The leukemia strikes back: a review of pathogenesis and treatment of secondary AML

Adult rhabdomyosarcoma combined with acute myeloid leukemia: A case report

BACKGROUND

Rhabdomyosarcoma is a tumor of mesenchymal origin. Secondary leukemia is a complication of previous transformation to other hematologic disorders or is a treatment-related acute myeloid leukemia secondary to cytotoxic chemotherapy or radiation therapy for other malignancies.

CASE SUMMARY

We present the case of a 36-year-old female patient who was diagnosed with rhabdomyosarcoma and acute myeloid leukemia. Further disease progression was observed after multiline chemotherapy. Eventually, the patient suffered cerebral hemorrhage, which resulted in death.

CONCLUSION

The incidence of rhabdomyosarcoma in adults is extremely low, and secondary leukemia caused by rhabdomyosarcoma is even rarer. Secondary leukemia has a very poor prognosis and a low overall survival rate.

Spatial proteomics identifies a spectrum of immune dysregulation in acquired bone marrow failure syndromes

Poor graft function (PGF), manifested by multilineage cytopenias and complete donor chimerism post-allogeneic stem cell transplantation (alloSCT), and acquired aplastic anaemia (AA) are immune-mediated acquired bone marrow (BM) failure syndromes with a similar clinical presentation. In this study, we used spatial proteomics to compare the immunobiology of the BM microenvironment and identify common mechanisms of immune dysregulation under these conditions. Archival BM trephines from patients exhibited downregulation of the immunoregulatory protein VISTA and the M2 macrophage marker and suppressor of T-cell activation ARG1 with increased expression of the immune checkpoint B7-H3 compared to normal controls. Increased CD163 and CD14 expression suggested monocyte/macrophage skewing, which, combined with dysregulation of STING and VISTA, is indicative of an environment of reduced immunoregulation resulting in the profound suppression of hematopoiesis in these two conditions. There were no changes in the immune microenvironment between paired diagnostic AA and secondary MDS/AML samples suggesting that leukaemic clones develop in the impaired immune microenvironment of AA without the need for further alterations. Of the eight proteins with dysregulated expression shared by diagnostic AA and PGF, the diagnostic AA samples had a greater fold change in expression than PGF, suggesting that these diseases represent a spectrum of immune dysregulation. Unexpectedly, analysis of samples from patients with good graft function post-alloSCT demonstrated significant changes in the immune microenvironment compared to normal controls, with downregulation of CD44, STING, VISTA, and ARG1, suggesting that recovery of multilineage haematopoiesis post-alloSCT does not reflect recovery of immune function and may prime patients for the development of PGF upon further inflammatory insult. The demonstrable similarities in the immunopathology of AA and PGF will allow the design of clinical interventions that include both patient cohorts to accelerate therapeutic discovery and translation.

'Secondary' acute lymphoblastic/lymphocytic leukemia - done playing second fiddle?

Acute lymphoblastic/lymphocytic leukemia (ALL) occurring post-cancer diagnosis (secondary ALL - sALL) is increasingly recognized as a discrete entity, constituting up to as much as 5-10% of all new ALL diagnoses, and carrying its own biologic, prognostic and therapeutic significance. In this review, we will outline the history and current state of research into sALL. We will explore the evidence for differences underlining its existence as a distinct subgroup, as well as examining what might be driving such differences etiologically, including prior chemotherapy. We will examine these distinctions on population-, chromosomal-, and molecular-levels, and we will consider whether they translate to differences in clinical outcome, and whether they do - or should - warrant differences in treatment selection.

Chromosomal aberrations and prognostic analysis of secondary acute myeloid leukemia-a retrospective study

Background

Secondary acute myeloid leukemia (S-AML) patients generally have a poor prognosis, but the chromosomal aberrations of S-AML have been rarely reported. We aimed to explore the chromosomal aberrations and clinical significance in patients with S-AML.

Patients and methods

The clinical characteristics and karyotypes of 26 patients with S-AML were retrospectively analyzed. The overall survival (OS) was measured from the time of the patients' transition to AML (i.e., at S-AML diagnosis).

Results

The study included 26 S-AML patients (13 males and 13 females), with a median age of 63 years (range, 20-77 years). They transformed from various hematologic malignancies or solid tumors; most of them were secondary to myelodysplastic syndrome (MDS). About 62% of the S-AML patients showed chromosomal aberrations. The serum lactate dehydrogenase (LDH) level in S-AML patients with abnormal karyotype was higher than those with normal karyotype. Apart from the differences in treatment regimens, S-AML patients with chromosomal aberrations had shorter OS (P < 0.05).

Conclusion

S-AML patients with abnormal karyotype have higher LDH levels and shorter OS than normal karyotype patients, and the OS of hypodiploidy was much shorter than hyperdiploid.

Poor post-induction outcomes in patients with acute myeloid leukemia previously treated with hypomethylating agents

Patients with acute myeloid leukemia (AML) who have failed hypomethylating agents (HMA) have a poor prognosis. We examined whether high intensity induction chemotherapy could abrogate negative outcomes in 270 patients with AML or other high-grade myeloid neoplasms. Prior HMA therapy was significantly associated with a lower overall survival (OS) as compared to a reference group of patients with secondary disease without prior HMA therapy (median 7.2 vs 13.1 months). In patients with prior HMA therapy, high intensity induction was associated with a non-significant trend toward longer OS (median 8.2 vs 4.8 months) and decreased rates of treatment failure (39% vs 64%). These results redemonstrate poor outcomes in patients with prior HMA and suggest possible benefit of high intensity induction that should be evaluated in future studies.

Characteristics and Outcomes of Secondary Acute Myeloid Leukemia and Acute Myeloid Leukemia With Myelodysplasia-Related Changes: Multicenter Study From the Thai Acute Leukemia Study Group

BACKGROUND

Secondary acute myeloid leukemia (sAML) and AML with myelodysplasia-related changes (AML-MRC) both result in dismal outcomes. This retrospective study aimed to determine whether these features are poor prognostic factors independent of older age and adverse cytogenetics, which are commonly associated with a poor prognosis.

METHODS

The characteristics and real-world outcomes of sAML and AML-MRC from the Thai AML registry database were investigated.

RESULTS

From a total of 992 newly diagnosed AML patients, 315 (31.8%) patients were classified into sAML or AML-MRC subtypes. Older age, low white blood cell (WBC) count, low bone marrow blast, and adverse cytogenetic risk were commonly present in sAML and AML-MRC compared to de novo AML. Complete remission after 7 + 3 induction therapy occurred in 42.3% of patients with sAML or AML-MRC and 62.4% of de novo AML (P < .001). The median overall survival (OS) of sAML, AML-MRC, and de novo AML were 6.9, 7.0, and 12.2 months, respectively (P < .001). The independent prognostic factors for inferior OS were older age, intermediate-risk or adverse-risk cytogenetics, WBC count > 100 × 10⁹/L, poor performance status, and a subgroup of AML-MRC with the morphologic criteria of multilineage dysplasia (AML-MRC-M). In addition, sAML, AML-MRC, and a WBC count > 100 × 10⁹/L were pre-treatment prognostic factors associated with poor relapse-free survival (P = .006, P = .017, and P < .001, respectively).

CONCLUSION

Both sAML and AML-MRC are independently associated with poor outcomes in Thai patients. Our study supports AML-MRC-M as an adverse prognostic factor for OS.

Lymphocyte Transformation Test Based on Lymphocyte Changes Observed by a Hematology Analyzer before and after Phytohemagglutinin Stimulation

Objective. The lymphocyte transformation test is a classical test for the detection of cellular immune function and is based on subjective judgment. In this study, we have established an objective novel lymphocyte transformation test using the hematology analyzer to observe lymphocyte transformation. Methods. Whole blood cells were cultured using a whole blood method with a lymphocyte culture medium; phytohemagglutinin was used to stimulate the experimental samples, and control was set up at the same time. After the whole blood cells were cultured, the number of lymphocytes in the two groups was observed using a hematology analyzer, and the conversion rate was calculated. The new method was used to observe differences in lymphocyte conversion in the peripheral blood of patients with hematopathy and healthy persons. Results. There were significant differences between the stimulated peripheral blood group and the blank group. The transformation rate of peripheral blood lymphocytes in patients with hematopathy was significantly lower than that in healthy persons; the difference was statistically significant ( $P<0.05$ ). Conclusion. Lymphocyte transformation can be observed using a hematology analyzer. The lymphocyte transformation test that is based on the determination of lymphocyte count by a hematology analyzer has important clinical value.

Clinical Outcomes of Acute Myeloid Leukemia Patients Harboring the RUNX1 Mutation: Is It Still an Unfavorable Prognosis? A Cohort Study and Meta-Analysis

Acute myeloid leukemia (AML) with mutated RUNX1 (RUNX1mut) is considered to have an unfavorable prognosis. However, recent studies have reported comparable survival outcomes with wild-type RUNX1 (RUNX1wt). To assess the clinical outcomes of AML with and without RUNX1mut, we performed a prospective cohort study and systematic review and meta-analysis. The study enrolled 135 patients (27 with RUNX1mut; 108 with RUNX1wt). There were no significant differences in the median OS and RFS of the RUNX1mut and RUNX1wt groups (9.1 vs. 12.2 months; p = 0.268 and 7.8 vs. 14.6 months; p = 0.481, respectively). A subgroup analysis of de novo AML patients with intermediate-risk cytogenetics showed similar outcomes. Our meta-analysis pooled data from 23 studies and our study. The complete remission rate was significantly lower in the RUNX1mut group (pooled odds ratio: 0.42). The OS, RFS, and event-free survival rates also favored the RUNX1wt group (pooled risk ratios: 1.36, 1.37, and 1.37, respectively). A subgroup analysis of de novo AML patients with intermediate-risk cytogenetics demonstrated nearly identical OS and RFS outcomes. This study confirms that patients with AML and RUNX1mut had poor prognoses. Nonetheless, in de novo AML with intermediate-risk cytogenetics, the survival outcomes of both groups were comparable.

Acute myeloid leukemia secondary to acute B lymphoblastic leukemia treated with maintenance therapy in a child: A case report

BACKGROUND

Acute lymphoblastic leukemia (ALL) has the highest incidence among childhood hematologic cancers. Exposure to certain cytotoxic therapies for ALL is correlated with a higher risk of secondary malignancies.

CASE

We report a rare case of a 6-year-old girl being diagnosed with secondary acute myeloid leukemia (AML) during her maintenance phase of treatment for ALL with TEL-AML1 fusion gene, approximately 17 months after the primary diagnosis.

CONCLUSION

This case indicates that we should recognize the increased risk of secondary AML for pediatric ALL patients with TEL-AML1 fusion gene if multiple alkylating drugs and inhibitors for topoisomerase II are included in induction chemotherapy.

Comparative study of treosulfan plus Fludarabine (FT14) with busulfan plus Fludarabine (FB4) for acute myeloid leukemia in first or second complete remission: An analysis from the European Society for Blood and Marrow Transplantation (EBMT) Acute Leukemia Working Party (ALWP)

Different doses of treosulfan plus fludarabine have shown advantage over reduced intensity regimens. However, data comparing higher doses of treosulfan to myeloablative busulfan are limited. Thus, we compared outcomes between FT14 (fludarabine 150/160 mg/m² and treosulfan 42 g/m², or FT14) over FB4 (fludarabine 150/160 mg/m² and busulfan 12.8 mg/kg). We retrospectively studied patients from European Society for Blood and Marrow Transplantation registry: a) adults diagnosed with acute myeloid leukemia (AML), b) recipients of first allogeneic hematopoietic stem cell transplantation (HSCT) from unrelated or sibling donor (2010-2020), c) HSCT at first or second complete remission, d) conditioning with FT14 or FB4. FT14 recipients (n = 678) were older, with higher rates of secondary AML, unrelated donors, peripheral blood grafts, and adverse cytogenetics, but lower percentage of female donor to male recipient compared to FB4 (n = 2025). Analysis was stratified on age. In patients aged < 55 years, FT14 was associated with higher relapse incidence (RI) and lower Leukemia-Free Survival (LFS). In patients aged≥55 years, acute GVHD CI was higher in FB4, without significant differences in other outcomes. Although FT14 has been used for higher-risk HSCT patients, our large real-world multicenter study suggests that FB4 is associated with better outcomes compared to FT14 in younger patients.

Therapy‑related acute myeloid leukemia: A case series

Patients with primary cancer receiving chemotherapy and/or radiotherapy may develop therapy-related acute leukemia (t-AL). Therapy-related acute myeloid leukemia (t-AML) accounts for the majority of these cases and is frequently associated with a variety of cytogenetic and molecular abnormalities. The aim of the present study was to explore the clinical characteristics, treatments and prognosis of patients with t-AML. A total of 272 cases of AML treated at our institution between 2016 and 2020 were reviewed, among which nine cases of t-AML were identified for analysis. All patients had received alkylating or topoisomerase II inhibitor chemotherapy drugs for primary cancer treatment and three patients had received radiotherapy. A total of nine patients had been administered recombinant human granulocyte colony-stimulating factor (G-CSF). The median latency period for the nine patients with t-AML was 25 months (range, 10–240 months). The molecular cytogenetic abnormalities included t(15:17)(q22:q21), inv(16)(p13q22), del(5)(q22), CBFB/MYH11(+), FLT3(+), NARS(+), IDH(+), TET2(+), and TP53(+). Out of nine patients with t-AML, eight received chemotherapy, two of whom underwent HSCT. The median survival time of the nine patients with t-AML was 10 months and the 2-year-survival rate was 44.4%. Greater clarity around the diagnosis and treatment is required to improve the outcomes of patients with t-AML.

Validation of AML-score in Older Adults Receiving CPX-351 Intensive Induction Chemotherapy for Treatment of Secondary Acute Myeloid Leukemia

INTRODUCTION/BACKGROUND

The AML-Score has been validated in patients receiving traditional induction chemotherapies but not CPX-351. We conducted a retrospective analysis to evaluate, among patients with secondary acute myeloid leukemia who received intensive induction with CPX-351, if the AML-Score associates with (1) complete remission (CR) and (2) early mortality (EM) within 60 days of induction.

MATERIALS AND METHODS

We abstracted demographic and clinical data from consecutive patients receiving CPX-351 at Sidney Kimmel Cancer Center at Thomas Jefferson University Hospital between September 2017 and November 2020. We used descriptive statistics and receiver operating curves to evaluate the relationship between AML-Score and rates of CR and EM.

RESULTS

In total, 40 patients were included. 27 (67.5%) were male, 27 (67.5%) were white, 36 (90.0%) were not Hispanic or Latino, and 29 (72.5%) were aged ≥60 years. Twenty-seven patients (67.5%) had a CR, and 4 (10%) experienced EM. Observed rates of CR and EM generally increased with increasing predicted risk. The area under the curve was 0.75 (95% CI 0.60-0.90) for CR and 0.82 (95% CI 0.68-0.96) for EM.

CONCLUSION

The AML-Score tool trends in the correct direction for predicting CR and EM, and thus may facilitate oncologist prognostication and treatment planning for patients receiving CPX-351. However, its clinical utility is limited by its underestimation of the risk of CR and overestimation of the risk of EM. Further validation in a larger cohort is needed to calculate accurate point estimates of CR and EM risk in this population.

Treatment of AML Relapse After Allo-HCT

With advances in allogeneic hematopoietic stem cell transplant (allo-HCT), disease relapse has replaced transplant-related mortality as the primary cause of treatment failure for patients with acute myeloid leukemia (AML). The efficacy of allo-HCT in AML is a consequence of a graft-versus-leukemia (GVL) effect that is mediated by T lymphocytes, and unique mechanisms of immune evasion underlying post-allo-HCT AML relapses have recently been characterized. Relapsed AML following allo-HCT presents a particularly vexing clinical challenge because transplant-related toxicities, such as graft-versus-host (GVHD) and infections, increase the risk of treatment-related morbidity and mortality. In general, the prognosis of relapsed AML following allo-HCT is poor with most patients failing to achieve a subsequent remission and 2-year survival consistently <15%. The two factors that have been found to predict a better prognosis are a longer duration of post-transplant remission prior to relapse and a lower disease burden at the time of relapse. When considered in combination with a patient's age; co-morbidities; and performance status, these factors can help to inform the appropriate therapy for the treatment of post-transplant relapse. This review discusses the options for the treatment of post-transplant AML relapse with a focus on the options to achieve a subsequent remission and consolidation with cellular immunotherapy, such as a second transplant or donor lymphocyte infusion (DLI). While intensive reinduction therapy and less intensive approaches with hypomethylating agents have long represented the two primary options for the initial treatment of post-transplant relapse, molecularly targeted therapies and immunotherapy are emerging as potential alternative options to achieve remission. Herein, we highlight response and survival outcomes achieved specifically in the post-transplant setting using each of these approaches and discuss how some therapies may overcome the immunologic mechanisms that have been implicated in post-transplant relapse. As long-term survival in post-transplant relapse necessarily involves consolidation with cellular immunotherapy, we present data on the efficacy and toxicity of both DLI and second allo-HCT including when such therapies are integrated with reinduction. Finally, we provide our general approach to the treatment of post-transplant relapse, integrating both novel therapies and our improved understanding of the mechanisms underlying post-transplant relapse.

Secondary Acute Myeloid Leukemia (sAML): Similarly Dismal Outcomes of AML After an Antecedent Hematologic Disorder and Therapy Related AML

Therapy related acute myeloid leukemia (tAML) and secondary AML after an antecedent hematologic disorder (sAML-AHD) are often addressed together, blurring any clinical and prognostic differences. Among 516 AML patients, we compared characteristics and outcomes of 149 patients with "sAML" (sAML-AHD: 104, tAML: 45), uniformly and intensively treated during the last 2 decades at 1 center. Clinical outcomes of the whole "sAML" cohort were significantly inferior compared to de novo AML and in both intermediate and poor cytogenetic risk groups. Adverse karyotype had no effect on survival in tAML, while it was a negative predictor in sAML-AHD. Both groups showed similarly dismal outcome, with low complete remission rates (CR 44% vs. 41%) and median overall survival (OS 7 vs. 10.5 months). Allogeneic hematopoietic cell transplantation (alloHCT) recipients in CR1 had superior median OS (24 vs. 8 months). By multivariate analysis, alloHCT was an independent predictor of outcome, while karyotype was for sAML-AHD only. In conclusion, both "sAML" groups have inferior outcomes after chemotherapy, with adverse karyotype affecting primarily sAML-AHD. Until new treatment approaches are available, only alloHCT offers a survival advantage.

Survival Advantage of Treosulfan Plus Fludarabine Before Allogeneic Hematopoietic Cell Transplantation for Older or Comorbid Patients With Myeloid Malignancies

We have previously shown an advantage of a myeloablative conditioning regimen with reduced toxicity (Fludarabine 150 mg/m², Treosulfan 42 g/m², FluTreo) compared to a reduced-intensity regimen. We aimed to determine long-term safety and efficacy of FluTreo. We prospectively studied consecutive patients who received FluTreo in our center (2014-2019) on the basis of age (≥50 years), hematopoietic cell transplantation comorbidity index (HCT-CI) ≥2, or both. FluTreo recipients were then compared to a historical control group. We studied 68 FluTreo recipients, with a median age of 58.5 years and HCT-CI of 3. We calculated cumulative incidence (CI) of acute (grade 2-4) and moderate/severe chronic graft-versus-host disease (GVHD) (29.9% and 25%, respectively). The 3-year CI of treatment-related mortality was 19.1%, associated only with acute GVHD (P < .001). With a median follow-up of 27.3 (range 5.7-84.5) months in surviving patients, the 3-year overall survival (OS) was 56.6%, and disease-free survival (DFS) was 54.9%. Median survival has not yet been reached. Among pretransplantation and transplantation factors, only HCT-CI was associated with DFS and OS (P = .022 and P = .043, respectively). FluTreo recipients aged ≥50 with HCT-CI ≤ 2 had favorable DFS and OS compared with patients aged ≥50 with HCT-CI ≤2 after myeloablative conditioning. Our real-world study confirms that HCT with FluTreo expands the transplant population with favorable outcomes compared to previously used conditions. The choice of HCT in patients of a rather older age and comorbidity index needs to be revisited.

Allogeneic stem cell transplantation for AML patients with RUNX1 mutation in first complete remission: a study on behalf of the acute leukemia working party of the EBMT

Acute myeloid leukemia with runt-related transcription factor 1 gene mutation (RUNX1+ AML) is associated with inferior response rates and outcome after conventional chemotherapy. We performed a retrospective, registry-based analysis to elucidate the prognostic value of RUNX1 mutation after allogeneic stem cell transplantation (alloSCT). All consecutive adults undergoing alloSCT for AML in first complete remission (CR1) between 2013 and 2019 with complete information on conventional cytogenetics and RUNX1 mutational status were included. Endpoints of interest were cumulative relapse incidence, non-relapse mortality, overall and leukemia-free survival (OS/LFS), and GvHD-free/relapse-free survival. A total of 674 patients (183 RUNX1+, 491 RUNX1−) were identified, with >85% presenting as de novo AML. Median follow-up was 16.4 (RUNX1+) and 21.9 (RUNX1−) months. Survival rates showed no difference between RUNX1+ and RUNX1− patients either in univariate or multivariate analysis (2-year OS: 67.7 vs. 66.1%, p = 0.7; 2-year LFS: 61.1 vs. 60.8%, p = 0.62). Multivariate analysis identified age, donor type and poor cytogenetics as risk factors for inferior outcome. Among patients with RUNX+ AML, older age, reduced intensity conditioning and minimal residual disease at alloSCT predicted inferior outcome. Our data provide evidence that the negative influence of RUNX1 mutations in patients with AML can be overcome by transplantation in CR1.

Targeting CD300f to enhance hematopoietic stem cell transplantation in acute myeloid leukemia

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) significantly reduces the rate of relapse in acute myeloid leukemia (AML) but comes at the cost of significant treatment-related mortality. Despite the reduction in relapse overall, it remains common, especially in high-risk groups. The outcomes for patients who relapse after transplant remains very poor. A large proportion of the morbidity that prevents most patients from accessing allo-HSCT is due to toxic nonspecific conditioning agents that are required to remove recipient hematopoietic stem and progenitor cells (HSPCs), allowing for successful donor engraftment. CD300f is expressed evenly across HSPC subtypes. CD300f has transcription and protein expression equivalent to CD33 on AML. We have developed an anti-CD300f antibody that efficiently internalizes into target cells. We have generated a highly potent anti-CD300f antibody-drug conjugate (ADC) with a pyrrolobenzodiazepine warhead that selectively depletes AML cell lines and colony forming units in vitro. The ADC synergizes with fludarabine, making it a natural combination to use in a minimal toxicity conditioning regimen. Our ADC prolongs the survival of mice engrafted with human cell lines and depletes primary human AML engrafted with a single injection. In a humanized mouse model, a single injection of the ADC depletes CD34+ HSPCs and CD34+CD38-CD90+ hematopoietic stem cells. This work establishes an anti-CD300f ADC as an attractive potential therapeutic that, if validated in transplant models using a larger cohort of primary AML samples, will reduce relapse rate and toxicity for patients with AML undergoing allo-HSCT.

PI3 kinase signaling pathway in hematopoietic cancers: A glance in miRNA's role

Hematopoietic cancers are among the most common malignancies worldwide, which are divided into different types depending on the origin of tumor cells. In recent years, the pivotal role of different signaling pathways in the onset and progression of these cancer types has been well established. One of these pathways, whose role in blood malignancies has been well-defined, is PI3K/mTOR/AKT axis. The signaling pathway involves in a wide variety of important biological events in cells. It is clear that dysregulation of mediators involved in PI3 kinase signaling takes a pivotal role in cancer development. Considering the undeniable role of miRNAs, as one of the well-known families of non-coding RNAs, in gene regulation, we aimed to review the role of miRNAs in regulation of PI3 kinase signaling effectors in hematopoietic cancers.

Allogeneic hematopoietic stem cell transplantation for therapy-related myeloid neoplasms following treatment of a lymphoid malignancy

Advances in lymphoma treatment lead to increasing numbers of long-term survivors. Thus, secondary therapy-related myeloid neoplasms (t-MN) gain clinical relevance. We analyzed 38 t-MN patients receiving an allogeneic stem cell transplantation (SCT) after successful cytotoxic treatment of Hodgkin lymphoma (n = 9), non-Hodgkin lymphoma (n = 24), and multiple myeloma (n = 5), who had developed t-AML (n = 20) or t-MDS (n = 18). Overall survival (OS) and relapse-free survival at 3 years after allogeneic SCT were 43% and 39%. The cumulative incidences of relapse and non-relapse mortality (NRM) at 3 years were 19% and 42%. More than one therapy line for the lymphoid malignancy resulted in a significantly higher NRM rate and inferior 3-year-OS. Our data indicate that allogeneic SCT for patients with t-MN after treatment of a lymphoid malignancy leads to OS rates comparable to patients transplanted for de novo MN. Multiple lines of lymphoma therapy increase NRM and lead to inferior survival after allogeneic SCT.

Hyper-SUMOylation of ERG Is Essential for the Progression of Acute Myeloid Leukemia

Leukemia is a malignant disease of hematopoietic tissue characterized by the differentiation arrest and malignant proliferation of immature hematopoietic precursor cells in bone marrow. ERG (ETS-related gene) is an important member of the E26 transformation-specific (ETS) transcription factor family that plays a crucial role in physiological and pathological processes. However, the role of ERG and its modification in leukemia remains underexplored. In the present study, we stably knocked down or overexpressed ERG in leukemia cells and observed that ERG significantly promotes the proliferation and inhibits the differentiation of AML (acute myeloid leukemia) cells. Further experiments showed that ERG was primarily modified by SUMO2, which was deconjugated by SENP2. PML promotes the SUMOylation of ERG, enhancing its stability. Arsenic trioxide decreased the expression level of ERG, further promoting cell differentiation. Furthermore, the mutation of SUMO sites in ERG inhibited its ability to promote the proliferation and inhibit the differentiation of leukemia cells. Our results demonstrated the crucial role of ERG SUMOylation in the development of AML, providing powerful targeted therapeutic strategies for the clinical treatment of AML.

The prognostic implications of tetraploidy/near-Tetraploidy in acute myeloid leukemia: a case series and systematic review of the literature

The prognostic significance and optimal management of tetraploidy/near-tetraploidy acute myeloid leukemia (T/NT AML) remains unclear given its limited data. This is especially true after factoring in additional chromosomal alterations, which carry their own prognostic weight. Here, we analyze 128 cases of T/NT in AML from the literature along with two additional cases, which is the largest review of this subject to date. Based on our retrospective analysis, we found that regardless of the risk status attributed to cytogenetics, the prognosis of tetraploid or near-tetraploid AML is dismal and should be incorporated within the unfavorable risk group. Complete remission is paramount to survival in this population. Specific induction protocols for high-risk AML appear to have higher rates of complete remission in the T/NT AML population. Moreover, longer overall survival can be achieved with chemotherapy followed by allogeneic stem cell transplantation at first complete remission.

Functional Classification of TP53 Mutations in Acute Myeloid Leukemia

Mutations of the TP53 gene occur in a subset of patients with acute myeloid leukemia (AML) and confer an exceedingly adverse prognosis. However, whether different types of TP53 mutations exert a uniformly poor outcome has not been investigated yet. Here, we addressed this issue by analyzing data of 1537 patients intensively treated within protocols of the German-Austrian AML study group. We classified TP53 mutations depending on their impact on protein structure and according to the evolutionary action (EAp53) score and the relative fitness score (RFS). In 98/1537 (6.4%) patients, 108 TP53 mutations were detected. While the discrimination depending on the protein structure and the EAp53 score did not show a survival difference, patients with low-risk and high-risk AML-specific RFS showed a different overall survival (OS; median, 12.9 versus 5.5 months, p = 0.017) and event-free survival (EFS; median, 7.3 versus 5.2 months, p = 0.054). In multivariable analyses adjusting for age, gender, white blood cell count, cytogenetic risk, type of AML, and TP53 variant allele frequency, these differences were statistically significant for both OS (HR, 2.14; 95% CI, 1.15-4.0; p = 0.017) and EFS (HR, 1.97; 95% CI, 1.06-3.69; p = 0.033). We conclude that the AML-specific RFS is of prognostic value in patients with TP53-mutated AML and a useful tool for therapeutic decision-making.

Secondary Acute Myeloid Leukemia: A Primary Challenge of Diagnosis and Treatment

Secondary acute myeloid leukemia (sAML) is a complex diagnosis that includes AML caused by either an antecedent hematologic disease (AML-AHD) or from previous treatment with chemotherapy or radiation. This disease carries a poor prognosis and is historically chemorefractory; additionally, often patients are ineligible for standard chemotherapy because of advanced age and other comorbidities. The advances of molecular diagnostics and reclassification of World Health Organization criteria have aided in the categorization of this disease. This article describes the etiology and pathophysiology of sAML, and delves into past successful treatments as well as promising new treatments.

Mitochondrial dysfunction and oxidative stress in bone marrow stromal cells induced by daunorubicin leads to DNA damage in hematopoietic cells

Cytotoxic chemotherapies could cause the dysregulation of hematopoiesis and even put patients at increased risk of hematopoietic malignancy. Therapy-related leukemia is mainly caused by cytotoxic chemotherapy-induced genetic mutations in hematopoietic stem/progenitor cells (HSPCs). In addition to the intrinsic mechanism, some extrinsic events occurring in the bone marrow (BM) microenvironment are also possible mechanisms involved in genetic alteration. In the present study, we investigated the damage to BM stromal cells induced by a chemotherapy drug, daunorubicin (DNR) and further identified the DNA damage in hematopoietic cells caused by drug-treated stromal cells. It was found that treatment with DNR in mice caused a temporary reduction in cell number in each BM stromal cell subpopulation and the impairment of clonal growth potential in BM stromal cells. DNR treatment led to a tendency of senescence, generation of intracellular reactive oxygen species, production of cytokines and chemokines, and dysfunction of mitochondrial in stromal cells. Transcriptome microarray data and gene ontology (GO) or gene set enrichment analysis (GSEA) showed that differentially expressed genes that were down-regulated in response to DNR treatment were significantly enriched in mitochondrion function, and negative regulators of reactive oxygen species. Surprisingly, it was found that DNR-treated stromal cells secreted high levels of H₂O₂ into the culture supernatant. Furthermore, coculture of hematopoietic cells with DNR-treated stromal cells led to the accumulation of DNA damage as determined by the levels of histone H2AX phosphorylation and 8-oxo-2'-deoxyguanosine in hematopoietic cells. Overall, our results suggest that DNR-induced BM stromal cell damage can lead to genomic instability in hematopoietic cells.

Treatment Strategies for Therapy-related Acute Myeloid Leukemia

Prospective evidence for management of therapy-related acute myeloid leukemia (t-AML) is limited, with evidence extrapolated from major AML trials. Optimal treatment is challenging and needs consideration of patient-specific, disease-specific, and therapy-specific factors. Clinical trials are recommended, especially for unfit patients or those with unfavorable cytogenetics or mutations. CPX-351 as an upfront intensive chemotherapy is preferred for fit patients; venetoclax with decitabine or azacitidine is an option for patients unfit for intensive chemotherapy. Hematopoietic cell transplant, the only curative option, should be offered to eligible patients with intermediate or unfavorable t-AML or patients with good-risk AML with minimal residual disease. Ongoing clinical trials focusing on treatment of t-AML, including targeted agents and immunotherapy, bode well for the future.

Targeting ADP-ribosylation by PARP inhibitors in acute myeloid leukaemia and related disorders

Acute myeloid leukaemia (AML) is a highly heterogeneous disease characterized by uncontrolled proliferation, block in myeloid differentiation and recurrent genetic abnormalities. In the search of new effective therapies, identification of synthetic lethal partners of AML genetic alterations might represent a suitable approach to tailor patient treatment. Genetic mutations directly affecting DNA repair genes are not commonly present in AML. Nevertheless, several studies indicate that AML cells show high levels of DNA lesions and genomic instability. Leukaemia-driving oncogenes (e.g., RUNX1-RUNXT1, PML-RARA, TCF3-HLF, IDH1/2, TET2) or treatment with targeted agents directed against aberrant kinases (e.g., JAK1/2 and FLT3 inhibitors) have been associated with reduced DNA repair gene expression/activity that would render leukaemia blasts selectively sensitive to synthetic lethality induced by poly(ADP-ribose) polymerase inhibitors (PARPi). Thus, specific oncogenic chimeric proteins or gene mutations, rare or typically distinctive of certain leukaemia subtypes, may allow tagging cancer cells for destruction by PARPi. In this review, we will discuss the rationale for using PARPi in AML subtypes characterized by a specific genetic background and summarize the preclinical and clinical evidence reported so far on their activity when used as single agents or in combination with classical cytotoxic chemotherapy or with agents targeting AML-associated mutated proteins.

Blast Transformation in Myeloproliferative Neoplasms: Risk Factors, Biological Findings, and Targeted Therapeutic Options

Myeloproliferative neoplasms represent a heterogenous group of disorders of the hematopoietic stem cell, with an intrinsic risk of evolution into acute myeloid leukemia. The frequency of leukemic evolution varies according to myeloproliferative neoplasms subtype. It is highest in primary myelofibrosis, where it is estimated to be approximately 10–20% at 10 years, following by polycythemia vera, with a risk of 2.3% at 10 years and 7.9% at 20 years. In essential thrombocythemia, however, transformation to acute myeloid leukemia is considered relatively uncommon. Different factors are associated with leukemic evolution in myeloproliferative neoplasms, but generally include advanced age, leukocytosis, exposure to myelosuppressive therapy, cytogenetic abnormalities, as well as increased number of mutations in genes associated with myeloid neoplasms. The prognosis of these patients is dismal, with a medium overall survival ranging from 2.6–7.0 months. Currently, there is no standard of care for managing the blast phase of these diseases, and no treatment to date has consistently led to prolonged survival and/or hematological remission apart from an allogeneic stem cell transplant. Nevertheless, new targeted agents are currently under development. In this review, we present the current evidence regarding risk factors, molecular characterization, and treatment options for this critical subset of myeloproliferative neoplasms patients.