PB1776 REAL WORLD DATA OF CLINICAL CHARACTERISTICS AND TREATMENT OUTCOMES OF ADULT PATIENTS WITH DE NOVO CORE‐BINDING FACTOR ACUTE MYELOID LEUKEMIA
Authors: Mirgh S.P. , Kapoor J. , Garg A. , Khushoo V. , Mohan B. , bothra S. , Agrawal N. , Ahmad R. , Bhurani D. 
Published: June 2019

Background:

Core binding factor acute myeloid leukemia (CBF‐AML) are responsible for approximately 20% of all adult acute myeloid leukemia. They are considered to have a relatively good prognosis, and traditionally do not need consolidation with allogenic stem cell transplant in first remission. CBF‐AML data from India has been rarely reported.

Aims:

The purpose of this study was to study the clinical characteristics and survival outcomes in newly diagnosed adults with de‐novo CBF‐AML.

Methods:

We conducted a retrospective analysis of 29 patients diagnosed with core binding factor acute myeloid leukemia who presented to our institution over a period of six years (2013‐2018). Probabilities of survival were computed using Kaplan meier method and univariate analysis was done using log rank method.

Results:

We found 29 patients diagnosed with CBF‐AML. Median age of patients was 40years (range 15 to 70). Fatigue was the most common symptom (n = 19), followed by fever (n = 15), bleeding (n = 7) and extramedullary disease (n = 2). Mean duration of symptoms were 7 weeks. 41% patients (n = 12) had splenomegaly at presentation. More than two‐third patients (n = 20) had ECOG performance status 0‐1 at presentation. On cytogenetics, inv16 was found in 27.5% patients (n = 8), and t(8;21) in 65% (n = 19), whereas 2 patients had both. Intriguingly, two third patients with inv16 had monocytosis and abnormal promonocytes in peripheral smear at presentation. 55% (n = 16) had elevated LDH. Majority of patients presented with anemia (Hb < 8), thrombocytopenia (platelet < 40,000) and leukocytosis. Hyperleukocytosis was unusual, and seen in 3 patients. Additional cytogenetic abnormalities in patients with t(8;21) included loss of sex chromosomes, trisomy17 and hypotetraploidy. Similarly,trisomy8,22 and chromosome 7 abnormalities were additionally present in inv16 group. FLT3 mutations were observed in 5 patients, whereas 1 patient had biallelic CEBPA. However, cKIT was done only in 4 patients which was negative. Over the treatment period, mean duration of chemotherapy induced neutropenia (neutrophil < 500/mm3) and thrombocytopenia (platelet < 20,000/mm3) were 10.4 days and 11.7 days, respectively. During induction therapy, fungal pneumonia was seen in 29% patients (n = 4/21), whereas proven gram negative and gram positive sepsis accounted for 25% (n = 6/21) and 19% (n = 4/21) patients, respectively. Over a median follow‐up period of 15 months (95% CI – 11.06‐18.9), median overall survival for t(8;21) and inv16 cohort was 18 months and 10 months, respectively. 4 year overall survival and progression free survival was 49 ± 18% and 24 ± 14%, respectively. On univariate analysis, ECOG PS >1 significantly affected overall survival (p = 0.026), whereas anemia (Hb < 8gm/dl) was found to have a trend towards inferior overall survival (p = 0.064) and progression free survival (p = 0.064). Additional cytogenetic abnormalities or leukocyte counts did not affect survival.

Summary/Conclusion:

Poor performance status and anemia are factors responsible for poor survival in Indian patients with CBF‐AML. Further studies are needed to clarify the clinical effects of cytogenetics in patients with CBF‐AML, between Asian and Western countries.

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