Cells are the building blocks of our body. Cancer begins in the cells. Accoding to need new cells form by replacing old cells that die. Sometimes, this process goes wrong. New cells form when you don't need them, and old cells don't die when they should. The extra cells can form a tumor. When the tumors become malignant stage then it is called cancer. Malignant tumor cells can invade nearby tissues or break away and spread to other parts of the body.
Childhood cancers can occur suddenly, without early symptoms and have a high rate of cure. The most common children's cancer is leukemia, brain tumors, lymphoma and soft tissue sarcoma. Symptoms and treatment depend on the cancer type and how advanced it is. Treatment methods include surgery, radiation and chemotherapy.