Contributions
Abstract: PB1684
Type: Publication Only
Background
Acute erythroid leukemia is a morphologically distinct and rare entity designated as M6 in FAB classification. In Korea, patients with AML-M6 have been treated as acute myeloid leukemia with intensive chemotherapy whenever possible rather than as myelodysplastic syndrome. The 2016 revision of the WHO reclassified erythroid/myeloid subtype (a case with ≥ 50% BM erythroid precursors and ≥ 20% myeloblasts among non-erythroid cells) to MDS category based on the close biological and genetic relationships between them.
Aims
The aims of this multi-center study were to characterize clinical characteristics and treatment outcomes in patients with newly diagnosed acute erythroid leukemia.
Methods
Clinical data from newly diagnosed M6-AML patients between 2002 and 2012 at 11 academic centers were retrieved from the electronic registry data of AML/MDS working party of Korean Society of Hematology. Conventional cytogenetic analysis was performed on metaphase cells prepared from bone marrow aspirate by G-banding technique. Patients were classified according to the UK MRC cytogenetic risk criteria and the International Prognostic Scoring System (IPSS) risk groups for MDS based on karyotypes. Survival curves were analyzed using the Kaplan-Meier method and compared with a log-rank test. A p-value < 0.05 was considered statistically significant.
Results
A total of 84 patients with AEL (M6-AML) as defined by 2008 WHO classification criteria were included in this study. The median age at diagnosis was 55 years with following distribution: age ≤ 49, 34 patients (40.5%); age 50 – 59, 17 (20.2%) patients; 60 – 69, 19 (22.6%) patients; age ≥ 70, 14 (16.7%) patients. There were 50 (59.5%) males and 34 (40.5%) females. Median hemoglobin, white blood cell count, and platelet count were 8 g/dL, 3.69 × 109/L, and 58 × 109/L, respectively. Peripheral blood blasts were observed in 55 (65.5%) patients. Cytogenetic results were available in 80 patients. Among them, karyotype was normal in 43 (53.8%) and complex in 13 (15.5%) patients, respectively. Trisomy 8 was observed in ten (12.5%) patients. Monosomies of chromosome 5 and 7 were observed in five (6.2%) and four (5.0%) patients, respectively. Four (5.0%) patients had t(9;22)(q34;q11.2). Cytogenetic risk groups according to UKMRC criteria were intermediate in 63 (78.8%) patients, and poor in 17 (21.2%) patients. Seventy-two (85.7%) patients received induction chemotherapy and 55 patients (76.4%) achieved complete remission. Nineteen patients received two or three cycles of induction chemotherapy. Thirty-eight patients (45.2%) underwent allogeneic hematopoietic stem cell transplantation (HSCT): 8 patients, matched-sibling donor; 15 patients, matched-unrelated donor; 5 patients, alternative donor were used. Treatment-related mortality of HSCT was observed in five (17.9%) patients. Fourteen (16.7%) among the study patients relapsed. The median overall survival (OS) of total 84 study patients was 21 months. Patients with intermediate risk karyotype showed better median OS than those with poor risk karyotype (22 months vs. 7 months, P = 0.020). The median OS was similar in patients with good and intermediate IPSS, but significantly worse in patients with poor IPSS (21 months, 27 months, 7 months, respectively, P = 0.026).
Conclusion
Patients in this study were younger than previous studies. The most common aberrations in chromosomes are trisomy 8, followed by numerical changes in chromosome 5 and 7. The median in total patients was 21 months with many patients received intensive treatment, including HSCT in 45.2% of patients. We also confirmed that patients with poor-risk karyotypes had very poor median OS of 7 months. Therefore, we suggest that although erythroid/myeloid subtype is similar to the MDS with excess blast, treatment decision might be carefully considered according to the karyotype risk.
Session topic: 4. Acute myeloid leukemia - Clinical
Keyword(s): Survival, Erythroid, Clinical outcome, Acute Myeloid Leukemia
Abstract: PB1684
Type: Publication Only
Background
Acute erythroid leukemia is a morphologically distinct and rare entity designated as M6 in FAB classification. In Korea, patients with AML-M6 have been treated as acute myeloid leukemia with intensive chemotherapy whenever possible rather than as myelodysplastic syndrome. The 2016 revision of the WHO reclassified erythroid/myeloid subtype (a case with ≥ 50% BM erythroid precursors and ≥ 20% myeloblasts among non-erythroid cells) to MDS category based on the close biological and genetic relationships between them.
Aims
The aims of this multi-center study were to characterize clinical characteristics and treatment outcomes in patients with newly diagnosed acute erythroid leukemia.
Methods
Clinical data from newly diagnosed M6-AML patients between 2002 and 2012 at 11 academic centers were retrieved from the electronic registry data of AML/MDS working party of Korean Society of Hematology. Conventional cytogenetic analysis was performed on metaphase cells prepared from bone marrow aspirate by G-banding technique. Patients were classified according to the UK MRC cytogenetic risk criteria and the International Prognostic Scoring System (IPSS) risk groups for MDS based on karyotypes. Survival curves were analyzed using the Kaplan-Meier method and compared with a log-rank test. A p-value < 0.05 was considered statistically significant.
Results
A total of 84 patients with AEL (M6-AML) as defined by 2008 WHO classification criteria were included in this study. The median age at diagnosis was 55 years with following distribution: age ≤ 49, 34 patients (40.5%); age 50 – 59, 17 (20.2%) patients; 60 – 69, 19 (22.6%) patients; age ≥ 70, 14 (16.7%) patients. There were 50 (59.5%) males and 34 (40.5%) females. Median hemoglobin, white blood cell count, and platelet count were 8 g/dL, 3.69 × 109/L, and 58 × 109/L, respectively. Peripheral blood blasts were observed in 55 (65.5%) patients. Cytogenetic results were available in 80 patients. Among them, karyotype was normal in 43 (53.8%) and complex in 13 (15.5%) patients, respectively. Trisomy 8 was observed in ten (12.5%) patients. Monosomies of chromosome 5 and 7 were observed in five (6.2%) and four (5.0%) patients, respectively. Four (5.0%) patients had t(9;22)(q34;q11.2). Cytogenetic risk groups according to UKMRC criteria were intermediate in 63 (78.8%) patients, and poor in 17 (21.2%) patients. Seventy-two (85.7%) patients received induction chemotherapy and 55 patients (76.4%) achieved complete remission. Nineteen patients received two or three cycles of induction chemotherapy. Thirty-eight patients (45.2%) underwent allogeneic hematopoietic stem cell transplantation (HSCT): 8 patients, matched-sibling donor; 15 patients, matched-unrelated donor; 5 patients, alternative donor were used. Treatment-related mortality of HSCT was observed in five (17.9%) patients. Fourteen (16.7%) among the study patients relapsed. The median overall survival (OS) of total 84 study patients was 21 months. Patients with intermediate risk karyotype showed better median OS than those with poor risk karyotype (22 months vs. 7 months, P = 0.020). The median OS was similar in patients with good and intermediate IPSS, but significantly worse in patients with poor IPSS (21 months, 27 months, 7 months, respectively, P = 0.026).
Conclusion
Patients in this study were younger than previous studies. The most common aberrations in chromosomes are trisomy 8, followed by numerical changes in chromosome 5 and 7. The median in total patients was 21 months with many patients received intensive treatment, including HSCT in 45.2% of patients. We also confirmed that patients with poor-risk karyotypes had very poor median OS of 7 months. Therefore, we suggest that although erythroid/myeloid subtype is similar to the MDS with excess blast, treatment decision might be carefully considered according to the karyotype risk.
Session topic: 4. Acute myeloid leukemia - Clinical
Keyword(s): Survival, Erythroid, Clinical outcome, Acute Myeloid Leukemia