Comparison of allogeneic stem cell transplant conditioning regimens in AML, MDS and CLL

Objective: The purpose of this hypothesis-driven review was to compare the prognostic outcomes of busulfan/cyclophosphamide combination therapy versus total bone irradiation in patients with acute myeloid leukemia. Methods:A systematic search for randomized control trials, observational studies, meta-analyses, comparative studies, and systematic reviews comparing busulfan/ cyclophosphamide versus total bone irradiation conditioning regimens for allograft stem cell transplantation in patients with acute myeloid leukemia was performed using the following databases: PubMed, Medline, EBSCOhost, DynaMed, Google Scholar, and Cochrane Library.Studies were assessed for inclusion/exclusion criteria and methodological quality.Results: A total of 9 studies were selected, pooling 15,004 HLA-matched participants of all ages with acute myeloid leukemia; this included 8,483 participants who received a total bone irradiation regimen and 6,521 who received a busulfan/cyclophosphamide regimen.Based on forest plot analysis, bubble-scatter plot analysis, Cohen's d test, and an unpaired t-test (for effect size), no statistically significant difference was found between the use of total bone irradiation and busulfan/ cyclophosphamide conditioning regimens on increased overall survival and disease-free survival in patients with acute myeloid leukemia (effect size: 0.20; relative risk: 1.27; 95% confidence interval 0.80-2.01,p=0.36).Serious adverse effects of total bone irradiation and busulfan/cyclophosphamide combination therapy were: graft versus host disease, alopecia, interstitial pneumonia, and cataract.Conclusion: A busulfan/cyclophosphamide allogeneic stem cell transplantation conditioning regimen does not ameliorate prognosis (overall survival, disease-free survival, graft vs. host, and relapse rate) compared to a total bone irradiation conditioning regimen in patients with acute myeloid leukemia.This conclusions invalidity is questioned based on limitations of studies and inclusivity of multiple leukemic conditions amongst a broad population.