[Outcomes of DNMT3A⁺ Myelodysplastic Syndrome Patients Treated with Decitabine]

To study therapeutic efficacy and side effects of single decitabine for DNMT3A⁺ myelodysplastic syndrome (MDS) patients.

The clinical characteristics, efficacy and side effects of 59 myelodysplastic syndrome patients received the decitabine therapy in our center from January 2015 to December 2018 were retrospectively analyzed. Based on gene mutations, these patients were divided into 2 groups: DNMT3A⁺ MDS patients (n=27) and DNMT3A^- MDS patients (n=32). All patients in two groups were treated with decitabine for 4 circles. The efficacy and side effects in the two groups were compared.

The median age of patients in DNMT3A⁺ MDS group was 56.2 (37-81) which was no statistic difference from DNMT3A^- MDS group. And there was no statistical difference including age, white blood cells, hemoglobin and platelet count between the two groups (P＞0.05). The ORR and complete response (CR) rate of DNMT3A⁺ group were 70.37% and 40.74%, the ORR and CR rate of DNMT3A^- group were 40.63% and 21.88% respectively. Significant differences were observed in ORR rate (P=0.035) between two groups. However, significant differences did not found in CR rate (P=0.159) between two groups, The similar adverse reaction was observed in DNMT3A⁺ and DNMT3A^- MDS patients. Among the 59 patients, 21 patients showed TP53+ mutation. DNMT3A⁺/TP53⁺ MDS patients (n=13) had similar ORR and CR compared with the DNMT3A^-/TP53⁺ MDS patients (n=8) (P＞0.05). The overall survival (OS) in DNMT3A⁺ MDS group and DNMT3A^- MDS group were 29.1±13.4 months and 27.8±14.4 months, respectively, no significant differences between two groups were observed (P=0.475).

Decitabine treatment is an effective and safe for DNMT3A⁺ MDS patients, but not shows better survival advantage.