Citations

AbstractETV6 mutations are rare but recurrent somatic events in myeloid neoplasms and are negatively prognostic in myelodysplastic syndrome. We set out to examine the clinical and molecular characteristics of patients undergoing investigation for myeloid neoplasms, found to have deleterious ETV6 mutations. ETV6 mutations occurred in 33 of 5793 (0.6%) cases investigated and predominantly in high‐risk disease entities including MDS with increased blasts, primary myelofibrosis and AML, myelodysplasia‐related. In three cases, isolated iso (17q) karyotype was concurrently detected, an otherwise rare karyotype in myeloid neoplasms. ETV6 mutations were frequently subclonal and never occurred as an isolated abnormality with ASXL1 (n = 22, 75%), SRSF2 (n = 14, 42%) and SETBP1 (n = 11, 33%) the predominant co‐mutations. Restricting to patients with MDS, higher rates of ASXL1, SETBP1, RUNX1 and U2AF1 mutations occurred in ETV6 mutated cases, relative to a consecutive control cohort with wild‐type ETV6. The median OS of the cohort was 17.5 months. This report highlights the clinical and molecular associations of somatic ETV6 mutations in myeloid neoplasms, suggests their occurrence as a later event, and proposes further translational research questions for their role in myeloid neoplasia.

Abstract Disease Overview JAK2 unmutated or non‐polycythemia vera (PV) erythrocytosis encompasses a heterogenous spectrum of hereditary and acquired entities. Diagnosis Foremost in the evaluation of erythrocytosis is the exclusion of PV through JAK2 (inclusive of exons 12–15) mutation screening. Initial assessment should also include gathering of previous records on hematocrit (Hct) and hemoglobin (Hgb) levels, in order to streamline the diagnostic process by first distinguishing longstanding from acquired erythrocytosis; subsequent subcategorization is facilitated by serum erythropoietin (Epo) measurement, germline mutation screening, and review of historical data, including comorbid conditions and medication list. Hereditary erythrocytosis constitutes the main culprit in the context of longstanding erythrocytosis, especially when associated with a positive family history. In this regard, a subnormal serum Epo level suggests EPO receptor mutation. Otherwise, considerations include those associated with decreased (high oxygen affinity Hgb variants, 2,3‐bisphosphoglycerate deficiency, PIEZO1 mutations, methemoglobinemia) or normal oxygen tension at 50% Hgb saturation (P50). The latter include germline oxygen sensing pathway ( HIF2A–PHD2–VHL ) and other rare mutations. Acquired erythrocytosis commonly results from central (e.g., cardiopulmonary disease, high‐altitude habitat) or peripheral (e.g., renal artery stenosis) hypoxia. Other noteworthy conditions associated with acquired erythrocytosis include Epo‐producing tumors (e.g., renal cell carcinoma, cerebral hemangioblastoma) and drugs (e.g., testosterone, erythropoiesis stimulating agents, sodium‐glucose cotransporter‐2 inhibitors). Idiopathic erythrocytosis is an ill‐defined terminology that presumes the existence of an increased Hgb/Hct level without an identifiable etiology. Such classification often lacks accounting for normal outliers and is marred by truncated diagnostic evaluation. Management Current consensus treatment guidelines are not supported by hard evidence and their value is further undermined by limited phenotypic characterization and unfounded concerns for thrombosis. We are of the opinion that cytoreductive therapy and indiscriminate use of phlebotomy should be avoided in the treatment of non‐clonal erythrocytosis. However, it is reasonable to consider therapeutic phlebotomy if one were to demonstrate value in symptom control, with frequency determined by symptoms rather than Hct level. In addition, cardiovascular risk optimization and low dose aspirin is often advised. Future Directions Advances in molecular hematology might result in better characterization of “idiopathic erythrocytosis” and expansion of the repertoire for germline mutations in hereditary erythrocytosis. Prospective controlled studies are needed to clarify potential pathology from JAK2 unmutated erythrocytosis, as well as to document the therapeutic value of phlebotomy.

AbstractAcute myeloid leukemia (AML) is a challenging cancer in terms of achieving and maintaining long‐duration remissions. Many novel therapies have been added to the standard regimen (combining cytarabine and anthracycline “7 + 3”) to achieve such goals. Nilotinib is an oral multikinase inhibitor that is active against KIT tyrosine kinase, an important stem cell target. In this trial, we combined nilotinib with 7 + 3 induction (daunorubicin 60 mg/m2), high‐dose cytarabine consolidation, and subsequently, if the patient was a candidate, for 2 years' maintenance therapy in patients with AML and KIT (CD117) expression. Patients were allowed to proceed to allogeneic hematopoietic cell transplantation (HCT) if deemed necessary. Our primary goal was increased complete remission rate with this combination. Thirty‐four patients (with a median age 58.5 years) were enrolled on a single‐arm phase II bi‐institutional study; 21 (62%) patients achieved remission. The complete remission rate was 78% in evaluable patients. Thirteen of 34 (38%) patients had allogeneic HCT, all thirteen of which are still alive (100%). Common (>20%) grade 3 non‐hematological toxicities included febrile neutropenia, hypophosphatemia, elevated liver enzymes, and hypertension. Only one patient (3%) died in induction due to liver failure, which was thought secondary to daunorubicin. Our current study reveals good outcomes in patients who received HCT and may warrant a larger study to confirm our findings in that specific population.