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Watching for late effects
Cancer treatments can damage healthy cells when they are doing their job of removing or destroying cancer cells. This damage can lead to health problems months or years after cancer treatment is finished. Health problems that develop after cancer treatment is finished are called late effects.
Children who were treated for cancer will need follow-up care by a cancer specialist for the rest of their lives. This care includes regular testing to look for any late effects. This is one of the reasons why it is important to keep a record of their treatment. The record has important information, including the risk of late effects and a plan for follow-up. Having this information will help other healthcare providers know which late effects to watch for in the future.
The Children’s Oncology Group (COG) provides detailed information for survivors of childhood, adolescent and young adult cancer. Find out more about COG’s long-term follow-up guidelines for survivors.
Types of late effects
People who are treated for cancer as children can develop both physical and emotional late effects. Cancer treatments may affect:
- organ or body function
- growth and physical development
- mood and feelings
- thinking, learning and memory
- social and emotional development
Being treated for cancer as a child also increases the risk of developing a second cancer later in life.
Risk of late effects
The risk of developing late effects and the types of problems that can develop depend on many factors, including:
- the type of cancer
- where the cancer was in the body
- the child’s age at treatment
- the type of chemotherapy and cumulative dose (how much was given in total)
- the dose of radiation
- the area of the body treated with radiation
- genetic factors or health problems the child had before cancer
Follow-up visits after treatment for childhood cancer are done to make sure that the child recovers from treatment and stays healthy. For the first few years, the doctor will watch for any signs that the cancer may be coming back (recurring), which in most cases is unlikely. After a few years, follow-up visits focus more on monitoring for late effects from treatment. Children’s growing and developing bodies are at risk of permanent effects from treatment, which may not appear until much later in life.
Doctors will also use visits to:
- monitor normal growth and progression through puberty
- check for any problems with cognitive and psychosocial skills, including success in school
- teach health promotion and disease prevention
All survivors of childhood cancer should be followed for life because of the potential for long-term problems. Also, there is a slightly higher risk for children treated for cancer to develop second cancers in adulthood compared to children who have not been treated for cancer.
Appointments are more frequent right after the end of treatment, usually every 1–3 months. As time goes on, visits become less frequent. After a few years, visits are usually every 1–2 years. The schedule will vary depending on the type of cancer, treatment given and any problems the child may be having.
What to expect at a follow-up visit
The tests that may be done and how often they may be done depend on several factors, including:
- the type of cancer
- the area of the body affected
- the type of treatment received
- the child’s age during treatment
- how long it has been since treatment finished
A child who is part of a research protocol (clinical trial) will be followed up according to the guidelines in the protocol.
If a recurrence is found during any of the follow-up procedures, the oncology team will assess the child with cancer to determine the best treatment options.
Follow-up visits usually include the following procedures.
A physical examination is a routine test done to assess the child’s general health and development. It often includes a medical history. The doctor may ask about any symptoms or health problems the child has and how they are coping. The physical examination may include:
- questions about the child’s general health
- physical examination of the body systems
- questions about nutrition
- measurement of standing and sitting height and weight – recorded on a growth chart
- puberty status – based on Tanner Stages that describe the development of secondary sex characteristics (pubic hair, breast development in girls, penis and testicle development in boys)
- measurement of head circumference – for infants and young children
Imaging tests may be done to monitor for recurrence. These may include:
- computed tomography (CT) scan
- magnetic resonance imaging (MRI)
- gallium scan or PET scan – to check for recurrence in cases of lymphoma
- MIBG scan – for children treated for neuroblastoma
- bone scan
After a few years, the focus is to monitor for late side effects rather than recurrence of cancer, so routine imaging tests like those listed above are often stopped. They are done only if the child has symptoms that are worrisome. Imaging tests to monitor for late side effects may include:
- Echocardiogram (Echo) and electrocardiogram (ECG) may be used if the child had anthracycline drugs, had radiation involving the chest (mediastinal radiation) or has chronic graft-versus-host disease after stem cell transplant.
- Glomerular filtration rate (GFR) is used to monitor for kidney damage from chemotherapy or radiation therapy.
- Bone density scan checks bone density in children at risk for osteoporosis as a late side effect from chemotherapy or radiation therapy.
- Regular mammograms may be used for girls who had radiation involving the chest or spine (either at age 25 or 8 years after their last radiation treatment, whichever is later).
Follow-up blood tests may include:
- complete blood count
- blood chemistry
- bleeding and blood clotting factors (coagulation studies such as PT, PTT, INR, fibrinogen)
- growth hormone (GH) deficiency
- antibody studies to check for antibodies to viruses such as measles, mumps, rubella, tetanus, polio, hepatitis, HIV, cytomegalovirus, herpes simplex virus, Epstein-Barr virus and varicella virus (chicken pox virus)
- thyroid-stimulating hormone (TSH) and thyroxine (T4) levels if the child received radiation to the chest, head or total body
- hormone levels if there is a problem with puberty development
Children who were treated with radiation to the head and neck, chest, abdomen or pelvis may experience problems with puberty development and will be tested for hormone levels. Often a referral is made to an endocrinologist for specialized follow-up in this area. Males are tested for follicle stimulating hormone (FSH), luteinizing hormone (LH) and testosterone. Females are tested for follicle stimulating hormone (FSH), luteinizing hormone (LH) and estrogen.
Follow-up urine tests may include:
- homovanillic acid (HVA) and vanillylmandelic acid (VMA) may be used for children treated for neuroblastoma
Other tests and consultations
Depending on the type of cancer, these tests and consultations may be part of follow-up care:
Pulmonary function test (PFT) is most often used if the child was treated with chemotherapy drugs that could affect the lungs, such as bleomycin (Blenoxane), busulfan (Busulfex), carmustine (BiCNU, BCNU) and lomustine (CeeNU, CCNU). It is also used if the child had surgery or radiation therapy to the chest. History of infection, being ventilated, chronic graft-versus-host disease (after stem cell transplant) and asthma are other reasons why a child might have PFT.
Hearing exams are used to test hearing after treatment or if any new problems develop. Children are often followed up by an audiologist if they were treated with radiation therapy to the brain or head or had chemotherapy drugs that could affect hearing, such as cisplatin or aminoglycosides.
Eye exams are usually done every year. Eye exams check for the development of cataracts and changes in vision. Children are often followed up by an eye doctor, especially if they were treated with radiation therapy to the brain or head, have graft-versus-host disease or were treated with steroids.
Orthopedics may be part of follow-up after surgery for bone cancer.
Physiotherapy may be part of follow-up for children having problems with muscle strength, physical function and mobility (due to peripheral neuropathy).
Occupational therapy may be part of follow-up for children having problems with physical and cognitive skills.
Dental exams are usually done every year. Special follow-up may be necessary for children who had radiation therapy to the head or neck area, had chemotherapy when they were 5 years or younger or have chronic graft-versus-host disease.
Psychology consults may be part of follow-up for children who have learning disabilities or trouble coping, such as anxiety, mood disturbances, low self-esteem, anger or post-traumatic stress disorder.
A procedure that uses gallium (a radioisotope) to produce images of structures and organs inside the body.
Doctors use gallium scan to look for inflammation, an abscess (collection of pus), tumours or other signs of disease. They may also use gallium scans to measure a person’s response to cancer treatment.
Gallium scan is a type of nuclear scan.
Great progress has been made
Some cancers, such as thyroid and testicular, have survival rates of over 90%. Other cancers, such as pancreatic, brain and esophageal, continue to have very low survival rates.