Background

Elderly patients with acute myeloid leukemia (AML) has generally poor prognosis prognosis in accordance with their unfavorable clinical and biologic features. Hypomethylating agents have shown potential in the treatment of AML as well as myelodysplastic syndrome (MDS). In this retrospective study, we compared the outcomes of elderly AML patients according to induction treatment options: decitabine versus intensive chemotherapy. We also tried to identify specific subsets of patients who are most likely to benefit from decitabine or intensive chemotherapy.

Methods

This study included elderly patients aged 65 years or older who received induction treatment with decitabine or intensive chemotherapy for newly diagnosed AML at a single institute. The endpoints for this study were overall survival (OS), response, and event-free survival (EFS). Response included complete remission (CR), CR with incomplete hematologic recovery (CRi), and CR with partial hematologic recovery (CRh).

Results

A total of 107 patients, decitabine for 75 and intensive chemotherapy for 32, were analyzed. Decitabine was given as 20 mg/m2/day for 5 days every 4 weeks. Median 5 courses (range, 1-43) were delivered to the patients and 16 patients were still on decitabine treatment at the time of analysis. Intensive chemotherapy regimens included cytarabine plus daunoruribin (n=21) or idarubicin (n=10), and hyper-CVAD (n=1): 25 patients received one course and 7 received two courses for induction treatment. The rate for CR + CRi + CRh (CRR) was 38.6% (39 of 101 assessable patients). With a median follow-up duration of 14.8 months (95% confidence interval [CI], 12.0-22.8) among surviving patients, 79 patients died and 22 relapsed. The median OS and EFS were 12.3 months (95% CI, 10.0-14.7) and 4.1 months (95% CI, 2.5-5.7), respectively. Decitabine showed lower CRR (26.1% vs. 65.6, P<0.001) with similar EFS (median 3.4 vs. 6.1 months, P=.338) and OS (median 11.0 vs. 14.8 months, P=.124) compared to intensive chemotherapy (Figure 1). Multivariate analysis demonstrated that induction treatment option, peripheral blood (PB) blast percentage, and leukemia type (secondary vs. de novo) were independent risk factors for CRR. A presence of FLT3-ITD mutation, complex karyotype, and higher PB blast percentage were independently associated with shorter OS. Subgroup analysis for OS showed that intensive chemotherapy was superior to decitabine in patients with FLT3-ITD mutation (median 9.5 vs. 2.6 months, P=.025) and poor cytogenetic risk (10.8 vs. 6.1 months, P=.027), but decitabine showed tendency towards a longer OS compared to intensive chemotherapy in those with monosomy 7 or del(7q) (11.7 vs. 3.3 months, P=.093; Figure 2).

Conclusion

Decitabine showed similar OS to intensive chemotherapy despite of lower response rate in elderly AML patients. Clinical outcomes of specific subgroups seemed to be different according to induction treatment options. Further studies are warranted for selection of optimal treatment options for elderly AML patients.

Disclosures

No relevant conflicts of interest to declare.

Author notes

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Asterisk with author names denotes non-ASH members.

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