Remission in Acute Myeloid Leukemia (AML): Definition and Significance

Complete Remission (CR) in AML is a rigorously defined milestone indicating eradication of detectable leukemia and restoration of hematopoiesis.

Standard Criteria (ELN / IWG)

• Marrow: <5% blasts; normocellular (20–60% cellularity); no Auer rods; no extramedullary disease.
• Blood: ANC ≥1,000/µL; Platelets ≥100,000/µL; Transfusion independence.
• Peripheral Blasts: 0%
• Duration: Sustained (typically confirmed on repeat marrow at count recovery).

Refined Definitions

• CRh: CR with partial hematologic recovery (ANC ≥500, Plt ≥50k).
• CRi: CR with incomplete recovery (one lineage
• MRD-Negative CR: CR + flow cytometry/NGS negative (<10⁻⁴ to 10⁻⁶). Strongest predictor of durable remission.
• Morphologic Leukemia-Free State (MLFS): Marrow <5% blasts but counts not recovered.

Prognostic Impact

• CR required for transplant eligibility.
• MRD-negative CR → superior DFS/OS.
• Failure to achieve CR (primary refractory) → poor outcome; clinical trial/novel agents.

Post-Remission Therapy

• Consolidation: Intermediate/high-dose cytarabine (3–4 cycles) or Allo-HSCT (intermediate/adverse risk).
• Maintenance: FLT3 inhibitors (midostaurin/gilteritinib), CC-486 (oral azacitidine), or clinical trial.
• Surveillance: Marrow q3–6mo × 2 yrs, then annually; MRD monitoring increasingly standard.

CR ≠ Cure. Relapse risk persists; lifelong vigilance needed.