1. Chapter 11
Cancer in Children

2. 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

3. 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

4. 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

5. 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

6. 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

7. 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

8. 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