Supplementary Material for: Neutropenia in the First Cycle of Consolidation Chemotherapy with High-Dose Cytarabine Is Not Associated with the Incidence of Relapse in Adult Acute Myeloid Leukemia Patients in First Complete Remission

Background: It has been reported that prolonged neutropenia during post-remission chemotherapy is associated with a reduced risk of disease relapse in pediatric acute myeloid leukemia (AML) patients. Methods: We retrospectively reviewed the charts of adult AML patients in first complete remission (CR1) who underwent consolidation chemotherapy with high-dose cytarabine. Those receiving allogeneic hematopoietic cell transplantation in CR1 were excluded. We calculated the D-index, which is an area-based neutropenia index. The patients were divided into 2 groups using the median value of the D-index during the first cycle of consolidation chemotherapy (C#1). Results: Fifty-six patients were included. The 2-year cumulative incidence of relapse was 54.8% (95% confidence interval (CI): 37.5-73.8) in patients with a D-index < 5,118 and 62.0% (95%CI: 42.7-81.4) in those with a D-index ≥ 5,118 (P = 0.56). In a multivariate analysis, intermediate / adverse cytogenetic risk (HR 2.76), performance status ≥ 2 (HR 5.55) and 2 cycles of induction chemotherapy required to achieve CR1 (HR 4.29) were identified as significant factors associated with relapse. The D-index at C#1 did not have a significant impact. Conclusions: In contrast to pediatric patients, the severity of neutropenia is not associated with a risk of disease relapse in adult AML patients.