EVI1 Expression Predicts Poor Survival in Acute Myeloid Leukemia Patients Undergoing Allogeneic Hematopoietic Cell Transplantation with Myeloblastic Conditioning

Abstract

The ecotropic viral integreation site 1 (EVI1 or MECOM) gene mapping to chromosome 3q26 exerts significant oncogene biological effects of anti-apoptosis, proliferation and differentiation on hematopoietic cells. It is considered as a poor prognostic factor in acute myeloid leukemia (AML). EVI1 positive AML accounts for about 10% of de novo AML pts. The remission rate and long time survive are poor. Whether allogeneic hematopoietic stem cell transplantation (allo-HSCT) could salvage such kind of malignancy is still unknown. We conducted a survey of 161 AML pts (median age, 35 years[y]; range 8-60y) after first complete remission undergoing myeloblastic allo-HSCT at the first affiliated hospital of Soochow University. Source of hematopoietic stem cells came from match or partial matched related, unrelated or umbilical cord blood (UCB) donors (Table 1). Pretreated specimens were obtained and real-time polymerase chain reaction was performed to detect expression of EVI1-1d (one major splice of EVI1) and common EVI1 (cEVI) (normalized to PBGD gene). Standard plasmids of EVI1 and PBGD were prepared as calibrators. 13 nonmalignant single lineage cytopenia pts were tested as baseline. Quantities of EVI1-1d and cEVI ranges from negative to 154.2%PBGD and negative to 1214.3%PBGD in each group. Above five and ten folds to baseline in EVI1-1d and cEVI respectively were considered as positive. Accordingly 27 pts were EVI1 positive while 134 pts were negative (16.8% vs 83.2% separately). Unfavorable cytogenetic abnormalities showed a high proportion in EVI1 pos (11/27) than neg group (12/134). 5 and 40 mutations were detected in each group. Three cytogenetic abnormality concerning 11p15 pts expressed high level of EVI1.Positive expression of EVI1 indicated significant shorter progress-free survival and overall survival (P= 0.0352 and 0.0436 respectively) comparing with negative group (Figure 1).Table 1Sources of donorsMatched (n)Partial mathed (n)siblings825Parents or sons/daughters/30Unrelated PBSC2610Unrelated UCB35 [Display omitted] [Display omitted] Progress-free Survival (upper) and Overall Survival (below) in myeloblastic allo-HSCT pts according to EVI1 expressionIn conclusion, high level of evi1 expression predicts worse prognosis even after myeloblastic allo-HSCT. New treatment strategies post allo-HSCT are needed to improve long time survival in such kinds of pts. DisclosuresNo relevant conflicts of interest to declare.