Attenuated Dose of Idarubicin for the Elderly De Novo Acute Myeloid Leukemia with Normal Karyotype.

The incidence of acute myeloid leukemia (AML) increases with age. Because of poor performance status, co-morbidity and treatment-related side effects, a conventional dose chemotherapy containing anthracyclins may be toxic to the majority of elderly patients. In contrast, the administration of suboptimal dose of myelosuppressive chemotherapy could lead to an unsuccessful clinical outcome including lower complete remission (CR) rate. To evaluate the effect of attenuated dose of idarubicin, compared to the standard dose, on the clinical outcome and chemotherapy-related complications, we analyze the consecutive 32 elderly de novo AML patients (range, 60 – 74 years) with normal karyotype. Eleven patients received one cycle of conventional-dose remission induction chemotherapy (idarubicin, 12 mg/m²/day on days 1–3 and cytarabine 100mg/m²/day on days 1–7) (Group 1) and 21 patients received attenuated-dose idarubicn (8 mg/m²/day on days 1–3) and cytarabine (100mg/m²/day on days 1–7) (Group 2). Six cases (54.5%) in Group 1 and 12 cases (57.1%) in Group 2 had CR. The difference of CR between the two groups was not significant (P = 0.59). The intervals from the chemotherapy-starting date to the date of CR documentation were not also different between two groups (median 31.5 days on Group 1 vs 27.0 days on Group 2) (P = 0.29). The median number of transfusion requirement during the induction therapy was not different in the red blood cells (10 units, each) and platelets (16.5 units in Group 1 vs 18.0 units in Group 2; P > 0.05). Thirty patients received the recombinant human granulocyte colony-stimulating factor (G-CSF) three days after termination of chemotherapy. The duration of G-CSF administration was not different between two groups (P = 0.86). However, the frequency of septicemia and septic shock after induction chemotherapy was statistically significantly higher in Group 1 (54.5% and 9.5%, respectively) compared to that in Group 2 (36.3% and 0.5%, respectively) (P < 0.01). We also observed a higher incidence of clinically-documented invasive fungal infection in Group 1 (45.5%) compared to Group 2 (15.0%), although the difference was not statistically significant (P = 0.095). The incidence of other regimen-related toxicities including renal dysfunction, hepatic dysfunction and heart failure was not different between two groups. Overall survival and disease-free survival also were not different between the groups. In conclusion, the attenuated dose of idarubicin can be recommended for the remission induction chemotherapy for the elderly de novo AML patients with normal karyotype since it is associated with lower incidence of sepsis and septic shock with comparable CR rate.