Acute Erythroid Leukemia Clinicopathologic Determinants of Survival: Analysis of a Pooled Database

Background Acute erythroid leukemia (AEL), a rare and aggressive subtype of acute myeloid leukemia (AML), is characterized by the predominant proliferation of immature erythroid precursors in the bone marrow and peripheral blood. Representing less than 5% of AML cases, AEL poses significant diagnostic and therapeutic challenges due to its atypical clinical presentation and the lack of standardized treatment protocols. AEL's prognosis remains poor. The determinants of survival outcomes in this disease are not very well defined. Therefore, we conducted this pooled real-world database analysis to identify the prognostic factors, clinicopathological characteristics, and therapeutic strategies that influence survival in this rare disease. Methods To study the demographic characteristics, molecular and immunohistochemical signatures, therapeutic interventions, prognostic factors, and survival, we compiled a pooled database of cases that satisfy the diagnostic criteria for AEL. Kaplan-Meier survival curves were constructed. Cox proportional hazards model and Log-rank tests were used to assess the influence of demographic and clinicopathologic factors on overall survival (OS). Results A total of 169 patients with confirmed AEL were identified. The median age was 62. There was a male preponderance with M:F of 2.7. The median duration of symptoms before diagnosis was 5.5 months. Constitutional symptoms and splenomegaly were present in 67% and 10% of the cases, respectively. The median OS of the cohort was 3 months. While majority of the cases were de novo AEL (65%), some cases developed in the context of hematologic malignancies (14%), solid cancers (2%), and MDS/MPN (18%). Patients older than 65 had worse median OS (2 vs. 4 months, p=0.0001). Those who presented with >80% erythroblasts also had worse OS (2 vs 4 months, p=0.004). However, de novo AEL was associated with better OS (4 vs 2.8 months, p=0.003). Sex, levels of WBC, Hgb, and Platelets, IHC/Immunophenotype, and presence of constitutional symptoms did not impact OS. Compared to no treatment, chemotherapy and stem cell transplant had incrementally superior OS (1 vs. 3 vs. 9 months, p=0.0001). Those who received intensive AML regimens also had better OS (p=0.005). Furthermore, patients who achieved CR as their best response also had a superior median OS (9 vs. 2.6 months, p<0.0001). Conclusion This study presents updated clinicopathologic data from a large, pooled cohort of patients with AEL. It identifies age, % marrow erythroblasts, intensity of therapy, and quality of response to treatment as critical determinants of OS.