Childhood cancer is rare and is much less common than cancer in adults. There are many different type of cancer that can affect children and childhood cancers can cause many different symptoms. Therefore, any child should be seen by a GP or other healthcare professional if you are concerned about any unexplained symptoms.
The treatments and outcome (prognosis) for childhood cancers are improving all the time. Most children who are diagnosed with cancer will be cured.
How common are childhood cancers?
Childhood cancer is much less common than adult cancer. Cancer in children accounts for less than 1 in 100 of all new cancer cases in the UK. About 1 in 500 children in the UK will develop some form of cancer by 14 years of age.
Since the late 1970s, the number of children diagnosed with cancer has increased by more than a quarter in the UK. However, over the last 10 years, the number of children diagnosed with cancer has stayed almost the same.
Leukaemia, brain cancers and lymphomas cause more than two thirds of all cancers diagnosed in children. Leukaemia is the most commonly diagnosed cancer in children.
How does cancer affect the child and their family?
About 8 out of 10 children are now successfully treated. However childhood cancer can cause severe problems for the child and their family in addition to the physical effects of the cancer.
Treatments are usually very effective but medicines used to treat cancers (chemotherapy) may cause side effects such as tiredness, feeling sick, not wanting to eat, and hair loss. Treatments can last for months or even years, which means long stays in hospital and being away from family, friends and school.
Children of school age may fall behind with their school work. Children who have cancer may be very tired all the time because of both the cancer and the treatments. They may feel too tired to do anything. Some children diagnosed with cancer may be very withdrawn, anxious or depressed.
Any child with cancer and their family may need a lot of support. There is a great deal of help available, such as from:
- The cancer specialist.
- Doctors and nurses on the hospital ward.
- The GP.
- Cancer nurse specialists.
- Social workers.
- Play specialists.
- A psychologist or a psychotherapist.
There are also may support groups that can help (see below).
What are the causes of cancer in children?
Much less is known about the causes of cancer in children than about cancers in adults. Although some risk factors are known, most children with cancer don't have any of these risk factors. Many children who do have risk factors won't go on to develop cancer. The cause of cancer for children is probably a combination of a number of different factors. The known risk factors include:
- Inherited medical conditions.
- Problems with development in the womb.
- Exposure to infections.
- Exposure to radiation.
- Previous cancer treatments.
A number of other possible risk factors have been reported but studies have found no evidence. These possible risk factors include electromagnetic fields and vitamin K injection in newborn babies.
Certain inherited (genetic) conditions can increase a child's risk of developing some types of cancers. For example, children with Down's syndrome are up to 20 times more likely than other children to develop leukaemia. Leukaemia is still very rare, even in children with Down's syndrome.
Problems with development in the womb
Some childhood cancers such as a type of kidney cancer (Wilms' tumour) and a type of eye cancer (retinoblastoma) start before the baby is born.
Many parts of the baby's body develop very early in the pregnancy. Sometimes some of the cells remain as very immature cells instead of developing normally. Usually these immature cells eventually mature by themselves during early childhood. However, occasionally they don't mature properly and they develop into cancer cells.
Exposure to infections
Epstein Barr virus (EBV) is a common infection in young children. It usually causes no symptoms but it can cause glandular fever (infectious mononucleosis), especially in teenagers. In very rare cases, EBV can be a factor in the development of certain cancers such as certain types of lymphoma (see below).
Exposure to radiation
Children exposed to radiation after the atomic bombings in Japan had a much greater risk of developing leukaemia. Children who have radiotherapy for cancer have a slightly greater risk of developing another type of cancer later on. However, this risk is very small compared to the risk to their health if the original cancer had not been treated with radiotherapy.
Previous cancer treatments
Past treatment with chemotherapy can increase the risk of cancers (for example, acute leukaemia) many years later. This risk is also very small compared with the risk to their health if the original cancer had not been treated with chemotherapy.
Which cancers can affect children?
There are many different types of childhood cancer. The following list includes the most common types of childhood cancer:
Leukaemia is a cancer of the bone marrow and blood. It is the most common type of childhood cancer. There are two main types of childhood leukaemia - acute lymphoblastic leukaemia and acute myeloid leukaemia. Chronic myeloid leukaemia affects a small number of children.
Leukaemias can cause various symptoms - these include:
- Bone and joint pain.
- Tiredness (fatigue).
- Pale skin (anaemia).
- Abnormal bleeding or bruising.
- High temperature (fever).
- Weight loss.
Brain cancer and spinal tumours
Brain cancers and spinal cancers are the second most common cancers in children. They cause about 1 in 4 of childhood cancers. There are many types of brain tumours. The treatment and outlook (prognosis) for each is different.
Brain cancers in children may cause various symptoms - these include:
- A feeling of sickness (nausea).
- Being sick (vomiting).
- Blurred or double vision.
- Fits (seizures)
- Difficulty with walking or with handling objects.
Spinal cord tumours are much less common than brain tumours, both in children and in adults.
Lymphomas most often start in glands (lymph nodes) and other lymph tissues, such as the tonsils. Lymphomas can also affect the bone marrow and other organs. Lymphomas cause about 1 in 10 childhood cancers.
Symptoms depend on which part of the body is affected by the lymphoma. Symptoms may include:
- Weight loss.
- High temperature.
- Lumps under the skin in the neck, armpit or groin (these lumps are due to swollen lymph glands).
- Hodgkin's lymphoma is much more more common in adults than in children. Hodgkin's lymphoma is very rare in children younger than 5 years of age.
- Non-Hodgkin's lymphoma is more common in children than Hodgkin's lymphoma. It is more likely than Hodgkin's lymphoma to occur in younger children but it is still very rare in children younger than 3 years of age.
Soft tissue sarcomas
Soft tissue sarcomas account for about 7 in 100 of childhood cancers. Rhabdomyosarcoma is the name of the most common type of soft tissue sarcoma in children, causing just over half of all soft tissue sarcomas in children.
Soft tissue sarcomas can start in nearly any place in the body, including:
- The head and neck.
- The groin.
- The tummy (abdomen).
- The pelvis.
- An arm or leg.
Soft tissue sarcomas may cause pain, a lump (swelling) or both
Neuroblastoma is a cancer of specialised nerve cells, called neural crest cells. It causes about 6 in 100 of all childhood cancers.
This type of cancer usually develops in infants and young children. It is rarely found in children older than 10 years.
The tumour can start anywhere but most often starts in the tummy (abdomen), where it is noticed as a swelling. It can also cause bone pain and a high temperature.
About 9 in 10 kidney cancers in children are called Wilms' tumour (also known as nephroblastoma). Wilms' tumours account for about 5 in 100 of childhood cancers.
Wilms' tumours usually start in one kidney but rarely in both kidneys. Wilms' tumours are most often found in children aged about 3-4 years old. They are uncommon in children older than the age of 6 years.
Wilms' tumours can initially cause a swelling or lump in the tummy. Sometimes there may be other symptoms, such as high temperature, feeling sick or a poor appetite.
Cancers that start in the bones (primary bone cancers) occur most often in older children and teenagers. However, they can develop at any age. They account for about 3 in 100 of childhood cancers. The outcome (prognosis) for bone tumours is often not as good as for other childhood cancers. There are two main types of primary bone cancers that occur in children:
- Osteosarcoma is most common in teens, and usually develops in areas where the bone is growing quickly, such as the legs or arms. It often causes bone pain that becomes worse at night or with activity. It can also cause swelling in the area around the bone.
- Ewing's sarcoma is a less common type of bone cancer. It can also cause bone pain and swelling. It is most often found in young teenagers. The most common places for it to start are the hip (pelvic) bones, the chest wall (for example, the ribs or shoulder blades), or in the legs.
Germ cell tumours
Germ cells are the cells in the body that develop into sperm and eggs. They are mainly found in the ovary or testicle. They can also very rarely occur in other parts of the body. See also the separate leaflets called Testicular Cancer and Ovarian Cancer.
Liver cancers are rare in childhood. Most (about 4 in 5) childhood liver tumours are called hepatoblastomas and the rest are called hepatic carcinomas. The may present with swelling or pain in the tummy (abdomen) or other symptoms such as high temperature, feeling sick or a loss of appetite.
Retinoblastoma is a type of cancer that affects the lining of the eye (retina). It is very rare and causes about 2 in 100 of all childhood cancers. Retinoblastoma usually occurs in children around the age of 2 years. It is very rare in children older than 6 years of age.
Retinoblastomas are usually found because the child's eye looks unusual. Normally when you shine a light in a child's eye, the dark spot in the centre of the eye (pupil) looks red because of the blood vessels at the back of the eye. In an eye with retinoblastoma, the pupil often looks white or pink. This white glare of the eye may be first noticed after a flash photograph is taken.
What symptoms can be caused by cancer in children?
There are many different types of cancer. The symptoms will depend on the type of cancer, which part of the body is affected and whether the cancer has spread to other parts of the body.
The symptoms listed below are much more often caused by conditions other than cancer. However these symptoms occasionally indicate that a child may have cancer. If you have any concerns then you should take your child to see a GP or other healthcare professional.
- Feeling tired all the time.
- Frequent infections or flu-like symptoms.
- Unexplained sickness (vomiting).
- Unexplained sweating or high temperature (fever).
- Unexplained weight loss or poor appetite.
- An unexplained lump or firmness anywhere in the body.
- Unexplained swollen glands (see the separate leaflet called Swollen Lymph Glands).
- Back pain that doesn't go away and occurs at rest.
- Persistent headaches.
- Frequent bruising.
- Unexplained fits (seizures) or changes in vision or behaviour.
- Tummy (abdominal) pain or swelling.
- Blood in the wee (urine) - may indicate kidney or bladder cancer.
- Changes in appearance of the eye or unusual eye reflections in photos (retinoblastoma).
What are the treatments for children's cancers?
The aim of treatment for most children with cancer is to cure the cancer. The treatment will depend on the type of cancer but may involve surgery, radiotherapy and medicines to treat the cancer (chemotherapy). Children often develop different types of cancers to adults but they often have the same types of treatments.
Other treatments may also be needed for the symptoms caused by the cancer. These include medicines for pain relief and medicines to reduce other symptoms such as a feeling of sickness (nausea) and being sick (vomiting).
For some children the cancer cannot be cured and so the treatment is used to control the cancer by limiting the growth and spread of the cancer and to reduce symptoms.
Palliative care means caring for a child with advanced cancer that cannot be cured with treatment. Palliative care includes providing nutritional supplements to provide extra energy and vitamins if needed, as well as the treatment of pain and other symptoms.
Palliative care also includes providing psychological, social and spiritual support for the child and their family. The goal of palliative care is to achieve the best quality of life for the child and their family.
Even if a cure is not possible, a course of radiotherapy, an operation, or other techniques may be used to reduce the size of a cancer, which may reduce symptoms such as pain.
What is the outcome (prognosis)?
Even though cancer is very uncommon in children, it is the most common cause of death from illness in children between the ages of 1 and 15 years. However, the treatments and outcome for children with cancer are improving all the time.
In the 1960s only about 3 out of every 10 children with cancer were successfully treated. However, treatment for children with cancer has improved greatly. Now more than 8 out of every 10 children diagnosed with cancer will live for at least five years. Most of these children will be cured.
For some types of childhood cancer, such as acute lymphoblastic leukaemia and Wilms' tumours, this cure rate is even higher. Hodgkin's lymphoma and retinoblastoma are curable in more than 9 out of 10 children.
Further reading and references
Childhood Cancers: Treatment; National Cancer Institute
Improving outcomes with children and young people with cancer; NICE Cancer Service Guidance (2005)
Childhood cancers - recognition and referral; NICE CKS, November 2015 (UK access only)