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Cancer in ChildrenChapter 13

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Childhood Cancers Most originate from the mesodermal germ

layer The mesodermal layer gives rise to connective

tissue, bone, cartilage, muscle, blood, blood vessels, gonads, kidneys, and the lymphatic system

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Childhood Cancers Most common childhood cancers are

leukemias, sarcomas, and embryonic tumors Embryonic tumors

Originate during uterine life Immature embryonic tissue unable to mature or

differentiate into fully developed cells Commonly named with the term “blast”

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Childhood vs. Adult Cancers <1% of cancers Involves tissue Nonepithelial and

mesenchymal Short latency Ecogenetic

involvement Few prevention

strategies

>99% of cancers Involves organs Carcinomas Long latency period Strong environmental

and lifestyle influence 80% preventable

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Childhood vs. Adult Cancers Detection commonly

accidental 80% have metastasized

at time of diagnosis Responsive to

treatment Long-term

consequences with treatment

>70% cure

Screening linked to possible early detection

Cancers are local or regional at time of diagnosis

Less responsive to treatment

Fewer long-term consequences

<60% cure

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Etiology Genetic factors

Oncogenes and tumor-suppressor genes Chromosome abnormalities

Aneuploidy, amplifications, deletions, translocations, and fragility

High recurrence risk

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Etiology Environmental factors

Prenatal exposure Drugs and ionizing radiation

Increased parental age Childhood exposure

Drugs, ionizing radiation, or viruses Anabolic androgenic steroids, cytotoxic agents,

immunosuppressive agents, Epstein-Barr virus, and HIV

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Prognosis 78% of children with cancer are now cured Children are more responsive and are better

able to tolerate treatments More likely to be enrolled in clinical trials Long-term effects of treatment Psychological ramifications