Chapter 13
Cancer in Children
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Childhood Cancers
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Most common childhood cancers are
leukemias, sarcomas, and embryonic tumors
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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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Cancer in Adolescents and
Young Adults
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2% of all invasive cancers
Malignancy rate in 15- to 29-year-olds is three
times higher than that in children younger than
15 years
Most common cancers among 15- to 19-year-old
population in the United States


Hodgkin lymphoma, germ cell tumors, central nervous
system (CNS) tumors, non-Hodgkin lymphoma,
thyroid cancer, malignant melanoma, and acute
lymphocytic leukemia (ALL)
Many of the common malignancies in children
younger than 5 years of age are virtually absent
in 15- to 19-year-olds
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Childhood Cancers

Most originate from the mesodermal germ
layer
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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 vs. Adult Cancers
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<1% of cancers
Involves tissue
Nonepithelial and
mesenchymal
Short latency
Ecogenetic
involvement
Few prevention
strategies

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>99% of cancers
Involves organs
Carcinomas
Long latency period
Strong
environmental and
lifestyle influence
80% preventable
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Childhood vs. Adult Cancers
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Detection commonly
accidental
80% have
metastasized at time
of diagnosis
Responsive to
treatment
Long-term
consequences with
treatment
>70% cure
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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

Multifactorial
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Genetic
Environmental
Prenatal exposure
Childhood exposure
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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
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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
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78% of children with cancer are now cured
Children more responsive and better able to
tolerate treatments
More likely to be enrolled in clinical trials
Long-term effects of treatment
Psychologic ramifications
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