Survival of Older Adults With Newly Diagnosed Acute Myeloid Leukemia: Effect of Using Multiagent Versus Single-agent Chemotherapy

Background: Controversy exists regarding the optimal chemotherapy regimen for older adults with acute myeloid leukemia (AML). Patients and Methods: We analyzed data from the US National Cancer Data Base of 25,621 patients aged 60 to 79 years, with a diagnosis of AML from 2004 to 2014, who had received single-agent versus multiagent chemotherapy. A Cox proportional hazard model was used for overall survival (OS) analysis for the entire study cohort and separately for patients who had received single-agent (n = 6743) versus multiagent (n = 6743) chemotherapy, matched for age, Charlson comorbidity index, and AML subtype. Results: The use of multiagent chemotherapy was high overall (70%) but declined with factors, such as increasing age, Charlson comorbidity index, AML subtype other than good risk, academic center, lower rate of high school graduation, and more recent year of diagnosis. Patients treated with multiagent chemotherapy had greater 1-year OS (43% vs. 28%), especially for patients aged 60 to 69 years and those with good-risk AML or Charlson comorbidity index of 0 to 1. OS (hazard ratio, 1.32; 95% confidence interval, 1.28-1.36) remained more favorable for the multiagent chemotherapy group on multivariable analysis. This was confirmed in a matched cohort analysis. Conclusions: To the best of our knowledge, this is the largest real-world study that has demonstrated an association between factors such as age, comorbidity, and AML subtype and the use of multiagent chemotherapy. The use of multiagent chemotherapy was associated with improved OS, especially for patients aged <70 years, those with good-risk AML, and those with a low Charlson comorbidity index.