Oncology 1

Question 1

Epidemiology of childhood malignancy

Answer 1

1 in 500 by 15yrs

32% leukaemia
24% brain and spinal tumours
10% lymphomas
7% neuroblastomas
7% soft tissue sarcomas
6% Wilms tumour

Question 2

At which age are children affected by leukaemia?

Answer 2

at all ages

Question 3

At which age are children affected by neuroblastoma?

Answer 3

Almost always in the first 6 years of life

Question 4

At which age are children affected by Wilms tumour?

Answer 4

Almost always in the first 6 years of life

Question 5

At which age are children affected by Hodgkin lymphoma?

Answer 5

Adolescence and early life

Question 6

Commonest leukaemia in children?

Answer 6

Acute lymphoblastic leukaemia (ALL) - 80%

Most of the remainder is acute myeloid/non-lymphocytic leukaemia

Question 7

Presenting symptoms of acute lymphoblastic leukaemia

Answer 7

Peak at 2-5yrs.
Usually insidious onset over several weeks.

General - malaise, anorexia

Bone marrow infiltration :
Bone pain
Anaemia (pallor, lethargy)
Neutropenia (infection)
Thrombocytopenia (bruising, petechiae, nose bleeds)

Reticulo-endothelial infiltration: hepatosplenomegaly, Lymphadenopathy.

Other infiltration (usually when relapse):
CNS (headaches, vomiting, nerve palsies)
Testes: testicular enlargement

Question 8

Diagnosis of acute lymphoblastic leukaemia

Answer 8

FBC - usually low Hb, thrombocytopenia and circulating leukaemic blast cells

Bone marrow examination is ESSENTIAL for diagnosis.
Also for immunology and cytology (=prognosis)

CXR for mediastinal mass (in T cell disease)

Common subtype is in 75%, T cell subtype only in 15%.
Treatment varies according to subtype

Question 9

What is the general outline of treatment of standard-risk acute lymphoblastic leukaemia

Answer 9

Induction 5 weeks.

Week 5-8: consolidation.

Week 8-16: interim maintenance.

Week 16-23: delayed intensification.

Maintenance treatment continues from week 23 for further 2 (girls) or 3 (boys) years

Question 10

Agents used for Induction

Answer 10

Vincristine
Steroid (dexamethasone)
L-asparaginase
Intrathecal methotrexate

Question 11

Agents used in consolidation and CNS protection

Answer 11

IT methotrexate
Vincristine
Steroid
Thiopurine

Question 12

Agents used in interim and maintenance

Answer 12

Monthly vincristine and pulse (5days) steroid (dexamethasone)

Daily 6-mercaptopurine.

Weekly oral methotrexate.

Prophylactic co-trimoxazole to prevent pneumocystis carinii pneumonia

IT methotrexate

Question 13

Agents used in delayed intensification

Answer 13

Vincristine
Dexamethasone
Doxorubicin
L-Asparaginase
IT methotrexate
Cyclophosphamide

Question 14

Symptomatic management of acute lymphoblastic leukaemia

Answer 14

Blood transfusions for platelets and whole red cells (reduces bruising and bleeding and breathlessness)

Question 15

What is tumour lysis syndrome. Presentation and management

Answer 15

May develop at initial induction:

metabolic derangements caused by systemic and rapid release of intracellular contents as chemo destroys leukaemic blast cells

Hyperuricaemia
Hyperphosphataemia
Hypocalcaemia
Hyperkalaemia

Monitor electrolyte and uric acid levels
IV fluid therapy
Allopurinol may be useful

Question 16

How does remission induction work

Answer 16

Before starting, may require correction of anaemia (and risk of bleeding+infection) with blood transfusion.

Additional hydration and allopurinol are given to protect the kidney against the effects of rapid cell lysis.

Remission implies eradication of the leukaemic blasts and restoration of normal marrow function.

4 weeks of combination chemotherapy is given and current induction treatment schedules achieve remission rates of 95%

Question 17

What is intensification of chemotherapy?

Answer 17

A block of intensive chemotherapy given to consolidate remission.

Improves cure rate, but there is higher toxicity

Question 18

Why is intrathecal methotrexate used?

Answer 18

Cytotoxic drugs penetrate poorly into CNS (where leukaemic cells may survive).

It is used to prevent CNS relapse

Question 19

What is the role of continuing therapy?

Answer 19

Chemotherapy of modest intensity continued over a relatively long period of time (up to 3 years from diagnosis)

With co-trimoxazole prophylaxis to prevent Pneumocystis cariniipneumonia

Question 20

What treatment method is available for relapse?

Answer 20

High-dose chemotherapy with total body irradiation and bone marrow transplantation

Question 21

What are high-risk factors for the prognosis of acute lymphoblastic leukaemia

Answer 21

Age <1yr or >10yrs
WCC >50x10^9/L
Cytogenetic/molecular genetic abnormalities in tumour cells: MLL rearrangement, hypodiploidy (<44 chromosomes)

Speed of response to initial chemo: persistence of leukaemic blasts in the bone marrow is bad

High minimal residual disease Assessment score

These factors are used to group ALL by risk

Question 22

Which treatment adjustment is beneficial for the T-cell subtype of ALL

Answer 22

Addition of cyclophosphamide and intensive treatment with asparaginase