[Comparison of 10 mg/m² or 8 mg/m² idarubicin plus cytarabine regimen as induction chemotherapy for adult patients with newly diagnosed acute myeloid leukemia].

Objective: To compare the efficacy and toxicity of 10 mg/m² or 8 mg/m² idarubicin (Ida) combined with cytarabine (IA"3+7"regimen) as induction chemotherapy for adult patients with newly diagnosed acute myeloid leukemia (AML).

Methods: From June 2004 to October 2013, 335 adult AML (non acute promyelocytic leukemia) patients receiving the IA regimen as induction chemotherapy were enrolled, including 198 cases with 10 mg/m² Ida and 137 cases with 8 mg/m² Ida for 3 days. We compared the hematologic response, hematologic side effects and prognosis between the two regimens.

Results: Except for 4 early deaths, the complete remission (CR) rate after the first cycle of induction chemotherapy was 72.5%, 10.0% partial remission (PR) and 82.5% overall remission (OR) rate. The CR and OR rates were higher in the 10 mg/m² Ida group than the 8 mg/m² Ida group (CR: 78.9% vs 63.5%, P=0.003; OR: 88.2% vs 75.4%, P=0.007). Multivariate analysis showed that female, HGB≥100 g/L, FLT3-ITD mutation negative and 10 mg/m² Ida were favorable factors for CR. All patients presented cytopenias of grade Ⅳ. There was no differences on the recovery time of ANC≥0.5×10⁹/L and PLT≥20×10⁹/L after induction chemotherapy. Within a median follow-up of 14 (1-118) months, 98 (29.3%) patients relapsed, 92 (27.5%) died. The disease-free survival (DFS) and overall survival (OS) at 3 years were 53.2% and 58.9%, respectively. DFS and OS at 3-year were 34.2% and 37.4% in the chemotherapy cohort, 74.5% and 81.2% in the transplant cohort. 10 mg/m² Ida was an independent favorite factor for DFS (P=0.040) and OS (P=0.007).

Conclusion: As compared to 8 mg/m², 10 mg/m² Ida significantly improved the CR, with the same extent of hematological side effects, and was an independent favorite factor for DFS and OS.