SOHO 2026 Annual Meeting

INTRODUCTION

Background

Hyperleukocytosis in acute myeloid leukemia (AML) is associated with leukostasis, metabolic complications, and early mortality.

The prognostic significance of extreme hyperleukocytosis in real-world AML populations remains incompletely defined

AIM

Objective

To evaluate the association between extreme hyperleukocytosis and early mortality and complication outcomes in newly diagnosed AML.

Comparison: WBC >150,000/µL vs 50,000–150,000/µL.

METHOD

•Design: Retrospective cohort, TriNetX global health research network.

•Population: Adults ≥18 y with newly diagnosed non-APL AML and hyperleukocytosis (WBC ≥50,000/µL).

•Cohorts: WBC 50,000–150,000/µL (n=5,589) vs >150,000/µL (n=1,833).

•Matching: 1:1 propensity score on demographics, baseline labs, and comorbidities → 1,831 per arm.

•Primary: 7-, 14-, and 30-day all-cause mortality.

•Secondary (30 d): respiratory/critical-care composite, stroke, DIC, AKI/HD, sepsis.

RESULTS

Key findings

Patients with WBC >150,000/µL had significantly higher all-cause mortality at every timepoint after matching.

Absolute mortality risk differences

•+4.95% at 7 days

•+5.17% at 14 days

•+4.45% at 30 days

No significant differences between cohorts in the respiratory/critical-care composite, stroke, DIC, AKI/HD, or sepsis.

CONCLUSIONS

•Extreme hyperleukocytosis (WBC >150,000/µL) was associated with significantly higher early mortality in newly diagnosed AML.

•Rates of major organ complications were similar between groups despite the mortality difference.

•Supports extreme leukocytosis as an important prognostic marker; highlights the need for early, risk-adapted management.

CONCLUSIONS

•Extreme hyperleukocytosis (WBC >150,000/µL) was associated with significantly higher early mortality in newly diagnosed AML.

•Rates of major organ complications were similar between groups despite the mortality difference.

•Supports extreme leukocytosis as an important prognostic marker; highlights the need for early, risk-adapted management.

Extreme Hyperleukocytosis and Early Mortality in Acute Myeloid Leukemia: A Real-World Propensity-Matched Analysis