OBJECTIVETo compare the clinical efficacy and safety among different chemotherapeutic regimens in treatment of refractory/relapsed acute myeloid leukemia (AML).

METHODSThe clinical data of 67 refractory/relapsed AML patients enrolled from September 2008 to April 2013 were collected. The differences of clinical outcome and adverse events among the patients treated with decitabine combined with DAG regimen, CAG regimen or "3+7" regimen were analyzed.

RESULTSAmong 19 patients in decitabine treatment group, 5 (26.3%) achieved complete remission (CR), 4 (21.1%) partial remission (PR), with overall response rate (ORR) of 47.4 %. Of 26 patients in CAG regimen group, 8 (30.8%) achieved CR, 1 (3.8%) PR, with ORR of 34.6%. Of 22 patients in "3+7" regimen group, 4 (18.2%) achieved CR, with ORR of 18.2%. The ORR of decitabine group was significantly higher than that of "3+7" group (P<0.05). However, no significant difference of ORR was observed among the three groups (P>0.05). It was interesting to note that in decitabine group, the marrow blast counts were lower in CR patients compared with those in non-CR patients (P<0.05), while this was not found in "3+7" group (P>0.05) and CAG regimen group (P>0.05). Adverse events in the three groups were similar, mainly including myelosuppression, pulmonary infection, nausea, vomiting and liver dysfunction, and could be well tolerated. Followed- up to September 2013, the median overall survival (OS) of decitabine group, CAG regimen group and "3+7" group after relapse was 7.5, 4 and 3 months, respectively (P>0.05), while significant difference was obtained between decitabine group and "3+7" regimen group (P<0.05).

CONCLUSIONDecitabine combined with DAG regimen is effective and well tolerated in refractory/relapsed AML patients who were unsuitable for intensive chemotherapy and hematopoietic stem cell transplantation, and the patients with low marrow blast counts are more suitable for the application of decitabine combined with DAG regimen.