Abstract 4379: Survival among adults diagnosed with secondary acute myeloid leukemia
Authors: Sedeta Ephrem , Jemal Ahmedin , Nisotel Lauren , Sung Hyuna 
Published: April 2023

Abstract
Background: The burden of second primary cancers including secondary acute myeloid leukemia (sAML) is increasing in the United States; however, limited data exist regarding survival among individuals with sAML. This study aims to examine survival differences between sAML and AML arising de novo (dnAML) in relation to antecedent cancer types and the receipt of prior cancer treatment.
Methods: Individuals aged ≥20 years and diagnosed with sAML or dnAML between 2001 and 2018 and followed for vital status through 2019 were identified from Surveillance, Epidemiology, and End Results 17 database, covering 27% of the US population. The differences in AML-specific survival between individuals with sAML and dnAML were examined using multivariable Cox proportional hazards regression. Trends in five-year age-standardized relative survival from 2001-2014 were assessed using Joinpoint survival model for sAML and dnAML, separately.
Results: A total of 7,306 individuals diagnosed with sAML and 40,398 individuals with dnAML were included. During a median follow-up of 6 months, 78% of individuals with sAML died from AML compared to 71% of those with dnAML. In multivariable models, the risk of AML-specific mortality was 8% higher in individuals diagnosed with sAML than in those diagnosed with dnAML (hazard ratio [HR]=1.08, 95%CI=1.05-1.11), with the elevated risk more pronounced among those with younger ages at diagnosis (HR20-54 years=1.60, 95%CI=1.46-1.75 versus HR65+ years=0.99, 95%CI=0.96-1.03; Pinteraction&lt;0.0001) and those who received chemotherapy (HRchemotherapy yes=1.14, 95%CI=1.10-1.19 versus HRchemotherapy no/unknown=0.95, 95%CI=0.90-0.99; Pinteraction=0.0004). Subgroup analysis by antecedent cancer types showed that HRs substantially varied ranging from 0.74 (95%CI=0.57-0.95) for individuals with a history of thyroid cancer to 1.78 (95%CI=1.04-3.07) for those with a history of soft tissue sarcomas. Further subgroup analysis by the receipt of chemotherapy for antecedent cancers showed that the elevated risk was generally restricted to individuals with a history of chemotherapy receipt with some variations by cancer types. Five-year relative survival significantly increased from 2001 to 2014 for both sAML and dnAML; though the increase was slower for sAML (annual percent change [APC]=0.30%, 95% CI 0.20-0.40) compared with dnAML (APC=0.77%, 95%CI=0.69-0.84). Likewise, five-year survival for the most contemporary period (2010-2018) was substantially lower for sAML (9.8%, 95%CI=9.3-10.3) than for dnAML (22.8%, 95%CI=22.3-23.2).
Conclusion: Individuals with sAML had in general worse AML cause-specific survival compared with their dnAML counterparts, with the differences most pronounced among those diagnosed at younger ages and who received chemotherapy. The findings may inform targeted treatment and survivorship recommendations for cancer survivors who develop sAML.
Citation Format: Ephrem Sedeta, Ahmedin Jemal, Lauren Nisotel, Hyuna Sung. Survival among adults diagnosed with secondary acute myeloid leukemia. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4379.