Department of Internal Medicine, Section of Hematology, Yale School of Medicine, New Haven, Connecticut, USA. Division of Hematology and Oncology, University of Alabama School of Medicine, Birmingham, Alabama, USA. Leukemia Service, Memorial Sloan Kettering Cancer Center, New York, New York, USA.
BACKGROUND Up to 20% of patients with acute myeloid leukemia (AML) present with hyperleukocytosis, usually defined as a white blood cell (WBC) count greater than 100 × 10(9) /L. Given the high early mortality rate, emergent cytoreduction with either leukapheresis, hydroxyurea, or chemotherapy is indicated, but the optimal strategy is unknown. STUDY DESIGN AND METHODS For this systematic review and
meta-analysis we searched MEDLINE and EMBASE via Ovid, Scopus, Cochrane Central Register of Controlled Trials (CENTRAL), and Web of Science from inception through March 2020 for multiarm studies comparing early mortality rates of patients with AML treated with leukapheresis and those who were not. The risk ratio (RR) of early death for patients who received leukapheresis vs patients who did not was estimated using a sum of the log-ratio of individual study estimates weighted by sample size. RESULTS Among 13 two-arm, retrospective studies with 1743 patients (486 leukapheresis and 1257 nonleukapheresis patients), leukapheresis did not improve the primary outcome of early mortality compared to treatment strategies in which leukapheresis was not used (RR, 0.88; 95% confidence interval [CI], 0.69-1.13; P = .321) without statistically significant heterogeneity between studies (Cochran's Q, 18; P = .115; I(2) , 33.4%). Patients presenting with clinical leukostasis tended to be more likely to undergo leukapheresis (odds ratio, 2.01; 95% CI, 0.99-4.08; P = .052). CONCLUSION As we did not find evidence of a short-term mortality benefit and considering the associated complications and logistic burden, our results argue against the routine use of leukapheresis for hyperleukocytosis among patients with AML.