Classification Of Myeloid Neoplasms Research Articles

Acute myelomonoblastic leukemia in children, the particularities of extramedullary infiltration based on a clinical case

Childhood acute myeloidleukemia (AML) represents approximately 5% of childhood malignancies and 15% to 25% of pediatric acute leukemia. The extramedullary manifestation of infiltrating clonal blast populations in a variety of organs and tissues in acute myeloid leukemia (AML) is defined as a distinct entity in the 2016 WHO classification of myeloid neoplasms, myeloid sarcoma The rate of complete remission after induction chemotherapy was lower in patients with extramedullary infiltration, overall survival and event-free survival were not different between patients with and without extramedullary infiltration. Purpose of the study: Presentation of a clinical case of ALM type M4 with the presence of an extramedullary infiltrate in the tissue of the central nervous system in children. Materials and methods: The clinical, paraclinical, imaging data of the patient were studied in parallel with the specialized literature on similar cases. Results: Boy, 5 years old, goes to the doctor with accusations of bilateral palpebral edema, bilateral temporal region edema and bilateral exophthalmos , more pronounced on the left. In the general analysis of the blood: - Hemoglobin - 89 g/l , Leukocytes - 7.2 x 10^9/l; unsegmented neutrophil - 1%; segmented - 18%; lymphocytes - 44%; monocytes - 20%; blast cells - 16%; Platelets - 70 x 10^9/l;VSH - 44 mm/h. During the physical examination: the peripheral lymph nodes are palpable. No signs of central nervous system damage. It is supposed the diagnosis: Acute myeloid leukemia, sarcoma, or neuroblastoma. A medullary puncture: moderately cellular marrow was determined, with blastcells 15.2%. Morphologically, it is more similar to acute myelo-monoblastic leukemia FAB-M4. Computerized Tomography-multiple, hyperdense pathological foci, with localization with inand bilateral extraorbital, associated with exophthalmos. The formation from the sphenoid sinus extends to the nasopharynx , through the pterygopalatine fossa, with narrowing of the lumen and mass effect on the palatine tonsils. Immunophenotyping: CD45-/+ SS low 8% population, CD36+ 6%CD64+ monoblasts 8%, Promonocytes /monocytes – (CD64+/CD14+) 25%.He underwent treatment according to the AML BFM 2004 program with numerous complications, andcranial radiotherapy. At the moment, the child is in morphological remission. Conclusions. The differential diagnosis of hyperdense intracranial masses may include neuroblastoma, meningioma, lymphoma, metastases, or sarcomas. Correct and early diagnosis and initiation of specific treatment are essential to increase the survival rate in cases of acute leukemia in children.

The role of flow cytometry in the classification of myeloid disorders.

The World Health Organization classification (WHO-HAEM5) and the International Consensus Classification (ICC 2022) of myeloid neoplasms are based on the integration of clinical, morphologic, immunophenotypic, and genomic data. Flow cytometric immunophenotyping (FCIP) allows the identification, enumeration, and characterization of hematopoietic cells, and is therefore apowerful tool in the diagnosis, classification, and monitoring of hematological neoplasms. The vast majority of flow cytometry (FCM) studies in chronic myeloid neoplasms focus on its role in myelodysplastic neoplasms (MDS). FCM can also be helpful for the assessment of myeloproliferative neoplasms (MPN) and MDS/MPN, including the early detection of evolving myeloid or lymphoid blast crisis and the characterization of monocytic subsets. The classification of acute myeloid leukemia (AML) is primarily based on cytogenetic and molecular findings; however, FCIP is needed for subclassification of AML, not otherwise specified (NOS; ICC)/AML defined by differentiation (WHO-HAEM5). The main role of FCM in AML remains in making arapid diagnosis and as atool for measurable residual disease monitoring. Machine learning and artificial intelligence approaches can be used to analyze and classify FCM data. This article, based on an invited lecture at the 106th Annual Meeting of the German Society of Pathology in 2023, reviews the role of FCM in the classification of myeloid neoplasms, including recent publications on the application of artificial intelligence.

Bone and joint disease – Not always a rheumatological diagnosis

Abstract A 17-year-old female presented with a 7-day history of joint pains involving the bilateral knee, ankle and small joints of the hands and feet symmetrically, associated with bilateral knee joint swelling and early morning stiffness and bilateral red eyes. General examination was normal except for pallor. Musculoskeletal system examination revealed bilateral swollen and tender knee joints with restriction of movement along with tenderness in the bilateral shoulder, elbow, ankle joints and spine from T3 to T7 thoracic vertebral levels. Examination of other systems was normal. Investigations showed anaemia, elevated urea and creatinine. Skeletal survey showed multiple lytic lesions. Positron emission tomography revealed multiple punched-out lytic lesions in skull bones, scapulae, sternum, clavicles, ribs on both sides, vertebrae at multiple levels and in pelvic girdle bones. Few lesions showed mild 18fluorodeoxyglucose (18FDG) uptake, metaphyseal moth-eaten lysis in long bones with mild FDG uptake. Bone marrow biopsy and immunohistochemistry confirmed the diagnosis of acute B-cell lymphoblastic leukaemia. The terminology is according to 2016 revision of WHO classification of myeloid neoplasms and acute leukemia.

NPM1-mutated acute myeloid leukemia: New pathogenetic and therapeutic insights and open questions.

The nucleophosmin (NPM1) gene encodes for a multifunctional chaperone protein that is localized in the nucleolus but continuously shuttles between the nucleus and cytoplasm. NPM1 mutations occur in about one-third of AML, are AML-specific, usually involve exon 12 and are frequently associated with FLT3-ITD, DNMT3A, TET2, and IDH1/2 mutations. Because of its unique molecular and clinico-pathological features, NPM1-mutated AML is regarded as a distinct leukemia entity in both the International Consensus Classification (ICC) and the 5th edition of the World Health Organization (WHO) classification of myeloid neoplasms. All NPM1 mutations generate leukemic mutants that are aberrantly exported in the cytoplasm of the leukemic cells and are relevant to the pathogenesis of the disease. Here, we focus on recently identified functions of the NPM1 mutant at chromatin level and its relevance in driving HOX/MEIS gene expression. We also discuss yet controversial issues of the ICC/WHO classifications, including the biological and clinical significance of therapy-related NPM1-mutated AML and the relevance of blasts percentage in defining NPM1-mutated AML. Finally, we address the impact of new targeted therapies in NPM1-mutated AML with focus on CAR T cells directed against NPM1/HLA neoepitopes, as well as XPO1 and menin inhibitors.

Diagnosis and treatment of MPN in real life: exploratory and retrospective chart review including 960 MPN patients diagnosed with ET or MF in Germany

PurposeThe WHO 2016 re-classification of myeloproliferative neoplasms resulted in a separation of essential thrombocythemia (ET) from the pre-fibrotic and fibrotic (overt) phases of primary myelofibrosis (MF). This study reports on a chart review conducted to evaluate the real life approach regarding clinical characteristics, diagnostic assessment, risk stratification and treatment decisions for MPN patients classified as ET or MF after implementation of the WHO 2016 classification.MethodsIn this retrospective chart review, 31 office-based hematologists/oncologists and primary care centers in Germany participated between April 2021 and May 2022. Physicians reported available data obtained from patient charts via paper–pencil based survey (secondary use of data). Patient features were evaluated using descriptive analysis, also including diagnostic assessment, therapeutic strategies and risk stratification.ResultsData of 960 MPN patients diagnosed with essential thrombocythemia (ET) (n = 495) or myelofibrosis (MF) (n = 465) after implementation of the revised 2016 WHO classification of myeloid neoplasms was collected from the patient charts. While they met at least one minor WHO-criteria for primary myelofibrosis, 39.8% of those diagnosed with ET did not have histological BM testing at diagnosis. 63.4% of patients who were classified as having MF, however, did not obtain an early prognostic risk assessment. More than 50% of MF patients showed characteristics consistent with the pre-fibrotic phase, which was emphasized by the frequent use of cytoreductive therapy. Hydroxyurea was the most frequently used cytoreductive medication in 84.7% of ET and 53.1% of MF patients. While both ET and MF cohorts showed cardiovascular risk factors in more than 2/3 of the cases, the use of platelet inhibitors or anticoagulants varied between 56.8% in ET and 38.1% in MF patients.ConclusionsImproved histopathologic diagnostics, dynamic risk stratification including genetic risk factors for cases of suspected ET and MF are recommended for precise risk assessment and therapeutic stratification according to WHO criteria.

Philadelphia Negative MPNs, MDS/MPNs and MDS in the Context of Recent WHO Changes and Inclusion of Molecular Signatures into Prognostic Tools: A Single Centre Experience

Introduction: The fifth edition of WHO classification of myeloid neoplasms has introduced major changes in the defining criteria and grouping of MDS, MDS/MPNs and MPNs. Recently published literature has also cited the importance of new risk-scoring systems by integrating genomic profiling with hematologic and cytogenetic characteristics, in order to improve the prognostic discrimination of patients and represents a valuable tool for clinical decision-making. Aim: To find out the prevalence and molecular spectrum of Philadelphia-negative MPNs, MDS/MPNs and MDS in our subset of patients and henceforth to evaluate the impact on diagnosis, risk stratification and treatment decision-making of patients. Methods: This retrospective observational study included all newly diagnosed patients of non-Philadelphia positive MPNs, MDS, and MPN/MDS, in whom complete baseline diagnostic work-up was available including complete blood counts, bone marrow morphology and biopsy, cytogenetic and molecular studies. Results: The most frequent entities in our cohort of patients were primary myelofibrosis (32.8%), MDS (32.8%) and CMML (16.4%). In PIMF, 50% patients were JAK2- mutated while 30% were triple negative (JAK-, CALR-, MPL-). The commoner epigenetic modifiers among MPNs were ASXL1, TET2 and IDH2. The predominant CMML molecular signatures in our patients were NRAS, U2AF2, SETBP1, ASXL and SH2B3. There was no significant effect of WHO changes and recently introduced molecular scoring models on the diagnosis and risk stratification of all these MPN and MDS/MPN patients However, in MDS and PIMF patients, recent WHO subtyping plus IPSS-M & GIPSS scoring respectively enabled refining of risk groups. Conclusion: Molecular profiling helps in better risk stratification of patients across all groups as well as in making therapeutic decisions. However, in resource constrained settings, it is not always possible to stratify patients on the basis of molecular signatures and hence, scoring models such as DIPSS and IPSS-R holds their ground strongly even today for offering appropriate therapy to patients without compromising on quality care.

Clinical Feature and Effect of Demethylation Therapy in Pediatric Patients with Acute Myeloid Leukemia with Myelodysplasia-Related Changes

Objective:To better understanding of the clinical and biological features of childhood AML-MRC, in this study we retrospectively investigated 70 children with AML-MRC admitted to our hospital and compared with AML-NOS. We also analyzed the effect of demethylation drugs in introduction therapy among these patients. Study design: This retrospective cohort study was conducted at the Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College (IHCAMS). Newly diagnosed AML patients at our hospital between January 2009 and December 2021 with complete data regarding baseline characteristics and treatment outcomes were reevaluated as having AML-NOS or AML-MRC according to the 2016 WHO classification of myeloid neoplasms and acute leukemia, strictly excluding cases of therapy-related myeloid neoplasms and AML with recurrent genetic abnormalities. Patients with acute megakaryocytic leukemia were also excluded. Clinical and laboratory data were searched in electronic medical records. Follow-up information was obtained from electronic records or by contacting family members and was initialized from the day of diagnosis to May 31, 2022, or the day of death. Results: Among the 779 newly diagnosed AML patients in our center, 70 patients met the diagnostic criteria of AML-MRC and 73 patients were AML-NOS. Patients with AML-MRC had lower white blood cell count (9.1 (IQR 3.0~30.0) ×109/L vs.17.6 (IQR 5.9~86.8) ×109/L, p=0.002), lower hemoglobin level (74.5 (IQR 63.5~ 86.0) g/L vs. 80.0 (71.0, 94.0) g/L, p=0.025) and lower bone marrow proliferation level (p=0.001) compared with patients with AML-NOS. More FLT3-ITD positive patients were found in AML-NOS patients than AML-MRC patients (33.8% vs. 7.1%, p<0.001). Among the 70 AML-MRC patients, 41(58.6%) were diagnosed by myelodysplasia-related cytogenetics, 10(14.2%) from MDS history, and 19 (27.1%) from a multilineage dysplasia. Monosomy 7 or deletion 7q(-7/7q-) is the most frequent cytogenetic abnormality (21.6%) followed by complex karyotype (18.8%) in AML-MRC patients. Totally 56 AML-MRC patients and 71 AML-NOS patients accepted chemotherapy in out center. Induction treatment for 69 AML-NOS patients were idarubicin/ cytarabine/ etoposide (IAE) or mitoxantrone/cytarabine/ etoposide (MAE) therapy. For AML-MRC patients, demethylation drugs alone or demethylation drugs combined above regime were also used (15 case) besides IAE/MEA therapy (35 case). Six AML-MRC patients and 2 AML-NOS patients accepted homoharringtonine/cytarabine/ granulocyte colony-stimulating factor (HAG) and 3 patients received hematopoietic stem cell transplantation (HSCT) without induction chemotherapy. Overall complete remission (CR) rate of 1 course were 51.0% in AML-MRC and 68.2% in AML-NOS patients. In IAE/MAE group, higher CR rate were seen in AML-NOS patients (70.3%) than AML-MRC patients (48.4%) p= 0.06). AML-MRC patients treated with demethylation drugs seemed to have higher CR rate than introduced by IAE/MAE (64.2 % vs. 48.3%, p= 0.39). HSCT in CR1 were conducted in 29 AML-MRC patients and 19 AML-NOS patients. Median follow-up periods were 2.17 in AML-MRC group and 2.43 years in AML-NOS. Three-year overall survival (OS) and event-free survival (EFS) were 54.4% (95%CI 42.4%~69.8%) and 75.7% (95%CI 62.8%~91.1%) for AML-MRC, 42.3% (95%CI 30.2%~59.2%) and 45.8% (95%CI 32.8%~63.9%) for AML-NOS patients. Cox analysis revealed that HSCT were associated with higher OS (HR 0.21,95%CI 0.1~0.41, p< 0.001). In AML-MRC patients, 3-year OS in HSCT group were significantly higher than that in non-HSCT group [83.4% (95%CI,69.6%~99.8%) vs. 28.0% (95%CI,14.6%~53.9%), p<0.001]. AML-MRC patients with myelodysplasia-related cytogenetics exhibited lower 3-year OS (41.9% ,95%CI,27.5%~63.8%) compared with MDS history group (64.8% (95%CI,39.3%~100.0%) and multilineage dysplasia (77.1% (95%CI,57.3%~100.0%). complex karyotype (41.9% ,95%CI,27.5%~63.8%) and -7(7q-) (40.0% ,95%CI,21.5%~74.3%) AML-MRC patients had lower 3-year OS than normal karyotype (42.3%, 95%CI,21.8%~82.0%) and the other abnormal karyotype (63.5% ,95%CI,37.3%~100.0%) but without statistical difference. Conclusions: Childhood AML-MRC exhibited a comparable adverse outcome with AML-NOS which can be significantly improved by HSCT therapy. Demethylation may help improve the CR rate of AML-MRC. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Clinicopathologic Characteristics and Outcome of Acute Myeloid Leukemia with (AML) with Core Binding Factor (CBF) Rearrangements: A Retrospective Study

Background: Acute myeloid leukemia (AML) is a myeloid neoplasm, further sub- classified based on morphology, or cytogenetics, molecular genetics among other clinical and pathologic factors. AML with Core-binding factor rearrangement is cytogenetically defined by the presence of t(8;21) (q22;q22) or inv(16)(p13q22)/t(16;16)(p13;q22), commonly abbreviated as t(8;21) and inv(16), respectively or AML-CBF. According to World Health Organization (WHO) classification of myeloid neoplasms, patients with the recurring cytogenetic abnormalities t(8;21)(q22;q22), inv(16)(p13q22) or t(16;16)(p13;q22), should be considered to have (AML) even if the blast percentage is less than 20%. AML-CBF is historically known as good prognosis group of AML. This is an entirely retrospective study aiming to analyze the clinicopathologic characteristics for cases of AML-CBF in tertiary cancer center. Methods: We retrospectively analyzed data from the clinical database of our single tertiary hematology center, The National Center for Cancer Care and Research, Doha, Qatar. All patients diagnosed with AML and CBF during the period of January 2013 to December 2021. Results: Sixty-eight patients with CBF were identified. Males were predominant 47/68 (70 %) with a median age of 41 years (range, 18-77). At diagnosis, the Complete blood count showed a median hemoglobin of 8.1 g/dl, white blood cells of 35 x10^3/uL and platelets 58 x10^3/uL, median blast percentage of 45% in peripheral blood and 55 % in bone marrow (BM). BM shows marked hypercellularity in the majority of patients (79%) and was hypocellular in only 5 cases (8%). Sixty-Four patients (96%) had de novo AML, while 4 patients (4%) had secondary AML (therapy related). Subanalysis by age, < 40 years (n=36)(52%), in comparison to AML-CBF above 40 years, showed that the younger group had higher total leukocytic count 53 x10^3/uL compared to 15 x10^3/Ul in patients >40 (p=0.009), higher peripheral blasts (55 %) compared to 33 % (p=0.001) and higher BM blastS 61 % vs 48 % (p=0.05) and no therapy related cases (p =0.01). t (8; 21) was more frequent than inv(16)(p13q22)/t(16;16)(p13;q22 76% vs 24 % in AML-CBF with less than 40 years. The most detected cytogenetics abnormalities associated with CBF rearrangements were diploid cytogenetics in 35 patients (54%), followed by Complex KT in 9 patients (14%), -Y in 8(13 %). FLT 3-ITD was positive in 4/48 patients (8%), while NPM1 mutation was detected in 5/52.Kit mutation was positive in 6/15 patients (40%). Anthracycline-Cytarabine based regimen (3+7) was used most common as induction chemotherapy in 42 patients (69%), followed by Fludarabine-Cytarabine-Anthracycline (FLAG-Ida) regimen in 19 % of cases. Remission achieved in 67% of the patients after induction therapy. Twelve patients (19%) underwent allogenic bone marrow transplant. Patient characteristics are described in Table 1. The median overall survival (OS) was 81 %, with median of 37 months and progression free survival (PFS) 34 months. There was no statistically significant difference between FLT 3-ITD-positive and negative cases (p=0.2) or patients who had t (8; 21) vs t (16; 16) (p=0.8) or patient with complex karyotype (p=0.2). The progression free survival PFS for non-transplanted patients vs transplanted 20 months vs 16 months (p=0.8) Conclusion: AML with CBF is different and interesting subtype of AML. In our study, the majority of patients were young males with more prevalent t (8; 21). Younger patients (less than 40 years) with AML-CBF has higher WBCs and blasts percentage with less incidence of secondary AML. Association with complex karyotype or FLT 3-ITD wasn't show statistically significant inferior out come in our cohort and transplanted patients didn't show statistically significant advantage. This study is limited by sample size Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Clonal Megakaryocyte Dysplasia with Isolated Thrombocytosis Is a Distinct Myeloproliferative Neoplasm Phenotype

Introduction: About 15% of people with a myeloproliferative neoplasm (MPN) are identified as MPN, unclassifiable using the 2016 WHO classification. Methods: We tested whether persons with platelet concentration ≥450 × 10E+9/L, bone marrow megakaryocyte morphology typical of prefibrotic/early myelofibrosis (pre-MF), and no minor criteria of pre-MF should be classified as a distinct MPN subtype, clonal megakaryocyte dysplasia with isolated thrombocytosis (CMD-IT). Results: 139 subjects meet these criteria who we compared with primary myelofibrosis (PMF) including 402 with pre-MF and 521 with overt myelofibrosis. CMD-IT subjects were more likely female and younger. They had lower frequencies of JAK2^V617F compared with persons with PMF (55% vs. 70%; p < 0.001) and higher frequencies of CALR mutations (37% vs. 17%; p < 0.001). They also had lower frequency of variations associated with JAK2^V617F susceptibility, JAK2 46/1 (35% vs. 47%; p = 0.021), and VEGFA rs3025039 (12% vs. 17%; p = 0.030). Subjects with CMD-IT had lower incidences of thrombotic events compared with those with pre-MF (9.7% vs. 26%; p < 0.001) and longer survival (median, not reached vs. 23 years; HR = 0.34 (0.10, 0.30); p < 0.001). Conclusion: Our data indicate CMD-IT is a distinct MPN subtype and should be included in the classification of myeloid neoplasms.

PB1912: MYELODYSPLASTIC SYNDROME WITH ISOLATED 5Q DELETION AND ASSOCIATED 5Q DELETION TO 13Q DELETION

Background: The 5q deletion is the classic chromosomal abnormality in myelodysplastic syndrome (MDS). Critical regions are 5q31 and 5q33, leading to gene haplodeficiency and other pathogeneic mechanisms. 13q deletion occurs in about 2% of MDS cases. This deletion involved band 13q14. Aims: Here we describe cytogenetic abnormalities in a Tunisian cohort of MDS patients and we shed the light on cases with 5q deletion. Methods: Cytogenetic analyses of bone marrow cells were performed according to standard procedures for 12 Tunisian patients presenting with MDS. Cytogenetic analysis was performed on lymphocytes and bone marrow cells. Cultured cells were treated with colchicine and hypotonic KCl solution. The pellet was fixed and washed in methanol-acetic acid (3:1). The cells were resuspended in fixative and dropped onto slides. Chromosome-banding analysis was performed using RHG and GTG banding techniques. Three karyotypes and 25 metaphases were analyzed according to the International System for Human Cytogenetic Nomenclature. Results: Cytogenetic abnormalities were detected in 9 cases and del5q was recorded in four patients (3 patients with refractory anemia (RA) and a fourth with RA and excess blasts-T (RAEB-T)). The del5q was isolated in two RA cases as a del (5) (q13 q33) in a new diagnosed and a treated patients. It was associated in two patients: a RA patient explored during the evolution, harboring a del (5) (q12 q33) associated to a del (13) (q12 q14) and the RAEB-T patient harbouring a del (5) (q21 q31) associated to a clonal hyperploidy. Summary/Conclusion: The diagnosis of MDS was based on cytomorphology and cytogenetics. However, nowadays, an increasing number of molecular aberrations have been discovered and included in the WHO revised new classification of myeloid neoplasms. The del13q described in MDS seems to be a marker of the evolution of the clonal cells harboring 5q deletion. However, the molecular basis and the implicated genes of the deletion of the long arm of chromosome 13 associated to the 5q deletion clone remain until now not well explored.

Phase II trial of luspatercept with or without hydroxyurea for the treatment of patients with myelodysplastic/myeloproliferative neoplasms with ring sideroblasts and thrombocytosis or unclassifiable with ring sideroblasts.

TPS7080 Background: Myelodysplastic syndrome/myeloproliferative neoplasms (MDS/MPN) are classified as a distinct category under the World Health Organization (WHO) classification of myeloid neoplasms. MDS/MPN with RS and thrombocytosis (MDS/MPN-RS-T) and MDS/MPN, unclassifiable with &gt; 15% bone marrow ring sideroblasts (MDS/MPN-U-RS) have similar clinical and pathological characteristics with symptomatic or transfusion-dependent anemia as the predominant morbidity. Luspatercept has been approved in myelodysplastic syndromes with ring sideroblasts (MDS-RS) and MDS/MPN overlap syndromes, based on the phase 3 MEDALIST clinical trial which primarily included MDS-RS patients with an objective erythroid response rate of approximately 40 per cent. In this trial, some MDS-RS patients also experienced an increase in neutrophil and platelet counts. This raises a safety concern for MDS/MPN patients with elevated platelet or WBC counts such as MDS/MPN-RS-T and MDS/MPN-U-RS. Previous studies have shown clinical and biological differences between MDS-RS and MDS/MPN-RS-T, with the latter group at a significantly elevated risk for thrombotic events. Additionally, several MDS/MPN-RS-T patients are on hydroxyurea which may blunt the erythroid response of luspatercept. Therefore, it is imperative to establish the safety and efficacy of luspatercept in this patient group. Methods: This is an investigator-initiated, prospective, phase II study of luspatercept in MDS/MPN overlap neoplasms with ring sideroblasts and thrombocytosis or unclassifiable with ring sideroblasts with 2 arms; hydroxyurea-independent (cohort A) and hydroxyurea-dependent (cohort B). Hydroxyurea and/or aspirin use is allowed as per investigator discretion. The primary goal is to study the efficacy and safety of luspatercept in MDS/MPN-RS-T or MDS/MPN-U-RS with symptomatic anemia. The primary endpoint is to assess erythroid response rate as per the 2015 International Working Group MDS/MPN response criteria. Secondary endpoints include response duration, time to acute myeloid leukemia (AML) transformation, thrombosis rate, AML-free and overall survival. Inclusion criteria include newly diagnosed or relapsed/refractory adult patients with WHO-defined diagnosis of MDS/MPN-RS-T or MDS/MPN-U-RS with symptomatic or transfusion-dependent anemia and unlikely to respond (EPO level &gt; 200 IU/L) or intolerant to erythropoiesis stimulating agent (ESA) therapy. Prior therapy with lenalidomide, hypomethylating agents or immunosuppressive therapy is allowed. The overall plan is to enroll 54 patients across the three Mayo Clinic sites, Minnesota, Arizona and Florida. Enrollment to the trial began in January 2022 with 1 patient enrolled at the time of abstract submission. Clinical trial information: NCT05005182.

Myelodysplastic/myeloproliferative neoplasms-unclassifiable with isolated isochromosome 17q represents a distinct clinico-biologic subset: a multi-institutional collaborative study from the Bone Marrow Pathology Group

Classification of myeloid neoplasms with isolated isochromosome i(17q) [17p deletion with inherent monoallelic TP53 loss plus 17q duplication] is controversial. Most cases fall within the WHO unclassifiable myelodysplastic/myeloproliferative neoplasms (MDS/MPN-U) category. The uniformly dismal outcomes warrant better understanding of this entity. We undertook a multi-institutional retrospective study of 92 adult MDS/MPN-U cases from eight institutions. Twenty-nine (32%) patients had isolated i(17q) [MDS/MPN-i(17q)]. Compared to MDS/MPN without i(17q), MDS/MPN-i(17q) patients were significantly younger, had lower platelet and absolute neutrophil counts, and higher frequency of splenomegaly and circulating blasts. MDS/MPN-i(17q) cases showed frequent bilobed neutrophils (75% vs. 23%; P = 0.03), hypolobated megakaryocytes (62% vs. 20%; P = 0.06), and a higher frequency of SETBP1 (69% vs. 5%; P = 0.002) and SRSF2 (63% vs. 5%; P = 0.006) mutations that were frequently co-existent (44% vs. 0%; P = 0.01). TP53 mutations were rare. The mutation profile of MDS/MPN-U-i(17q) was similar to other myeloid neoplasms with i(17q) including atypical chronic myeloid leukemia, chronic myelomonocytic leukemia, myelodysplastic/myeloproliferative neoplasm with ring sideroblasts and thrombocytosis, myelodysplastic syndrome and acute myeloid leukemia, with frequent concomitant SETBP1/SRSF2 mutations observed across all the diagnostic entities. Over a median follow-up of 52 months, patients with MDS/MPN-i(17q) showed a shorter median overall survival (11 vs. 28 months; P < 0.001). The presence of i(17q) retained independent poor prognostic value in multivariable Cox-regression analysis [HR 3.686 (1.17–11.6); P = 0.026] along with splenomegaly. We suggest that MDS/MPN-i(17q) warrants recognition as a distinct subtype within the MDS/MPN-U category based on its unique clinico-biologic features and uniformly poor prognosis.

A call for revision of the World Health Organization classification system to include FLT3-ITD as a distinct entity

Acute Myeloid Leukemia (AML) is a heterogeneous malignancy driven by over 200 different cytogenetic abnormalities, giving rise to eight different subtypes, each identified as having a unique prognostic outcome and response to treatment. The World Health Organization (WHO) classification of myeloid neoplasms and acute leukemia describes specific subtypes and is widely used to treat and diagnose AML. However, the current WHO classification system is based primarily on treatment outcomes for adult patients. In recent years, the incorporation of genetic and molecular testing has aided in the identification of several distinct subtypes that are not yet recognized by the WHO classification system. One key genomic driver in some cases of AML is the internal tandem duplication (ITD) within the gene that codes for the FMS-like tyrosine kinase receptor-3 (FLT3). Pediatric AML patients with FLT3-ITD consistently have high relapse rates and low overall survival rates, which may be improved by intensifying and specifying treatment regimens. Despite increasing research showing the prognostic significance of FLT3-ITD AML and development of FLT3 inhibitors, this cytogenetically unique form of AML with a distinctly poor prognosis in children is not mentioned in the current WHO classification. The authors suggest the need for inclusion of FLT3-ITD as a distinct entity in the WHO classification due to its prognostic effect in pediatric AML in particular. Though advancements have been made in the understanding and treatment of FLT3-ITD AML, the application of current and future research will be limited without the inclusion of FLT3-ITD as a distinct entity.

Clinicopathologic Characteristic and Natural History of Patients with Non Hereditary, Non Polycythemia Vera (NH/NPV) Persistent Polycythemia

Introduction;Polycythemia Vera (PV), is one of the most common Philadelphia chromosome negative myeloproliferative disorders. The identification of Janus Kinase (JAK) 2 mutations and the publication of 2016 revision of WHO classification of myeloid neoplasms has improved diagnostic accuracy of PV. The lower cut-off values of Hemoglobin (Hb) and hematocrit (Hct) used in WHO diagnostic criteria, however, resulted in increased number of adult patients undergoing further evaluation for PV leading to identification of patients with acquired, idiopathic Persistent polycythemia (PP) who not meet WHO criteria for PV despite extensive work up. The clinicopathologic features, disease course, treatment and outcomes of these patients has not been well characterize. This study seeks to described clinicopathologic and molecular profile of cohort of adult patients with Non Hereditary, Non-Polycythemia Vera (NHNPV) Persistent Polycythemia.Methodology;Patients with PP diagnosed and followed up in Fresno community regional medical center/University of San Francisco (UCSF) Fresno, from January 2010 to December 2020 were reviewed. Patients who didn't meet WHO diagnostic criteria for PV after full evaluation including bone marrow biopsies were included in the study. Those with incomplete evaluation, clearly attributable secondary causes of polycythemia or erythropoietin (EPO) level above institutional laboratory reference range (2-18), were excluded from the study. Patients with polycythemia diagnosed at pediatric age were also excluded. The study was approved by institutional review board of UCSF Fresno.Results;129 subjects with JAK 2 Negative PP were reviewed of which 63 had EPO levels within or below the normal range (2-18).Of 36 patients who met the study inclusion and exclusion criteria, majority were males (70% N= 28) and non-Hispanic (56% N=20) with median age at diagnosis of 48.5 years (range 18-70 years). Half of the patients (N=18) have no identifiable etiology of PP. In patients with associated conditions, the most common is non-oxygen requiring clinical OSA (36%) and tobacco smoking (19.4%). Of note, all these patients have EPO level less than 10 which represents the median value of the local institutional defined normal range for EPO. Four (11%) patients have non-iron overloaded hemochromatosis gene mutation (1 Homozygous H63D HFE gene, 2 heterozygous mutation and one with unspecified mutation type).Average Hb and Hct at diagnosis was (17.26+/- 2.23) and (49.76+/- 6.34) respectively. Mean EPO level 7.05+/-2.75 with less than third of patients 8 (22%) with level less or equal to in 5 units. There is no statistically significance difference between mean diagnostic EPO level between males and females in the study (7.20+/-2.89 vs.6.51+/-2.26) and so is the Hct though males have numerically higher levels.The most common bone marrow morphology includes normocellularity (51.76+/-10.36) with erythroid hyperplasia (25%) or megakaryocyte hyperplasia without dysplasia (17%) and grade 1/3 fibrosis 6/36.Abnormal mutations were identified in 17 patients whose bone marrow biopsies were evaluated with limited or extensive next generation sequencing (NGS). Of those patients with available results, 6 patients (35% out of those with NGS) have identifiable previously well described genetic mutations {FANCA S1311fs*1, HGF R134H, TP53 splice site 97-2A>G, KMT2A (Gain), MLL3 (KMT2C) and AFF4, ASXL1 c.1934dupG/TrpfsX12 (p. Gly646)}.9 patients had variance of unknown significant (VUS) mutations (Table 1) with average of 6.2 mutation per patient. Only 1 VUS (TSC1 K587R) was reported in 2 different patients (#7, #9)Mild Myeloproliferative neoplasia (MPN) associated symptoms was reported in 22% of patient with Intermittent phlebotomy (72% N= 26) and aspirin (75% N=27) was the treatment for majority of patients. One patient died during the follow up period. No patient progressed to other MPN, myelofibrosis or AML during the study period.Conclusion;With improved diagnostic criteria and accuracy of PV, increased number of patients are diagnosed with NHNPV Persistent polycythemia. None of the mutation or VUS identified from extensive evaluation is recurrent in our cohort of patient. Longer follow up is needed to delineate clinical significance and prognosis of these mutation in patients with NHNPV persistent Polycythemia. [Display omitted] DisclosuresAbdulhaq: BMS, Alexion, Oncopeptides, Morphosys, Pfizer, Norvartis: Honoraria; Oncopeptides, Alexion, Amgen: Speakers Bureau; Morphosys, BMS, Amgen: Membership on an entity's Board of Directors or advisory committees.

Excess Mortality in Young Patients with Myeloproliferative Neoplasms

▪Introduction: Myeloproliferative neoplasms (MPNs) - essential thrombocythemia (ET), polycythemia vera (PV), and primary myelofibrosis (PMF) - are associated with significant morbidity and shortened survival, irrespective of age (Srour et al. Br J Hematol. 2016). Despite shortened survival, young MPN patients (pts) are often classified as “low-risk” and managed with aspirin alone, phlebotomy-only (PHL), or observation instead of potentially life-prolonging cytoreductive and/or disease-modifying treatment. Age-biased risk assessment and treatment practices deprive young pts from early intervention and access to clinical trials. Our goal is to highlight the unmet need for identifying and implementing life-prolonging treatment in young MPN pts. Here, we determine and compare the excess mortality from MPNs in young (<60 years) to older pts (≥60 years) in the United States (US).Methods: In this population-based study, demographic (age, sex, race), survival, and cause-of-death data were collected for MPN pts from the US Survey, Epidemiology, and End Results (SEER) registry between 2001-2017; and for the general US population from the Centers for Disease Control and Prevention Wide-ranging OnLine Data for Epidemiologic Research (CDC WONDER) database. SEER reports cancers classified by International Classification of Diseases for Oncology, version 3 (ICD-O-3), which evolved with the WHO classification of myeloid neoplasms in 2001 for ET, PV and PMF. Cause-of-death is reported by ICD-10 codes, which we categorized into cardiovascular (CVE), second cancers (CA), acute leukemia (AL), and others. Excess, or relative mortality was determined by the ratio of observed mortality in MPN pts (Kaplan-Meier estimate) over the expected mortality of the US population matched by age, sex, race, and birth-year (actuarial estimate). A one-sided log-rank test was used. Excess mortality of young compared to older pts was determined from a random-effects model using restricted maximum-likelihood estimator method. All analyses were performed using RStudio software v 1.4.1106.Results: The SEER query identified 40,333 MPN pts (ET: 17,420 (43%), PV: 18,027 (45%), PMF: 4,886 (12%)) diagnosed at a median age of 66 years (ET: 67, PV: 65, PMF: 69) of whom 20,470 (51%) were females (ET: 10,709 (61%), PV: 7,768 (43%), PMF: 1,993 (41%)). The 10-year mortality for ET, PV, and PMF pts <60 was 13%, 18%, and 49% respectively (versus 6% for controls); and ≥60 was 59%, 59%, and 87% respectively (versus 35% for controls) (Figure 1A). Excess all-cause mortality was higher in pts <60 compared to ≥60 with ET (2.75 versus 1.82, p<0.001), PV (3.16 versus 1.92, p<0.001), and PMF (10.6 versus 5.73, p<0.001) (Figure 1B). Excess CVE mortality was higher in PV<60 compared to PV≥60 (3.36 versus 2.55, p=0.036) but not in ET or PMF. Excess CA mortality was higher in PV<60 than PV≥60 (2.36 versus 1.53, p=0.002) but not in ET or PMF. Excess AL mortality was high for all pts, particularly PMF, and was not significantly different in pts <60 compared to ≥60Discussion: Excess or relative mortality emphasizes the burden of MPN-related death with current treatment. In this population-based study, we found excess mortality in young MPN pts (<60), greater than in older pts (≥60). This difference may result from age-biased risk assessment and treatment recommendations that recommend lower intensity therapy for young pts. It may be time to revisit these recommendations since accruing evidence demonstrates long-term safety, efficacy and potential survival benefit of available cytoreductive agents. Certain treatments such as interferon-alpha (IFN) may improve survival in PV (Abu-Zeinah et al. Leukemia. 2021), and a recent randomized clinical trial established superiority of IFN over standard of care PHL in young PV pts (Barbui et al. Lancet Hematol. 2021). These data advocate for early intervention with potentially disease-modifying treatment for all pts regardless of age. These data also call into question age-biased exclusions of many young pts from participation in clinical trials of established or promising drugs.Conclusion: Excess mortality of young MPN pts (<60) is unacceptably high and greater than that of older pts (≥60). Clinical trials testing early intervention with potentially life-prolonging treatments are required. [Display omitted] DisclosuresSilver: Abbvie: Consultancy; PharamEssentia: Consultancy, Speakers Bureau. Scandura: Abbvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Constellation: Research Funding; MPN-RF (Foundation): Research Funding; CR&T (Foudation): Research Funding; European Leukemia net: Honoraria, Other: travel fees . Abu-Zeinah: PharmaEssentia: Consultancy.

Mutant NPM1-regulated lncRNA HOTAIRM1 promotes leukemia cell autophagy and proliferation by targeting EGR1 and ULK3

BackgroundAcute myeloid leukemia (AML) with mutated nucleophosmin (NPM1), which displays a distinct long noncoding RNA (lncRNA) expression profile, has been defined as a unique subgroup in the new classification of myeloid neoplasms. However, the biological roles of key lncRNAs in the development of NPM1-mutated AML are currently unclear. Here, we aimed to investigate the functional and mechanistic roles of the lncRNA HOTAIRM1 in NPM1-mutated AML.MethodsThe expression of HOTAIRM1 was analyzed with a public database and further determined by qRT-PCR in NPM1-mutated AML samples and cell lines. The cause of upregulated HOTAIRM1 expression was investigated by luciferase reporter, chromatin immunoprecipitation and ubiquitination assays. The functional role of HOTAIRM1 in autophagy and proliferation was evaluated using western blot analysis, immunofluorescence staining, a Cell Counting Kit-8 (CCK-8) assay, a 5-ethynyl-2′-deoxyuridine (EdU) incorporation assay, flow cytometric analyses and animal studies. The action mechanism of HOTAIRM1 was explored through RNA fluorescence in situ hybridization, RNA pulldown and RNA immunoprecipitation assays.ResultsHOTAIRM1 was highly expressed in NPM1-mutated AML. High HOTAIRM1 expression was induced in part by mutant NPM1 via KLF5-dependent transcriptional regulation. Importantly, HOTAIRM1 promoted autophagy and proliferation both in vitro and in vivo. Mechanistic investigations demonstrated that nuclear HOTAIRM1 promoted EGR1 degradation by serving as a scaffold to facilitate MDM2-EGR1 complex formation, while cytoplasmic HOTAIRM1 acted as a sponge for miR-152-3p to increase ULK3 expression.ConclusionsTaken together, our findings identify two oncogenic regulatory axes in NPM1-mutated AML centered on HOTAIRM1: one involving EGR1 and MDM2 in the nucleus and the other involving the miR-152-3p/ULK3 axis in the cytoplasm. Our study indicates that HOTAIRM1 may be a promising therapeutic target for this distinct leukemia subtype.

How to unmask unique vulnerabilities in leukaemia

How to unmask unique vulnerabilities in leukaemia Acute myeloid leukaemia (AML) is a group of haematologic malignancies that have been traditionally difficult to classify and treat. Nucleophosmin (NPM1) mutations are the most frequent genetic alteration (about 30 per cent) in AML and NPM1-mutated AML is a new entity in the WHO classification of myeloid neoplasms. However, mechanisms of leukemogenesis and a specific therapy for this leukaemia are missing. The ContraNPM1AML project aims to unravel the complex network of molecular interactions that take place in this distinct genetic subtype and find their vulnerabilities to identify new targets for therapy. The expected discoveries will lead to novel therapeutic approaches and make clinical trials available to patients.

Deep Learning Algorithms Depict New Subgroups of AML and MDS Based on Genetics Only and Allow Distinction of Both Entities with High Accuracy of 90%

Since 45 years MDS and AML are separated according to the percentage of bone marrow blasts. Although this is an arbitrary threshold, it led to different therapeutic strategies and the discovery of more or less directly related cytogenetic changes. The last decade added a lot of molecular genetic information for diagnosis, prognosis and increasingly targeted treatment options. The vast majority of cytogenetic and molecular genetic findings however are common in both diseases, irrespective of blast count. However, the classification of myeloid neoplasms is still based on morphology. Therefore, we analyzed for the first time a large cohort of morphologically defined de novo AML (n=901) and MDS (n=2,097) patients (pts), all characterized by gene panel sequencing and cytogenetics, and applied deep learning algorithms to differentiate AML versus MDS based on genetics only. Mutation status of 22 recurrently mutated genes as well as 23 recurrent cytogenetic aberrations, including fusion transcripts and copy number variations, were used as markers.The dataset was initially filtered to exclude pts and genes with a large number of missing values, which would otherwise hamper the computational analysis of the cohort. The filtered dataset was randomly divided into a training (90%) and validation (10%) set. Subsequently we applied Lasso regression to classify AML versus MDS with 10-fold cross-validation. The whole procedure was repeated 1,000 times. We were able to classify AML versus MDS with an accuracy of 83%. Misclassification of 17% of pts indicated that these pts exhibited a genetic profile that could not be matched to the learned patterns of the two entities. Interestingly, the only cytogenetic markers that impacted classification at all but on a low level were PML - RARA and CBFB - MYH11, while 19 gene mutations were of high impact.Hence, we applied unsupervised k-modes clustering to partition the pts into k groups per entity. Here the dissimilarity of two gene profiles was determined by simple-matching distance and the optimal k was chosen based on internal measures and biological relevance of the groups using the 19 most relevant gene mutations as markers only.The analysis revealed 4 genetically distinct clusters for both the AML and MDS cohorts. Within AML 158 pts were grouped in one cluster, dominated by mutations in ASXL1, RUNX1, and SRSF2 . A second cluster (n=160) was mainly set up by pts with NPM1, IDH, and DNMT3A mutations, while a third cluster consisted of 41 pts with ASXL1, NRAS, and TET2 mutations. The remaining pts (n=541) grouped in cluster 4 showed no obvious pattern. 242 MDS pts were grouped in one cluster with also ASXL1, RUNX1, and SRSF2 mutations. A second cluster contained 216 MDS pts with mainly ASXL1, SRSF2, and TET2 mutations. A third cluster was dominated by pts with SF3B1 mutation (n=382), while cluster 4 again was a cluster with no obvious pattern (n=1,257).We performed the same analysis for both entities together and identified 6 different clusters (Fig.). The distribution of AML and MDS to the 6 clusters differed significantly, one cluster each was dominated by AML and MDS, respectively, although each cluster contained pts from both entities. Cluster 2 represented cases with SF3B1 and RUNX1 mutation, while cluster 3 was dominated by NPM1, IDH, and DNMT3A mutated AML pts. Cluster 4 contained preferentially pts with NPM1 and TET2 mutations and cluster 6 ASXL1, RUNX1, and TET2 mutated pts. Cluster 1 and 5 showed no obvious pattern. Interestingly, these 6 clusters showed different outcome within the AML and MDS subgroups, respectively (range median OS AML: 12 to 46 months, MDS: 9 months to not reached; p<0.001 for both groups).Using the 19 highly relevant genetic markers now for Lasso regression to classify AML versus MDS with 10-fold cross-validation we reached an accuracy of 90%.In conclusion, we here challenged arbitrary disease defining thresholds (20% of bone marrow blasts) and applied deep learning approaches and artificial intelligence to a cohort of AML and MDS pts. 1) We reproduced only on 19 molecular markers the standard diagnoses with an accuracy of 90%. 2) We detected specific molecular patterns shared from AML and MDS cases that were irrespective of the original WHO diagnoses. 3) The respective new patterns demonstrated different outcome within AML and MDS subgroups. This might be a first proof how future classification systems might be based on molecular data and deep learning algorithms. [Display omitted] DisclosuresMeggendorfer:MLL Munich Leukemia Laboratory: Employment. Walter:MLL Munich Leukemia Laboratory: Employment. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Kern:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership.

Impact of 9q Deletions on the Classification in AML

Background: In the 2016 revision of the World Health Organization (WHO) classification of myeloid neoplasms and acute leukemia the deletion of the long arm of chromosome 9 (del(9q)) was excluded as a defining cytogenetic abnormality for AML with myelodysplasia-related changes due to its frequent association with NPM1 and biallelic CEBPA mutations.Aim: Investigation of the frequency of del(9q) in AML and its accompanying molecular and cytogenetic abnormalities to assess whether or not del(9q) is associated with a myelodysplasia-related mutation profile.Patients and Methods: We evaluated 9762 AML patients (pts) diagnosed between 2005 and 2017 for del(9q) using chromosome banding analysis (CBA). Pts with del(9q) were further analyzed for mutations in NPM1 , CEBPA and RUNX1 with amplicon sequencing to categorize them according to the WHO classification. Pts without a class defining aberration or a complex aberrant karyotype were screened for AML- or MDS-related mutations (ASXL1, BCOR, EZH2, FLT3- ITD , FLT3- TKD , SF3B1, SRSF2, STAG2, TET2, TP53, U2AF1, WT1 and ZRSR2 ). Variants of unknown significance were excluded from statistical analysis. The size of the deleted region on chromosome 9 was evaluated by array CGH (Agilent Technologies, Santa Clara, CA) and NUP98 -rearrangements were investigated by FISH(MetaSystems, Altlussheim, Germany).Results: In 114/9762 pts (1 %) a del(9q) was detected by CBA. This cohort with del(9q) comprised 60 male and 54 female pts, median age was 63 years (range: 16 - 90 years). Del(9q) was accompanied by the following rearrangements: RUNX1-RUNX1T1 rearrangement in 20/114 pts (18 %), PML-RARA in 5/114 pts (4 %), KMT2A in 2/114 pts (2 %) and MECOM in 1/114 pts (1 %). In 20/114 pts (18 %) a NPM1 mutation and in 7/114 pts (6 %) a biallelic CEBPA mutation was observed. Furthermore, RUNX1 mutations were found in 3/114 pts (3 %). The remaining 56 pts (49 %) were divided into the following three groups: pts with del(9q) as a sole cytogenetic abnormality (del(9q) sole, 8/114 pts, 7 %), pts with one or two additional cytogenetic aberrations (del(9q) other, 19/114 pts, 17 %) and pts with complex aberrant karyotype (complex, 29/114 pts, 20 %) harboring 4 to 29 cytogenetic aberrations (median: 8). Cases with del(9q) sole and other (n = 27) were further characterized. NUP98 -FISH analysis revealed a NUP98 -rearrangement in 5/27 pts (19 %) in the del(9q) sole and other group. Moreover, two pts with del(9q) showed AML specific rearrangements (t(8;16)(p11;p13) and t(3;5)(q25;q35)). The most frequently mutated genes in del(9q) sole and other were: FLT3 -ITD (8/23 pts, 35 %), TET2 (7/27 pts, 26 %), FLT3 -TKD (4/21 pts, 19 %) and WT1 (3/26 pts, 11 %). A very high frequency of FLT3 -ITD and FLT3 -TKD were found in pts with del(9q) and balanced rearrangements (5/7 pts, 71 %).To identify whether pts with del(9q) sole and other rather resemble a molecular mutation profile typical for secondary AML arising from MDS (s-AML), the presence of gene mutations related to s-AML (according to Lindsley, et al., 2015, Blood) was evaluated. 9 pts (33 %) had a mutation in at least one of these genes, 14 pts (52 %) showed no such mutation and 4 pts (15 %) could not be fully analyzed.Array CGH showed that in pts with del(9q) sole the deletion size ranged from 14 - 42 Mb (median: 28 Mb), in pts with del(9q) other from 19 - 70 Mb (median: 32 Mb). A minimal deleted region for pts with del(9q) sole and other could not be determined for all pts due to the strong variation between the respective deleted regions.Follow up data was available for 75 pts with a median follow-up of 27 months. The median overall survival (OS) for pts with RUNX1-RUNX1T1 , NPM1 and bialleic CEBPA mutation was not reached. It was 73 month for pts with del(9q) sole and other and 16 month for pts with complex karyotype, RUNX1 mutations or MECOM rearrangements. The OS of first two groups did not differ significantly, but was significantly distinct from the last group (p = 0.03 and 0.03, respectively).Conclusion: In 1 % of AML pts a del(9q) was present. Del(9) frequently co-occured with RUNX1-RUNX1T1 , biallelic CEBPA and NPM1 mutations, NUP98 -rearrangements and other AML-typical translocations. A mutation signature typical for s-AML was infrequent. Thus, it seems reasonable that the del(9q) is no longer regarded as a defining cytogenetic abnormality for AML with myelodysplasia-related changes, in particular as prognosis in del(9q) cases with non-complex karyotype is favorable. DisclosuresBalk:MLL Munich Leukemia Laboratory: Employment. Stengel:MLL Munich Leukemia Laboratory: Employment. Meggendorfer:MLL Munich Leukemia Laboratory: Employment. Fasan:MLL Munich Leukemia Laboratory: Employment. Kern:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership.

Complete Responses of Myeloid/Lymphoid Neoplasms with Rearrangement of Pdgfra Presenting As AML/ALL/Myeloid Sarcoma to Imatinib Monotherapy

Background Patients with eosinophilia and FIP1L1-PDGFRA fusion protein accounted for approximately 23% (range, 3%-56%) of hyper-eosinophilias. In the 2008 and 2016 WHO classification of myeloid neoplasms, myeloid/lymphoid neoplasms with rearrangement of PDGFRA have been categorized as a distinct type of hematopoietic disorders. Reported cases mostly exhibit normal or mildly elevated bone marrow blasts at diagnosis and imatinib monotherapy is sufficient to induce rapid and complete hematopoietic responses. Patients with rearrangement of PDGFRA but presenting as AML/ALL or myeloid sarcomas are rare and the efficacy of imatinib monotherapy in these patients remains undefined.Methods Two male patients were diagnosed as myeloid neoplasms with rearrangement of PDGFRA in our hospital in 2016. Patient One (aged 31) was presenting as myeloid sarcoma with a 6.9×3.3cm mass on his chest wall and was treated with chemotherapy plus imatinib. Patient Two (aged 25) was presenting as AML with a bone marrow blasts of 27% and was treated with imatinib monotherapy. A literature review searching for patients with PDGFRA rearrangement but presented as AML/ALL/myeloid sarcoma was performed and efficacy of imatinib monotherapy was explored.Results Both of the cases from our hospital survived. Patient One received two cycles of standard chemotherapy (MA and IA) but failed to reduce the tumor size. Imatinib (400mg/d) was initiated immediately. His tumor shrunk dramatically in one week and he achieved complete molecular remission (CMR) in 4 weeks. Patient Two receiving imatinib monotherapy achieved complete hematopoietic remission (CHR) in 1 month and CMR in 3 months after initiation of imatinib (400mg/d). Both patients remain CHR and CMR till now (8 months and 18 months, respectively). We combined our data with 24 cases found in literature that presented as AML/ALL/myeloid sarcoma at diagnosis. All 26 patients were male, and the median age was 40 years (range, 21 to 46). We further compared outcomes of patients treated with imatinib monotherapy or with chemotherapy/HSCT plus imatinib. Most cases in the latter group were given imatinib after chemotherapy induction due to persistent eosinophilia, unsatisfied regress of tumor mass, continued positivity of PDGFRA fusion gene, or disease relapse. The 3-year probabilities of overall survival (OS) were 87.5% for the monotherapy group and 80% for the plus chemotherapy/HSCT group, which were of no statistical significance (p=0.919). In each group there was one patient died from imatinib resistance caused by a mutation in the fusion gene.Conclusions We reported two rare cases of myeloid neoplasms with rearrangement of PDGFRA but presenting as AML/myeloid sarcoma at diagnosis and showed their excellent responses to imatinib. By pooling data in literature we suggest imatinib monotherapy was comparable to combination of chemotherapy/HSCT and imatinib in overall survival rate. To our knowledge, this is the first study to specifically explore outcomes of various treatments for this disease. The efficacy of imatinib monotherapy emphasized importance of FIP1L1-PDGFRA detection at diagnosis of hematopoietic malignancies with eosinophilias. DisclosuresNo relevant conflicts of interest to declare.