Effective treatment of low-dose decitabine in myelodysplastic syndrome/myeloproliferative neoplasms

Primary myelofibrosis (PMF) is one of the Philadelphia negative myeloproliferative neoplasms (MPN). The main clinical features are obvious physical symptoms and symptomatic splenomegaly. It may be converse to leukemia and has a shortened life expectancy. Nowadays, the therapy for PMF is aimed at maintaining comfort and there is no curative treatment. PMF with myelodysplastic syndrome (MDS), called MDS/MPN-u, is rare and the treatment is complex. In this study, we want to discuss an effective treatment for MDS/MPN via a case report and literature review.

A female patient was diagnosed with MDS/MPN through bone marrow cytology, immunology, cell genetics, molecular biology, and pathology. She received thalidomide and prednisone as initial treatment. Ten months later, the first-line therapy had failed, she presented with clinically relevant pancytopenia and increased blasts in bone marrow. Because decitabine is one of the first-line treatments for MDS and the patient was frail, she received low-dose decitabine as second-line therapy. Decitabine was administered at 15 mg/m² once a week for 3 weeks, in a 4 week cycle. If there was improvement the treatment interval was prolonged.

After one cycle, the blasts in bone marrow were decreased to 0.5%. After four cycles, she felt comfortable and hematological improvement was achieved. The treatment interval was prolonged. After eight cycles, the spleen reduced to 2 cm under the rib, and she achieved complete hematological remission. After ten cycles, the mutation of JAK2/V617F expression was decreased from 60.63% to 0.01%. During the therapy, the patient presented with grade III-IV hematological toxicity after the first two cycles, but there were no side effects after subsequent cycles.

Our research showed that low-dose decitabine may be an effective treatment for MDS/MPN, especially in improving physical symptoms and achieving hematological remission. Besides, it may be possible to reverse positive JAK2 mutation.