Lasho, Terra L.

AbstractMonocytosis (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.

AbstractAtypical 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.

Key Points More than half of patients with PV or ET harbor DNA mutations/variants other than JAK2/CALR/MPL. The presence of some of these mutations adversely affects overall, leukemia-free, or myelofibrosis-free survival.

Key Points More than 80% of patients with PMF harbor DNA variants/mutations other than JAK2/CALR/MPL. Some of these variants/mutations adversely affect overall or leukemia-free survival independent of conventional risk stratification.

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.

In routine practice, the World Health Organization classification of systemic mastocytosis (SM) is also the de facto prognostic system; a core value is distinguishing indolent (ISM) from advanced SM (includes aggressive SM [ASM], SM with associated hematological neoplasm [SM‐AHN] and mast cell leukemia [MCL]). We sequenced 27 genes in 150 SM patients to identify mutations that could be integrated into a clinical‐molecular prognostic model for survival. Forty four patients (29%) had ISM, 25 (17%) ASM, 80 (53%) SM‐AHN and 1 (0.7%) MCL; overall KITD816V prevalence was 75%. In 87 patients, 148 non‐KIT mutations were detected; the most frequently mutated genes were TET2 (29%), ASXL1 (17%), and CBL (11%), with significantly higher mutation frequency in SM‐AHN > ASM > ISM (P < 0.0001). In advanced SM, ASXL1 and RUNX1 mutations were associated with inferior survival. In multivariate analysis, age > 60 years (HR = 2.4), hemoglobin < 10 g/dL or transfusion‐dependence (HR = 1.7), platelet count < 150 × 109/L (HR = 3.2), serum albumin < 3.5 g/dL (HR = 2.6), and ASXL1 mutation (HR = 2.3) were associated with inferior survival. A mutation‐augmented prognostic scoring system (MAPSS) based on these parameters stratified advanced SM patients into high‐, intermediate‐, and low‐risk groups with median survival of 5, 21 and 86 months, respectively (P < 0.0001). These data should optimize risk‐stratification and treatment selection for advanced SM patients. Am. J. Hematol. 91:888–893, 2016. © 2016 Wiley Periodicals, Inc.

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. Am. J. Hematol. 91:503–506, 2016. © 2016 Wiley Periodicals, Inc.

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%, JAK2 V617F 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 ( ASXL1 wt/ SETBP1 wt) 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. Am. J. Hematol. 91:492–498, 2016. © 2016 Wiley Periodicals, Inc.