Typically, the factors that trigger cancer in children are usually not the same factors that may cause cancer in adults, such as smoking or exposure to environmental toxins.

Rarely, there may be an increased risk of childhood cancer in kids who have a genetic condition, such as Downs syndrome. Those who have had chemotherapy or radiation treatment for a prior cancer episode may also have an increased risk of cancer. In almost all cases, however, childhood cancers arise from non-inherited mutations (or changes) in the genes of growing cells. Because these errors occur randomly and unpredictably, currently there is no effective way to prevent them.

Sometimes, a doctor may be able to spot early symptoms of cancer at regular checkups. However, some of these symptoms (such as fever, swollen glands, frequent infections, anemia, or bruises) are also associated with other infections or conditions that are not cancer. Because of this, it is not uncommon for both doctors and parents to suspect other childhood illnesses when cancer symptoms first appear.

Once cancer has been diagnosed, it is important for parents to seek help for their child at a medical center that specializes in pediatric oncology (treatment for childhood cancer).