Acute Lymphoblastic Leukaemia

Question 1

What is the most common leukaemia in children?

Answer 1

Acute Lymphoblastic leukaemia (ALL kids)

Question 2

What increases risk of ALL

Answer 2

Trisomy 21
Chromosolmal translocation
Prenatal exposure to X-rays. in utero infection

Question 3

What are the classifications of ALL?

Answer 3

B cell ALL
T cell ALL
Mature B-ALL = Burkitt’s lymphoma/leukaemia

Question 4

How does ALL present?

Answer 4

Pancytopenia
- Pallor, infection, bleeding
Fatigue
Anorexia
Fever
Bone pain
Painless lumps in neck, axilla, groin

cranial infiltration may lead to CNS effects - palsies
Testicular infiltration can lead to orchidomegaly

Question 5

What do bloods show in ALL?

Answer 5

Raised, normal or low WCC
Normochronic, normocytic anaemia
Thrombocytopenia
Raised Urate
Raised LDH

Question 6

What does the marrow show in ALL?

Answer 6

50-80% of nucleated cells will be blasts (immature)

Question 7

What tests in ALL?

Answer 7

Bloods, bone marrow aspirate
CSF analysis
Cytogenetic analysis - 80% genetic abnormality at diagnosis
Flow cytometry
CXR - may show mediastinal mass

Question 8

What will CSF show in ALL?

Answer 8

Pleocytosis (raised lymphocytes) with blast forms
Increased protein
Reduced glucose

Question 9

What factors worsen prognosis in ALL? Survival?

Answer 9

Unfavourable genetics - philadelphia chormosome (9,22)
Poor response to initial chemotherapy
Extra-medullary involvement - brain, testis

Age- children at 1-9 have better cure rates but under 1 and over 10 are higher risk
Initial WBC count > 50 is higher risk
Hyperdiploidy trisomy 4,10 or 17 is associated with better survival
Overall survival 80%

Question 10

Describe treatment of ALL

Answer 10

Induction therapy: 3drugs (vincristine, dex,L-asparaginase + intrathecal therapy (methotrexate+hydrocortisone)
In high risk, further daunorubicin

Consolidation phase - cranial irradiation if known CNS disease, further chemo

Maintenance phase - 2.5 years daily mercaptopurine, 3 monthly intrathecal drugs

Question 11

What are complications of ALL treatment? How to prevent?

Answer 11

Neutropenic sepsis- Revaccinate 6 months after chemotherapy
Hyperuricaemia - From massive cell death at induction - pre treat with increased fluid intake and allopurinol
Poor growth - monitor carefully
Cancer elsewhere - risk of CNS tumours or 2nd leukaemia is 3%
Thiopurine methyltransferse deficiency may cause a fatal myelosuppression when 6-MP is given - pre-treatment pharmagenomic TPMT analysis
Side effects - give ondansetron for sickness

Question 12

How does allopurinol work?

Answer 12

Reduces uric acid formation through enzyme inhibition