Acute Myelogenous Leukemia in the Elderly. Intensive Induction Chemotherapy Improves Survival

Acute Myeloid Leukemia (AML) in the elderly has poor prognoses and carries inferior results with therapy. The purpose of this study was to determine the incidence of elderly AML, examine clinical outcomes with treatment and investigate the impact of intensive induction chemotherapy and other variables such as such as age, leucocytoses, cytogenetics and presence of antecedent hematologic disorder (AHD) on survival, in a cohort of elderly patients with AML treated at our institution.

Patients and Methods: The retrospective review included all patients (age>59) treated between January 1999 and February 2008. Patients diagnosed with acute promyelocytic leukemia were excluded. Records were reviewed from time of diagnoses till death or last follow-up.

Statistical analyses: Median survival was calculated using Kaplan Meier method and differences in survival between patients treated with intensive chemotherapy and those receiving supportive care were compared using the logrank test which was also used to determine the association between survival and variables such as older age (<69 vs. ≥ 69), leucocytoses (WBC >10k), cytogenetics and history of AHD.

Results: Study cohort included 51 patients with age>59. This represented 29% of all AML cases (n=176) treated at our institution. 31(60.78%) were males. Mean age was 68.42 years, range (60–82) with 23 (45.10%) being >69 years of age. History of AHD was observed in 15 (29.41%). Results of cytogenetic studies were available for 29(56.86%) patients of which 11(37.93%) had poor risk cytogenetics with the remainder falling in the intermediate risk group. Elevated WBC count was seen in 25(49.02%). Intensive induction chemotherapy was administered with an anthracycline and cytarabine regimen to 42(82.35%) patients with an induction mortality of 26%. Total of 23 (54.76%) patients achieved first complete remission (CR1). Of those who achieved CR1, 19(82.60%) underwent consolidation. Median survival was 120 days, range (1–2035). By univariate analyses, survival was not affected by older age (p=0.98), poor cytogenetics (p=0.23) or history of AHD (p=0.59), but was affected by induction chemotherapy (p=0.0001), ability to achieve CR1 (p=0.0001) and elevated WBC (p=0.05). In multivariate analyses after adjusting for other variables risk of death was influenced by ability to achieve CR1 (HR 0.146), AHD (HR=2.66) and elevated WBC count (HR=2.48).

Conclusion: Elderly AML has poor clinical outcomes. Risk of death is reduced by intensive induction chemotherapy and achievement of CR1. It is increased by history of AHD and elevated WBC at presentation.