Key Facts
Children's cancers are rare and are quite different from the cancers that affect adults.
Leukaemia and brain tumours are the most common childhood cancers, making up 75% of the total.
Cure rates for childhood cancers are much higher than for most adult cancers with over 70% of all children being completely cured.
Quoted incidences are given in number of children per million per year:
| Leukaemia |
37 |
| Lymphoma |
24 |
| Brain/CNS |
25 |
| Neuroblastomas |
7 |
| Retinoblastomas |
3 |
| Wilms' tumour |
6 |
| Hepatic (liver) cancers |
2 |
| Rhabdomyosarcoma and other soft tissue tumours |
11 |
| Germ cell tumours |
14 |
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Key Figures
There is no European cancer registry data on childhood cancers.
In the USA, the Surveillance, Epidemiology and End Results (SEER) Program of the National Cancer Institute (NCI) provides age adjusted incidence rates for childhood cancers for the years 1975 – 1995.
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Cancer Types
Childhood Leukaemia
A form of cancer that affects the white blood cells. This leukaemia is usually Acute Lymphoblastic Leukaemia (ALL) and it can affect all children.
A reduced production of normal cells in the bone marrow results in a range of non-specific symptoms including:
- generalised weakness and fatigue
- infections
- bruising and bleeding
- bone and joint pain
- an enlarged spleen
- lymph nodes
The onset of these symptoms is rapid.
Medulloblastoma
The most common form of brain tumour in children. It causes headache, nausea and vomiting due to raised intracranial pressure. Medulloblastomas grow locally and tend to spread within the central nervous system. The majority of children with medulloblastoma are cured, with long term survival rates of 70-80%.
Neuroblastoma
Usually affects children under five years old. It starts most often in the nerve tissue of the adrenal glands but it can also develop from nerve tissue near the spine, in the abdomen, chest, neck, or in the spinal cord.
Neuroblastomas grow and spread quickly - affecting nearby lymph nodes, bones, bone marrow, liver and skin.
Lymphomas
Cancers that develop from cells of the lymphatic system. There are two main groups of lymphomas - Hodgkin's and Non-Hodgkin's lymphomas. Up to three children per 100,000 will develop lymphoma in childhood, making up about 10% of childhood cancers.
Wilms' tumour
A rare childhood form of kidney (renal) cancer. It affects approximately 10 children and adolescents under the age of 15 per one million of the population (about 6 % of all childhood cancers). The average age at diagnosis is three and a half. Treatment with surgery and chemotherapy, and sometimes radiotherapy, is very successful in 80-90% of children.
Rhabdomyosarcomas
Tumours arising from primitive muscle cells, that would normally develop into striated muscle cells. They account for 5-8% of childhood cancers, usually affecting children aged two to six, and teenagers aged 15 to 19 years old. The most common sites for rhabdomyosarcomas are the head and neck and around the eyes; the arms and legs, the chest and the genito-urinary tract.
Retinoblastomas
Develop from cells in the retina in the eye and contain very primitive cells. These tumours usually affect children under five and can affect one or both eyes. 40% of retinoblastomas are hereditary.
The treatment for retinoblastoma depends on how early the diagnosis is made - wherever possible the eye is not removed.
Germ cell tumours
Rare tumours developing in the foetus from cells that should become the ovaries or testes. Most of these tumours are benign and are very rare in children younger than 15 years. In most germ cell tumours there is no obvious cause but there is a higher risk of testicular germ cell tumours in males with undescended testes.
Osteosarcomas
Osteosarcomas are malignant tumours arising in the bones. Usually they develop at the growing point (metaphysis) of the long bones in the arms, legs and, most commonly, in the knee. They can also occur in the shoulder, pelvis, and skull. They typically affect teenagers and are twice as common in males.
Ewing's sarcoma
Ewing's sarcoma accounts for 10-15% of childhood bone cancers and 1% of all childhood cancers. They are most common in 10 to 20-year-olds. The tumour is made up of small round blue cells and usually occurs in the pelvis, thigh, lower leg, upper arm or ribs. The first symptom is usually a lump where the tumour is growing which may be noticed for the first time after a fall or some other injury. Often it is assumed that the tumour is a result of the injury but in fact it has only drawn attention to a lump that is already there.
Childhood liver tumours
They are very rare but are more common in boys than girls. There are two main types of cancer developing from liver cells: hepatoblastoma which usually occurs in children under five years of age and HepatoCellular Carcinoma (HCC) which is exceptionally rare and usually occurs in older children.
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Causes of Childhood Cancers
For the majority of childhood cancers there is no known cause but those with clear risk factors are listed below:
Acute Lymphoblastic Leukaemia – Down’s syndrome and Fanconi’s syndrome are known to be associated with a higher risk of developing leukaemia.
40% of retinoblastomas are hereditary.
There is a higher risk of testicular germ cell tumours in males with undescended testes.
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Prevention of Childhood Cancers
Even for those childhood cancers which have clear risk factors there are no practical measures that can be taken to prevent cancer developing.
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Common Symptoms
Childhood cancers include a diverse range of conditions. The presenting symptoms are equally varied and depend on the site of the original tumour and the effects on nearby structures.
Leukaemias cause a range of non-specific symptoms including:
- generalised weakness and fatigue
- infections
- bruising and bleeding
- bone and joint pain
- an enlarged spleen and lymph nodes.
The onset of these symptoms is rapid.
Brain tumours do not cause the same symptoms in every child however, common symptoms include:
- headaches which are worse in the morning
- nausea and vomiting
- problems with vision, hearing and speech
- loss of balance - being clumsy and unsteady
- sleepiness
- personality or behavioural change
- seizures (convulsions), movement or sensation changes
- in infants - an increase in head size.
The symptoms of spinal cord tumour are:
- pain in the back
- incontinence or difficulty in going to the toilet
- weakness in the legs - stumbling and falling over and difficulty in walking.
Common symptoms of lymphomas include:
- painless swellings in the neck, chest, underarm or groin (due to enlargement of the lymph nodes)
- fever
- night sweats
- unexplained weight loss
- itchy skin
Other tumours are first diagnosed after a lump is found.
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Diagnostic Tests
The combination of symptoms and clinical findings on examination will often be indicative of a particular form of tumour, however, as with all cancers a definitive diagnosis requires a biopsy.
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Treatment
Available treatments for childhood cancers include:
- surgery
- radiotherapy
- chemotherapy
- chemoradiation – combined radiotherapy and chemotherapy.
Patients may receive some or all of these treatments.
Leukaemia - Chemotherapy (drugs used to destroy abnormal cells) is the main treatment for acute lymphoblastic leukaemia. It involves the patient being given a combination of drugs in a series of treatment blocks.
In addition, radiotherapy is sometimes given to the brain if leukaemia cells are found in the fluid around the spine (or to prevent recurrence of the disease in the meninges in high risk patients). In very particular cases, radiotherapy is given to boys’ testicles as leukaemia cells can survive there even after chemotherapy.
Stem cell (bone marrow) transplants may be used in a small number of cases where it proves impossible to eradicate the disease using drug treatment alone. Before a transplant can take place, a session of high-dose chemotherapy and/or radiotherapy is given to destroy the patient’s existing bone marrow. Transplants work best early in the course of the disease.
The treatment for tumours of the brain and spinal cord is surgical removal of the tumour (as far as is reasonably possible) followed by radiotherapy and/or chemotherapy to destroy any cells that have not been removed during surgery (adjuvant therapy).
Neuroblastomas are treated with surgery to remove the tumour. This is followed by chemotherapy and then very careful monitoring once the treatment has finished. Radiotherapy is used very rarely after surgery to kill any cancer cells that have not been removed during surgery.
Lymphomas are generally treated with radiotherapy, chemotherapy and, in some cases, a bone marrow transplant. Radiotherapy can be combined with chemotherapy in the treatment of a lymphoma.
Wilms' tumour is treated with surgery and chemotherapy (and sometimes radiotherapy). Treatment is very successful in 80-90% of children.
Rhabdomyosarcomas are treated with a combination of surgery to remove the tumour and chemotherapy and/or radiotherapy to shrink the tumour before surgery or to reduce the risk of the cancer returning after surgery.
Retinoblastomas are treated with surgery, chemotherapy, cryotherapy (a way of destroying cancer cells by freezing them), light coagulation and radiotherapy. Whenever possible the eye is not removed.
Germ cell treatment may include:
- surgery to remove the tumour
- chemotherapy
- radiotherapy
- less commonly, bone marrow transplantation.
In the long term, hormone replacement may also be necessary. Some specific issues related to the conservation of fertility may be very different according to the disease presentation.
Osteosarcoma treatment depends on the exact type of osteosarcoma. Therapy is usually a combination of surgery (removing the tumour and replacing the bone with a bone graft or metal rod) and chemotherapy (usually ifosfamide, cisplatin, methotrexate, and doxorubicin). Radiotherapy is rarely used in treating osteosarcomas.
Ewing’s sarcomas are highly responsive to radiotherapy (unlike osteosarcomas) and so are treated with radiotherapy, as well as surgery and chemotherapy.
Childhood liver tumours are usually treated with chemotherapy followed by surgery. In very select cases a specialised form of radiotherapy (stereotactic radiotherapy) can be used as an alternative to surgery. In some cases a liver transplant will be necessary.
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Key Trends
Genomic testing to assess susceptibility of children to childhood cancers and potential response to treatment.
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Current Developments
Genomic testing to assess susceptibility of children to childhood cancers and their potential response to treatment should in the future lead to earlier diagnosis and more refined forms of treatment.
The use of targeted therapies and monoclonal antibodies in the treatment of childhood cancers is an important area of current research.
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