European LeukemiaNet-defined primary refractory acute myeloid leukemia: the value of allogeneic hematopoietic stem cell transplant and overall response

We sought to appraise the value of overall response and salvage chemotherapy, inclusive of allogeneic hematopoietic stem cell transplant (AHSCT), in primary refractory acute myeloid leukemia (prAML). For establishing consistency in clinical practice, the 2017 European LeukemiaNet (ELN) defines prAML as failure to attain CR after at least 2 courses of intensive induction chemotherapy. Among 60 consecutive patients (median age 63 years) correspondent with ELN-criteria for prAML, salvage was documented in 48 cases, 30/48 (63%) being administered intensive chemotherapy regimens and 2/48 consolidated with AHSCT as first line salvage. 13/48 (27%) attained response: CR, 7/13 (54%), CRi, 2/13 (15%), MLFS, 4/13 (31%). The CR/CRi rate was 9/48 (19%), with CR rate of 7/48 (15%). On univariate analysis, intermediate-risk karyotype was the only predictor of response (44% vs 17% in unfavorable karyotype; P = 0.04). Administration of any higher-dose (>1 g/m²) cytarabine intensive induction (P = 0.50), intensive salvage chemotherapy (P = 0.72), targeted salvage (FLT3 or IDH inhibitors) (P = 0.42), greater than 1 salvage regimen (P = 0.89), age < 60 years (P = 0.30), and de novo AML (P = 0.10) did not enhance response achievement, nor a survival advantage. AHSCT was performed in 12 patients with (n = 8) or without (n = 4) CR/CRi/MLFS. 1/2/5-year overall survival (OS) rates were 63%/38%/33% in patients who received AHSCT (n = 12) vs 27%/0%/0% in those who achieved CR/CRi/MLFS but were not transplanted (n = 5), vs 14%/0%/0% who were neither transplanted nor achieved CR/CRi/MLFS (n = 43; P < 0.001); the median OS was 18.6, 12.6 and 5.6 months, respectively. Although CR/CRi/MLFS bridged to AHSCT (n = 8), appeared to manifest a longer median OS (20 months), vs (13.4 months) for those with no response consolidated with AHSCT (n = 4), the difference was not significant P = 0.47. We conclude AHSCT as indispensable for securing long-term survival in prAML (p = 0.03 on multivariate analysis), irrespective of response achievement.

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.

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.

Prognostic interaction between ASXL1 and TET2 mutations in chronic myelomonocytic leukemia

Mutations involving epigenetic regulators (TET2~60% and ASXL1~40%) and splicing components (SRSF2~50%) are frequent in chronic myelomonocytic leukemia (CMML). On a 27-gene targeted capture panel performed on 175 CMML patients (66% males, median age 70 years), common mutations included: TET2 46%, ASXL1 47%, SRSF2 45% and SETBP1 19%. A total of 172 (98%) patients had at least one mutation, 21 (12%) had 2, 24 (14%) had 3 and 30 (17%) had >3 mutations. In a univariate analysis, the presence of ASXL1 mutations (P=0.02) and the absence of TET2 mutations (P=0.03), adversely impacted survival; while the number of concurrent mutations had no impact (P=0.3). In a multivariable analysis that included hemoglobin, platelet count, absolute monocyte count and circulating immature myeloid cells (Mayo model), the presence of ASXL1 mutations (P=0.01) and absence of TET2 mutations (P=0.003) retained prognostic significance. Patients were stratified into four categories: ASXL1wt/TET2wt (n=56), ASXL1mut/TET2wt (n=31), ASXL1mut/TET2mut (n=50) and ASXL1wt/TET2mut (n=38). Survival data demonstrated a significant difference in favor of ASXL1wt/TET2mut (38 months; P=0.016), compared with those with ASXL1wt/TET2wt (19 months), ASXL1mut/TET2wt (21 months) and ASXL1mut/TET2mut (16 months) (P=0.3). We confirm the negative prognostic impact imparted by ASXL1 mutations and suggest a favorable impact from TET2 mutations in the absence of ASXL1 mutations.

Calreticulin mutations and long-term survival in essential thrombocythemia

The impact of calreticulin (CALR) mutations on long-term survival in essential thrombocythemia (ET) was examined in 299 patients whose diagnosis predated 2006. Mutational frequencies were 53% for Janus kinase 2 (JAK2), 32% for CALR and 3% for MPL; the remaining 12% were 'triple-negative'. We confirmed the association of mutant CALR (vs JAK2V617F) with younger age (P=0.002), male sex (P=0.01), higher platelet count (0.0004), lower hemoglobin (P<0.0001), lower leukocyte count (0.02) and lower incidence of recurrent thrombosis (0.04). Triple-negative patients were also younger than their JAK2-mutated counterparts (P=0.003) and displayed lower hemoglobin (P=0.003), lower leukocyte count (<0.0001) and lower thrombotic events (P=0.02). Median follow-up time was 12.7 years and 47% of the patients were followed until death. Survival was the longest for triple-negative and shortest for MPL-mutated patients. Median survival was 19 years for JAK2 and 20 years for CALR-mutated cases (P=0.32); the corresponding figures for patients of age ⩽65 years were 26 and 32 years (P=0.56). The two mutational categories were also similar for leukemic (P=0.28) and fibrotic (P=0.28) progression rates. The current study is uniquely characterized by its very long follow-up period and provides accurate estimates of long-term survival in ET and complements current information on mutation-specific phenotype and prognosis.

Mutations and prognosis in primary myelofibrosis

Patient outcome in primary myelofibrosis (PMF) is significantly influenced by karyotype. We studied 879 PMF patients to determine the individual and combinatorial prognostic relevance of somatic mutations. Analysis was performed in 483 European patients and the seminal observations were validated in 396 Mayo Clinic patients. Samples from the European cohort, collected at time of diagnosis, were analyzed for mutations in ASXL1, SRSF2, EZH2, TET2, DNMT3A, CBL, IDH1, IDH2, MPL and JAK2. Of these, ASXL1, SRSF2 and EZH2 mutations inter-independently predicted shortened survival. However, only ASXL1 mutations (HR: 2.02; P<0.001) remained significant in the context of the International Prognostic Scoring System (IPSS). These observations were validated in the Mayo Clinic cohort where mutation and survival analyses were performed from time of referral. ASXL1, SRSF2 and EZH2 mutations were independently associated with poor survival, but only ASXL1 mutations held their prognostic relevance (HR: 1.4; P=0.04) independent of the Dynamic IPSS (DIPSS)-plus model, which incorporates cytogenetic risk. In the European cohort, leukemia-free survival was negatively affected by IDH1/2, SRSF2 and ASXL1 mutations and in the Mayo cohort by IDH1 and SRSF2 mutations. Mutational profiling for ASXL1, EZH2, SRSF2 and IDH identifies PMF patients who are at risk for premature death or leukemic transformation.

Incidence and risk factors for bleeding in 1104 patients with essential thrombocythemia or prefibrotic myelofibrosis diagnosed according to the 2008 WHO criteria

In an international study of 1104 patients with essential thrombocythemia (ET), a histological review according to the 2008 World Health Organization (WHO) criteria confirmed ET in 891 patients (WHO-ET, 81%), and revised the diagnosis to prefibrotic primary myelofibrosis (PMF) in 180 patients (PMF, 16%). Major bleeding during follow-up occurred in 55 (6%) WHO-ET and 21 (12%) PMF patients (P = 0.009), at a rate of 0.79 and 1.39% patients per year, respectively, (P = 0.039). In a multivariable analysis, predictors of bleeding included diagnosis of PMF (P = 0.05; hazard ratio (HR) 1.74), leukocytosis (P = 0.04; HR 1.74), previous hemorrhage (P = 0.025; HR 2.35) and aspirin therapy (P=0.001; HR 3.16). The analysis restricted to patients with WHO-ET confirmed previous hemorrhage (P = 0.043; HR 1.92) and aspirin (P=0.027; HR 2.24) as independent risk factors. The current study reveals that major bleeding associated with thrombocytosis might be relatively specific to PMF, as opposed to WHO-defined ET. Furthermore, it shows that low-dose aspirin exacerbates these hemorrhagic events of PMF. In contrast, thrombocytosis per se was not a risk factor for bleeding; however, low-dose aspirin had a synergistic hemorrhagic effect unmasking the bleeding tendency of patients with extreme thrombocytosis. These observations carry significant therapeutic implications in these two WHO entities.

Refined cytogenetic-risk categorization for overall and leukemia-free survival in primary myelofibrosis: a single center study of 433 patients

We have previously identified sole +9, 13q- or 20q-, as ‘favorable' and sole +8 or complex karyotype as ‘unfavorable' cytogenetic abnormalities in primary myelofibrosis (PMF). In this study of 433 PMF patients, we describe additional sole abnormalities with favorable (chromosome 1 translocations/duplications) or unfavorable (−7/7q-) prognosis and also show that other sole or two abnormalities that do not include i(17q), −5/5q-, 12p-, inv(3) or 11q23 rearrangement are prognostically aligned with normal karyotype, which is prognostically favorable. These findings were incorporated into a refined two-tired cytogenetic-risk stratification: unfavorable and favorable karyotype. The respective 5-year survival rates were 8 and 51% (hazard ratio (HR): 3.1, 95% confidence interval (CI): 2.2–4.3; P<0.0001). Multivariable analysis confirmed the International Prognostic Scoring System (IPSS)-independent prognostic value of cytogenetic-risk categorization and also identified thrombocytopenia (platelets <100 × 10⁹/l) as another independent predictor of inferior survival (P<0.0001). A similar multivariable analysis showed that karyotype (P=0.001) and platelet count (P=0.04), but not IPSS (P=0.27), predicted leukemia-free survival; the 5-year leukemic transformation rates for unfavorable versus favorable karyotype were 46 and 7% (HR: 5.5, 95% CI: 2.5–12.0; P<0.0001). This study provides the rationale and necessary details for incorporating cytogenetic findings and platelet count in future prognostic models for PMF.

The JAK2 46/1 haplotype confers susceptibility to essential thrombocythemia regardless of JAK2V617F mutational status-clinical correlates in a study of 226 consecutive patients

The germline JAK2 haplotype 46/1, tagged by the 'C' allele of single-nucleotide polymorphism (SNP) rs12343867 (C/T), has been associated with JAK2V617F (VF)-positive myeloproliferative neoplasms. SNP rs12343867 was genotyped using bone marrow DNA in 226 consecutive patients with essential thrombocythemia (ET) with concomitant analysis of VF allele burden. The incidence of the 46/1-linked C allele was significantly higher in ET (genotype: CC 15%, CT 52%, TT 33%; C-allele frequency: 41%) than in population controls (P<0.01). Genotype distributions were similar among VF-positive/VF-negative patients (genotype: CC 18/11%, CT 52/53%, TT 30/36%; C-allele: 44/38%; P=0.29). Haplotype 46/1 frequency was remarkably similar when comparing VF-negative patients to those with <10% VF allele burden, but significantly higher in the presence of >10% VF allele burden (genotype: CC 11/13/38%, CT 53/56/38%, TT 36/31/24%; C-allele frequency: 38/41/57%; P<0.01). The clinical features of 46/1-positive and -negative ET were indistinguishable, including blood counts, rate of thrombosis/disease transformation and survival. We conclude that JAK2 haplotype 46/1 confers susceptibility to developing ET independent of VF mutational status and does not seem to further affect the clinical phenotype or prognosis.

TET2 mutations and their clinical correlates in polycythemia vera, essential thrombocythemia and myelofibrosis

High-throughput DNA sequence analysis was used to screen for TET2 mutations in bone marrow-derived DNA from 239 patients with BCR-ABL-negative myeloproliferative neoplasms (MPNs). Thirty-two mutations (19 frameshift, 10 nonsense, 3 missense; mostly involving exons 4 and 12) were identified for an overall mutational frequency of approximately 13%. Specific diagnoses included polycythemia vera (PV; n=89), essential thrombocythemia (ET; n=57), primary myelofibrosis (PMF; n=60), post-PV MF (n=14), post-ET MF (n=7) and blast phase PV/ET/MF (n=12); the corresponding mutational frequencies were approximately 16, 5, 17, 14, 14 and 17% (P=0.50). Mutant TET2 was detected in approximately 17 and approximately 7% of JAK2V617F-positive and -negative cases, respectively (P=0.04). However, this apparent clustering of the two mutations was accounted for by an independent association between mutant TET2 and advanced age; mutational frequency was approximately 23% in patients > or =60 years old versus approximately 4% in younger patients (P<0.0001). The presence of mutant TET2 did not affect survival, leukemic transformation or thrombosis in either PV or PMF; a correlation with hemoglobin <10 g per 100 ml in PMF was noted (P=0.05). We conclude that TET2 mutations occur in both JAK2V617F-positive and -negative MPN, are more prevalent in older patients, display similar frequencies across MPN subcategories and disease stages, and hold limited prognostic relevance.

The impact of leukocytosis on survival, leukemic transformation, and thrombosis in polycythemia vera

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Background: A leukocyte count of > 15 ×109/L has recently been associated with myocardial infarction in polycythemia vera (PV). In the current study, we examine the impact of such degree of leukocytosis on survival, leukemic transformation (LT), and thrombosis in a large cohort of PV patients from a single institution Methods: Data was abstracted from the medical records of a consecutive cohort of patients with PV defined by the World Health Organization criteria. Results: i. Patient characteristics The study cohort included 459 patients (median age, 60 years). Median follow-up was 64 months. ii. Survival In a multivariable analysis, advanced age, leukocyte count of = 15 × 109/L, and arterial thrombosis at diagnosis were significantly associated with inferior survival. A prognostic model based on age = 60 years and leukocyte count = 15 × 109/L separated low-risk, intermediate-risk, and high-risk patient groups with respective median survivals of 272, 162, and 108 months (p<0.0001). iii. Leukemic transformation In a multivariable analysis, only leukocyte count was significantly associated with LT; median leukemia-free survival for patients with leukocyte count = 15 × 109/L was 273 months vs. not reached for those with lower leukocyte count (p<0.0001). iv. Thrombosis at diagnosis In multivariable analysis, arterial thrombosis at diagnosis was significantly associated with previous history of arterial thrombosis, hypertension, and tobacco use; venous thrombosis at diagnosis was significantly associated with previous venous event and splenomegaly. v. Thrombosis during follow- up In multivariable analysis, arterial thrombosis during follow-up was significantly associated with previous arterial event, hypertension, and tobacco use; venous thrombosis during follow-up was significantly associated with previous venous event, diabetes mellitus, advanced age, and leukocyte count = 1,500 × 109/L. Conclusions: The current study for the first time identifies leukocytosis as a risk factor for inferior survival, LT risk, and venous thrombosis in PV.

No significant financial relationships to disclose.

Clinical correlates of JAK2V617F allele burden in essential thrombocythemia

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Background: JAK2V617F occurs in approximately 50% of patients with essential thrombocythemia. Qualitative studies of mutation analysis have previously reported an association between JAK2V617F and advanced age, higher hemoglobin level, higher leukocyte count, and lower platelet count. A possible association with thrombotic complication has also been considered. Methods: Allele-specific, quantitative PCR analysis for JAK2V617F was performed on 176 patients with ET, using genomic DNA from archived bone marrow, which was collected within one year (n=72), between 1 and 5 years (n=64), or after 5 years (n=40) of diagnosis. Results: JAK2V617F was detected in 96 patients (55%), in whom mutant allele burden ranged from 1% to 100% (median 6.3%). Neither mutational frequency (p=0.37) nor mutant allele burden (p=0.62) was affected by the timing of bone marrow sample collection. Presence of JAK2V617F was significantly associated with higher hemoglobin level (p<0.0001), lower platelet count (p=0.001), higher leukocyte count (p=0.008), increased incidence of venous thrombosis occurring after diagnosis (p=0.02), and older age at diagnosis (p=0.03). All but age retained significance in multivariable analysis. In mutation-positive patients (n=96), JAK2V617F allele burden clustered between 1% and 22% in 94 cases, in whom it correlated directly and significantly with platelet and leukocyte counts, palpable splenomegaly at diagnosis, and venous thrombosis occurring after diagnosis. Conclusions: JAK2V617F allele burden imparts additional phenotypic effects in ET.

No significant financial relationships to disclose.

Risk stratification for survival and leukemic transformation in essential thrombocythemia: a single institutional study of 605 patients

Unlike the case with thrombosis, prognostic models for survival and leukemic transformation (LT) in essential thrombocythemia (ET) are not available. Among 605 patients with ET seen at our institution and followed for a median of 84 months, 155 died and LT was documented in 20 patients (3.3%). In a multivariable analysis, hemoglobin level below normal (females<120 g/l; males<135 g/l) was identified as an independent risk factor for both inferior survival and LT. Additional risk factors for survival included age > or =60 years, leukocyte count> or =15 x 10(9)/l, smoking, diabetes mellitus and thrombosis. For LT, platelet count> or =1000 x 10(9)/l but not cytoreductive therapy was flagged as an additional independent risk factor. In fact, four of the 20 patients (20%) with LT were untreated previously. We used the above information to construct prognostic models that effectively discriminated among low-, intermediate- and high-risk groups with respective median survivals of 278, 200 and 111 months (P<0.0001), and LT rates of 0.4, 4.8 and 6.5% (P=0.0009) respectively. Presence of JAK2V617F did not impact either survival or LT and mutational frequency was similar among the different risk groups.

Pulmonary infiltrates during chemotherapy-induced febrile neutropenia: incidence, patterns and outcomes

OBJECTIVE

To analyze the incidence, etiologies, radiographic patterns, and clinical outcomes of adult leukemics with prolonged febrile neutropenia and pneumonia.

METHODS

A retrospective study was conducted at a tertiary care hospital. The medical records of adult patients with acute myeloid leukemia diagnosed between January 1989 and June 2000 and undergoing induction chemotherapy were included. Only the patients who presented with a pulmonary infiltrate, secondary leukemia (e.g., transformed chronic myeloid leukemia underlying myelodysplastic syndrome, or disease following alkylating agent therapy) were included and those developing infiltrates following consolidation chemotherapy were excluded.

RESULTS

A total of 124 patients were admitted to the hospital with a diagnosis of AML during the study period. Thirty-one patients were excluded; 93 patients received induction chemotherapy and were included in the study analysis. The median age was 36 years (15 - 70 years); 58 males and 35 females. Sixty two percent patients received Cytosine Arabinoside (Ara-C), 17% received Etoposide, 11% received Ara-C and Mitoxantrone, and 6% received All-trans-retinoic Acid. The mean onset and duration of neutropenia were 5 and 15 days, respectively. Pulmonary infiltrates were identified during 45% of neutropenic episodes. A presumptive causative organism was isolated from 50% of patients with an infiltrate: Gram-positive bacteria were most common (47%) followed by Gram-negative bacilli (33%) and fungi (20%). Survival data were available for 88 patients; median disease free survival for the entire cohort was 7 months. Male sex (p=0.015), onset of neutropenia (p=0.02) and bilateral distribution of an infiltrate (p=0.03) were statistically significant predictors of early mortality. For patients with and without pneumonia, the median disease-free interval and overall survival were 2.5 and 4.6 months and 9 and 13 months (p=0.038 and p=0.095) respectively.

CONCLUSION

Neutropenia occurred at a mean of 5.0 after initiation of induction chemotherapy. The majority of patients had bilateral pulmonary infiltrates. Male sex, onset of neutropenia and bilateral distribution of an infiltrate were found to be statistically significant predictors of early mortality.