Risks and Causes of Pediatric Cancer

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 Pediatric 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 Pediatric 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 pediatric cancers, such as Wilms’ tumor (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 pediatric cancers such as Wilm’s tumors 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 in children of 3 or 4 years old. But if they don’t, they may begin to grow out of control and develop into a cancerous tumor.

Exposure to infections

Epstein Barr Virus (EBV) is very common infection in 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 whole 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.

Previous Cancer Treatments

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

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 pediatric cancer later on. The risk was low as compared with the 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.