3.3 - Cancer in Children and Adolescents

Question 1

Childhood cancer

Answer 1

• the leading cause of disease related death
• most common cases: leukemia, brain and CNS, lymphoma
• most prevalent is pediatric blood cancers (leukemia)

Question 2

Difference bw Childhood and Adult Cancer

Answer 2

Childhood
- rare
- aggressive
- RAPID growing
- common types: leukemia, lymphoma, brain tumours, bone cancer
- causes: deletion/overexpression of genes
- long-term side effects

Adult
- incidence increases w age
- common types: lung, breast, colon, prostate, pancreas
- causes: DNA alterations and lifestyle factors
- side effects are more manageable

Question 3

How Childhood Cancers Originate

Answer 3

• originate in MESODERMAL germ layer
• this layers gives rise to connective tissue, bone, cartilage, muscle, blood vessels, gonads, kidneys, lymphatic system

Common childhood cancers:
Leukemias - originate in bone marrow
Sarcomas - orginate in bone
Embryonic Tumours - originate in nerve cells

• these cancers are more noticeable/diagnosed at peak periods of growth
• fast growing
• lacks early symptoms

Question 4

What are embryonic tumours?

Answer 4

• originates from immature embryonic tissue that does not fully develop; tumours are frozen in an early stage of development (thus detected early)
• “Blast” - indicates origin is from embryonic tissue (ex. neuroblastoma, retinoblastoma)

Question 5

Cause of Childhood Cancers

Answer 5

• most are linked to genetic abnormalities
• most are not associated with environmental risk factors

2 Types of Genetic Factors

1) Chromosome Abnormalities
- aneuploidy (abnormal #)
- deletion, translocation
- congenital syndromes
1) Wilms Tumour
2) Down Syndrome

2) Oncogenes and Tumour Suppressor Genes
- mutations in these genes lead to uncontrolled proliferation - cancer

Question 6

Environmental Association with Childhood Cancers

Answer 6

1) Prenatal Exposure
- medications, chemotherapy agents
- procedures (exposure to X-rays)

2) Childhood Exposure
- medications
- viruses (ie. Epstein-Barr)
- electromagnetic fields

Question 7

Prognosis of Childhood Cancers

Answer 7

• childhood cancer is now being managed as a chronic disease rather than a fatal illness
• large majority of children (>70%) will be cured and survive
• cancer survivors face increased risk of developing secondary cancers and side effects later in life
• even after cured, children may experience effects later:
  - issues w/ growth & development
  - affected fertility
  • impacted cognitive function
  • increased risk of anxiety, depression, and post-traumatic stress