Other heart problems after treatment for childhood bone cancer include:

• inflammation or scarring of the protective covering of the heart (called pericarditis)
• hardening or narrowing of the heart arteries (called coronary artery disease)
• inability of the heart to pump blood properly (called congestive heart failure)

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

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

Find out more about heart problems.

Certain chemotherapy drugs, such as cisplatin and carboplatin, may cause hearing loss when they are given to very young children. This may lead to other concerns, such as delayed language development and impaired social development.

Hearing tests are usually done at the end of treatment and then once a year to monitor your childʼs hearing. If necessary, your child may need a hearing aid or speech therapy.

Find out more about hearing problems and speech-language problems.

Certain chemotherapy drugs 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, as well as infertility. The higher the total dose of chemotherapy, the greater the risk of damage.

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.

Kidney problems may be a concern for children who have high-dose chemotherapy or cisplatin as part of the chemotherapy regimen. Regular follow-up visits will let the doctor check how well the kidneys are working. Specific blood and urine tests are done to check if the kidneys are working properly or if your child needs further testing or treatment. Sometimes electrolyte supplements (with magnesium, calcium, potassium or phosphate) are given, at least on a temporary basis.

Find out more about kidney problems.

Childhood bone cancer usually develops during the teenage years, which can be a sensitive and challenging time. The disease and its treatment can affect how a child looks, along with how their body works, how they feel about their bodies (called body image) and how they see themselves (called self-esteem). It is common to be concerned, scared and anxious about changes in appearance and body function. Most children feel the greatest effects in the first year after diagnosis. But for some, these effects can last a long time.

Having bone cancer can affect school, work, sports or other activities. Attending school as much as possible during treatment is helpful because school provides a daily routine and keeps children connected to friends.

Talk to the healthcare team about support services available in your community. Some treatment centres may have programs to introduce children who have just been diagnosed with bone cancer to children who have completed treatment. Meeting another person who has had bone cancer can be helpful.

Childhood cancer survivors have a higher risk of developing a second cancer. Second cancer is different from recurrent cancer. In recurrent cancer, the same cancer comes back. In second cancer, a new cancer forms. This risk may be due to treatments, such as chemotherapy or radiation therapy. Nowadays, children treated for cancer have a lower risk of developing a second cancer than in the past. New chemotherapy combinations, lower doses of chemotherapy and lower doses of radiation that are more accurately targeted to the tumour have lowered the risk of a second cancer.

The risk of a second cancer is different for each child, depending on their cancer diagnosis and treatment received.

Chemotherapy with alkylating agents and etoposide can raise the risk of developing acute myelogenous leukemia (AML) or myelodysplastic syndrome (MDS).

Childhood cancer survivors have a higher risk of developing solid tumours, such as sarcomas. The risk varies depending on the treatments given. The risk of developing a solid tumour is mostly related to radiation therapy. The risk is higher if chemotherapy is given with radiation therapy.

Find out more about second cancers.

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