The investigators collected information of all the adolescents and children diagnosed cancer in Shanghai since January 2002, including their name, gender, the date of birth, the diagnosis date, disease diagnosis, residence address and the last follow-up time status (survival/death). The type of cancer included all malignant tumors such as Acute Lymphocytic Leukemia, Acute Myeloid Leukemia, Non-Hodgkin Lymphoma, Hodgkin Lymphoma, central nervous system tumors, Neuroblastoma, Wilms tumor and so on. Then the investigators would analyze the morbidity, mortality, disability and survival rate.