The Austrian biodatabase for chronic myelomonocytic leukemia (ABCMML) : A representative and useful real-life data source for further biomedical research

Characteristics of NRAS-mutated patients with chronic myelomonocytic leukemia in a national (ABCMML) and an international cohort (cBioPortal)

Big data from large international cooperations allow proving consistency of findings in national patient cohorts. We compared features in NRAS-mutated patients of the Austrian biodatabase for chronic myelomonocytic leukemia (ABCMML) with the chronic myelomonocytic leukemia (CMML) cohort documented in cBioPortal. It is consistently demonstrated in both CMML cohorts that NRAS mutations are associated with shorter overall survival, acute myeloid leukemia-free survival, increased white blood cell count, decreased platelet values and the presence of blast cells in peripheral blood. Hemoglobin values did not differ between patients with or without NRAS mutations in either cohort. Validation of data in CMML patients using two independent cohorts, ensures the quality standards for clinical decision making.

Features of RUNX1-mutated patients with chronic myelomonocytic leukemia in a national (ABCMML) and international cohort (cBioPortal)

Big data collected in large international cooperations now allow validation of findings from traditional national patient cohorts for proving consistency. In this study, we compared findings in RUNX1-mutated patients of the Austrian biodatabase for chronic myelomonocytic leukemia (ABCMML) with the CMML cohort documented in cBioPortal. In the cBioPortal cohort, RUNX1-mutated patients had significantly inferior survival and AML-free survival as compared to nonmutated patients. In the ABCMML cohort, survival and AML-free survival were numerically shorter in RUNX1-mutated patients than in wildtype patients, but this did not reach significance. Regarding phenotype, in both cohorts, RUNX1-mutated patients had a significantly higher proportion of patients with thrombocytopenia and lower metric values for platelets as compared to wildtype patients. Validation of data, as we have done in this study in CMML patients using two independent cohorts, ensures the quality standards that are required for their use in clinical decision making.

Acute myeloid leukemia in the next-generation sequencing era : Real-world data from an Austrian tertiary cancer care center

BACKGROUND

Next-generation sequencing (NGS) has recently entered routine acute myeloid leukemia (AML) diagnostics. It is paramount for AML risk stratification and identification of molecular therapeutic targets. Most NGS feasibility and results data are derived from controlled clinical intervention trials (CCIT). We aimed to validate these data in a real-world setting.

PATIENTS, MATERIALS AND METHODS

This study retrospectively analyzed 447 AML patients treated at an Austrian tertiary cancer care center. A total of 284 out of the 447 cases were treated between 2013-2023 when NGS was locally available for the clinical routine.

RESULTS

The NGS was successfully performed from bone marrow biopsies and aspirates, with processing times decreasing from 22 days in 2013/2014 to 10 days in 2022. Molecular therapeutic target(s) were identified by NGS in 107/284 (38%) cases and enabled risk stratification in 10 cases where conventional karyotyping failed. Concerning molecular landscape, TET2 (27%), FLT3 (25%), DNMT3A (23%), and NPM1 (23%) were most frequently mutated. Comparing older and younger patients (cut-off 70 years) showed enrichment in older people for mutations affecting DNA methylation (72% vs. 45%; P < 0.001) and the spliceosome (28% vs. 11%; P = 0.006) and more cellular signaling mutations in younger patients (61% vs. 46%; P = 0.022). Treatment outcomes corroborated a significant survival benefit in the recent NGS era and patients treated with novel/molecularly targeted drugs. Ultimately, biospecimens of these patients are stored within a leukemia biobank, generating a valuable tool for translational science.

CONCLUSION

Our study validates data from CCIT and supports their relevance for treatment decisions in a real-world setting. Moreover, they demonstrate the feasibility and benefits of NGS within a routine clinical setting.

Temporal trend in survival for chronic myelomonocytic leukemia in the US: a population-based study

Outcomes for chronic myelomonocytic leukemia (CMML) are insufficiently characterized at the population level. We analyzed epidemiological trends for patients between 2001 and 2017, focusing on age, sex, race, and long-term survivors. Using the Surveillance, Epidemiology, and End Results Program, we studied 3929 patients, in four time-period (tp) cohorts, based on year of diagnosis [2001-2004 (tp1); 2005-2009 (tp2); 2010-2013 (tp3); 2014-2017 (tp4)]. Stable incidence overall, male predominance, and higher incidence for White versus Black and 'Other' races were noted. Three-year relative survival (RS) increased from 27.9% to 36.9% between tp1 and tp4. The most pronounced increase occurred between tp1 and tp2. All subgroups generally experienced RS improvements over time, except notably Black patients. Improvements for patients aged 85+ (3-year RS 8.4-23.6% between tp1 and tp4) and increases in long-term survivors (5-year OS from 13.2-22.3%) were observed. Additional study is warranted to explore these associations, particularly for Black patients.

Treatment options and survival in real life during the past three decades in patients with chronic myelomonocytic leukemia

The impact of treatment on the outcome of chronic myelomonocytic leukemia (CMML) patients over a longer period of time and the potential role of predictive factors are not well defined. In a retrospective observational study, we analyzed 168 CMML patients regarding treatment options and survival during the past three decades. The proportion of patients treated with hydroxyurea (HU), intensive chemotherapy, and azacitidine (AZA) was 65/19/0% before 2000, 51/25/32% from 2000-2010, and 36/12/53% after 2010, respectively. Median overall survival (OS) increased from 10 months before 2000 to 23 months thereafter (p = 0.021). AZA-treated patients but not patients treated with other treatment options had improved survival as compared to CMML patients without AZA therapy (19 vs. 25 months, p = 0.041). When looking at subgroups, the following patient cohorts had a significant survival benefit in association with AZA therapy: patients with Hb > 10 g/dL, patients with monocytosis > 10 G/L, and patients with mutations in RASopathy genes.

Significance of reduced renal function in patients with chronic myelomonocytic leukemia

In a retrospective study, we analyzed the prevalence of increased creatinine levels in 166 patients with chronic myelomonocytic leukemia (CMML), their potential prognostic impact, and potential correlations with laboratory and molecular features. Increased creatinine values (> 1.1 mg/dl) were found in 71 of 166 (43%) patients. The median survival of patients with increased creatinine values was significantly shorter than in patients without impairment of renal function (20 vs. 52 months, p < 0.001). Patients with increased creatinine values were older, were more often male, had higher leukocyte counts, higher monocyte counts, and higher lactatdehydrogenase (LDH) values. There was a trend toward a higher prevalence of CBL and ASXL1 mutations in patients with renal impairment. Our findings show a high prevalence of renal abnormalities in patients with CMML. Increased creatinine values were identified as a new prognostic marker. These findings may be important for the individualized management of this heterogenous group of patients.

Significance of hypergammaglobulinemia in patients with chronic myelomonocytic leukemia

Chronic inflammation is often indicated by a relative increase in the gamma globulin fraction in the serum electrophoresis. In a retrospective study, we analyzed the prevalence of relative hypergammaglobulinemia in 60 patients with chronic myelomonocytic leukemia (CMML), its potential prognostic impact, and potential correlations with laboratory and molecular features. Relative hypergammaglobulinemia (> 20%) was found in 25/60 (42%) patients. The median survival of patients with relative hypergammaglobulinemia was significantly shorter than in patients without hypergammaglobulinemia (10 vs. 24 months, p = 0.018). There was no difference between the groups regarding leukocyte count, hemoglobin value, and platelet count, but a higher prevalence of NRAS mutations and a lower prevalence of ZRSR2 mutations in patients with hypergammaglobulinemia. Our results show that hypergammaglobulinemia is present in a proportion of CMML patients and that this abnormality is associated with poor overall survival. The role of chronic inflammation in the pathophysiology of CMML needs to be further investigated.

Significance of C-reactive protein in patients with chronic myelomonocytic leukemia

In a retrospective study, we analyzed the prevalence of elevated C‑reactive protein (CRP) serum levels in 148 patients with chronic myelomonocytic leukemia (CMML), their potential prognostic impact, and potential correlations with laboratory features. Normal, up to 10-fold, and more than 10-fold elevated CRP levels were found in 18%, 59%, and 23% of CMML patients, respectively. Using the CRP cutoff value of 10 mg/L of the widely used Glasgow score, high CRP values were associated with inferior survival (13 vs. 39 months, p = 0.014), which retained prognostic significance in multivariate analysis. High CRP values were associated with lower hemoglobin levels. The survival difference between patients with normal (< 5 mg/L) and elevated CRP levels persisted after exclusion of patients with clinical infection. These findings indicate that in CMML patients, the presence of an acute-phase reaction is associated with a poor outcome, independent of clinical infection.

Significance of cardiovascular comorbidity in patients with chronic myelomonocytic leukemia

In a retrospective study, we analyzed the prevalence of common cardiovascular comorbidities in 310 patients with chronic myelomonocytic leukemia (CMML), their potential prognostic impact, and potential correlations with laboratory and molecular features. 115 (36%) patients had a documented cardiovascular comorbidity. In these patients, coronary heart disease 41/115 (36%), atrial fibrillation 34/115 (29%), and hypertension 75/115 (64%) were documented. None of these conditions had a significant impact on survival. Unexpectedly, patients with cardiovascular comorbidity had a lower number of circulating blasts and a lower prevalence of EZH2 mutations. Moreover, time to transformation was significantly longer in these patients. Cardiovascular comorbidity does not seem to have a major impact on prognosis in CMML patients. The unexpected lower transformation rate in these patients needs to be further investigated.

Real-World Data on Chronic Myelomonocytic Leukemia: Clinical and Molecular Characteristics, Treatment, Emerging Drugs, and Patient Outcomes

Despite emerging molecular information on chronic myelomonocytic leukemia (CMML), patient outcome remains unsatisfactory and little is known about the transformation to acute myeloid leukemia (AML). In a single-center cohort of 219 CMML patients, we explored the potential correlation between clinical features, gene mutations, and treatment regimens with overall survival (OS) and clonal evolution into AML. The most commonly detected mutations were TET2, SRSF2, ASXL1, and RUNX1. Median OS was 34 months and varied according to age, cytogenetic risk, FAB, CPSS and CPSS-Mol categories, and number of gene mutations. Hypomethylating agents were administered to 37 patients, 18 of whom responded. Allogeneic stem cell transplantation (alloSCT) was performed in 22 patients. Two-year OS after alloSCT was 60.6%. Six patients received targeted therapy with IDH or FLT3 inhibitors, three of whom attained a long-lasting response. AML transformation occurred in 53 patients and the analysis of paired samples showed changes in gene mutation status. Our real-world data emphasize that the outcome of CMML patients is still unsatisfactory and alloSCT remains the only potentially curative treatment. However, targeted therapies show promise in patients with specific gene mutations. Complete molecular characterization can help to improve risk stratification, understand transformation, and personalize therapy.

Molecular Pathogenesis of Chronic Myelomonocytic Leukemia and Potential Molecular Targets for Treatment Approaches

Numerous examples in oncology have shown that better understanding the pathophysiology of a malignancy may be followed by the development of targeted treatment concepts with higher efficacy and lower toxicity as compared to unspecific treatment. The pathophysiology of chronic myelomonocytic leukemia (CMML) is heterogenous and complex but applying different research technologies have yielded a better and more comprehensive understanding of this disease. At the moment treatment for CMML is largely restricted to the unspecific use of cytotoxic drugs and hypomethylating agents (HMA). Numerous potential molecular targets have been recently detected by preclinical research which may ultimately lead to treatment concepts that will provide meaningful benefits for certain subgroups of patients.

Impact of age on the cumulative risk of transformation in patients with chronic myelomonocytic leukaemia

In older patients with chronic myelomonocytic leukaemia (CMML) and limited life expectancy due to age and or comorbidities, it is particularly important to consider the risk of transformation for individualised treatment decisions. There is limited information on potential differences between younger and older CMML patients regarding the cumulative risk of transformation as well as haematological, molecular and biologic characteristics. We analysed data from the Austrian Biodatabase for CMML (ABCMML) to compare these parameters in 518 CMML patients. Categorisation of patients into 3 age-related groups: <60 years, 60-79 years and ≥80 years, showed a significantly lower risk of transformation at higher age by competing risk analysis, with a 4-year risk of 39%, 23% and 13%, respectively (P < .0001). The lower probability of transformation was associated with a lower percentage of blast cells in the peripheral blood (PB) of older patients. Furthermore, we provide a simple score based on age, PB blasts and platelet counts that allowed us to define subgroups of CMML patients with a different cumulative transformation risk, including a low-risk group with a transformation risk of only 5%. Our findings may facilitate reasonable treatment decisions in elderly patients with CMML.

Myelomonocytic skewing in chronic myelomonocytic leukemia: phenotypic, molecular and biologic features and impact on survival

BACKGROUND

Myelomonocytic skewing is considered as a key pathophysiologic phenomenon in chronic myelomonocytic leukemia (CMML), but its prevalence and potential correlation with phenotypic, genotypic, and clinical features are poorly defined.

METHODS

Skewed differentiation toward the myelomonocytic over erythroid commitment as indicated by an inverse ratio of myelomonocytic/erythroid colonies was investigated in 146 patients with CMML by semisolid in vitro cultures.

RESULTS

There was a high prevalence of myelomonocytic skewing in patients with CMML (120/146, 82%); whereas, this phenomenon was rare in normal individuals (1/98, 1%). Patients with CMML with myelomonocytic skewing had higher white blood cell and peripheral blast cell counts, and lower platelet values. The number of mutations in genes of the epigenetic and/or splicing category was higher in CMML patients with as compared with patients without skewing. Patients with myelomonocytic skewing had more frequently mutations in RASopathy genes and higher growth factor independent myeloid colony formation. Interestingly, the lack of myelomonocytic skewing discriminated patients with CMML with a particularly favorable prognosis (60 vs 19 months, P = .003) and a minimal risk of transformation.

CONCLUSION

Myelomonocytic skewing as determined by semisolid cultures can discriminate subgroups of patients with CMML with a different phenotype, a different genotype, and a different prognosis.

Micro-RNA-125a mediates the effects of hypomethylating agents in chronic myelomonocytic leukemia

BACKGROUND

Chronic myelomonocytic leukemia (CMML) is an aggressive hematopoietic malignancy that arises from hematopoietic stem and progenitor cells (HSPCs). Patients with CMML are frequently treated with epigenetic therapeutic approaches, in particular the hypomethylating agents (HMAs), azacitidine (Aza) and decitabine (Dec). Although HMAs are believed to mediate their efficacy via re-expression of hypermethylated tumor suppressors, knowledge about relevant HMA targets is scarce. As silencing of tumor-suppressive micro-RNAs (miRs) by promoter hypermethylation is a crucial step in malignant transformation, we asked for a role of miRs in HMA efficacy in CMML.

RESULTS

Initially, we performed genome-wide miR-expression profiling in a KrasG12D-induced CMML mouse model. Selected candidates with prominently decreased expression were validated by qPCR in CMML mice and human CMML patients. These experiments revealed the consistent decrease in miR-125a, a miR with previously described tumor-suppressive function in myeloid neoplasias. Furthermore, we show that miR-125a downregulation is caused by hypermethylation of its upstream region and can be reversed by HMA treatment. By employing both lentiviral and CRISPR/Cas9-based miR-125a modification, we demonstrate that HMA-induced miR-125a upregulation indeed contributes to mediating the anti-leukemic effects of these drugs. These data were validated in a clinical context, as miR-125a expression increased after HMA treatment in CMML patients, a phenomenon that was particularly pronounced in cases showing clinical response to these drugs.

CONCLUSIONS

Taken together, we report decreased expression of miR-125a in CMML and delineate its relevance as mediator of HMA efficacy within this neoplasia.

Molecular Basis and Clinical Application of Growth-Factor-Independent In Vitro Myeloid Colony Formation in Chronic Myelomonocytic Leukemia

We have originally reported that colony-forming units granulocyte/macrophage (CFU-GM) formation is an in vitro feature of chronic myelomonocytic leukemia (CMML) and a strong predictor for short survival. Elucidation of the molecular basis underlying this in vitro phenomenon could be helpful to define molecular features that predict inferior outcome in patients. We studied the correlation between the mutational landscape and spontaneous colony formation in 164 samples from 125 CMML patients. As compared to wildtype samples, spontaneous in vitro CFU-GM formation was significantly increased in samples containing mutations in NRAS, CBL and EZH2 that were confirmed as independent stimulatory factors by multiple regression analysis. Inducible expression of mutated RAS but not JAK2 was able to induce growth factor independence of Ba/F3 cells. Whereas high colony CFU-GM growth was a strong unfavorable parameter for survival (p < 0.00001) and time to transformation (p = 0.01390), no single mutated gene had the power to significantly predict for both outcome parameters. A composite molecular parameter including NRAS/CBL/EZH2, however, was predictive for inferior survival (p = 0.00059) as well as for increased risk of transformation (p = 0.01429). In conclusion, we show that the composite molecular profile NRAS/CBL/EZH2 derived from its impact on spontaneous in vitro myeloid colony formation improves the predictive power over single molecular parameters in patients with CMML.

Clinical, Hematologic, Biologic and Molecular Characteristics of Patients with Myeloproliferative Neoplasms and a Chronic Myelomonocytic Leukemia-Like Phenotype

Patients with a myeloproliferative neoplasm (MPN) sometimes show a chronic myelomonocytic leukemia (CMML)-like phenotype but, according to the 2016 WHO classification, a documented history of an MPN excludes the diagnosis of CMML. Forty-one patients with an MPN (35 polycythemia vera (PV), 5 primary myelofibrosis, 1 essential thrombocythemia) and a CMML-like phenotype (MPN/CMML) were comprehensively characterized regarding clinical, hematologic, biologic and molecular features. The white blood cell counts in MPN/CMML patients were not different from CMML patients and PV patients. The hemoglobin values and platelet counts of these patients were higher than in CMML but lower than in PV, respectively. MPN/CMML patients showed myelomonocytic skewing, a typical in vitro feature of CMML but not of PV. The mutational landscape of MPN/CMML was not different from JAK2-mutated CMML. In two MPN/CMML patients, development of a CMML-like phenotype was associated with a decrease in the JAK2 V617F allelic burden. Finally, the prognosis of MPN/CMML (median overall survival (OS) 27 months) was more similar to CMML (JAK2-mutated, 28 months; JAK2-nonmutated 29 months) than to PV (186 months). In conclusion, we show that patients with MPN and a CMML-like phenotype share more characteristics with CMML than with PV, which may be relevant for their classification and clinical management.

Correlation of RAS-Pathway Mutations and Spontaneous Myeloid Colony Growth with Progression and Transformation in Chronic Myelomonocytic Leukemia-A Retrospective Analysis in 337 Patients

Although the RAS-pathway has been implicated as an important driver in the pathogenesis of chronic myelomonocytic leukemia (CMML) a comprehensive study including molecular and functional analyses in patients with progression and transformation has not been performed. A close correlation between RASopathy gene mutations and spontaneous in vitro myeloid colony (CFU-GM) growth in CMML has been described. Molecular and/or functional analyses were performed in three cohorts of 337 CMML patients: in patients without (A, n = 236) and with (B, n = 61) progression/transformation during follow-up, and in patients already transformed at the time of sampling (C, n = 40 + 26 who were before in B). The frequencies of RAS-pathway mutations (variant allele frequency ≥ 20%) in cohorts A, B, and C were 30%, 47%, and 71% (p < 0.0001), and of high colony growth (≥20/105 peripheral blood mononuclear cells) 31%, 44%, and 80% (p < 0.0001), respectively. Increases in allele burden of RAS-pathway mutations and in numbers of spontaneously formed CFU-GM before and after transformation could be shown in individual patients. Finally, the presence of mutations in RASopathy genes as well as the presence of high colony growth prior to transformation was significantly associated with an increased risk of acute myeloid leukemia (AML) development. Together, RAS-pathway mutations in CMML correlate with an augmented autonomous expansion of neoplastic precursor cells and indicate an increased risk of AML development which may be relevant for targeted treatment strategies.

RAF Kinase Inhibitor Protein in Myeloid Leukemogenesis

RAF kinase inhibitor protein (RKIP) is an essential regulator of intracellular signaling. A somatic loss of RKIP expression is a frequent event in solid human cancers, and a role of RKIP as metastasis-suppressor is widely accepted nowadays. Recently, RKIP loss has been described in acute myeloid leukemia (AML) and a series of other myeloid neoplasias (MNs). Functional in vitro and in vivo experiments revealed that RKIP is an essential player within the development of these liquid tumors; however, the respective role of RKIP seems to be complex and multi-faceted. In this review, we will summarize the current knowledge about RKIP in myeloid leukemogenesis. We will initially describe its involvement in physiologic hematopoiesis, and will then proceed to discuss its role in the development of AML and other MNs. Finally, we will discuss potential therapeutic implications arising thereof.