A group of children with cancer that has been formed based on certain characteristics of the children and their disease. These may include age at diagnosis, stage of cancer, and cancer biology. Risk groups may also be based on the chance of being cured or the chance that the cancer will come back. Childhood cancer risk groups are used to plan treatment and follow-up care for certain types of cancer, such as neuroblastoma and rhabdomyosarcoma. Risk groups may be described as low risk, intermediate risk, or high risk.