Standard-Intensity Induction and Intermediate/High-Dose Cytarabine Consolidation Can Improve Survival for Elderly Patients with Newly Diagnosed Acute Myeloid Leukemia: A Retrospective Cohort Study

BACKGROUND: There is great uncertainty in the treatment of elderly patients with acute myeloid leukemia (AML), which leads to great challenges in treatment decision. The aim of this study is to find more suitable induction therapy and consolidation therapy for elderly AML patients. METHODS: A total of 149 consecutive newly diagnosed elderly AML patients (aged ≥60 years) who received induction chemotherapy in our medical center from January 2015 to December 2019 were retrospectively analyzed. RESULTS: After the first induction treatment, the complete remission/or complete remission with incomplete hematologic recovery (CR/CRi) rates in the standard-intensity chemotherapy group was significantly higher than that in the low-intensity chemotherapy group (58.2% vs 32.9%, p = 0.003). Compared with the low-intensity chemotherapy, the incidence of severe infection in the standard-intensity chemotherapy was significantly increased (p < 0.001), but the early mortality was comparable. One hundred and seven patients received minimal residual disease (MRD) examination after the first induction treatment; and MRD was negative accounting for 51.9% in the standard-intensity chemotherapy group, while only 32.7% in the low-intensity group (p = 0.05). The 2-year-overall survival (OS) of patients in standard-intensity induction chemotherapy group (37.2%) was slightly higher than that in low-intensity induction chemotherapy group (23.4%) (p = 0.075). Eighty-one CR/CRi patients received intermediate or high dose cytarabine (n = 35) or sequential chemotherapy regimens (n = 46) as consolidation treatment. The 2-year OS and event-free survival (EFS) of patients in the intermediate or high-dose cytarabine group were significantly higher than those in the sequential chemotherapy regimens group (73.0% vs 38.5%, p = 0.002; 54.8% vs 35.0%, p = 0.035). CONCLUSION: Our results showed that standard-intensity induction chemotherapy can significantly improve the CR rate for elderly AML patients, and does not increase the early mortality; consolidation therapy with intermediate or high-dose cytarabine can significantly improve EFS and OS for elderly AML patients achieved CR.