Post-remission outcomes in AML patients with high hyperleukocytosis and inaugural life-threatening complications

Patients with hyperleukocytic (HL) acute myeloid leukemia (AML) are at higher risk of early death. Initial management of these patients is challenging, not fully codified and heterogenous. Retrospective studies showed that several symptomatic measures might decrease early death rate but long-term data are scarce. We aimed to analyze whether the therapeutic measures carried out urgently at diagnosis may influence the outcome among HL AML patients having achieved who survived inaugural complications.

We retrospectively reviewed all medical charts from patients admitted to Saint-Louis Hospital between January, 1st 1997 and December, 31st 2018 with newly diagnosed AML and white blood cell (WBC) count above 50x109/L. Outcome measures were cumulative incidence of relapse (CIR), treatment-related mortality (TRM) defined as relapse-free death, and overall survival. Univariate and multivariate analyses were performed using Cox proportional hazards models.

A total of 184 patients with HL AML in complete remission (CR) were included in this study. At 2 years after CR. 62.5% of patients were alive, at 5 years, cumulated incidence of relapse was 55.8%. We found that every therapeutic measure, including life-sustaining therapies carried out in the initial phase of the disease, did not increase the relapse risk. The use of hydroxyurea for more than 4 days was associated with a higher risk of relapse. At the end of the study, 94 patients (51.1%) were still alive including 23 patients out of 44 aged less than 60 yo that were able to return to work.

We show that the use of emergency measures including life sustaining therapies does not come at the expense of a higher risk of relapse or mortality, except in the case of prolonged use of hydroxyurea. Patients with HL AML should be able to benefit from all available techniques, regardless of their initial severity.