In an analysis of data from the European Society of Blood and Marrow Transplantation (EBMT) registry, researchers found that patients with secondary (transformed) acute myeloid leukemia (AML) have varying outcomes dependent on the myeloid neoplasm they had prior to progressing to AML – myelodysplastic syndromes (MDS), myeloproliferative neoplasms (MPN), or chronic myelomonocytic leukemia (CMML) – and other risk factors. The investigators, led by Nicolaus Kröger, MD, from the University Medical Center Hamburg-Eppendorf in Hamburg, Germany, compared 3-year survival outcomes in patients with transformed AML who received allogeneic hematopoietic cell transplantation (alloHCT) between 2000 and 2014.
The study evaluated outcomes in 4,214 patients (39% female; 61% male) according to antecedent disease:
- MDS (n=3,541)
- CMML (n=251)
- MPN (n=422)
The median age at alloHCT was 58 years (range = 18-79 years), and 59 percent of patients received a reduced-intensity (RIC) conditioning regimen. The majority of patients received stem cells from an unrelated donor (62%), and 50 percent were in complete remission (CR) at the time of alloHCT.
Within the different primary disease subgroups, patients with a primary diagnosis of MDS were more often in CR (53%) at the time of transplant, compared with patients with underlying diagnoses of CMML (47%) or MPN (43%). RIC was also more frequently used in MDS patients (65%) than in CMML (64%) and MPN patients (58%; p values not provided).
After a median follow-up of 46.5 months, the estimated 3-year relapse-free survival (RFS) and overall survival (OS) rates for the entire group were 36 percent (95% CI 34-38) and 40 percent (95% CI 33-42), respectively. The cumulative incidences of relapse and non-relapse mortality were 37 percent (95% CI 35-39) and 27 percent (95% CI 26-29), respectively.
In a univariate analysis, patients with MDS had a significantly better 3-year OS and RFS than patients with CMML (41% vs. 36% and 37% vs. 30%) and MPN (41% vs. 32% and 37% vs. 25%; p<0.001 for both). The survival benefit resulted primarily from a lower incidence of relapse at 3 years (35% vs. 43% vs. 50%, p<0.001).
This study is limited by its retroactive registry design, and molecular data were not routinely available from patients.
Kröger N, Eikema D, de Wreede L, et al. Different outcome of allogeneic stem cell transplantation for transformed acute myeloid leukemia derived from MDS, CMML or MPN. A retrospective study of the Chronic Malignancies Working Party (CMWP) of EBMT. Oral abstract presented at the 43rd Annual Meeting of the European Society for Blood and Marrow Transplantation, March 28, 2017; Marseilles, France.