[Long-term hypomethylating agents in patients with myelodysplastic syndromes: a multi-center retrospective study]

Objective: To evaluate the efficacy and safety of hypomethylating agents (HMA) in patients with myelodysplastic syndromes (MDS) . Methods: A total of 409 MDS patients from 45 hospitals in Zhejiang province who received at least four consecutive cycles of HMA monotherapy as initial therapy were enrolled to evaluate the efficacy and safety of HMA. Mann-Whitney U or Chi-square tests were used to compare the differences in the clinical data. Logistic regression and Cox regression were used to analyze the factors affecting efficacy and survival. Kaplan-Meier was used for survival analysis. Results: Patients received HMA treatment for a median of 6 cycles (range, 4-25 cycles) . The complete remission (CR) rate was 33.98% and the overall response rate (ORR) was 77.02%. Multivariate analysis revealed that complex karyotype (P=0.02, OR=0.39, 95%CI 0.18-0.84) was an independent favorable factor for CR rate. TP53 mutation (P=0.02, OR=0.22, 95%CI 0.06-0.77) was a predictive factor for a higher ORR. The median OS for the HMA-treated patients was 25.67 (95%CI 21.14-30.19) months. HMA response (P=0.036, HR=0.47, 95%CI 0.23-0.95) was an independent favorable prognostic factor, whereas complex karyotype (P=0.024, HR=2.14, 95%CI 1.10-4.15) , leukemia transformation (P<0.001, HR=2.839, 95%CI 1.64-4.92) , and TP53 mutation (P=0.012, HR=2.19, 95%CI 1.19-4.07) were independent adverse prognostic factors. There was no significant difference in efficacy and survival between the reduced and standard doses of HMA. The CR rate and ORR of MDS patients treated with decitabine and azacitidine were not significantly different. The median OS of patients treated with decitabine was longer compared with that of patients treated with azacitidine (29.53 months vs 20.17 months, P=0.007) . The incidence of bone marrow suppression and pneumonia in the decitabine group was higher compared with that in the azacitidine group. Conclusion: Continuous and regular use of appropriate doses of hypomethylating agents may benefit MDS patients to the greatest extent if it is tolerated.