Chapter 11 Cancer in Children

Childhood Cancer Incidence Rare but is leading cause of death from disease in children In 2004, mortality rate was 2.4 per 100,000 cases Survival rates have dramatically improved over past 30 years

Childhood Cancer (cont’d) Most originate from the mesodermal germ layer Layer gives rise to connective tissue, bone, cartilage, muscle, blood, blood vessels, gonads, kidneys, and the lymphatic system Most sarcomas vs. carcinomas in adults Diagnosed during vs. peak growth periods Fast growing and without early signs

Childhood Cancer (cont’d) Most common childhood cancers are leukemias, sarcomas, and embryonic tumors Embryonic tumors Originate during intrauterine life Immature embryonic tissue unable to mature or differentiate into fully developed cells Diagnosed early in life

Childhood Cancer (cont’d) Leukemia Most common malignancy in children Children with Down syndrome have a 10 to 20 times greater risk for developing Sarcoma Bone tumors Osteosarcoma and Ewing sarcoma Other common cancers Neuroblastoma, Wilms tumor, rhabdomyosarcoma, retinoblastoma

Etiology Most do not demonstrate predisposing environmental factors Genetic factors: Chromosome abnormalities Aneuploidy, amplifications, deletions, translocations, and fragility Certain congenital syndromes and cancers occur together Wilms tumor and urogenital abnormalities Down syndrome and leukemia Oncogenes and tumor-suppressor genes Fanconi anemia, Bloom syndrome

Etiology (cont’d) Environmental factors: Prenatal exposure Drugs and ionizing radiation Childhood exposure Drugs, secondhand smoke, ionizing radiation, viruses Anabolic androgenic steroids, cytotoxic agents, immunosuppressive agents, Epstein-Barr virus, and AIDS

Prognosis More than 70% of children cured Survival rates higher in children under 15 years Younger are more likely to be enrolled in clinical trials Survivors have increased risk of cancer later in life Residual and long-term effects of treatment Psychologic sequelae