WHAT IS CHILDREN’S CANCER?

Children’s cancer is much less common than adult cancer. 

In the UK around 1,900 children (aged 0 – 14 years) get diagnosed with cancer each year. This number includes non cancerous (benign) brain tumours. Children develop different types of cancers than adults but they often have the same types of treatments.

What are the most common types of childhood cancer?

It’s important to remember that cancer in children is rare. Out of the different types of cancer the most common type in childhood are:

• acute leukaemias
• cancers of the brain and spinal cord

Other types of children’s cancers include:

• lymphoma (cancer that starts in the lymphatic system)
• muscle or bone cancers, such as rhabdomyosarcoma, osteosarcoma, and Ewing’s sarcoma. Rhabdomyosarcoma is most common type diagnosed in children.
• neuroblastoma (a cancer of nerve cells)
• Wilms’ tumours (a type of kidney cancer)
• retinoblastoma (a type of eye cancer)

How often is childhood cancer cured?

In the 1960s about 20 to 30 out of every 100 children (20 to 30%) with cancer were successfully treated. But since then treatment for children with cancer has improved greatly.

Now more than 80 out of every 100 children (80%) diagnosed with cancer will live for at least 5 years or more. Most of these children will be cured. Hodgkin lymphoma and an eye cancer called retinoblastoma are curable in more than 95 out of 100 children (95%).

Even though cancer is not common in children, it is the leading cause of death from illness in children between the ages of 1 and 15. The second most common cause of death in children is accidents. 

The number of children dying from different types of cancers have gone down, but the amount of childhood deaths from cancer overall has gone up.

SIGNS AND SYMPTOMS OF CANCER IN CHILDREN

Cancer symptoms can be very similar to those of other childhood illnesses. Remember the symptoms we list here are not usually cancer. See your child’s doctor if they have any of the following symptoms:

• they’re unable to wee or have blood in their wee
• an unexplained lump, firmness or swelling anywhere in the body
• tummy (abdominal) pain or swelling that doesn’t go away
• back or bony pain that doesn’t go away, or pain that wakes your child up in the night
• unexplained seizures (fits) or changes in their behaviour and mood
• headaches that don’t go away
• frequent or unexplained bruising or a rash of small red or purple spots that can’t be explained
• unusual paleness
• feeling tired all the time
• frequent infections or flu-like symptoms
• unexplained vomiting (being sick)
• unexplained high temperature (fever) or sweating
• feeling short of breath
• changes in the appearance of the eye or unusual eye reflections in photos

Risks and causes of cancer in children

Parents of children with cancer can sometimes feel like something they did, or didn’t do, caused their child’s cancer. We don’t know what causes, or how to prevent most childhood cancers and no one should feel blamed.

Although we have identified a number of lifestyle changes that can help to reduce the risk of adults developing cancer. It doesn’t look like there is anything we can do to prevent most childhood cancers.

Cancer is not infectious. You can’t catch it from another person and your child can’t pass it on to their siblings or other children in their school. It is unlikely for 2 children in one family to get diagnosed with childhood cancer.

Risk factors for children’s cancers are not well understood. This is because this group of cancers are rare and there are lots of different types. This makes them difficult for researchers to study.

There are some known risk factors that can increase the risk of a child developing cancer. The list below gives some examples.

It is important to note that most children with cancer aren’t affected by any of them. And many children who are affected by these risk factors won’t go on to develop cancer.

Known risk factors

These include:

• medical conditions
• problems with development in the womb
• exposure to infections
• exposure to radiation
• previous cancer treatments

Medical conditions

Certain conditions can increase a child’s risk of developing some types of cancers.

For example, children with Down’s syndrome are 10 to 20 times more likely to get leukaemia  than other children. Leukaemia is still very rare, even in children with Down’s syndrome.

Genetics

Retinoblastoma is a rare type of eye cancer. Some children are born with a change (mutation) in the retinoblastoma gene, also known as the RB1 gene. This may be because they inherited the gene from one of their parents. Or because a change happened to this gene during the very early stages of its development in the womb. Most children who have a change to the RB1 gene develop retinoblastoma. About 40 out of 100 children diagnosed (40%) have the inheritable type of retinoblastoma. This often affects both eyes (bilateral).

Some other childhood cancers, such as Wilms’ tumour (kidney cancer in children), may have a genetic link. But the link isn’t as clear as with retinoblastoma.

Problems with development in the womb

Some childhood cancers such as Wilm’s tumours and retinoblastomas begin when the baby is still inside their mother.

When a baby is growing in the womb, many parts of the body, such as the kidneys and eyes, develop very early on. Sometimes something goes wrong and some of the cells that should have turned into developed (mature) cells to form a part of the body don’t. Instead they remain as very early (immature) cells.

Usually, these immature cells don’t cause any problems and mature by themselves by the time the child is 3 or 4 years old. But if they don’t, they may begin to grow out of control and develop into a cancerous tumour.

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) in teenagers and young adults. While glandular fever can be very unpleasant, it usually passes within a few weeks and it doesn’t mean that you go on to develop cancer. Once infected, a person remains a carrier of EBV for life, but the virus normally doesn’t cause any symptoms at all.

In rare cases, infection with EBV can contribute to the development of cancers such as Hodgkin lymphoma and Burkitt’s lymphoma.

Most people get infected with EBV as a child and stay infected for life without ever experiencing any symptoms. Because of how common it is, there is nothing you can do to prevent you, or your child, coming into contact with EBV at the moment.

Exposure to radiation

Cancer treatment can also include radiotherapy. It uses a type of radiation called ionising radiation. Children who have radiotherapy for cancer have a slightly greater risk of developing another type of cancer later on. But the risk is small compared to the risk to their health if the original cancer was not treated with radiotherapy.

Radon gas is a natural radioactive gas and it is a type of ionising radiation. It is found in the air at a low level outdoors, but it can sometimes build up to high concentrations indoors. Because it is a natural gas, it is difficult for us to control our exposure to it. Overall, studies so far have only suggested that there might be a weak link between indoor levels of radon gas and risk of childhood leukaemia.

Previous cancer treatments

Past treatment with chemotherapy can increase the risk of cancers such as acute leukaemia. But this is often many years later in children and adults.

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