Leukemia (peds)

Background

• Most common cancer in children (33% of all malignancies)
• ALL
  • 3/4 of pediatric leukemias
  • 5-year survival 75%-80%
  • Peak incidence 3-5yr old
• AML
  • 1/5 of pediatric leukemias
  • Worse prognosis
  • More complications (more intense chemo tx required)

Clinical Features

• Signs/symptoms due to bone marrow infiltration and failure
  • Pallor, fatigue, easy bleeding, fever, infection
  • Bone/joint pain
  • Hepatomegaly or splenomegaly
• Hyperleukocytosis
  • Clinically significant when WBC > 200K in AML, >300K in ALL
  • Cerebral circulation: HA, AMS, visual changes, sz, CVA
  • Pulmonary circulation: SOB, hypoxemia

Differential Diagnosis

Leukemias will often involve >1 cell line; other conditions restricted to single line

• Aplastic anemia
• Iron deficiency anemia
• Viral infection (EBV, CMV, Parvo)
• Immune thrombocytopenia
• Rheumatologic diseases

Diagnosis

• CBC
  • If suggestive of leukemia also order:
    • Chemistry, Ca, Phos, Mg, Uric acid, LFT, LDH, coags, T+S, CXR

Treatment

• Transfusion
  • Options
    • Irradiated: for very immunosuppressed (to prevent graft vs host)
    • Leukocyte-reduced: for patients likely to receive multiple RBC or plts in future
    • CMV seronegative: for <1yr old, if might need bone marrow transplant in future
  • Anemia
    • 10 cc/kg of pRBCs raises Hb by 3 gm/dL
    • Raise Hb to >8
  • Thrombocytopenia
  • 0.1 unit/kg results in 30-50K increase in plt count
  • Risk of spontaneous ICH is extremely low until plt <5K
  • Transfuse if:
    • Asymptomatic w/ plt <10K
    • Invasive procedures require plt >50K
• Hyperleukocytosis
  • Aggressive IV hydration
  • Urinary alkalinization (pH 7-7.5)
  • Allopurinol (for Tumor Lysis Syndrome (TLS))
  • Avoid diuretics and pRBC transfusion (plts ok)
  • Give plts if <20K
  • Leukapheresis