Abstract
Background:
The incidence for acute myelogenous leukemia (AML) is on the rise in the United States (US). Roughly 20,000 new AML patients are expected to occur in 2016 in the US (data from Surveillance Epidemiology and End Results Program). It is mainly a disease of older individuals with median age of 67 years. Unfortunately, most patients are not cured. Recent data suggest that early referral for hematopoietic stem cell transplant (HSCT) leads to more favorable outcomes, particularly those with non-good risk cytogenetics compared to alternate therapies. The objective of our study was to assess the use of upfront HSCT among AML patients with a focus on patients with non-good risk cytogenetics and determine disparity in its access based on sociodemographic and regional considerations.
Methods:
We analyzed data obtained from National Cancer Data Base (NCDB) Participant User Files for patients diagnosed with AML between 2004 and 2013 using the International Classification of Diseases for Oncology version 3 (ICD-O-3) codes 9840-9861, 9865-9874, 9891-9931. The data is collected prospectively by joint program of Commission on Cancer (CoC) and American Cancer Society. It covers nationwide oncology outcome from more than 1,500 CoC-accredited hospitals. Over 70% of all newly diagnosed cancer cases in the US are captured by NCDB. Since unique ICD-O-3 codes exist for the good-risk but not for intermediate- or poor-risk AML, we categorized the AML subtypes as good risk or non-good risk for analytic purposes. We considered patients with t(15;17), inv(16) and t(8;21) with corresponding ICD-O codes of 9871, 9896, and 9866, as good-risk patients. All others were considered non-good risk. Proportion of HSCT usage was estimated in various subgroups with 95% confidence intervals calculated using robust estimates of standard error.
Results:
We identified 80,087 patients who were diagnosed with AML between 2004 and 2013. Majority of these patients were Whites (85.9%), males (53.8%) and between the ages of 40 and 79 years (71.5%). The overall use of upfront HSCT increased consistently over time. This occurred predominantly among the non-good risk AML from a rate of 6.5% in 2004 to 12.5% in 2013 (Figure). Non-good risk patients who were Black, had Medicare insurance, with lower annual household income, and treated at facilities located in the East, South and Central parts of US ( AL, KY, MS, TN) had less access to HSCT (Table).
Conclusion:
The use of upfront HSCT in AML has almost doubled in the past decade, predominantly among those with non-good risk cytogenetics. Nevertheless, we found substantial disparity among sociodemographic and geographic subgroups. Future studies should try to understand and address how to bridge this gap.
Disclosures
No relevant conflicts of interest to declare.
Myeloablative busulfan/cytoxan conditioning versus reduced-intensity fludarabine/melphalan conditioning for allogeneic hematopoietic stem cell transplant in patients with acute myelogenous leukemia
