Blast phase myeloproliferative neoplasm: Mayo-AGIMM study of 410 patients from two separate cohorts

A total of 410 patients with blast phase myeloproliferative neoplasm (MPN-BP) were retrospectively reviewed: 248 from the Mayo Clinic and 162 from Italy. Median survival was 3.6 months, with no improvement over the last 15 years. Multivariable analysis performed on the Mayo cohort identified high risk karyotype, platelet count < 100 × 10⁹/L, age > 65 years and transfusion need as independent risk factors for survival. Also in the Mayo cohort, intensive chemotherapy resulted in complete remission (CR) or CR with incomplete count recovery (CRi) rates of 35 and 24%, respectively; treatment-specified 3-year/5-year survival rates were 32/10% for patients receiving allogeneic stem cell transplant (AlloSCT) (n = 24), 19/13% for patients achieving CR/CRi but were not transplanted (n = 24), and 1/1% in the absence of both AlloSCT and CR/CRi (n = 200) (p < 0.01). The survival impact of AlloSCT (HR 0.2, 95% CI 0.1–0.3), CR/CRi without AlloSCT (HR 0.3, 95% CI 0.2–0.5), high risk karyotype (HR 1.6, 95% CI 1.1–2.2) and platelet count < 100 × 10⁹/L (HR 1.6, 95% CI 1.1–2.2) were confirmed to be inter-independent. Similar observations were made in the Italian cohort. The current study identifies the setting for improved short-term survival in MPN-BP, but also highlights the limited value of current therapy, including AlloSCT, in securing long-term survival.

Prognostic risk model for patients with high-risk polycythemia vera and essential thrombocythemia

INTRODUCTION

Polycythemia Vera (PV) and Essential Thrombocythemia (ET) are the most frequent Philadelphia chromosome-negative myeloproliferative neoplasms, the other entity being myelofibrosis. Management of patients with PV and ET is fraught with difficulties as they have an inherent tendency to cause thrombotic and hemorrhagic events. There are no curative treatment options, therefore it is important that a risk-adapted treatment approach is applied. Areas covered: This review discusses existing literature about prognosis in PV and ET, and addresses critical aspects related to defining 'high-risk' disease. In addition to the traditional risk factors such as age and prior thrombotic history, we discuss the prognostic impact of additional parameters such as cardiovascular risk factors, white blood cell count, karyotype and gene mutations. Expert commentary: We use age>60 years, presence of JAK2 mutation and a prior thrombotic history as the principle determinants of 'high-risk' for thrombosis in PV and ET, dividing the patients into very-low, low, intermediate and high-risk disease. Typically, low-risk patients are treated either with observation or aspirin alone. High-risk patients require cytoreductive therapies, along with aspirin and/or systemic anticoagulation. Intermediate-risk patients are treated on a case-by-case basis. Further, we aim to maintain a hematocrit <45% with aggressive phlebotomy in patients with PV.

Therapy related-chronic myelomonocytic leukemia (CMML): Molecular, cytogenetic, and clinical distinctions from de novo CMML

Therapy related myeloid neoplasms (t-MN) including therapy related myelodysplastic syndromes (t-MDS) and acute myeloid leukemia (t-AML) are associated with aggressive disease biologies and poor outcomes. In this large (n = 497) and informative (inclusive of molecular and cytogenetic information) chronic myelomonocytic leukemia (CMML) patient cohort, we demonstrate key biological insights and an independent prognostic impact for t-CMML. T-CMML was diagnosed in 9% of patients and occurred approximately 7 years after exposure to prior chemotherapy and/or radiation therapy. In comparison to de novo CMML, t-CMML patients had higher LDH levels, higher frequency of karyotypic abnormalities and had higher risk cytogenetic stratification. There were no differences in the distribution of gene mutations and unlike t-MDS/AML, balanced chromosomal translocations, abnormalities of chromosome 11q23 (1%) and Tp53 mutations (<2%) were uncommon. Molecularly integrated CMML prognostic models were not effective in risk stratifying t-CMML patients and responses to hypomethylating agents were dismal with no complete responses. Median overall (OS) and leukemia free survival (LFS) was shorter for t-CMML in comparison to d-CMML (Median OS 10.9 vs 26 months and median LFS 50 vs 127 months) and t-CMML independently and adversely impacted OS (P = .0001 HR 2.1 95% CI 1.4-3.0). This prognostic impact was retained in the context of the Mayo Molecular Model (P = .001, HR 2.4, 95% CI 1.5-3.7) and the GFM prognostic model (P < .0001, HR 2.15, 95% CI 1.5-3.7). In summary, we highlight the unique genetics and independent prognostic impact of t-CMML, warranting its inclusion as a separate entity in the classification schema for both CMML and t-MN.

Risk factors for arterial versus venous thrombosis in polycythemia vera: a single center experience in 587 patients

In a recent International Working Group on Myeloproliferative Neoplasms Research and Treatment (IWG-MRT) study, prior arterial events and hypertension were predictors of subsequent arterial thrombosis whereas prior venous events and age ≥65 years predicted venous thrombosis in polycythemia vera (PV). In the current study, we sought to validate the above findings and identify additional predictors of arterial versus venous thrombosis. At a median follow up of 109 months, thrombosis after diagnosis occurred in 128 (22%) patients; 82 (14%) arterial and 57 (10%) venous events. On multivariate analysis, prior arterial events (<0.0001), hyperlipidemia (p = 0.03), and hypertension (p = 0.02) predicted subsequent arterial events. In comparison, prior venous events (p = 0.05), leukocytosis ≥11 × 10⁹/L (p = 0.002), and major hemorrhage (p = 0.02) were predictors of subsequent venous events. Salient associations with arterial thrombosis included age ≥ 60 years, hypertension, diabetes, hyperlipidemia and normal karyotype whereas age ≤ 60 years, females, palpable splenomegaly and history of major hemorrhage were associated with venous thrombosis. TET2 or ASXL1 mutations did not impact arterial nor venous thrombosis. In conclusion, we identify distinct associations for arterial versus venous thrombosis in PV and confirm that a prior arterial or venous thrombotic event is the most reliable predictor of subsequent events.

MIPSS70: Mutation-Enhanced International Prognostic Score System for Transplantation-Age Patients With Primary Myelofibrosis

Purpose To develop a prognostic system for transplantation-age patients with primary myelofibrosis (PMF) that integrates clinical, cytogenetic, and mutation data. Patients and Methods The study included 805 patients with PMF age ≤ 70 years recruited from multiple Italian centers and the Mayo Clinic (Rochester, MN), forming two independent learning and validation cohorts. A Cox multivariable model was used to select from among a list of 22 variables those that were predictive of overall survival (OS). Integrated clinical and genetic prognostic models with (MIPSS70-plus) or without (MIPSS70) cytogenetic information were developed. Results Multivariable analysis identified the following as significant risk factors for OS: hemoglobin < 100 g/L, leukocytes > 25 × 10⁹/L, platelets < 100 × 10⁹/L, circulating blasts ≥ 2%, bone marrow fibrosis grade ≥ 2, constitutional symptoms, absence of CALR type-1 mutation, presence of high-molecular risk mutation (ie, ASXL1, EZH2, SRSF2, IDH1/ 2), and presence of two or more high-molecular risk mutations. By assigning hazard ratio (HR)-weighted points to these variables, three risk categories were delineated for the MIPSS70 model; 5-year OS was 95% in low-risk, 70% in intermediate-risk, and 29% in high-risk categories, corresponding to median OS of 27.7 years (95% CI, 22 to 34 years), 7.1 years (95% CI, 6.2 to 8.1 years), and 2.3 years (95% CI, 1.9 to 2.7 years), respectively. In the MIPSS70-plus model, which included cytogenetic information, four risk categories were delineated, with 5-year OS of 91% in low-risk, 66% in intermediate-risk (HR, 3.2; 95% CI, 1.9 to 5.2), 42% in high-risk (HR, 6.4; 95% CI, 4.1 to 10.0), and 7% very high-risk categories (HR, 17.0; 95% CI, 9.8 to 29.2). Both models remained effective after inclusion of older patients in the analysis. Conclusion MIPSS70 and MIPSS70-plus provide complementary systems of risk stratification for transplantation-age patients with PMF and integrate prognostically relevant clinical, cytogenetic, and mutation data.

Targeted next-generation sequencing in myelodysplastic syndromes and prognostic interaction between mutations and IPSS-R

A 27-gene panel was used for next-generation sequencing (NGS) in 179 patients (median age 73 years) with primary myelodysplastic syndromes (MDS); risk distribution according to the revised International Prognostic Scoring System (IPSS-R) was 11% very high, 18% high, 17% intermediate, 38% low and 16% very low. At least one mutation/variant was detected in 147 (82%) patients; 23% harbored three or more mutations/variants. The most frequent mutations/variants included ASXL1 (30%), TET2 (25%), SF3B1 (20%), U2AF1 (16%), SRSF2 (16%), TP53 (13%), RUNX1 (11%), and DNMT3A (10%). At a median follow up of 30 months, 148 (83%) deaths and 26 (15%) leukemic transformations were recorded. Multivariable analysis of mutations/variants identified ASXL1 (HR 1.7, 95% CI 1.2-2.5), SETBP1 (HR 4.1, 95% CI 1.6-10.2) and TP53 (HR 2.2, 95% CI 1.3-3.4) as risk factors for overall and SRSF2 (HR 3.9, 95% CI 1.5-10.2), IDH2 (HR 3.7, 95% CI 1.2-11.4), and CSF3R (HR 6.0, 95% CI 1.6-22.6) for leukemia-free survival. Addition of age to the multivariable model did not affect these results while accounting for IPSS-R weakened the significance of TP53 mutations/variants (P = .1). An apparently favorable survival impact of SF3B1 mutations was no longer evident after adjustment for IPSS-R. Approximately 41% and 20% of patients harbored at least one adverse mutation/variant for overall and leukemia-free survival, respectively. Number of mutations/variants did not provide additional prognostic value. The survival impact of adverse mutations was most evident in IPSS-R very low/low risk patients. These observations suggest that targeted NGS might assist in treatment decision-making in lower risk MDS.

Histone deacetylase inhibitors reduce differentiating osteoblast-mediated protection of acute myeloid leukemia cells from cytarabine

The bone marrow microenvironment protects acute myeloid leukemia (AML) cells during chemotherapy and is a major factor in relapse. Here, we examined which type(s) of bone marrow cells are responsible for the relapse of AML following treatment with cytarabine (Ara-C), and we identified a means to inhibit this protection. To determine the protective cell type(s), AML cells were treated with Ara-C, and AML cell survival in the presence or absence of osteoblast lineage cells was assessed. Cultured AML cells and patient bone marrow isolates were each significantly protected from Ara-C-induced apoptosis by co-culture with differentiating osteoblasts. Moreover, pretreating differentiating osteoblasts with the histone deacetylase inhibitors (HDACi) vorinostat and panobinostat abrogated the ability of the differentiating osteoblasts to protect AML cells. Together, our results indicate that differentiating osteoblasts have the potential to promote residual AML in the bone marrow following standard chemotherapy and act via a mechanism requiring HDACi-sensitive gene expression. Using HDACi to target the leukemic microenvironment in combination with Ara-C could potentially improve treatment of AML. Moreover, other strategies for manipulating bone marrow osteoblasts may also help eradicate AML cells and reduce relapse.

Risk factors and a prognostic model for postsplenectomy survival in myelofibrosis

Palliative treatment in myelofibrosis (MF) includes transfusion support, JAK2 inhibitors, involved field radiotherapy and splenectomy. To assist in selecting patients who are likely to benefit from splenectomy, we looked into risk factors for postsplenectomy survival, in 120 consecutive cases (median age 66 years); at the time of splenectomy, 61% displayed red cell transfusion need, 49% platelet count <100 × 10(9)/L, 25% leukocyte count >25 × 10(9)/L, 60% constitutional symptoms and 13% circulating blasts ≥5%; dynamic international prognostic scoring system risk categories were 21% high, 55% intermediate-2, 21% intermediate-1 and 3% low. Among informative cases, karyotype was abnormal in 60% and driver mutational status was JAK2 75%, CALR 15%, MPL 4% and triple-negative 6%. At median follow-up of 1.3 years, from time of splenectomy, 95 (79%) deaths and 30 (25%) leukemic transformations were recorded. Median postsplenectomy survival was 1.5 years; in multivariable analysis, survival was adversely affected by age >65 years, transfusion need, leukocyte count >25 × 10(9)/L and circulating blasts ≥5%; these variables were subsequently used to devise an HR-weighted scoring system with high (3-4 risk factors), intermediate (2 risk factors) and low (0-1 risk factors) risk categories; the corresponding postsplenectomy median survivals were 0.3 (HR 5.9, 95% CI 3.2-11.0), 1.3 (HR 2.9, 95% CI 1.8-4.6) and 2.9 years. Postsplenectomy survival was not affected by driver mutational status or occurrence of leukemic transformation. Leukemia-free survival was predicted by very high risk karyotype. The observations from the current study might help identify appropriate candidates for splenectomy in MF.

Gender and survival in essential thrombocythemia: A two-center study of 1,494 patients

Based on suggestive information from recent epidemiologic data and earlier retrospective studies, we revisited the effect of gender on survival in 1,494 patients with essential thrombocythemia (ET). The primary study population included 904 patients from the Mayo Clinic (median age 58 years; 65% females); risk distribution, according to the international prognostic score for ET (IPSET), was 23% high, 42% intermediate and 35% low. Multivariable analysis that included IPSET-relevant risk factors identified male sex (HR 1.6, 95% CI 1.3-2.0), age ≥60 years (HR 4.3, 95% CI 3.4-5.4) and leukocyte count ≥11 × 10(9)/L (HR 1.5, 95% CI 1.3-1.9) as independent predictors of shortened survival. These findings were confirmed by analysis of a separate cohort of 590 ET patients (65% females) from the University of Florence, Italy, with corresponding HRs (95% CI) of 1.6 (1.1-2.5), 4.6 (2.2-9.5) and 1.8 (1.1-2.8). The independent prognostic effect of gender was further corroborated by a separate multivariable analysis against IPSET risk categories; HR (95% CI) for the Mayo Clinic/Florence cohorts were 1.5/1.6 (1.2/1.1-1.8/2.5) for male sex, 6.8/7.5 (5.0/3.1-9.3/18.3) for IPSET high risk and 2.8/4.1 (2.1/1.8-3.8/9.5) for IPSET intermediate risk. Furthermore, the survival disadvantage in men was most apparent in IPSET high risk category and in patients older than 60 years. In both patient cohorts, thrombosis history garnered significance in univariate, but not in multivariable analysis. The observations from the current study suggest that women with ET live longer than their male counterparts and that gender might supersede thrombosis history as a risk variable for overall survival.

Therapeutic options for leukemic transformation in patients with myeloproliferative neoplasms

Approximately 5-10% of patients with Philadelphia chromosome negative myeloproliferative neoplasms (MPN) comprising of essential thrombocythemia, polycythemia vera and primary myelofibrosis) experience transformation to acute myeloid leukemia (AML, ≥20% blasts). Treatment options for post-MPN AML patients are limited, as conventional approaches like standard chemotherapy, fail to offer long-term benefit. Median survival for secondary AML is ∼2.4 months. Post-MPN AML therefore represents an area of urgent clinical need. At present, allogeneic stem cell transplant (ASCT) following induction therapy is the best therapeutic option. Patients ineligible for ASCT are treated with hypomethylating agents. New agents under investigation include histone deacetylase inhibitors, JAKinhibitors and agents targeting the BRD4 protein. Combined treatment strategies involving these novel agents are being tested. In this review we present the current evidence regarding treatment options for post-MPN AML patients.

Inactivation of Receptor Tyrosine Kinases Reverts Aberrant DNA Methylation in Acute Myeloid Leukemia

Purpose: Receptor tyrosine kinases (RTKs) are frequently deregulated in leukemia, yet the biological consequences of this deregulation remain elusive. The mechanisms underlying aberrant methylation, a hallmark of leukemia, are not fully understood. Here we investigated the role of RTKs in methylation abnormalities and characterized the hypomethylating activities of RTK inhibitors.Experimental Design: Whether and how RTKs regulate expression of DNA methyltransferases (DNMTs), tumor suppressor genes (TSGs) as well as global and gene-specific DNA methylation were examined. The pharmacologic activities and mechanisms of actions of RTK inhibitors in vitro, ex vivo, in mice, and in nilotinib-treated leukemia patients were determined.Results: Upregulation of RTKs paralleled DNMT overexpression in leukemia cell lines and patient blasts. Knockdown of RTKs disrupted, whereas enforced expression increased DNMT expression and DNA methylation. Treatment with the RTK inhibitor, nilotinib, resulted in a reduction of Sp1-dependent DNMT1 expression, the diminution of global DNA methylation, and the upregulation of the p15^INK4B gene through promoter hypomethylation in AML cell lines and patient blasts. This led to disruption of AML cell clonogenicity and promotion of cellular apoptosis without obvious changes in cell cycle. Importantly, nilotinib administration in mice and human patients with AML impaired expression of DNMTs followed by DNA hypomethylation, TSG re-expression, and leukemia regression.Conclusions: Our findings demonstrate RTKs as novel regulators of DNMT-dependent DNA methylation and define DNA methylation status in AML cells as a pharmacodynamic marker for their response to RTK-based therapy, providing new therapeutic avenues for RTK inhibitors in overcoming epigenetic abnormalities in leukemia. Clin Cancer Res; 23(20); 6254-66. ©2017 AACR.

Monocytosis in polycythemia vera: Clinical and molecular correlates

Monocytosis (absolute monocyte count, AMC ≥ 1 × 10⁹ /L) might accompany a spectrum of myeloid neoplasms, other than chronic myelomonocytic leukemia (CMML). In the current study, we examined the prevalence, laboratory and molecular correlates, and prognostic relevance of monocytosis in polycythemia vera (PV). Among 267 consecutive patients with World Health Organization (WHO)-defined PV, 55 (21%) patients displayed an AMC of ≥1 × 10⁹ /L and 18 (7%) an AMC of ≥1.5 × 10⁹ /L. In general, PV patients with monocytosis were significantly older and displayed higher frequencies of leukocytosis (81% vs. 50% at AMC ≥1 × 10⁹ /L) and TET2/SRSF2 mutations (57%/29% vs. 19%/1% at AMC ≥ 1.5 × 10⁹ /L). In univariate analysis, AMC ≥1.5 × 10⁹ /L adversely affected overall (OS; P = .004; HR 2.6, 95% CI 1.4-4.8) and myelofibrosis-free (MFFS; P = .02; HR 4.4, 95% CI 1.3-15.1) survival; during multivariable analysis, significance was borderline sustained for OS (P = .05) and MFFS (P = .06). Other independent risk factors for OS included unfavorable karyotype (P = .02, HR 3.39, 95% CI 1.17-9.79), older age (P < .0001, HR 3.34 95% CI 1.97-5.65), and leukocytosis ≥15 × 10⁹ /L (P = .004, HR 2.04, 95% CI 1.26-3.29). In conclusion, in the current study, we encountered a higher than expected prevalence of monocytosis in patients with PV and the mutation profile and age distribution of PV patients with monocytosis is akin to those of patients with CMML and might partly contribute to their worse prognosis.

Targeted next generation sequencing and identification of risk factors in World Health Organization defined atypical chronic myeloid leukemia

Atypical chronic myeloid leukemia (aCML) is an aggressive myeloid neoplasm with overlapping features of myelodysplastic syndromes (prominent granulocytic dysplasia) and myeloproliferative neoplasms (neutrophilic leukocytosis). We studied 25 molecularly-annotated and World Health Organization defined aCML patients; median age 70 years, 84% males. Cytogenetic abnormalities were seen in 36% and gene mutations in 100%. Mutational frequencies were, ASXL1 28%, TET2 16%, NRAS 16%, SETBP1 12%, RUNX1 12%, ETNK1 8%, and PTPN11 4%. Fifteen patients (60%) had >1 mutation, while 9 (36%) had ≥3. The median overall survival (OS) was 10.8 months and at last follow up (median 11 months), 17 (68%) deaths and 2 (8%) leukemic transformations were documented. On univariate analysis, survival was adversely impacted by advanced age (P = .02), low hemoglobin (P = .01), red blood cell transfusion dependence (P = .03), high white blood cell count (P = .02), TET2 (P = .03), NRAS (P = .04), PTPN11 (P = .02) mutations and the presence of ≥3 gene mutations (P = .006); ASXL1, SETBP1, and ETNK1 mutations did not impact OS. In multivariable analysis, advanced age (P = .003) [age >67: HR 10.1, 95% CI 1.3-119], low hemoglobin (P = .008) [HB< 10 gm/dL: HR 8.2, 95% CI 1.6-23.2] and TET2 mutations (P = .01) [HR 8.8, 95% CI 1.6-47.7] retained prognostic significance. We then used age >67 years, hemoglobin <10 gm/dL and the presence of TET2 mutations (each counted as one risk factor) to create a hazard ratio weighted prognostic model; effectively stratifying patients into two risk categories, low (0-1 risk factor) and high (≥2 risk factors), with median OS of 18 and 7 months, respectively.

Interaction between ring sideroblasts and treatment with hypomethylating agents (HMA) in patients with refractory anemia with ring sideroblasts

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Background: Myelodysplastic syndromes (MDS) are a group of myeloid neoplasms defined by ineffective hematopoiesis, dysplastic morphologic features, and variable risks of progression to acute myeloid leukemia (AML). Refractory anemia with ring sideroblasts (RARS) is a subtype of MDS defined by < 5% basts and > 15% ring sideroblasts (per 2008 WHO). Because RARS is a lower risk disease which does not frequently require HMA therapy, very little is known about the effects of HMA on RARS. Methods: A total of 1325 MDS patients’ data from 1993-2016 at Mayo Clinic were reviewed after appropriate IRB approval was obtained. All cases had their bone marrow slides reviewed at our center. Patients were considered for our study if they received HMA for their RARS. Response was identified based on MDS IWG 2006 criteria. Prognostic factors were analyzed by univariate and multivariate analyses. Survival estimates were calculated using Kaplan-Meier curves. Results: 168 of the initial 1325 patient were RARS (14%); only 14 (8%) were treated with HMA. Median age was 72 years (range, 51-85); half were males, with median overall survival of 91.3 months. The median number of ring sideroblasts (RS) at diagnosis was 40% (range 10-85%). Of the 14 patients, 11 (79%) received azacitidine (AZA), 2 (14%) decitabine (DAC) and one received both (7%). The median number of cycles for AZA was 6.5 (range, 2-28) vs 6 cycles for DAC (range, 1-24). Of the 14 patients receiving HMA, only 3 responded (21%) achieving hematologic improvement. All 3 responders received AZA. 6 of the 14 RARS patients (43%) had their bone marrow biopsy repeated after HMA therapy, 3 of whom were among the responders to AZA therapy and 3 were non-responders. In 5 patients, ring sideroblasts decreased after HMA therapy by a median of 15% (range 0-80); they remained the same in 1 patient; one patient who had developed AML had a decrease in RS from 85% to 5%. Conclusions: RARS is a low-risk subtype of MDS that is infrequently treated with HMA (8% in our study). Response rate to HMA (21%) was inferior to known rates in MDS. HMA therapy seems to decrease the number of ring sideroblasts irrespective of response. RARS patients should be treated on clinical trials if available.

Clinical significance of HFE gene mutations in patients with refractory anemia with ring sideroblasts (RARS)

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Background: RARS is a subtype of myelodysplastic syndromes (MDS) defined by < 5% blasts and ≥15% ring sideroblasts (WHO 2008). Hereditary hemochromatosis is a disorder characterized by dysregulations in iron absorption, largely associated with C282Y and H63D mutations of the HFE gene. Iron levels are elevated in both disorders and pathophysiologic correlations were suggested. HFE gene mutations were previously found higher in MDS compared to controls (50% vs 36%) ( Nearman et al, Am J Hematol 2007). Methods: A total of 168 RARS patients’ data from 1994 to 2015 at Mayo Clinic were reviewed after appropriate IRB approval was obtained. All cases had their bone marrow slides reviewed at our center. We searched patients’ records retrospectively to Identify those tested for HFE gene (C282Y, H62D, S65C) mutations, done inside or outside our institution. Survival estimates were calculated using Kaplan-Meier curves. Results: Out of the 168 RARS patients, only 17 (10%) were tested for HFE gene mutations. Out of the 17 tested, 11 (65%) were found to have mutations; 2 of which (18%) had homozygous H63D mutation, 1 patient (9%) had double heterozygous H63D and C282Y mutations, 5 (45%) had only one H36D heterozygous mutation vs 3 patients (27%) with only one C282Y heterozygous mutation. Only one patient was tested for the additional S65C mutation and it was not detected. H63D mutation was present in a total of 8 patients (73%) vs C282Y mutation which was present in 4 patients (36%). Bone marrow iron stores were increased in all 17 tested patients, except one who had decreased stores, this patient had one heterozygous C282Y mutation. Median overall survival (mOS) was 117 months in the HFE mutated patients vs 75 months in the non-mutated (p = 0.6). Conclusions: Our study found the HFE gene, when tested, to be mutated in higher frequencies among patients with RARS compared to that reported in the general population (65% vs 36%), with H63D mutation in almost three quarters of all mutated patients. Although it did not reach statistical significance, the longer survival observed among HFE mutated patients compared to the wild-type raises the question whether testing for HFE gene mutations among patients with MDS-RARS should be further explored.

Effect of echocardiogram prior to induction therapy for acute myeloid leukemia on detection of cardiac dysfunction and treatment modifications

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Background: Standard induction therapy for acute myeloid leukemia (AML) includes “cytarabine and anthracycline”. Anthracyclines are known to cause acute, subacute and chronic cardiac complications ( Lefrak , EA et al, Cancer 1973:32(2):302-314; Singal, PK et al, NEJM 1998;339(13):900-905). It is recommended to do base line cardiac function assessment with echocardiogram prior to induction therapy containing anthracycline. This study was done to find the frequency of changes made in avoiding anthracycline usage following this evaluation. Methods: The Mayo clinic data base was interrogated to identify patients with newly diagnosed AML who underwent echocardiogram prior to anthracycline containing induction chemotherapy. Echocardiogram results, including left ventricular ejection fraction (LVEF), diastolic dysfunction, valvular disease, and any resultant treatment alterations were reviewed. Results: Three hundred twenty six patients were identified. The median (range) age was 61 (17-82) years and 62% were male. The median (range) LVEF was 65% (30-87), and 3 (0.9%) patients had LVEF < 50% (range 30-47%). Of these 3 patients, 1 had 4 vessel CABG a decade ago, his EF was 46% and treated with full dose idarubicin; 2 of them presented with blastic crisis, 1 had EF 46% and improved to 51% after 5 days and then given daunorubicin, the other one had an EF of 30% and treated with 50% dose reduced cytarabine alone. Sixty five (23%) patients had previous chemotherapy or radiation exposure, including 24 (7.4 %) with previous anthracycline, 14 (4.3%) had prior radiation to the chest wall. No patient with previous chemotherapy or radiation exposure had a reduced LVEF. Conclusions: Echocardiography prior to anthracycline therapy rarely detects abnormal LVEF. Screening echo may be helpful in those presented with leukemic blastic crisis or had previous exposure to chemo-radiation.

Prognostic and therapeutic impact of cytogenetic abnormalities in patients with myelodysplastic/myeloproliferative neoplasms, unclassifiable

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Background: The 2016 WHO classification includes myelodysplastic/myeloproliferative neoplasms, unclassifiable (MDS/MPN-U), as an MDS/MPN overlap syndrome not meeting criteria for well-defined entities such as CMML. No standard prognostication or treatment guidelines exist for such patients. Methods: We retrospectively identified MDS/MPN-U cases from 1990-2016 through our myeloid malignancies database. All bone marrow reports were reviewed to ensure compliance with 2016 WHO criteria. Clinical & cytogenetic parameters at diagnosis were assessed & compared with treatment outcomes. Results: Eighty nine patients met study criteria, with a median age of 69 years (range: 37-93); 58 (65%) males. Median follow-up was 22.2 months (range: 0-172), with 41 (46%) deaths & 13 (15%) leukemic transformations. Median OS was 24.8 months (range: 0-172). 43 (53%) patients had an abnormal karyotype, with common abnormalities being trisomy 8 (12%), complex karyotype (9%) & del (20q) (6%). Given the fewer types of abnormalities identified, the IPSS cytogenetic stratification was more effective than IPSS-R, with risk categorization including; 45 good (55%), 20 intermediate (25%) & 16 high risk (20%) respectively (8 unavailable). On univariate analysis, increased age (p = 0.05), decreased hemoglobin (p = 0.02), higher ANC (p = 0.03), circulating immature myeloid cells (p = 0.02), higher LDH (p = 0.009), absence of bone marrow ring sideroblasts (p = 0.001) & higher risk (intermediate & high) IPSS cytogenetic categories (p = 0.01) adversely impacted OS. In a multivariate model that included the aforementioned variables, higher risk IPSS cytogenetics retained a negative prognostic impact (p = 0.04). 28 patients received a median of 6 cycles (range: 1-21) of hypomethylating agent therapy (HMA), with an overall response rate of 18% (CR-3, PR-2). All responders had an abnormal karyotype (p = 0.01). However, HMA did not affect either OS or LFS. Conclusions: Intermediate & high risk IPSS cytogenetic categories independently & adversely impact survival in WHO defined MDS/MPN-U patients. HMA use did not impact OS; however, patients with abnormal karyotypes were more likely to respond.

Safety and feasibility of lower antithrombin replacement targets in adult patients with hematological malignancies receiving asparaginase therapy<sup/>

The optimal antithrombin(AT) activity parameters for replacement as thromboprophylaxis following asparaginase remains unclear. This single-center, retrospective study evaluated two sets of AT replacement thresholds and targets in adults receiving asparaginase-containing chemotherapy. AT supplementation adhered to institutional standards, which lowered the AT activity target from 100% to 80% in 6/2014. Ninety-two patients were evaluated. Cumulative thrombosis incidence was 16% at 6 months (95%CI:6.8-24.0, maximum follow-up 315 days) with similar incidence between the 80% and 100% target groups, 14% (2 of the 14) and 13% (10 of the 78), respectively, with a small non-Line-Related DVT incidence (3%). Most thrombotic events occurred during induction chemotherapy and demonstrated no associations with replacement target, cumulative days or cumulative area under AT activity target, number of asparaginase doses, or cumulative asparaginase dose. Median estimated AT replacement expenditure was $34,963USD (IQR $16,260USD to $79,319USD) per patient. Cost-effectiveness and optimization of AT replacement for thromboprophylaxis following asparaginase requires prospective evaluation.

The prognostic relevance of serum lactate dehydrogenase and mild bone marrow reticulin fibrosis in essential thrombocythemia

The 2016 World Health Organization (WHO) diagnostic criteria for myeloproliferative neoplasms (MPN) underscore the prognostically-relevant distinction between essential thrombocythemia (ET) and prefibrotic primary myelofibrosis (pre-PMF). In addition, leukocytosis has been identified as an important prognostic marker in otherwise WHO-defined ET. However, controversy remains regarding the objectivity of morphologic criteria in distinguishing ET from pre-PMF and the precise prognostic cutoff values for leukocytosis. Serum lactate dehydrogenase (LDH) level might be a biologically more accurate measure of leukocyte turnover and a more sensitive marker of pre-PMF, in otherwise WHO-defined ET. In the current study of 183 consecutive patients with WHO-defined ET, the presence of grade 1 bone marrow (BM) fibrosis did not affect presenting clinical or laboratory features; in contrast, increased serum LDH at diagnosis was associated with leukocytosis (p = .002), thrombocytosis (p < .001), palpable splenomegaly (p = .03) and higher international prognostic score (IPSET) (p = .002); serum LDH did not correlate with BM fibrosis, JAK2/CALR/MPL or TET2/ASXL1 mutations. In univariate analysis, risk factors for survival included age ≥60 years (p = .002; HR 10.2, 95% CI 2.3-44.6), male sex (p = .02; HR 3.2, 95% CI 1.2-8.2), leukocyte count ≥15 × 10⁹ /L (p = .007; HR 4.7, 95% CI 1.5-14.6), and increased serum LDH (p = .002; HR 3.7, 95% CI 1.5-9.1), but not BM fibrosis (p = .17). In multivariable analysis, age, sex and serum LDH remained significant; serum LDH also remained significant, in the context of IPSET (p = .003) and in patients with leukocytosis (p = .003). We conclude that serum LDH level carries an independent prognostic value for survival in ET and might represent a biologically more accurate surrogate for leukocytosis.

The 2016 revised World Health Organization definition of 'myelodysplastic syndrome with isolated del(5q)'; prognostic implications of single versus double cytogenetic abnormalities

The definition of the myelodysplastic syndrome (MDS) subtype 'MDS with isolated del(5q)' was expanded to include cases with one additional non-chromosome 7 based cytogenetic abnormality in the 2016 revised World Health Organization classification. This study applied the revised definition to a large primary MDS cohort, and evaluated the prognostic impact of the additional cytogenetic abnormality. Seventy-two of 1067 patients (7%) met the 'MDS with isolated del(5q)' criteria, 11 (1%) of whom had an additional cytogenetic abnormality. There was no survival difference between patients in whom del(5q) occurred alone, compared to those with one additional cytogenetic abnormality (P = 0·52).

Prognostic relevance of lymphocytopenia, monocytopenia and lymphocyte-to-monocyte ratio in primary myelodysplastic syndromes: a single center experience in 889 patients

Current prognostic models for myelodysplastic syndromes (MDS), including the Revised International Prognostic Scoring System (IPSS-R), do not account for host immunity. We retrospectively examined the prognostic relevance of monocytopenia, lymphocytopenia and lymphocyte-to-monocyte ratio (LMR) in a cohort of 889 patients with primary MDS. After a median follow-up of 27 months, 712 (80%) deaths and 116 (13%) leukemic transformation were documented. In univariate analysis, subnormal absolute lymphocyte count (ALC) <0.9 × 10⁹/l; P=0.001), ALC<1.2 × 10⁹/l (P=0.0002), subnormal absolute monocyte count (AMC) <0.3 × 10⁹/l (P=0.0003), LMR (P⩽0.0001) and LMR⩾5 (P=0.03) were all associated with inferior overall survival. In multivariable analysis that included other risk factors, significance was retained for LMR (P=0.02) and became borderline for ALC <1.2 × 10⁹/l (P=0.06). Analysis in the context of IPSS-R resulted in P-values of 0.06 for ALC<1.2 × 10⁹/l, 0.7 for monocytopenia and 0.2 for LMR. Leukemia-free survival was not affected by ALC, AMC or LMR. The observations from the current study suggest a possible detrimental role for altered host immunity in primary MDS, which might partly explain the therapeutic benefit of immune-directed therapy, including the use of immune modulators; however, IPSS-R-independent prognostic value for either ALC or AMC was limited.

Prognostic impact of bone marrow fibrosis in polycythemia vera: validation of the IWG-MRT study and additional observations

In 2012, the International Working Group for Myeloproliferative Neoplasms (MPN) Research and Treatment (IWG-MRT) reported an associations between mild bone marrow (BM) fibrosis (⩾grade 1) in polycythemia vera (PV) and a lower incidence of thrombosis during the clinical course and a higher risk of fibrotic progression. The objective in the current study of 262 patients with PV was to validate these observations and also identify other risk factors for myelofibrosis-free survival (MFFS). About 127 (48%) patients displayed ⩾grade 1 reticulin fibrosis at the time of diagnosis; presenting clinical and laboratory features were not significantly different between patients with or without BM fibrosis. In univariate analysis, BM fibrosis had no significant impact on overall, leukemia-free or thrombosis-free survival, whereas a significant association was noted for MFFS (P=0.009, hazard ratio 2.9; 95% confidence interval 1.32–6.78); other risk factors for MFFS included leukocytosis ⩾15 × 10⁹/l, presence of palpable splenomegaly and abnormal karyotype. During multivariable analysis, leukocytosis ⩾15 × 10⁹/l, palpable splenomegaly and ⩾grade 1 BM reticulin fibrosis remained significant. The current study validates the previously observed association between ⩾grade 1 BM reticulin fibrosis in PV and subsequent fibrotic progression, and identifies leukocytosis and palpable splenomegaly as additional risk factors for fibrotic progression; additional studies are required to clarify the impact of BM fibrosis on thrombosis and that of abnormal karyotype on MFFS.

DNMT3A mutations are associated with inferior overall and leukemia-free survival in chronic myelomonocytic leukemia

DNMT3A mutations are seen in ∼5% of patients with chronic myelomonocytic leukemia (CMML) and thus far, have had an indeterminate prognostic impact on survival. We carried out this study to assess the prognostic impact of DNMT3A mutations on a larger informative cohort of CMML patients (n = 261). DNMT3A mutations were seen in 6% (n = 16); 56% (n = 9) male, with a median age of 64 years. Eighty-one % of DNMT3A mutations were missense, with the Arg882 mutational hot spot accounting for 63% of all changes. Five (31%) patients had an abnormal karyotype whereas concurrent gene mutations (SF3B1/SRSF2/U2AF1-56%, TET2-50%, and ASXL1-25%) were seen in all patients. Apart from a higher frequency of SF3B1 (P = 0.0001) and PTPN11 (P = 0.005) mutations and a lower frequency of SRSF2 (P = 0.004) mutations, there were no significant differences between DNMT3A mutated patients and their wildtype counterparts. In univariate analysis, survival was shorter in DNMT3A mutated (median 8 months) versus wildtype (median 27 months) patients (P = 0.0007; HR 2.9, 95% CI 1.5-5.7); with other variables of significance including lower hemoglobin (P = 0.002), higher leukocyte count (P = 0.0009), higher monocyte count (P = 0.0012), circulating blast % (P = 0.001), circulating immature myeloid cells (P = 0.01), bone marrow blast % (P = 0.045), abnormal karyotype (P = 0.02), and ASXL1 (P = 0.01) mutations. In a multivariable model that included the aforementioned variables, when both DNMT3A and ASXL1 mutations were added, only DNMT3A (P < 0.0001) and ASXL1 (P = 0.004) mutations remained significant. DNMT3A mutations were also predictive of a shortened leukemia-free survival. These findings warrant inclusion of DNMT3A mutations in molecularly integrated CMML prognostic models. Am. J. Hematol. 92:56-61, 2017. © 2016 Wiley Periodicals, Inc.

Acute leukemia in pregnancy: a single institution experience with 23 patients

Management of acute leukemia during pregnancy presents a considerable challenge. Herein, we review our experience of 23 patients diagnosed with acute leukemia; during pregnancy at the Mayo Clinic between 1962 and 2016. Ten (43.4%), seven (30.4%), and six (26.2%) patients were diagnosed in first, second, and third trimester, respectively. In approximately, 50% (n = 11) therapeutic terminations or spontaneous abortions occurred. Fifty percent (2/4) of patients diagnosed during either first or second trimester who delayed chemotherapy by greater than one week died during induction therapy. Eleven patients received chemotherapy while pregnant which led to four fetal losses and seven deliveries (five full-term and two preterm deliveries). No congenital malformations were reported. Eighteen patients (78%) achieved complete remission. At a median follow up of 55 months, seven patients (30%) remain alive. In summary, we provide a comprehensive description of maternal and fetal outcomes and insight into management of acute leukemia during pregnancy.

Allogeneic hematopoietic stem cell transplant in adult patients with myelodysplastic syndrome/myeloproliferative neoplasm (MDS/MPN) overlap syndromes

MDS/MPN (myelodysplastic syndrome/myeloproliferative neoplasm) overlap syndromes are myeloid malignancies for which allogeneic hematopoietic stem cell transplant (allo-HSCT) is potentially curative. We describe transplant outcomes of 43 patients - 35 with chronic myelomonocytic leukemia, CMML (of which 17 had blast transformation, BT) and eight with MDS/MPN-unclassifiable (MDS/MPN,U). At median follow-up of 21 months, overall survival (OS), cumulative incidence of relapse (CIR) and non-relapse mortality (NRM) were 55%, 29%, and 25% respectively in CMML without BT and 47%, 40%, and 34% respectively in CMML with BT. Higher HSCT-comorbidity index (HSCT-CI >3 versus ≤3; p = 0.015) and splenomegaly (p = 0.006) predicted worse OS in CMML without BT. In CMML with BT, engraftment failure (p = 0.006) and higher HSCT-CI (p = 0.03) were associated with inferior OS, while HSCT within 1-year of diagnosis was associated with improved OS (p = 0.045). In MDS/MPN,U, at median follow-up of 15 months, OS, CIR, and NRM were 62%, 30%, and 14%, respectively.

Validation of the revised International Prognostic Score of Thrombosis for Essential Thrombocythemia (IPSET-thrombosis) in 585 Mayo Clinic patients

The primary objective of treatment in essential thrombocythemia (ET) is to prevent thromboembolic complications. In this regard, advanced age and thrombosis history have long distinguished "low" from "high" risk patients. More recently, JAK2V617F and cardiovascular (CV) risk factors were identified as additional modifiers, leading to the development of a 3-tiered International Prognostic Score of Thrombosis for ET (IPSET-thrombosis): "low," "intermediate," and "high". The international data set used to develop IPSET-thrombosis was recently re-analyzed in order to quantify the additional pro-thrombotic effect of JAK2V617F and CV risk factors in specific risk subcategories. The revised IPSET-thrombosis identified four risk categories based on three adverse variables (thrombosis history, age >60 years and JAK2V617F): very low (no adverse features), low (presence of JAK2V617F), intermediate (age >60 years) and high (presence of thrombosis history or presence of both advanced age and JAK2V617F). In this study of 585 patients with ET (median age 68 years; 61% female), we validated the revised IPSET-thrombosis by confirming significant differences in thrombosis risk between "very low" and "low" (HR 2.4, 95% CI 1.1 - 5.3) and between "intermediate" and "high" (HR 2.3, 95% CI 1.1 - 5.2) risk patients. Furthermore, in multivariable analysis, only JAK2V617F (HR=1.8, CI= 1.07 - 2.94) and history of thrombosis (HR=2.1, CI= 1.20 - 3.58) were independently predictive of future thrombotic events. The revised IPSET-thrombosis needs confirmation in prospective studies, especially in terms of risk-adapted therapy that includes the need for aspirin therapy in very low risk, twice-daily aspirin therapy for low risk and cytoreductive therapy for low or intermediate risk patients.

Fludarabine-Busulfan Reduced-Intensity Conditioning in Comparison with Fludarabine-Melphalan Is Associated with Increased Relapse Risk In Spite of Pharmacokinetic Dosing

Fludarabine with busulfan (FB) and fludarabine with melphalan (FM) are commonly used reduced-intensity conditioning (RIC) regimens. Pharmacokinetic dosing of busulfan (Bu) is frequently done for myeloablative conditioning, but evidence for its use is limited in RIC transplants. We compared transplant outcomes of FB versus FM using i.v. Bu targeted to the area under the curve (AUC). A total of 134 RIC transplants (47 FB and 87 FM) for acute myelogenous leukemia and myelodysplastic syndrome were identified, and median follow-up of the cohort was 40 months (range, 0 to 63.3). A significantly higher 2-year cumulative incidence of relapse (CIR) was associated with FB versus FM at 35.6% versus 17.3%, respectively (P = .0058). Furthermore, 2-year progression-free survival rates were higher for FM versus FB at 60.5% versus 48.7%, respectively (P = .04). However, 2-year rates of nonrelapse mortality (NRM) and overall survival (OS) were similar. The need for dose adjustment based on AUC did not alter relapse risk or NRM. Patients with Karnofsky performance status ≥ 90 who received FM had a 2-year OS rate of 74.8% versus 48.3% for FB (P = .03). FB use remained prognostic for relapse in multivariable analysis (hazard ratio, 2.75; 95% confidence interval, 1.28 to 5.89; P = .0097). In summary, in spite of AUC-directed dosing, FB compared with FM was associated with a significantly higher CIR.

Predictors of survival in refractory anemia with ring sideroblasts and thrombocytosis (RARS-T) and the role of next-generation sequencing

Refractory anemia with ring sideroblasts and thrombocytosis (RARS-T) shares overlapping features of myelodysplastic syndromes (MDS) and myeloproliferative neoplasms (MPN). RARS-T is characterized by SF3B1 and JAK2 mutations and prognosis is considered to be better than MDS but not as good as MPN. The objective of the study was to identify predictors of survival in RARS-T. We analyzed clinical and laboratory variables in 82 patients and applied a 27-gene NGS assay to 48 marrow samples obtained at diagnosis. 94% of patients had ≥1 mutations; common mutations being: SF3B1 85%, JAK2V617F 33%, ASXL1 29%, DNMT3A 13%, SETBP1 13% and TET2 10%. In a multivariable survival analysis (n = 82), anemia (P = 0.02) [HB< 10 gm/dl: HR 2.3, 95% CI 1.2-4.6] and abnormal karyotype (P =.01) [HR 6.1, 95% CI 2.7-13.8] were independently prognostic for inferior survival. In patients with NGS information (n = 48), univariate analysis showed association between poor survival and presence of SETBP1 (P = 0.04) or ASXL1 (P = 0.08) mutations whereas the absence of these mutations (ASXL1wt/SETBP1wt) was favorable (P = 0.04); the number of concurrent mutations did not provide additional prognostication (P = 0.3). We developed a HR-weighted prognostic model, with 2 points for an abnormal karyotype, 1 point for either ASXL1 and/or SETBP1 mutations, and 1 point for a HB level < 10 gm/dl, which effectively stratified patients into three risk categories; low (0 points), intermediate (1 point) and high (≥2 points), with median survivals of 80, 42 and 11 months respectively (P = 0.01). In summary, we confirm the unique mutational landscape in RARS-T and provide a novel mutation-enhanced prognostic model.

Calreticulin variant stratified driver mutational status and prognosis in essential thrombocythemia

About 85% of patients with essential thrombocythemia (ET) harbor one of three driver mutations: JAK2, calreticulin (CALR), and MPL; the remaining ( ∼15%) are wild type for all three mutations and are referred to as being "triple negative." Furthermore, CALR mutations in ET are structurally classified as type 1/type 1-like or type 2/type 2-like variants. The objective of the current study was to examine the impact of CALR mutation variant stratified driver mutational status on overall (OS), myelofibrosis-free (MFFS), thrombosis-free, and leukemia-free survival (LFS) in ET; 495 patients (median age 58 years; 61% females) with ET were fully annotated for the their driver mutational status: 321 (65%) harbored JAK2, 109 (22%) CALR, and 12 (2%) MPL mutations and 11% were triple-negative. Among the 109 CALR-mutated cases, 52% were classified as type 1/type 1-like and 48% as type 2/type 2-like. In univariate analysis, triple-negative patients displayed the best and MPL mutated the worst OS (P = 0.007); however, the difference in OS was no longer apparent on multivariable analysis that included age and sex as covariates (P = 0.5). LFS was also similar among the different mutational groups (P = 0.6) whereas MFFS was significantly shorter in MPL-mutated patients on both univariate and multivariable analyses (age-adjusted P = 0.02; HR 7.9, 95% CI 2.0-31.5). Also in multivariable analysis that included thrombosis history, age, and cardiovascular risk factors, the presence of JAK2 or MPL mutations was independently associated with higher risk of thrombosis (P = 0.02; HR 1.9, 95% CI 1.1-3.4). In conclusion, driver mutational status in ET does not appear to influence overall or LFS, even after CALR variant stratification. However, the presence of MPL mutations might be associated with a higher risk of fibrotic transformation and the presence of JAK2/MPL mutations with higher risk of thrombosis.