All kinds of cancer progress in the same way — cells grow out of control, develop abnormal sizes and shapes, exceed their typical boundaries inside the body, and destroy neighboring cells. ln time, cancerous cells can spread (metastasize) to other organs and tissues.
As cancer cells grow, they demand more and more of the body's nutrition. Cancer takes a person's strength, destroys organs and bones, and weakens the body's defenses against other illnesses.
Cancer is uncommon in children, but can happen. The most common childhood cancers are leukemia, lymphoma, and brain cancer. As kids enter the teen years, osteosarcoma (bone cancer) is more common.
Most of the time, doctors don't know why kids get cancer. The things that cause cancer in kids are usually not the same ones that cause cancer in adults, such as smoking or exposure to environmental toxins. In children, a genetic condition, such as Down syndrome, can sometimes increase the risk of cancer. Kids who have had chemotherapy or radiation treatment for cancer are more likely to get cancer again.
In most cases, however, childhood cancers come from random mutations (changes) in the genes of growing cells. Because these changes happen randomly and unpredictably, there is no effective way to prevent them.
Sometimes, a doctor might spot early symptoms of cancer at regular checkups. However, some symptoms of cancer (such as fever, swollen glands, frequent infections, anemia, or bruises) can happen with other childhood infections or conditions that are more common than cancer. Because of this, both doctors and parents might suspect other childhood illnesses when cancer symptoms first appear.
Once cancer has been diagnosed, it's important for parents to seek help from a medical center that specializes in pediatric oncology (treatment of childhood cancer).