Principles Of Mx In Pediatric

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Principles Of Mx In Pediatric Oncology
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Principles of Mx in Pediatric Oncology

• Key points
• Pediatric cancer is a treatable disease but
  the
• management is complicated, prolonged and
  costly.
• Cancer in children differs from cancer in
  adults.
• Treatment requires a team of specialised
  health
• experts.
• All three modalities of treatment viz.
  chemotherapy,
• radiotherapy and surgery are required, with
  good
• supportive care.

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Principles of Mx in Pediatric Oncology

• Key points
• Chemotherapy
• 1. Chemotherapy administered in combination
• regimens
• 2. Standardised protocols should be utilised to
• treat patients.
• 3. Adherence to protocols without omission or
• reduction of drug doses is important
• 4. Risk adapted therapy based on prognostic
• factors .

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Progress In Cancer Therapy
Five - year Survival Rates for Childhood Cancer
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Progress in cancer therapy
92
78
70
69
52
28
28
18
4
3
All sites ALL AML
NHL Hodgkins


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Progress in cancer therapy
92
64
61
60
35
33
25
20
Brain Wilms
Neuroblastoma Bone
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Differences In Cancer Characteristics For
Childhood and Adult Cancers
Childhood Cancer Adult Cancer Incidence
patterns similar Incidence patterns vastly
between countries, different between
countries, lower proportion related
to higher proportion related to Exogenous
exposure exogenous exposure For a given
level of exogenous For a given level of
exogenous exposure (e.g. radiation) exposure
(e.g. Tobacco) less variability in incidence
more variability in incidence
rates Higher proportion related
Higher proportion related to inherited
susceptibility exogenous exposures
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Differences In Cancer Characteristics For
Childhood and Adult Cancer
Childhood Cancer Adult Cancer Primary
sites Primary sites Involves tissues
(I.e. hematopoetic, Involves organs ( e.g.
breast, lymphatic, CNS, SNS, muscle, bone)
lung, colon, prostate, uterus) Malignancies
are neuroectodermal Malignancies involve
epithelial and mesoderm derived
tumors tissues 80 are disseminated at
diagnosis Most local or regional at
diagnosis Early detection
mostly accidental Early detection improves
with during routine examination education
and screening
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Differences In Cancer Characteristics For
Childhood and Adult Cancer
Childhood Cancer Adult Cancer Less
opportunity for development More
heterogeneous, of newer clones, more long
time multiple steps in genetically
homogeneous development Greater
effectiveness of cytotoxic Less effective
cytotoxic therapies therapies Few risk
factors known and Many known risk factors
less opportunity for greater opportunity
for primary prevention primary
prevention
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Beneficial Effects of Adjuvant Chemotherapy on
Survival of Patients With Common Forms of
Pediatric Cancer
Survival () Tumor Without
adjuvant With adjuvant chemotherapy c
hemotherapy Wims tumor 40 90 Ewin
gs sarcoma 5 50 -
60 Lymphomas lt 10 50 -
60 Rhabdomyosarcoma 10 - 20 65 Osteosarc
oma 15 65 Astrocytoma 20
45
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Principles of Cancer Therapy

• Chemotherapy
• Radiotherapy
• Surgery
• BMT/ Stem Cell Transplant

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Cancer Chemotherapy Modes of Administration

• Combination chemotherapy
• Adjuvant chemotherapy
• Neo-adjuvant chemotherapy
• Dose intensity
• Mega therapy

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Combination Chemotherapy-Rationale

• To overcome natural drug resistance
• To delay development of acquired resistance
• Synergistic cytotoxic effects
• Less toxicity

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Adjuvant Chemotherapy

• In children undetectable metastic disease at
  diagnosis
• Given after local therapy surgery and/
  radiotherapy
• Aim to prevent metastic recurrence by
  eliminating micro-metastic tumor deposits

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Neoadjuvant chemotherapy

• Useful in many pediatric cancers
• Wilms tumor
• Osteogenic and Ewings Sacrcoma
• Rhabdomyosarcoma
• Retinoblastoma
• Rationale
• Reduces tumor bulk to downstage cancer
• Makes Organ saving surgery possible
• Take care of Micrometastasis
• In-vivo chemotherapy drug sensetivity testing

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Dose Intensity Chemotherapy

• Anticancer drugs - steep dose response
• curve ? small ? dose ? ?? therapeutic
• effect
• Maximum dose intensity max dose at
• shortest interval imp. in treatment
• regimens (g / wk)
• Message To cure a cancer give maximum possible
• dose as soon as possible. Arbitrary reducing in
• dose for fear of toxicity is the worst possible
  thing
• to do.

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Radiotherapy

• Teletherapy
• Linear accelerators
• Cobalt-60
• Multiplanar treatment planning
• Brachytherapy
• Placement of needles in the tumor
• Aim radiation dose to target volume
• prevent damage to adjacent normal tissues

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Cranial Irradiation
CT SCAN WITH TUMOR LATERAL PORT ANTERIOR PORT
POSTERIOR PORT PORT ARRANGEMENT ASTROCYTOMA
EPENDYMOMA OLIGODENDROGLIOMA PNET
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Surgery

• Diagnostic purposes
• Supportive care
• First Second look surgery
• Organ-preserving surgery
• Debulking surgery
• Use of CT RT ? less mutilating operative Sx

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Chemotherapy Protocols

• Minimize dose related toxicities
• Allow recovery of normal tissues
• 2 - 3 wkly cycles
• Choose agents with differing side effects
• Sequential use of CT RT

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Chemotherapy Current Strategies

• Low intensity maintenance therapy
• Prolonged infusions - ? toxicity
• Drug combination dose intensity (g/wk)
• Shorter duration of CT in Vogue

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Basic Chemotherapy Guidelines

• Rule 1 - double check all dosages
• Rule 2 - drugs for different routes (e.g. IV
  IT)
• should never be placed in same tray
• Rule 3 - avoid extravasation 2 - syringe
  technique
• Rule 4 - pay attention to potential side effects

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Chemotherapy In Infancy

• Response of cancer similar as in older children
• Special problems related to metabolism
• - variable fluid compartments
• - liver immaturity
• - low GFR
• - gut absorption erratic
• Reliable venous access
• Use body wt for drug dose calculations
• (or 1/2 surface area dose)

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• Say Yes ! To Childhood Cancer
• UNICEF Initiative for the year
  2002

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Childhood Cancer Why Yes ?

• Improved 5 year survival in childhood ca
• Better physician awareness
• early diagnosis
• Prompt treatment favorable outcome

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