AUTHOR=Li Si-Qi , Fan Qiao-Zhen , Xu Lan-Ping , Wang Yu , Zhang Xiao-Hui , Chen Huan , Chen Yu-Hong , Wang Feng-Rong , Han Wei , Sun Yu-Qian , Yan Chen-Hua , Tang Fei-Fei , Liu Yan-Rong , Mo Xiao-Dong , Wang Xin-Yu , Liu Kai-Yan , Huang Xiao-Jun , Chang Ying-Jun 

TITLE=Different Effects of Pre-transplantation Measurable Residual Disease on Outcomes According to Transplant Modality in Patients With Philadelphia Chromosome Positive ALL

JOURNAL=Frontiers in Oncology

VOLUME=10

YEAR=2020

URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2020.00320

DOI=10.3389/fonc.2020.00320

ISSN=2234-943X

ABSTRACT=<p><bold>Background:</bold> This study compared the effects of pre-transplantation measurable residual disease (pre-MRD) on outcomes in Philadelphia chromosome (Ph)-positive ALL patients who underwent human leukocyte antigen-matched sibling donor transplantation (MSDT) or who received unmanipulated haploidentical SCT (haplo-SCT).</p><p><bold>Methods:</bold> A retrospective study (<italic>n</italic> = 202) was performed. MRD was detected by RT-PCR and multiparameter flow cytometry.</p><p><bold>Results:</bold> In the total patient group, patients with positive pre-MRD had a higher 4-year cumulative incidence of relapse (CIR) than that in patients with negative pre-MRD (26.1% vs. 12.1%, <italic>P</italic> = 0.009); however, the cumulative incidence of non-relapse mortality (NRM) (7.4% vs. 15.9%, <italic>P</italic> = 0.148), probability of leukemia-free survival (LFS) (66.3% vs. 71.4%, <italic>P</italic> = 0.480), and overall survival (OS) (68.8% vs. 76.5%, <italic>P</italic> = 0.322) were comparable. In the MSDT group, patients with positive pre-MRD had increased 4-year CIR (56.4% vs. 13.8%, <italic>P</italic> &lt; 0.001) and decreased 4-year LFS (35.9% vs. 71.0%, <italic>P</italic> = 0.024) and OS (35.9% vs. 77.6%, <italic>P</italic> = 0.011) compared with those with negative pre-MRD. In haplo-SCT settings, the 4-year CIR (14.8% vs. 10.7%, <italic>P</italic> = 0.297), NRM (7.3% vs. 16.3%, <italic>P</italic> = 0.187) and the 4-year probability of OS (77.7% vs. 72.3%, <italic>P</italic> = 0.804) and LFS (80.5% vs. 75.7%, <italic>P</italic> = 0.660) were comparable between pre-MRD positive and negative groups. In subgroup patients with positive pre-MRD, haplo-SCT had a lower 4-year CIR (14.8% vs. 56.4%, <italic>P</italic> = 0.021) and a higher 4-year LFS (77.7% vs. 35.9%, <italic>P</italic> = 0.036) and OS (80.5% vs. 35.9%, <italic>P</italic> = 0.027) than those of MSDT. Multivariate analysis showed that haplo-SCT was associated with lower CIR (HR, 0.288; <italic>P</italic> = 0.031), superior LFS (HR, 0.283; <italic>P</italic> = 0.019) and OS (HR, 0.252; <italic>P</italic> = 0.013) in cases with a positive pre-MRD subgroup.</p><p><bold>Conclusions:</bold> Our results indicate that the effects of positive pre-MRD on the outcomes of patients with Ph-positive ALL are different according to transplant modality. For Ph-positive cases with positive pre-MRD, haplo-SCT might have strong graft-vs.-leukemia (GVL) effects.</p>