OBJECTIVETo explore the relationship between induction chemotherapy cycles to achieve complete remission (CR) and prognosis in patients with acute myeloid leukemia(AML).

METHODSFrom April 2004 to December 2013, 397 adult patients with newly diagnosed AML (acute promyelocytic leukemia excluded) received the idarubicin combined with cytarabine (IA)"3+7" regimen as the first induction chemotherapy were enrolled in the study. Therapeutic effect, relapse and survival of these patients were discussed. Patients underwent continuous consolidation chemotherapy, and some eligible patients received allogeneic hematopoietic stem cell transplantation (allo-HSCT) in the first complete remission.

RESULTSOf 397 patients, 347 evaluable patients achieved CR after 1-4 cycles induction chemotherapy.The median follow-up was 18.0 (2.4-115.4) months in survivors, the cumulative incidence of relapse (CIR), disease-free survival (DFS) and overall survival (OS) at 3 years were 33.0%, 58.6% and 67.1%, respectively. Multivariate analysis revealed that unfavorable cytogenetics, more cycles to achieve CR and post-remission treatment without allo-HSCT were independent risk factors affecting DFS and OS. FLT3-ITD mutation positive was another independent risk factor affecting DFS. There was no statistic difference between patients who achieved CR after one cycle (n=255) and two cycles (n=73) treatment in DFS and OS (P>0.05). DFS and OS in patients who achieved CR after 3 or 4 cycles(n=19)were significantly lower than the above two groups (P<0.05). Multivariate analysis among 183 patients who received consistent chemotherapy showed that achieving CR within 2 cycles was the favorable factor affecting DFS and OS (P=0.001, P=0.035).

CONCLUSIONAchieving CR within 2 cycles of induction chemotherapy was associated with better prognosis among adult CR patients with AML.