Late effects of treatments for childhood bone cancer

The cancer treatment that saves children's lives may cause side effects in the years after the treatment has ended. These side effects of treatment are called late effects.

The risk of late effects depends on many things, including the type and amount of treatment and the child's age at the time of treatment. Having long-term follow-up care after treatment means the healthcare team can catch late effects early and start taking care of them right away. Talk to the healthcare team about 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 to remove the tumour. 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. More surgeries and other procedures may be needed to help the treated bone grow or to make the limbs the same length.

Problems with an internal prosthesis, such as it breaking or becoming loose, can happen as children grow or from physical activity. The 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. Children who have a low neutrophil count (called neutropenia) may be given antibiotics to lessen the chance of infection. Neutrophils help defend the body against bacteria, viruses and types of fungus. 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.

Sometimes children who have an arm or leg amputated feel pain or changes in sensation in the area of the missing limb. This is called phantom pain. Symptoms can include pain, burning, throbbing or itching.

Phantom pain can start 1 to 4 weeks after surgery. For many children, it gets better during the first year as they get used to wearing their prosthesis. For some children, phantom pain can become a long-term problem.

Medicine can often help phantom pain.

Find out more about pain.

Radiation therapy to the chest can have late effects on the heart, including scarring of the heart muscle. Certain chemotherapy drugs, such as doxorubicin, can also affect the heart. 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 (coronary artery disease)
• scarring or weakening of the heart muscle (cardiomyopathy)
• abnormal heartbeat (arrhythmia)
• inability of the heart to pump blood properly (congestive heart failure)

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

Find out more about heart problems.

Certain chemotherapy drugs, such as cisplatin and carboplatin, can damage the inner ear. This damage can lead to permanent hearing loss (usually high frequency sounds) or changes in balance. Hearing damage can also affect a child's social, emotional and intellectual development. Hearing tests are usually done at the end of treatment and then may be done after treatment to monitor the child's hearing. Using hearing aids or having speech therapy can help children with this late effect.

Find out more about hearing problems.

Radiation therapy and some chemotherapy drugs used to treat childhood cancer, such as cyclophosphamide and ifosfamide (Ifex), can damage the reproductive system and how it works. The higher the total dose of chemotherapy, the greater the risk of damage. Reproductive system problems could mean early or delayed puberty or fertility problems.

The doctor will monitor the child's sexual development at each follow-up visit. If it appears that puberty is delayed, hormone replacement therapy may be needed so that sexual development can occur.

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 their chemotherapy plan. Regular follow-up visits will let the doctor check kidney function. Specific blood and urine tests are done to check if the kidneys are working properly or if the 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 it keeps children connected to friends. But when recovering from treatment and adjusting to life after treatment, it's important to remember that all children will do this at their own pace.

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. Seeing another person who has had bone cancer can be helpful.

Childhood cancer survivors have a higher risk of developing a second cancer. This risk may be due to treatments, such as chemotherapy or radiation therapy. Children treated for cancer today have a lower risk of developing a second cancer than they did 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 and the Children's Oncology Group (COG) long-term follow-up guidelines.

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.