Leukaemia

Lesson Objectives

By the end of this lesson, learners should be able to:

1. Define leukaemia and differentiate between acute and chronic forms.

2. Classify leukaemia by morphology and disease course: ALL, AML, CML.

3. Recognize clinical signs and symptoms of leukaemia in children.

4. Identify appropriate investigations for diagnosis.

5. Understand supportive care and transfusion requirements.

6. Apply chemotherapy protocols for ALL, AML, and CML in children.

7. Appreciate special considerations such as CNS prophylaxis, infection control, and ATRA therapy.

Description

Leukaemia is a group of malignant disorders arising from a single transformed progenitor cell in the haemopoietic system. Untreated acute leukaemia is rapidly fatal; chronic leukaemia progresses slowly but is ultimately fatal. It is classified according to cell type and speed:

• Acute Lymphoblastic Leukaemia (ALL)

• Acute Myeloid Leukaemia (AML)

• Chronic Myeloid Leukaemia (CML)

Chronic lymphocytic leukaemia is rare in children.

Acute Lymphoblastic Leukaemia (ALL)

Description:
Clonal proliferation of lymphoid cells in the bone marrow, leading to marrow infiltration and failure.

Signs and Symptoms:

Investigations:

Supportive Care

ALL Chemotherapy Protocol

Phases:

1. Steroid Prophase: Prednisolone 60 mg/m² × 7 days, repeat peripheral smear on day 8.

2. Induction (4 weeks):

   • Prednisolone 40 mg/m² daily × 3 weeks

   • Vincristine 1.5 mg/m² IV weekly (days 1, 8, 15, 22)

   • L-Asparaginase 6000 IU/m² IM (days 1, 3, 5, 8, 10, 12)

   • Daunorubicin 25 mg/m² IV (days 1, 8) if high-risk

   • Age-adjusted IT Methotrexate (days 1, 8, 15, 28)

   • Bone marrow assessment day 28–35

3. Consolidation (4 weeks):

   • Prednisolone 60 mg/m² × 14 days

   • Cytarabine 75 mg/m² IV push (days 1–4, 8–11)

   • Cyclophosphamide 1000 mg/m² IV (day 1)

   • 6-Mercaptopurine 60 mg/m² orally × 14 days

   • L-Asparaginase 6000 IU/m² IM (days 15, 17, 19, 22, 24, 26)

   • Vincristine 1.5 mg/m² IV push (days 15, 22)

   • IT Methotrexate days 1, 8, 15

4. Interim Maintenance (8 weeks):

   • Vincristine 1.5 mg/m² IV push (days 1, 11, 21, 31)

   • Methotrexate IV 100 mg/m² day 1, escalate by 50 mg/m² on days 11, 21, 31, 41

5. Delayed Intensification (8 weeks):

   • Vincristine 1.5 mg/m² IV (days 1, 8, 15, 43, 50)

   • L-Asparaginase 6000 IU/m² IM (days 3, 5, 7, 10, 12, 14)

   • Dexamethasone 10 mg/m² orally (days 1–7, 22–28)

   • Doxorubicin 25 mg/m² IV (days 1, 8, 15)

   • Prednisolone 60 mg/m² orally (days 29–42)

   • Cytarabine 75 mg/m² IV (days 29–32, 36–39)

   • Cyclophosphamide 1000 mg/m² IV day 29

   • 6-Mercaptopurine 60 mg/m² orally (days 29–42)

6. Maintenance (22 months, 8 cycles of 12 weeks each):

   • 6-Mercaptopurine 75 mg/m² daily

   • Methotrexate 20 mg/m² orally weekly (if IT MTX week 1)

   • Dexamethasone 6 mg/m² orally (days 1–5, 29–33, 57–61)

   • Vincristine 1.5 mg/m² IV push (days 1, 29, 57)

   • Cranial radiation for CNS3 infiltration: 18 Gy/10 fractions

Acute Myeloid Leukaemia (AML)

Signs and Symptoms:
Recurrent infections, fever, pallor, easy bruising, spontaneous bleeding/DIC, bone & joint pain, hepatosplenomegaly, lymphadenopathy.

Chemotherapy Protocol:

Acute Promyelocytic Variant:

• ATRA 45 mg/m² orally BID × 90 days during first induction

• Second cycle: ATRA × 15 days

• Third cycle: ATRA × 15 days + high-dose cytarabine 1000 mg IV × 1–4, BID, 4 hr infusion

• Maintenance: ATRA 45 mg/m²/day orally days 1–15 every 3 months for 2 years, 6-Mercaptopurine 60 mg/m²/day, Methotrexate 20 mg/m² weekly × 2 years

Chronic Myeloid Leukaemia (CML)

Description:
CML is a myeloproliferative neoplasm with Philadelphia chromosome t(9;22) and BCR-ABL1 fusion gene. Accounts for <5% of childhood leukaemia.

Treatment: