AZACITIDINE IN MYELODYSPLASTIC SYNDROMES - 10 YEARS OF EXPERIENCE IN AN
ONCOLOGY PORTUGUESE CENTRE
Catarina Dantas Rodrigues1, Mário Sousa Pimenta2, José Guilherme Freitas2, Ana Ribeiro Baldaia3, Luísa
Lopes dos Santos3, Dulcineia Pereira2, Cláudia Moreira2, Isabel Oliveira4, Nélson Domingues4, Ana
Espirito-Santo4, Ângelo Martins4, Ilídia Moreira4, Luisa Viterbo4, Sérgio Chacim4 and José Mariz5
(1)Hematology Service, Centro Hospitalar de Tondela Viseu, Viseu, Portugal, (2)Onco-hematology
Service, Instituto Português Oncologia do Porto Francisco Gentil, Porto, Portugal,
(3)Immunohemotherapy Service, Instituto Português Oncologia do Porto Francisco Gentil, Porto,
Portugal, (4)Instituto Português de Oncologia do Porto, Porto, Portugal, (5)Onco-hematology
Department, Instituto Português de Oncologia do Porto, F.G., E.P.E., Porto, Portugal
I
ntroduction: Myelodysplastic syndromes (MDS) are a heterogeneous group of clonal stem
cell disorders, characterized by ineffective haemotopoiesis leading to peripheral blood (PB)
cytopenias, with a tendency to evolve to acute myeloid leukemia (AML). According to the
international prognosis scoring system (IPSS), treatment naïve patients with intermediate-2
(INT2) and high risk (HR) have a median survival of 1.2 years and 0.4 years, respectively, and
25% evolve to AML in 1.1 and 0.2 years. Treatment options for adults not eligible for
haematopoietic stem cell transplantation are not curative and their effect on survival is
limited. Azacitidine is an hypomethylating agent that has been shown to prolong survival,
delay leukemic transformation in HR patients and reduce transfusion dependence.
Aim: To characterize the clinical characteristics of patients with MDS treated with azacitidine,
their outcomes and progression to AML.
Methods: We identified 51 patients diagnosed with MDS and treated with azacitidine,
between 2010 and 2020 in an Oncology Portuguese centre. Diagnosis, classification and
stratification were based on the presence of PB cytopenias, bone marrow dysplasia/blasts and
clonal cytogenetic abnormalities. Endpoints were overall survival (OS) and time to
transformation for AML (TTT).
Results: This study included 51 patients (ratio M:F 23:28) with a median age at diagnosis of
67 years (28-81) and median IPSS score of INT2. Twenty-eight patients (55%) had MDS with
multilineage dysplasia, 22 (43%) with excess blasts type 1 and 2 and one patient (2%) had ring
sideroblasts. Median time from diagnosis to starting azacitidine was 1 month (<1 – 92). The
median number of cycles was 5 (1 – 7), with 23 patients (45%) completing 7 cycles. Twenty-two
patients (43%) achieved complete remission or improved their blood count, 19 of which
continued with maintenance. Twenty-five patients (49%) suspended treatment earlier due to
lack of response and 2 due to adverse events (arrhythmia and febrile neutropenia). One
patient was still in active treatment and there was one loss of follow-up. A total of 20 patients
(39%) progressed to AML. In the INT2 and HR groups, 25% of patients evolved to AML during
the first 13 and 11 months, respectively. After a median follow-up time of 17 months (3-140),
there were 39 deaths, 61.5% due to infection. Median OS stratified by IPSS risk score was 16
(IC 95%: 5.8-26.2) and 17 months (IC 95%: 0.4-23.6) in INT2 and HR patients.
Conclusion: In this population, azacitidine delayed transformation to AML in comparison to
the IPSS study, specially in the HR group (11 vs 4.8 months). When analysing OS, there was a
slight improvement in INT2 patients (16 vs 14.4 months).
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