Allogeneic hematopoietic cell transplantation in adult patients with myelodysplastic/myeloproliferative neoplasms

BACKGROUND: In adults, the 2 main types of myelodysplastic/myeloproliferative neoplasms (MDS/MPN) are chronic myelomonocytic leukemia (CMML) and atypical chronic myeloid leukemia (aCML). Both are associated with a poor prognosis. Allogeneic hematopoietic cell transplantation (HCT) is the only known curative treatment modality for these diseases, but data on outcomes following such treatment are limited. We analyzed the outcomes of patients with MDS/MPN after allogeneic HCT. METHODS: This retrospective study included 10 patients with MDS/MPN who received allogeneic HCT at Asan Medical Center from 2002 to 2010. Of these 10 patients, 7 had CMML, 2 had aCML, and 1 had unclassifiable MDS/MPN. Five patients received a myeloablative conditioning (MAC) regimen (busulfan-cyclophosphamide), and 5 received reduced-intensity conditioning (RIC) regimen. RESULTS: Neutrophil engraftment was achieved in all patients. After a median follow-up of 47.5 months among surviving patients, 4 had relapsed and 5 had died. There was only 1 treatment-related death. The 5-year rates of overall, relapse-free, and event-free survival were 42.2%, 51.9%, and 46.7%, respectively. Relapse was the leading cause of treatment failure, and all relapses were observed in patients who had received RIC and who did not develop chronic graft-versus-host disease. CONCLUSION: Allogeneic HCT can induce durable remission in patients with MDS/MPN, but RIC cannot replace MAC in patients eligible for myeloablative treatments.

JAK2 V617F mutation in myelodysplastic syndrome, myelodysplastic syndrome/myeloproliferative neoplasm, unclassifiable, refractory anemia with ring sideroblasts with thrombocytosis, and acute myeloid leukemia

BACKGROUND: The JAK2 V617F mutation has been noted in the cases of polycythemia vera, essential thrombocythemia, and primary myelofibrosis patients. This mutation occurs less frequently in acute myeloid leukemia (AML) and other hematologic diseases, such as myelodysplastic syndrome (MDS); myelodysplatic syndrome/myeloproliferative neoplasm, unclassifiable (MDS/MPN-U); and refractory anemia with ring sideroblasts with thrombocytosis (RARS-T). METHODS: Patients diagnosed with hematologic diseases other than MPN who visited Seoul St Mary's Hospital from January 2007 to February 2010 were selected. A total of 43 patients were enrolled in this study: 12 MDS, 9 MDS/MPN-U, 7 RARS-T, and 15 AML patients. The diseases were diagnosed according to the 2008 WHO classification criteria. Data obtained from JAK2 V617F mutation analysis and cytogenetic study as well as complete blood count and clinical data were analyzed. RESULTS: Of the 43 patients, 6 (13.9%) harbored the JAK2 V617F mutation. The incidence of the JAK2 V617F mutation in each patient group was as follows: 8.3% (1/12), MDS; 22.2% (2/9), MDS/MPN-U; 14.3% (1/7), RARS-T; and 13.3%, (2/15) AML. The platelet count was higher than 450x10(9)/L in 3 of the 6 patients (50%) harboring the JAK2 V617F mutation, and it was in the normal range in the remaining 3 patients. Among the 6 patients, 1 MDS and 1 MDS/MPN-U patients had the 46,XX,del(20)(q11.2) karyotype. CONCLUSION: The JAK2 V617F mutation is associated with an increased platelet count in MDS, MDS/MPN-U, RARS-T, and AML patients. Cytogenetic abnormalities of del(20)(q11.2) occurred in 1/3 of patients with the JAK2 V617F mutation but further studies are required to confirm this association.