The Influence of Monosomal Karyotype On Survival in Patients with Acute Myeloid Leukemia After Allogeneic Hematopoietic Stem Cell Transplantation: A Retrospective Survey On Behalf of the Acute Leukemia Working Party of the European Group for Blood and Marrow Transplantation (EBMT)
Authors: Brands-Nijenhuis Angelique V.M. , Labopin Myriam , Schouten Harry C. , Volin Liisa , Socié Gérard , Cornelissen Jan J , Attal Michel , Tabrizi Reza , Esteve Jordi , Mohty Mohamad 
Published: October 2019

Abstract
Abstract 158

Introduction:
Monosomal karyotype (MK) has been shown to be associated with a very poor prognosis in AML patients (Breems, 2008). Whether allogeneic hematopoietic stem cell transplantation (alloHSCT) performed in an early phase can overcome the adverse prognosis in this cytogenetic patient category is currently unknown. To address this issue we performed a retrospective analysis on data from the registry of the EBMT among patients with primary AML who underwent alloHSCT in CR1.
Patients and methods: A total of 4119 patients with primary AML and known cytogenetic abnormalities at diagnosis that underwent alloHSCT in CR1 were included in the analysis. Survival curves were calculated with Kaplan-Meier method. Log rank test and Cox regression analysis were used to determine statistical significance.

Results:
Median follow-up was 24 months (range 2–374). Overall, 171 patients (4.2%) fulfilled criteria for MK and 297 patients (7.2%) for complex karyotype (CK), with 115 patients fulfilling both conditions (MK and CK). Both the presence of a MK (2-yr OS: 35.5% versus 63.2%, p<0.0001) and CK (2-yr OS: 48.8% versus 61.9%, p<0.0001) were associated with a poorer outcome when compared with the remaining cytogenetics subtypes. Given the significant overlap between both categories, we further analyzed their prognostic impact after defining four subgroups of patients: MK but not CK (56 patients; MK+CK-), no MK but CK (180 patients; MK-CK+), MK and CK (115 patients; MK+CK+), and patients without either MK or CK (MK-CK-). Outcome of the MK-CK- subgroup did not differ according to cytogenetics. Patients harboring a MK, regardless concomitant presence of a CK, presented with a poorer OS after alloHSCT (2-yr OS: 31.7–43.0% versus 61.1%, p<0.0001). On the contrary patients with a CK but not MK showed a similar outcome than MK-CK- (2-yr OS: 61.1% versus 63.3%, p=0.170). Moreover, multivariate analysis confirmed the independent negative impact of MK (HR:1.90, range 1.5–2.4; p<0.0001) together with age, interval diagnosis-transplant, AML subtype, WBC at diagnosis, T-cell depletion, number of induction cycles and use of TBI during conditioning, whereas the presence of a CK did not retain its negative prognostic value.

Conclusion:
These results indicate that MK is a better indicator for poor outcome than CK after alloHSCT in patients with primary AML in CR1. Nonetheless, the potential curative role of alloHSCT for a subset of patients with MK should be further investigated.

Reference:
DA Breems, WLJ van Putten, GE de Greef, SL van Zelderen-Bhola, KBJ Gerssen-Schoorl, CHM Mellink, A Nieuwint et al. Monosomal karyotype in acute myeloid leukemia: a better indicator of poor prognosis than a complex karyotype. J Clin Oncol 2008;26(29):4791–7.

Disclosures:
No relevant conflicts of interest to declare.