- Leukemia: The most common type of pediatric cancer, affecting the blood and bone marrow. - Brain Tumors: These include medulloblastomas and gliomas. - Lymphomas: Affect the lymphatic system, including Hodgkin's and non-Hodgkin's lymphoma. - Neuroblastoma: A cancer that arises from immature nerve cells and affects mostly infants and young children. - Wilms Tumor: A kidney cancer that primarily affects children.