Preleukaemic clonal haemopoiesis and risk of therapy-related myeloid neoplasms: a case-control study

Improved outcomes and treatment guidance in pediatric therapy-related AML: AML-BFM study group recommendations

ABSTRACT

Therapy-related acute myeloid leukemia (AML; tAML) is one of the most feared therapy-emergent complications. This study aims to determine the clinical and pathological significance and define therapeutic implications and poor prognosticators in pediatric tAML. We analyzed a total of 119 pediatric patients (aged 2-20 years) who were centrally diagnosed with tAML within the Acute Myeloid Leukemia Berlin-Frankfurt-Münster (AML-BFM) study group between 1993 and 2019. Compared with de novo AML, tAML was associated with decreased white blood count and involvement of the central nervous system. Latency to tAML was inversely correlated with age at primary malignancy. Patients with tAML were more likely to have abnormal karyotypes, overrepresenting KMT2A rearrangements, the unfavorable cytogenetics -7/del(7q), as well as complex and monosomal karyotypes, whereas core-binding AML was underrepresented. The occurrence of stratification-relevant molecular genetics was comparable with de novo AML, whereas CEBPAdm was absent in tAML. Survival rates in tAML improved from 10% ± 6% in AML-BFM 1993/1998 to 50% ± 10% in the registries 2012/2017; however, this is still worse than de novo AML. Hematopoietic stem cell transplantation (HSCT) in no evidence of leukemia (NEL; <5% blasts) after 2 induction cycles greatly improved survival. Adverse cytogenetics, previous ionizing radiation (>35 Gy), and latency ≤1 year were identified as the strongest poor prognosticators. Over the past 26 years, outcome and survival significantly improved in pediatric tAML. Our results suggest that HSCT in NEL after 2 induction cycles is the most promising therapeutic approach for achieving improved survival. Radiation, adverse cytogenetics, and latency ≤1 year should be considered as poor prognosticators in pediatric tAML.

Clonal hematopoiesis, cardiovascular disease and cancer treatment-induced cardiotoxicity

Clonal hematopoiesis (CH) arises when a substantial proportion of mature blood cells is derived from a single hematopoietic stem cell lineage. It is considered to be a premalignant state that predisposes individuals to an increased risk of cancers. Recently, emerging evidence has demonstrated a strong association between CH and both the incidence and mortality of cardiovascular diseases (CVD), with the relative risks being comparable to those attributed to traditional cardiovascular risk factors. In addition, CH has been suggested to play a role in CVD and anti-cancer treatment-related cardiotoxicity amongst cancer survivors. Moreover, certain forms of chemotherapy and radiation therapy have been shown to promote the clonal expansion of specific CH-related mutations. Consequently, CH may play a substantial role in the realm of cardio-oncology. In this review, we discuss the association between CH with cancer and CVD, with a special focus on anti-cancer treatment-related cardiotoxicity, discuss possible future research avenues and propose a systematic approach for clinical practice.

Bone marrow microenvironment in myelodysplastic neoplasms: insights into pathogenesis, biomarkers, and therapeutic targets

Myelodysplastic neoplasms (MDS) represent a heterogeneous group of malignant hematopoietic stem and progenitor cell (HSPC) disorders characterized by cytopenia, ineffective hematopoiesis, as well as the potential to progress to acute myeloid leukemia (AML). The pathogenesis of MDS is influenced by intrinsic factors, such as genetic insults, and extrinsic factors, including altered bone marrow microenvironment (BMM) composition and architecture. BMM is reprogrammed in MDS, initially to prevent the development of the disease but eventually to provide a survival advantage to dysplastic cells. Recently, inflammation or age-related inflammation in the bone marrow has been identified as a key pathogenic mechanism for MDS. Inflammatory signals trigger stress hematopoiesis, causing HSPCs to emerge from quiescence and resulting in MDS development. A better understanding of the role of the BMM in the pathogenesis of MDS has opened up new avenues for improving diagnosis, prognosis, and treatment of the disease. This article provides a comprehensive review of the current knowledge regarding the significance of the BMM to MDS pathophysiology and highlights recent advances in developing innovative therapies.

Risk of secondary myeloid neoplasms following treatment in patients with grade I-II follicular lymphoma: a retrospective cohort study

BACKGROUND

To assess the association between initial treatment modalities and the risk of developing subtypes of myeloid neoplasms (MNs) in survivors with grade I-II follicular lymphoma (FL) and to evaluate their impact on survival outcomes.

METHODS

Patients diagnosed with grade I-II FL as their first malignancy were identified from the Surveillance, Epidemiology, and End Results (SEER) database. Fine-Gray competing risk regression and Poisson regression were used to evaluate the treatment-associated risk (RR) for MNs and the Kaplan-Meier method was applied to assess the survival outcomes.

RESULTS

Among 19,326 FL patients, 9539 patients (49.36%) received chemotherapy, and 2890 patients (14.95%) received radiotherapy as part of their initial treatment. With a median follow-up time of 103 months, 90, 82, and 23 patients developed myelodysplastic syndromes (MDS), acute myeloid leukemia (AML), and myeloproliferative neoplasms (MPN), respectively. In both multivariable competing risk regression analysis and Poisson regression analysis, chemotherapy was found to be associated with a higher risk of developing MDS (adjusted hazard ratio (HR), 1.85; 95% confidence interval (CI), 1.13-3.02; adjusted RR, 1.88; 95% CI, 1.18-3.04), total AML (adjusted HR, 2.22; 95% CI, 1.33-3.71; adjusted RR, 2.24; 95% CI, 1.37-3.78), and AML with myelodysplasia-related changes (AML-MRC) (adjusted HR, 3.42; 95% CI, 1.24-9.44; adjusted RR, 3.48; 95% CI, 1.52-9.07). Additionally, radiotherapy also increased the risk of AML-MRC (adjusted HR, 2.74; 95% CI, 1.12-6.72; adjusted RR, 2.73; 95% CI, 1.10-6.08). The development of AML or MDS was associated with worse overall survival (OS) and disease-specific survival (DSS) in grade I-II FL survivors.

CONCLUSION

Initial chemotherapy and radiotherapy in patients with grade I-II FL were associated with increased risk of certain subtypes of MNs, such as MDS and AML. The importance of balancing risks and benefits should be emphasized in initial FL treatment.

How I treat secondary acute myeloid leukemia

ABSTRACT

Secondary acute myeloid leukemia (sAML) has traditionally been used to designate any AML disease arising from an antecedent hematologic disorder or after prior cytotoxic or radiation therapy. We now know sAML comprises multiple disease entities with distinct clinical and biological features: AML, myelodysplastic related; myeloproliferative neoplasm-blast phase; and AML post-cytotoxic therapy. These entities largely represent adverse-risk phenotypes with the majority of patients experiencing suboptimal outcomes with standard therapeutic options. Given the aging general population and the increased life span of individuals receiving DNA-damaging agents for other medical conditions, the incidence of these diseases is steadily rising and now comprise ∼25% to 30% of all new AML diagnoses. Despite the plethora of novel agents approved for AML since 2017, many either are not applicable to sAML (ie, lacking a targetable mutation), have limited efficacy, or have not been studied in these specific entities. Furthermore, these patients are underrepresented in clinical trials, and novel therapeutic options are critically needed. Here, we present multiple patient cases exemplifying the new nomenclature and classification of the diseases comprising sAML and highlighting their diverse presentations. We provide our therapeutic approach for each clinical scenario and discuss the challenges of treatment with the currently available armamentarium.

Biomarkers in clonal haematopoiesis of indeterminate potential (CHIP) linking cardiovascular diseases, myeloid neoplasms and inflammation

There is increasing evidence that points to ubiquity of clonal haematopoiesis of indeterminate potential (CHIP) especially with rising age. CHIP has been associated with a multitude of inflammatory, cardiovascular and malignant conditions. In this review article, we evaluate the current literature on CHIP and clinical associations with cardiovascular and haematological diseases. We also discuss high risk features of CHIP that predispose to haematological malignancies, as well as further zoom in on the association between clonal haematopoiesis and therapy-related myeloid neoplasm (tMN). CHIP increases risk of atherosclerotic cardiovascular disease and other cardiovascular conditions such as heart failure, arrhythmias and valvular disease. Hematopoietic clones with mutations in TP53 and spliceosome gene U2AF1 in particularly have repeatedly been shown to increase risk for AML. Other factors such as increased clonal size i.e. variant allele fraction (VAF), clonal complexity have also been shown to increase risk for haematological malignancy. In this comprehensive review, we consolidate the most recent advancements in the understanding of clonal haematopoiesis of indeterminate potential (CHIP) and its associations with cardiovascular and haematological disease. This review is also one of the first to focus on potential biochemical markers routinely utilized in clinical practice that may suggest a more sinister progression of CHIP. We hope to provide physicians with a nuanced perspective on the evolving landscape of CHIP, and offering valuable insights into its clinical implications and potential prognostic indicators.

Clonal Hematopoiesis in Women With Breast Cancer

PURPOSE

Clonal hematopoiesis (CH) has been associated with a variety of adverse outcomes, most notably hematologic malignancy and ischemic cardiovascular disease. A series of recent studies also suggest that CH may play a role in the outcomes of patients with solid tumors, including breast cancer. Here, we review the clinical and biological data that underlie potential connections between CH, inflammation, and breast cancer, with a focus on the prevalence and impact of clonal hematopoiesis of indeterminate potential in patients with breast cancer.

METHODS

We summarize data from multiple studies, including a series of cohorts of patients with breast cancer, to assess the prevalence of CH, the relationship between CH and exposure to cytotoxic therapy, and the correlation between CH and breast cancer-specific outcomes.

RESULTS

Our findings indicate that CH is prevalent among patients with breast cancer, particularly those treated with cytotoxic therapies. However, there are no definitive data to support an association between the presence of CH and breast cancer-specific outcomes.

CONCLUSION

Current data do not support routine CH testing in patients with breast cancer, nor should the presence of CH influence decisions regarding breast cancer therapy in most patients. However, larger, long-term studies are necessary to further define the implications of CH in patients with breast cancer and guide clinical decision making.

Genetic and epigenetic bases of long-term adverse effects of childhood cancer therapy

Over the past decade, genome-scale molecular profiling of large childhood cancer survivorship cohorts has led to unprecedented advances in our understanding of the genetic and epigenetic bases of therapy-related adverse health outcomes in this vulnerable population. To facilitate the integration of knowledge generated from these studies into formulating next-generation precision care for survivors of childhood cancer, we summarize key findings of genetic and epigenetic association studies of long-term therapy-related adverse effects including subsequent neoplasms and cardiomyopathies among others. We also discuss therapy-related genotoxicities including clonal haematopoiesis and DNA methylation, which may underlie accelerated molecular ageing. Finally, we highlight enhanced risk prediction models for survivors of childhood cancer that incorporate both genetic factors and treatment exposures, aiming to achieve enhanced accuracy in predicting risks for this population. These new insights will hopefully inspire future studies that harness both expanding omics resources and evolving data science methodology to accelerate the translation of precision medicine for survivors of childhood cancer.

How I treat older patients with Ph/BCR-ABL-negative acute lymphoblastic leukemia

ABSTRACT

Despite advancements in new treatments, management of older patients with acute lymphoblastic leukemia (ALL) remains an unmet medical need. With increasing age, patients with ALL have a significantly lower complete remission rate, higher early mortality and relapse rate, and poorer survival than younger patients. This is attributed to a higher prevalence of adverse prognostic factors among older individuals and reduced tolerance to chemotherapy. Progress has been made in tailoring moderately intensive chemotherapy protocols for Philadelphia chromosome (Ph)/BCR::ABL-negative ALL in older patients, and recent phase 2 studies have explored integrating immunotherapy into initial treatment with very promising results. However, establishing new standard regimens for this age group remains and improving general management strategy is a pending task.

How I treat sickle cell disease with gene therapy

ABSTRACT

In 2023, 2 different gene therapies were approved for individuals with severe sickle cell disease (SCD). The small number of patients treated on the pivotal clinical trials that led to these approvals have experienced dramatic short-term reductions in the occurrence of painful vaso-occlusive crises, but the long-term safety and efficacy of these genetic therapies are yet to be ascertained. Several challenges and treatment-related concerns have emerged in regard to administering these therapies in clinical practice. This article discusses the selection and preparation of individuals with SCD who wish to receive autologous gene therapy, as well as the salient features of the care needed to support them through a long and arduous treatment process. I specifically focus on postinfusion care, as it relates to immune monitoring and infection prevention. Compared with allogeneic hematopoietic cell transplantation, delivering autologous gene therapy to an individual with SCD has distinct nuances that require awareness and special interventions. Using clinical vignettes derived from real-life patients, I provide perspectives on the complex decision-making process for gene therapy for SCD based on currently available data and make recommendations for evaluating and supporting these patients.

Myeloid clonal hematopoiesis of indeterminate potential in patients with chronic lymphocytic leukemia

ABSTRACT

Clonal hematopoiesis of indeterminate potential (CHIP) in patients with chronic lymphocytic leukemia (CLL) has not been extensively characterized. The objective of this study was to describe the prevalence of myeloid CHIP (M-CHIP) in patients with CLL, and to determine its association with time to first treatment (TTFT) and overall survival (OS). We retrospectively analyzed data from patients participating in a prospective CLL database at the Dana-Farber Cancer Institute who had standard-of-care targeted 95-gene next-generation sequencing (NGS) performed. A schema was devised to classify mutations as M-CHIP related. M-CHIP was analyzed as a binary (present/absent) and categorical (≥2 vs 1 vs 0 mutations) predictor. We included 966 patients (median age at time of NGS, 65 years; 38% female). Overall, 747 (77%) patients had NGS performed before CLL treatment, whereas 219 (23%) had it performed after receiving treatment. Median follow-up time from NGS was 1.9 years. The prevalence of M-CHIP in untreated (12%) and treated (24%) patients with CLL was similar to that described in previous literature. M-CHIP prevalence appeared to increase with age in untreated patients, but appeared consistent across age in treated patients, suggesting that treatment (85% had prior chemotherapy) may have an impact on M-CHIP emergence even in younger patients. The presence of ≥2 M-CHIP mutations was associated with OS, even accounting for prior treatment and age, but was driven by a small subset of patients (n = 28). M-CHIP was not associated with TTFT. These findings support continued work into characterizing the effects of M-CHIP in patients with CLL.

Implications of Clonal Hematopoiesis in Hematological and Non-Hematological Disorders

Clonal hematopoiesis (CH) is associated with an increased risk of developing myeloid neoplasms (MNs) such as myelodysplastic neoplasm (MDS) and acute myeloid leukemia (AML). In general, CH comprises clonal hematopoiesis of indeterminate potential (CHIP) and clonal cytopenia of undetermined significance (CCUS). It is an age-related phenomenon characterized by the presence of somatic mutations in hematopoietic stem cells (HSCs) and hematopoietic stem and progenitor cells (HSPCs) that acquire a fitness advantage under selection pressure. Individuals with CHIP have an absolute risk of 0.5-1.0% per year for progressing to MDS or AML. Inflammation, smoking, cytotoxic therapy, and radiation can promote the process of clonal expansion and leukemic transformation. Of note, exposure to chemotherapy or radiation for patients with solid tumors or lymphomas can increase the risk of therapy-related MN. Beyond hematological malignancies, CH also serves as an independent risk factor for heart disease, stroke, chronic obstructive pulmonary disease, and chronic kidney disease. Prognostic models such as the CH risk score and MN-prediction models can provide a framework for risk stratification and clinical management of CHIP/CCUS and identify high-risk individuals who may benefit from close surveillance. For CH or related disorders, therapeutic strategies targeting specific CH-associated mutations and specific selection pressure may have a potential role in the future.

Nontransplant treatment approaches for myeloid neoplasm with mutated TP53

TP53-mutated myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) remain a challenging spectrum of clonal myeloid disease with poor prognosis. Recent studies have shown that in AML, MDS, and MDS/AML with biallelic TP53 loss, the TP53-mutated clone becomes dominant. These are highly aggressive diseases that are resistant to most chemotherapies. The latest 2022 International Consensus Classification categorizes these diseases under "myeloid disease with mutated TP53." All treatment approaches have not improved survival rates for this disease. Many newer therapies are on the horizon, including chimeric antigen receptor T/NK-cell therapies, mutated p53 reactivators, Fc fusion protein, and monoclonal antibodies targeting various myeloid antigens. This review summarizes the current approaches for myeloid disease with TP53 mutation and provides an overview of emerging nontransplant approaches.

Impact of immunological aging on T cell-mediated therapies in older adults with multiple myeloma and lymphoma

The treatment landscape for lymphoma and multiple myeloma, which disproportionally affect older adults, has been transformed by the advent of T cell-mediated immunotherapies, including immune checkpoint inhibition, T cell-engaging bispecific antibodies, and chimeric antigen receptor (CAR) T cell therapy, during the last decade. These treatment modalities re-enable the patient's own immune system to combat malignant cells and offer the potential for sustained remissions and cure for various diseases.Age profoundly affects the physiological function of the immune system. The process of biological aging is largely driven by inflammatory signaling, which is reciprocally fueled by aging-related alterations of physiology and metabolism. In the T cell compartment, aging contributes to T cell senescence and exhaustion, increased abundance of terminally differentiated cells, a corresponding attrition in naïve T cell numbers, and a decrease in the breadth of the receptor repertoire. Furthermore, inflammatory signaling drives aging-related pathologies and contributes to frailty in older individuals. Thus, there is growing evidence of biological aging modulating the efficacy and toxicity of T cell-mediated immunotherapies.Here, we review the available evidence from biological and clinical studies focusing on the relationship between T cell-mediated treatment of hematologic malignancies and age. We discuss biological features potentially impacting clinical outcomes in various scenarios, and potential strategies to improve the safety and efficacy of immune checkpoint inhibitors, T cell-engaging bispecific antibodies, and CAR-T cell therapy in older patients.

Pediatric therapy-related hematologic neoplasms show enrichment for KMT2A rearrangement and lymphoblastic phenotype

In children, therapy-related hematologic neoplasms (t-HN) are uncommon. Many are driven by genetic events independent of clonal hematopoiesis. We sought to understand the clinical and genetic factors of pediatric t-HN in a large independent cohort. Fifty-six t-HN were retrospectively identified. Chromosome microarray, next-generation and/or RNA sequencing were performed. Patients had primary hematologic, solid, or central nervous system tumors. t-HN included myeloid (t-MN) and lymphoblastic (t-ALL) phenotypes. Approximately half of the cases harbored KMTA2A rearrangement (KMT2Ar). Among t-HN without KMT2Ar, genetic drivers were heterogeneous, including diverse fusions or aneuploidy. Approximately 18% harbored 17p deletions and/or TP53 mutations. EFS/OS was not associated with t-HN lineage or KMT2Ar, but HSCT was associated with improved EFS and OS. We detail one of the largest cohorts to date of pediatric t-HN, confirming frequent KMT2Ar and t-ALL.

Therapy-related myelodysplastic syndromes and acute myeloid leukemia

Progress always comes at a price: the field of oncology has seen unprecedented progress in treatment options recently for many solid and hematologic cancers. Unfortunately, these long-term survivors of prior cancer and cytotoxic therapy exposure are at higher risk of therapy-related myelodysplastic syndromes/acute myeloid leukemia (t-MDS/AML.) T-MDS/AML is a myeloid malignancy which occur after exposure to chemotherapy or radiation therapy for unrelated malignancy. T-MDS/AML is associated with adverse cytogenomic features and poor prognosis. While advances in the field of clonal hematopoiesis and germline variants has unraveled the molecular underpinnings of t-MDS/AML, we have miles to go in terms of t-MDS/AML directed therapy and improvement in outcomes. In this review, we discuss the epidemiology of t-MDS/AML, clinical and biological insights, evolution of t-MDS/AML and available treatment options.

Clinical impact of clonal hematopoiesis in hematopoietic cell transplantation: a review, meta-analysis, and call to action

Hematopoietic cell transplantation (HCT) is the only potentially curative treatment option for many patients with hematologic malignancies. While HCT outcomes have improved drastically over the years, patients and clinicians continue to face numerous survivorship challenges, such as relapse, graft-versus-host disease, and secondary malignancies. Recent literature suggests that clonal hematopoiesis (CH), the presence of a recurrent somatic mutation in hematopoietic cells, in HCT patients or donors may be associated with outcomes in autologous and allogeneic HCT. Herein, we perform a review of the literature and summarize reported associations between CH and clinical outcomes in HCT. For commonly reported outcomes, we used meta-analysis methods to provide estimates of effect sizes when combining results. A total of 32 articles with relevant and independent contributions were included, covering both autologous (N=19) and allogeneic (N=13) HCT. The articles report variable risk for developing outcomes according to CH characteristics, patient disease status, and method of HCT. Using meta-analysis of available results, HCT outcomes with statistically significant effects by CH status include therapy-related myeloid neoplasms (odds ratio =3.65; 95% confidence interval [CI]: 2.18-6.10) and overall survival (hazard ratio [HR]=1.38; 95% CI: 1.20-1.58) in autologous HCT and relapse (HR=0.80; 95% CI: 0.68-0.94) in allogeneic HCT. However, heterogeneity, biases, and limitations in the literature provide challenges for informing the translation of CH to clinical decision- making. We conclude with a call to action and discussion of next steps to build upon the current literature and provide granularity to the true clinical impact of CH in the setting of HCT.

Myeloid neoplasms post cytotoxic therapy: epidemiology, pathogenesis outcomes, prognostic factors, and treatment options

Myeloid neoplasms post cytotoxic therapy (MN-pCT) are a category includes AML, MDS, and MDS/MPN arising in patients exposed to cytotoxic (DNA-damaging) therapy for an unrelated condition in 2022 version World Health Organization (WHO) classification. With improved survival of patients with tumors, the incidence of MN-pCT after chemotherapy and/or radiation therapy among patients with tumors has gradually risen. However, the outcome of MN-pCT is poorer than that of primary myeloid neoplasms. This review summarizes the current understanding based on existing research, as a foundation for further research on MN-pCT.

Impact of cytotoxic therapy on clonal hematopoiesis and myeloid neoplasms in breast cancer patients

Clonal hematopoiesis (CH), which is characterized by variants of hematopoietic stem cells, increases the risk of subsequent myeloid neoplasms (MNs). This study aimed to investigate the prevalence and characteristics of CH variants in breast cancer (BC) patients treated with cytotoxic therapy (CT), focusing on those who developed MNs after cytotoxic therapy (MN-pCT). We retrospectively analyzed 107 BC patients from a biobank and sequenced peripheral blood and bone marrow samples from 31 CH-associated genes at 2 time points. We analyzed changes in CH for paired samples: T0 to T1 (before and after CT) and T1 to T2 (after CT vs greater CT exposure). Additionally, we compared CH variants in patients with and without MN-pCT. 29% of patients harbored CH variants that were restricted to 8 genes and DNMT3A was the most frequent variant. Among 54 patients with paired samples (T1 to T2), the variant allele frequency (VAF) of CH variants significantly increased after greater CT exposure (P = .02). However, there were no significant changes in VAF before and after CT. Five of the 9 patients who developed MN-pCT harbored CH variants. TP53 was the most frequently mutated gene, but it did not significantly affect MN-pCT risk compared to patients without CH variants. Although the presence of CH did not directly predict MN-pCT development in patients with BC, CT induced changes in CH genes. Further studies are required to determine the role of specific CH variants in the risk of MN-pCT and their potential as predictive biomarkers.

Therapy-Related Myeloid Neoplasms: Complex Interactions among Cytotoxic Therapies, Genetic Factors, and Aberrant Microenvironment

Therapy-related myeloid neoplasm (t-MN), characterized by its association with prior exposure to cytotoxic therapy, remains poorly understood and is a major impediment to long-term survival even in the era of novel targeted therapies due to its aggressive nature and treatment resistance. Previously, cytotoxic therapy-induced genomic changes in hematopoietic stem cells were considered sine qua non in pathogenesis; however, recent research demonstrates a complex interaction between acquired and hereditary genetic predispositions, along with a profoundly senescent bone marrow (BM) microenvironment. We review emerging data on t-MN risk factors and explore the intricate interplay among clonal hematopoiesis, genetic predisposition, and the abnormal BM microenvironment. Significance: t-MN represents a poorly understood blood cancer with extremely poor survival and no effective therapies. We provide a comprehensive review of recent preclinical research highlighting complex interaction among emerging therapies, hereditary and acquired genetic factors, and BM microenvironment. Understanding the risk factors associated with t-MN is crucial for clinicians, molecular pathologists, and cancer biologists to anticipate and potentially reduce its incidence in the future. Moreover, better understanding of the molecular pathogenesis of t-MN may enable preemptive screening and even intervention in high-risk patients.

Sex-Based Differences in Risk of Therapy-Related Myeloid Neoplasms

PURPOSE

Therapy-related myeloid neoplasm (t-MN) is a life-threatening complication of autologous peripheral blood stem cell (PBSC) transplantation for non-Hodgkin lymphoma (NHL). Previous studies report an association between clonal hematopoiesis (CH) in PBSC and risk of t-MN, but small samples precluded examination of risk within specific subpopulations.

METHODS

Targeted DNA sequencing was performed to identify CH mutations in PBSC from a retrospective cohort of 984 patients with NHL (median age at transplant, 57 years; range, 18-78). Fine-Gray proportional subdistribution hazard regression models estimated association between number of CH mutations and t-MN, adjusting for demographic, clinical, and therapeutic variables. Secondary analyses evaluated the association between CH and t-MN among males and females.

RESULTS

CH was identified in PBSC from 366 patients (37.2%). t-MN developed in 60 patients after a median follow-up of 5 years. Presence of ≥2 mutations conferred increased t-MN risk (adjusted hazard ratio [aHR], 2.10; 95% CI [1.08 to 4.11]; P = .029). CH was associated with increased t-MN risk among males (aHR, 1.83 [95% CI, 1.01 to 3.31]) but not females (aHR, 0.56 [95% CI, 0.15 to 2.09]). Although the prevalence and type of CH mutations in PBSC were comparable, the 8-year cumulative incidence of t-MN was higher among males vs. females with CH (12.4% v 3.6%) but was similar between males and females without CH (4.9% v 3.9%). Expansion of CH clones from PBSC to t-MN was seen only among males.

CONCLUSION

presence of CH mutations in PBSC confers increased risk of t-MN after autologous transplantation in male but not female patients with NHL. Factors underlying sex-based differences in risk of CH progression to t-MN merit further investigation.

Impact of cancer therapy on clonal hematopoiesis mutations and subsequent clinical outcomes

ABSTRACT

Exposure to cancer therapies is associated with an increased risk of clonal hematopoiesis (CH). The objective of our study was to investigate the genesis and evolution of CH after cancer therapy. In this prospective study, we undertook error-corrected duplex DNA sequencing in blood samples collected before and at 2 time points after chemoradiation in patients with esophageal or lung cancer recruited from 2013 to 2018. We applied a customized workflow to identify the earliest changes in CH mutation count and clone size and determine their association with clinical outcomes. Our study included 29 patients (87 samples). Their median age was 67 years, and 76% (n = 22) were male; the median follow-up period was 3.9 years. The most mutated genes were DNMT3A, TET2, TP53, and ASXL1. We observed a twofold increase in the number of mutations from before to after treatment in TP53, which differed from all other genes examined (P < .001). Among mutations detected before and after treatment, we observed an increased clone size in 38% and a decreased clone size in 5% of TP53 mutations (odds ratio, 3.7; 95% confidence interval [CI], 1.75-7.84; P < .001). Changes in mutation count and clone size were not observed in other genes. Individuals with an increase in the number of TP53 mutations after chemoradiation experienced shorter overall survival (hazard ratio, 7.07; 95% CI, 1.50-33.46; P = .014). In summary, we found an increase in the number and size of TP53 CH clones after chemoradiation that were associated with adverse clinical outcomes.

Distinct landscape and clinical implications of therapy-related clonal hematopoiesis

Therapy-related clonal hematopoiesis (t-CH) is defined as clonal hematopoiesis detected in individuals previously treated with chemotherapy and/or radiation therapy. With the increased use of genetic analysis in oncological care, the detection of t-CH among cancer patients is becoming increasingly common. t-CH arises through the selective bottleneck imposed by chemotherapies and potentially through direct mutagenesis from chemotherapies, resulting in a distinct mutational landscape enriched with mutations in DNA damage-response pathway genes such as TP53, PPM1D, and CHEK2. Emerging evidence sheds light on the mechanisms of t-CH development and potential strategies to mitigate its emergence. Due to its unique characteristics that predominantly affect cancer patients, t-CH has clinical implications distinct from those of CH in the general population. This Review discusses the potential mechanisms of t-CH development, its mutational landscape, mutant-drug relationships, and its clinical significance. We highlight the distinct nature of t-CH and call for intensified research in this field.

Clonal hematopoiesis of indeterminate potential is rare in pediatric patients undergoing autologous stem cell transplantation

Clonal hematopoiesis of indeterminate potential (CHIP) describes recurrent somatic gene mutations in the blood of healthy individuals, associated with higher risk for hematological malignancies and higher all-cause mortality by cardiovascular disease. CHIP increases with age and is more common in adult patients after chemotherapy or radiation for cancer. Furthermore, in some adult patients undergoing autologous stem cell transplantation (ASCT) or thereafter, CHIP has been identified. In children and adolescents, it remains unclear how cellular stressors such as cytotoxic therapy influence the incidence and expansion of CHIP. We conducted a retrospective study on 33 pediatric patients mostly with solid tumors undergoing ASCT for presence of CHIP. We analyzed CD34+ selected peripheral blood stem cell grafts after several cycles of chemotherapy, prior to cell infusion, by next-generation sequencing including 18 "CHIP-genes". Apart from a somatic variant in TP53 in one patient no other variants indicative of CHIP were identified. As a CHIP-unrelated finding, germline variants in CHEK2 and in ATM were identified in two and four patients, respectively. In conclusion, we could not detect "typical" CHIP variants in our cohort of pediatric cancer patients undergoing ASCT. However, more studies with larger patient numbers are necessary to assess if chemotherapy in the pediatric setting contributes to an increased CHIP incidence and at what time point.

Clonal Hematopoiesis in Patients With Human Immunodeficiency Virus and Cancer

BACKGROUND

Cancer-related deaths for people with human immunodeficiency virus (PWH) are increasing due to longer life expectancies and disparately poor cancer-related outcomes. We hypothesize that advanced biological aging contributes to cancer-related morbidity and mortality for PWH and cancer. We sought to determine the impact of clonal hematopoiesis (CH) on cancer disparities in PWH.

METHODS

We conducted a retrospective study to compare the prevalence and clinical outcomes of CH in PWH and people without HIV (PWoH) and cancer. Included in the study were PWH and similar PWoH based on tumor site, age, tumor sequence, and cancer treatment status. Biological aging was also measured using epigenetic methylation clocks.

RESULTS

In 136 patients with cancer, PWH had twice the prevalence of CH compared to similar PWoH (23% vs 11%, P = .07). After adjusting for patient characteristics, PWH were 4 times more likely than PWoH to have CH (odds ratio, 4.1 [95% confidence interval, 1.3-13.9]; P = .02). The effect of CH on survival was most pronounced in PWH, who had a 5-year survival rate of 38% if they had CH (vs 59% if no CH), compared to PWoH who had a 5-year survival rate of 75% if they had CH (vs 83% if no CH).

CONCLUSIONS

This study provides the first evidence that PWH may have a higher prevalence of CH than PWoH with the same cancers. CH may be an independent biological aging risk factor contributing to inferior survival for PWH and cancer.

Therapy-related AML: long-term outcome in a large cohort of AML-patients with intensive and non-intensive therapy

Therapy-related acute myeloid leukemia (t-AML) often exhibits adverse (genetic) features. There is ongoing discussion on the impact of t-AML on long-term outcome in AML. Therefore, we retrospectively analyzed clinical and biological characteristics of 1133 AML patients (225 t-AML patients and 908 de novo AML patients) with a median follow-up of 81.8 months. T-AML patients showed more adverse genetic alterations, higher age and more comorbidities as compared to de novo AML. Median OS in intensively treated t-AML patients was 13.7 months as compared to 39.4 months in de novo AML (p < 0.001). With non-intensive therapy, OS did not differ significantly (p = 0.394). With intensive therapy, significant differences in favor of de novo AML were observed in the ELN intermediate I/II (p = 0.009) and adverse (p = 0.016) risk groups but not within favorable risk groups (APL p = 0.927, ELN favorable p = 0.714). However, t-AML was no independent risk factor for OS (p = 0.103), RR (p = 0.982) and NRM (p = 0.320) in the multivariate analysis. A limitation of our study is an ELN 2010 risk stratification due to a lack of more comprehensive molecular data according to ELN 2022. We conclude that therapeutic algorithms in t-AML, in particular with regard to allo-HSCT, should be guided by ELN genetic risk rather than classification as t-AML alone. Our data support the WHO and ICC 2022 classifications, which include t-AML as diagnostic qualifier rather than a separate subcategory.

Subsequent malignant neoplasms after primary hematological malignancy in adult patients

Patients with primary hematological malignancy (HM) are at an elevated risk of subsequent malignant neoplasms (SMNs), which is a common concern after treatment of primary cancer. We identified 45,533 patients aged ≥20 years and diagnosed with primary HM in Finland from 1992 to 2019 from the Finnish Cancer Registry and estimated standardized incidence ratios (SIR) and excess absolute risks per 1000 person-years (EAR) for SMNs. A total of 6076 SMNs were found (4604 solid and 1472 hematological SMNs). The SIRs were higher for hematological SMNs (SIR 4.9, 95% confidence interval [CI] 4.7-5.2) compared to solid SMNs (SIR 1.5, 95% CI 1.4-1.5). The SIRs for hematological SMNs were highest in the young HM patients aged 20-39 years (SIR 9.2, 95% CI 6.8-12.2 in males and SIR 10.5, 95% CI 7.2-14.7 in females) and decreased by age of first primary HM. However, EARs for hematological SMNs were highest in the older patients, aged 60-79 years at their first primary HM (EAR 5.7/1000 and 4.7/1000 in male and female patients, respectively). In conclusion, the incidence of both hematological and solid SMNs were increased in hematological cancer patients. The relative risk (SIR) was highest among younger HM patients with hematological SMNs. The absolute second cancer burden reflected by high EAR arises from solid malignancies in older patients. Our results accentuate the need for vigilance in the surveillance of HM patients.

The role of clonal progression leading to the development of therapy-related myeloid neoplasms

Therapy-related myeloid neoplasms (t-MN) are characterized by aggressive features and a dismal prognosis. Recent evidence suggests a higher incidence of t-MN in individuals harboring clonal hematopoiesis of indeterminate potential (CHIP). In order to gain insight into CHIP-driven malignant progression, we gathered data from ten published reports with available detailed patient characteristics at the time of primary malignancy and t-MN development. Detailed clinical and molecular information on primary malignancy and t-MN were available for 109 patients: 43% harbored at least one somatic mutation at the time of the primary malignancy. TET2 and TP53 mutations showed an increasing variant allele frequency from CHIP to t-MN. ASXL1-associated CHIP significantly correlated with the emergence of TET2 and CEBPA mutations at t-MN, as well as U2AF1-driven CHIP with EZH2 mutation and both IDH2 and SRSF2-driven CHIP with FLT3 mutation. DNMT3A-driven CHIP correlated with a lower incidence of TP53 mutation at t-MN. In contrast, TP53-driven CHIP correlated with a complex karyotype and a lower tendency to acquire new mutations at t-MN. Patients with multiple myeloma as their first malignancy presented a significantly higher rate of TP53 mutations at t-MN. The progression from CHIP to t-MN shows different scenarios depending on the genes involved. A deeper knowledge of CHIP progression mechanisms will allow a more reliable definition of t-MN risk.

SOHO State of the Art Updates and Next Questions: An Update on Higher Risk Myelodysplastic Syndromes

Higher-risk myelodysplastic syndromes (HR-MDS) are clonal myeloid neoplasms that cause life-limiting complications from severe cytopenias and leukemic transformation. Efforts to better classify, prognosticate, and assess therapeutic responses in HR-MDS have resulted in publication of new clinical tools in the last several years. Given limited current treatment options and suboptimal outcomes, HR-MDS stands to benefit from the study of investigational agents.Higher-risk myelodysplastic syndromes (HR-MDS) are a heterogenous group of clonal myeloid-lineage malignancies often characterized by high-risk genetic lesions, increased blood transfusion needs, constitutional symptoms, elevated risk of progression to acute myeloid leukemia (AML), and therapeutic need for allogeneic bone marrow transplantation. Use of blast percentage and other morphologic features to define myelodysplastic neoplasm subtypes is rapidly shifting to incorporate genetics, resulting in a subset of former HR-MDS patients now being considered as AML in presence of leukemia-defining genetic alterations. A proliferation of prognostic tools has further focused use of genetic features to drive decision making in clinical management. Recently, criteria to assess response of HR-MDS to therapy were revised to incorporate more clinically meaningful endpoints and better match AML response criteria. Basic science investigations have resulted in improved understanding of the relationship between MDS genetic lesions, bone marrow stromal changes, germline predispositions, and disease phenotype. However, therapeutic advances have been more limited. There has been import of the IDH1 inhibitor ivosidenib, initially approved for AML; the Bcl-2 inhibitor venetoclax and liposomal daunorubicin/cytarabine (CPX-351) are under active investigation as well. Unfortunately, effective treatment of TP53-mutated disease remains elusive, though preliminary evidence suggests improved outcomes with oral decitabine/cedazuridine over parenteral hypomethylating agent monotherapy. Investigational agents with novel mechanisms of action may help expand the repertoire of treatment options for HR-MDS and trials continue to offer a hopeful therapeutic avenue for suitable patients.

Clinical and Therapeutic Implications of Clonal Hematopoiesis

Clonal hematopoiesis (CH) is an age-related process whereby hematopoietic stem and progenitor cells (HSPCs) acquire mutations that lead to a proliferative advantage and clonal expansion. The most commonly mutated genes are epigenetic regulators, DNA damage response genes, and splicing factors, which are essential to maintain functional HSPCs and are frequently involved in the development of hematologic malignancies. Established risk factors for CH, including age, prior cytotoxic therapy, and smoking, increase the risk of acquiring CH and/or may increase CH fitness. CH has emerged as a novel risk factor in many age-related diseases, such as hematologic malignancies, cardiovascular disease, diabetes, and autoimmune disorders, among others. Future characterization of the mechanisms driving CH evolution will be critical to develop preventative and therapeutic approaches.

Clonal hematopoiesis of indeterminate potential as a prognostic factor: a systematic review and meta-analysis

ABSTRACT

With advances in sequencing, individuals with clonal hematopoiesis of indeterminate potential (CHIP) are increasingly being identified, making it essential to understand its prognostic implications. We conducted a systematic review of studies comparing the risk of clinical outcomes in individuals with and without CHIP. We searched MEDLINE and EMBASE and included original research reporting an outcome risk measure in individuals with CHIP, adjusted for the effect of age. From the 3305 studies screened, we included 88 studies with 45 to 470 960 participants. Most studies had a low-to-moderate risk of bias in all domains of the Quality in Prognostic Factor Studies tool. Random-effects meta-analyses were performed for outcomes reported in at least 3 studies. CHIP conferred an increased risk of all-cause mortality (hazard ratio [HR], 1.34; 95% confidence interval, 1.19-1.50), cancer mortality (HR, 1.46; 1.13-1.88), composite cardiovascular events (HR, 1.40; 1.19-1.65), coronary heart disease (HR, 1.76; 1.27-2.44), stroke (HR, 1.16; 1.05-1.28), heart failure (HR, 1.27; 1.15-1.41), hematologic malignancy (HR, 4.28; 2.29-7.98), lung cancer (HR, 1.40; 1.27-1.54), renal impairment (HR, 1.25; 1.18-1.33) and severe COVID-19 (odds ratio [OR], 1.46; 1.18-1.80). CHIP was not associated with cardiovascular mortality (HR, 1.09; 0.97-1.22), except in the subgroup analysis restricted to larger clones (HR, 1.31; 1.12-1.54). Isolated DNMT3A mutations did not increase the risk of myeloid malignancy, all-cause mortality, or renal impairment. The reasons for heterogeneity between studies included differences in definitions and measurements of CHIP and the outcomes, and populations studied. In summary, CHIP is associated with diverse clinical outcomes, with clone size, specific gene, and inherent patient characteristics important mediators of risk.

Impact of clonal haematopoiesis on atherosclerotic cardiovascular disease according to low-density lipoprotein cholesterol levels in general population

AIMS

Clonal haematopoiesis of indeterminate potential (CHIP), defined as a clonal expansion of age-related recurrent somatic mutations, has recently emerged as a novel cardiovascular risk factor. However, the precise role of CHIP in the development of atherosclerotic cardiovascular disease (ASCVD) remains unclear.

METHODS AND RESULTS

Among 4300 asymptomatic Korean participants aged 40-79 years, we investigated the risk of ASCVD by CHIP and the interplay between CHIP and conventional risk factors in ASCVD development. Additionally, we assessed changes in coronary arteries based on the presence of CHIP using coronary computed tomography angiography (CCTA). CHIP was present in 363 participants (8.4%), and its prevalence increased with age. Commonly mutated genes were DNMT3A, TET2, and ASXL1, in order. During the follow-up (median 4.7 years), 18 ASCVD cases (5.0%) were observed in CHIP carriers vs. 62 (1.6%) in non-carriers (P < 0.001), indicating an elevated risk of ASCVD associated with CHIP [adjusted hazard ratio (HR) 2.49; 95% confidence interval (CI) 1.45-4.29; P < 0.001]. Notably, with high levels of LDL cholesterol, CHIP enhanced the risk of ASCVD (adjusted HR 6.20; 95% CI 3.14-12.23; P < 0.001), demonstrating synergism between CHIP and LDL cholesterol levels (S-index 4.94; 95% CI 1.08-22.53; P = 0.039). Serial CCTAs confirmed that CHIP, in conjunction with high LDL cholesterol levels, had a significant early impact on coronary arteries, revealing new measurable coronary atherosclerosis, mainly with unstable plaque, in proximal lesions.

CONCLUSION

The presence of CHIP was significantly associated with the risk of ASCVD, promoting the early stage of atherosclerosis through synergy with high LDL cholesterol in the general population.

Clonal Hematopoiesis and Therapy-Related Myeloid Neoplasms After Autologous Transplant for Hodgkin Lymphoma

PURPOSE

Therapy-related myeloid neoplasm (t-MN) is a life-threatening complication of autologous peripheral blood stem cell transplantation (aPBSCT) for Hodgkin lymphoma (HL). Although previous studies have reported an association between clonal hematopoiesis (CH) in the infused PBSC product and subsequent post-aPBSCT risk of t-MN in patients with non-HL, information about patients with HL treated with aPBSCT is not available.

METHODS

We constructed a retrospective cohort of 321 patients with HL transplanted at a median age of 34 years (range, 18-71). Targeted DNA sequencing of PBSC products performed for CH-associated or myeloid malignancy-associated genes identified pathogenic mutations in these patients.

RESULTS

CH was identified in the PBSC product of 46 patients (14.3%) with most prominent representation of DNMT3A (n = 25), PPM1D (n = 7), TET2 (n = 7), and TP53 (n = 5) mutations. Presence of CH in the PBSC product was an independent predictor of t-MN (adjusted hazard ratio [aHR], 4.50 [95% CI, 1.54 to 13.19]). Notably all patients with TP53 mutations in the PBSC product developed t-MN, whereas none of the patients with DNMT3A mutations alone (without co-occurring TP53 or PPM1D mutations) did. Presence of TP53 and/or PPM1D mutations was associated with a 7.29-fold higher hazard of t-MN when compared with individuals carrying no CH mutations (95% CI, 1.72 to 30.94). The presence of TP53 and/or PPM1D mutations was also associated with a 4.17-fold higher hazard of nonrelapse mortality (95% CI, 1.25 to 13.87). There was no association between CH and relapse-related mortality.

CONCLUSION

The presence of TP53 and/or PPM1D mutations in the PBSC product increases the risk of post-aPBSCT t-MN and nonrelapse mortality among patients with HL and may support alternative therapeutic strategies.

The impact of cytotoxic therapy on the risk of progression and death in clonal cytopenia(s) of undetermined significance

ABSTRACT

Clonal cytopenia of undetermined significance (CCUS) is defined by a myeloid driver mutation in the context of otherwise unexplained cytopenia. CCUS has an inherent risk of progressing to myeloid neoplasm. However, it is unknown how exposure to previous cytotoxic therapy may impact the risk of progression and survival. We stratified patients with CCUS by prior exposure to DNA-damaging therapy. Of 151 patients, 46 (30%) had received cytotoxic therapy and were classified as therapy-related CCUS (t-CCUS), whereas 105 (70%) had de novo CCUS. A lower proportion of t-CCUS had hypercellular marrows (17.8% vs 44.8%, P = .002) but had higher median bone marrow blast percentages. After a median follow-up of 2.2 years, t-CCUS had significantly shorter progression-free survival (PFS, 1.8 vs 6.3 years; hazard ratio [HR], 2.1; P = .007) and median overall survival (OS; 3.6 years vs not reached; HR, 2.3; P = .007) compared with CCUS. Univariable and multivariable time-to-event analyses showed that exposure to cytotoxic therapy independently accounted for inferior PFS and OS. Despite the similarities in clinical presentation between CCUS and t-CCUS, we show that exposure to prior cytotoxic therapies was an independent risk factor for inferior outcomes. This suggests that t-CCUS represents a unique clinical entity that needs more stringent monitoring or earlier intervention strategies.

Therapy-related chronic myelomonocytic leukemia does not have the high-risk features of a therapy-related neoplasm

ABSTRACT

Therapy-related myeloid neoplasms (t-MNs) arise after exposure to cytotoxic therapies and are associated with high-risk genetic features and poor outcomes. We analyzed a cohort of patients with therapy-related chronic myelomonocytic leukemia (tCMML; n = 71) and compared its features to that of de novo CMML (dnCMML; n = 461). Median time from cytotoxic therapy to tCMML diagnosis was 6.5 years. Compared with dnCMML, chromosome-7 abnormalities (4% vs 13%; P = .005) but not complex karyotype (3% vs 7%; P = .15), were more frequent in tCMML. tCMML was characterized by higher TP53 mutation frequency (4% vs 12%; P = .04) and lower NRAS (6% vs 22%, P = .007) and CBL (4% vs 12%, P = .04) mutation frequency. Prior therapy with antimetabolites (odd ratio [OR], 1.22; 95% confidence interval [CI], 1.05-1.42; P = .01) and mitotic inhibitors (OR, 1.24; 95% CI, 1.06-1.44; P = .009) was associated with NF1 and SETBP1 mutations whereas prior mitotic inhibitor therapy was associated with lower TET2 mutation frequency (OR, 0.71; 95% CI, 0.55-0.92; P = .01). Although no differences in median overall survival (OS) were observed among tCMML and dnCMML (34.7 months vs 35.9 months, P = .26), multivariate analysis for OS revealed that prior chemotherapy was associated with increased risk of death (hazard ratio, 1.76; 95% CI, 1.07-2.89; P = .026). Compared with a cohort of therapy-related myelodysplastic syndrome, tCMML had lower TP53 mutation frequency (12% vs 44.4%, P < .001) and less unfavorable outcomes. In summary, tCMML does not exhibit the high-risk features and poor outcomes of t-MNs.

SOHO State of the Art Updates and Next Questions | Next Questions: Acute Lymphoblastic Leukemia

The integration of immune and targeted therapies into the treatment of acute lymphoblastic leukemia (ALL) has significantly improved outcomes, reduced the intensity and duration of chemotherapy, and the reliance on allogeneic stem cell transplantation (SCT). In younger patients with Philadelphia chromosome (Ph)-negative ALL, treatment with Hyper-CVAD and blinatumomab +/- inotuzumab has improved the 3-year overall survival (OS) to above 85%. In older patients, using less intensive chemotherapy (mini-Hyper-CVD) in combination with inotuzumab and blinatumomab has improved the 5-year OS rate to 50%. In Ph+ ALL, the chemotherapy-free combinations of blinatumomab and ponatinib (or dasatinib) have become a new standard of care resulting in 3-year OS of 85% to 90%. Because the methotrexate-cytarabine courses were omitted in the nonchemotherapy regimens, central nervous system (CNS) relapses were noted, particularly in patients with a WBC count > 70 × 109/L, requiring to consider increasing the number of prophylactic intrathecals (from 12 to 15) and perhaps developing a CNS risk-directed high-dose systemic chemotherapy. In relapsed/refractory ALL, a dose-dense regimen integrating blinatumomab and inotuzumab with low-intensity chemotherapy followed by consolidation with chimeric antigen receptor T-cell therapy is being investigated. The detection of measurable residual disease (MRD) following ALL therapy is predictive of disease relapse. Using next-generation sequencing allows the detection of MRD at 1 × 10-6 which was shown to be superior to multiparameter flow cytometry and polymerase chain reaction in predicting relapse, and could be used to decide on the duration of therapy or need to change therapy. Herein, we review the recent updates and areas of unmet need in ALL.

Dynamics of clonal hematopoiesis under DNA-damaging treatment in patients with ovarian cancer

Clonal hematopoiesis (CH) driven by mutations in the DNA damage response (DDR) pathway is frequent in patients with cancer and is associated with a higher risk of therapy-related myeloid neoplasms (t-MNs). Here, we analyzed 423 serial whole blood and plasma samples from 103 patients with relapsed high-grade ovarian cancer receiving carboplatin, poly(ADP-ribose) polymerase inhibitor (PARPi) and heat shock protein 90 inhibitor (HSP90i) treatment within the phase II EUDARIO trial using error-corrected sequencing of 72 genes. DDR-driven CH was detected in 35% of patients and was associated with longer duration of prior PARPi treatment. TP53- and PPM1D-mutated clones exhibited substantially higher clonal expansion rates than DNMT3A- or TET2-mutated clones during treatment. Expansion of DDR clones correlated with HSP90i exposure across the three study arms and was partially abrogated by the presence of germline mutations related to homologous recombination deficiency. Single-cell DNA sequencing of selected samples revealed clonal exclusivity of DDR mutations, and identified DDR-mutated clones as the origin of t-MN in two investigated cases. Together, these results provide unique insights into the architecture and the preferential selection of DDR-mutated hematopoietic clones under intense DNA-damaging treatment. Specifically, PARPi and HSP90i therapies pose an independent risk for the expansion of DDR-CH in a dose-dependent manner.

Clonal evolution of hematopoietic stem cells after cancer chemotherapy

Normal hematopoietic stem and progenitor cells (HSPCs) inherently accumulate somatic mutations and lose clonal diversity with age, processes implicated in the development of myeloid malignancies 1 . The impact of exogenous stressors, such as cancer chemotherapies, on the genomic integrity and clonal dynamics of normal HSPCs is not well defined. We conducted whole-genome sequencing on 1,032 single-cell-derived HSPC colonies from 10 patients with multiple myeloma (MM), who had undergone various chemotherapy regimens. Our findings reveal that melphalan treatment distinctly increases mutational burden with a unique mutation signature, whereas other MM chemotherapies do not significantly affect the normal mutation rate of HSPCs. Among these therapy-induced mutations were several oncogenic drivers such as TET2 and PPM1D . Phylogenetic analysis showed a clonal architecture in post-treatment HSPCs characterized by extensive convergent evolution of mutations in genes such as TP53 and PPM1D . Consequently, the clonal diversity and structure of post-treatment HSPCs mirror those observed in normal elderly individuals, suggesting an accelerated clonal aging due to chemotherapy. Furthermore, analysis of matched therapy-related myeloid neoplasm (t-MN) samples, which occurred 1-8 years later, enabled us to trace the clonal origin of t-MNs to a single HSPC clone among a group of clones with competing malignant potential, indicating the critical role of secondary mutations in dictating clonal dominance and malignant transformation. Our findings suggest that cancer chemotherapy promotes an oligoclonal architecture with multiple HSPC clones possessing competing leukemic potentials, setting the stage for the selective emergence of a singular clone that evolves into t-MNs after acquiring secondary mutations. These results underscore the importance of further systematic research to elucidate the long-term hematological consequences of cancer chemotherapy.

Therapy-Related Myeloid Neoplasm: Biology and Mechanistic Aspects of Malignant Progression

Therapy-related myeloid neoplasms (t-MN) arise after a documented history of chemo/radiotherapy as treatment for an unrelated condition and account for 10-20% of myelodysplastic syndromes and acute myeloid leukemia. T-MN are characterized by a specific genetic signature, aggressive features and dismal prognosis. The nomenclature and the subsets of these conditions have changed frequently over time, and despite the fact that, in the last classification, they lost their autonomous entity status and became disease qualifiers, the recognition of this feature remains of major importance. Furthermore, in recent years, extensive studies focusing on clonal hematopoiesis and germline variants shed light on the mechanisms of positive pressure underpinning the rise of driver gene mutations in t-MN. In this manuscript, we aim to review the evolution of defining criteria and characteristics of t-MN from a clinical and biological perspective, the advances in mechanistic aspects of malignant progression and the challenges in prevention and management.

Clonal hematopoiesis and its impact on the aging osteo-hematopoietic niche

Clonal hematopoiesis (CH) defines a premalignant state predominantly found in older persons that increases the risk of developing hematologic malignancies and age-related inflammatory diseases. However, the risk for malignant transformation or non-malignant disorders is variable and difficult to predict, and defining the clinical relevance of specific candidate driver mutations in individual carriers has proved to be challenging. In addition to the cell-intrinsic mechanisms, mutant cells rely on and alter cell-extrinsic factors from the bone marrow (BM) niche, which complicates the prediction of a mutant cell's fate in a shifting pre-malignant microenvironment. Therefore, identifying the insidious and potentially broad impact of driver mutations on supportive niches and immune function in CH aims to understand the subtle differences that enable driver mutations to yield different clinical outcomes. Here, we review the changes in the aging BM niche and the emerging evidence supporting the concept that CH can progressively alter components of the local BM microenvironment. These alterations may have profound implications for the functionality of the osteo-hematopoietic niche and overall bone health, consequently fostering a conducive environment for the continued development and progression of CH. We also provide an overview of the latest technology developments to study the spatiotemporal dependencies in the CH BM niche, ideally in the context of longitudinal studies following CH over time. Finally, we discuss aspects of CH carrier management in clinical practice, based on work from our group and others.

Cancer patients with clonal hematopoiesis die from primary malignancy or comorbidities despite higher rates of transformation to myeloid neoplasms

BACKGROUND

The occurrence of somatic mutations in patients with no evidence of hematological disorders is called clonal hematopoiesis (CH). CH, whose subtypes include CH of indeterminate potential and clonal cytopenia of undetermined significance, has been associated with both hematologic cancers and systemic comorbidities. However, CH's effect on patients, especially those with concomitant malignancies, is not fully understood.

METHODS

We performed a retrospective evaluation of all patients with CH at a tertiary cancer center. Patient characteristics, mutational data, and outcomes were collected and analyzed.

RESULTS

Of 78 individuals included, 59 (76%) had a history of cancer and 60 (77%) had moderate to severe comorbidity burdens. DNMT3A, TET2, TP53, and ASXL1 were the most common mutations. For the entire cohort, the 2-year overall survival rate was 79% (95% CI: 70, 90), while the median survival was not reached. Of 20 observed deaths, most were related to primary malignancies (n = 7, 35%), comorbidities (n = 4, 20%), or myeloid neoplasms (n = 4, 20%). Twelve patients (15%) experienced transformation to a myeloid neoplasm. According to the clonal hematopoiesis risk score, the 3-year transformation rate was 0% in low-risk, 15% in intermediate-risk (p = 0.098), and 28% in high-risk (p = 0.05) patients. By multivariate analysis, transformation was associated with variant allele frequency ≥0.2 and hemoglobin <10 g/dL.

CONCLUSIONS

In a population including mostly cancer patients, CH was associated with comorbidities and myeloid transformation in patients with higher mutational burdens and anemia. Nevertheless, such patients were less likely to die of their myeloid neoplasm than of primary malignancy or comorbidities.

High-risk and silent clonal hematopoietic genotypes in patients with nonhematologic cancer

ABSTRACT

Clonal hematopoiesis (CH) identified by somatic gene variants with variant allele fraction (VAF) ≥ 2% is associated with an increased risk of hematologic malignancy. However, CH defined by a broader set of genotypes and lower VAFs is ubiquitous in older individuals. To improve our understanding of the relationship between CH genotype and risk of hematologic malignancy, we analyzed data from 42 714 patients who underwent blood sequencing as a normal comparator for nonhematologic tumor testing using a large cancer-related gene panel. We cataloged hematologic malignancies in this cohort using natural language processing and manual curation of medical records. We found that some CH genotypes including JAK2, RUNX1, and XPO1 variants were associated with high hematologic malignancy risk. Chronic disease was predicted better than acute disease suggesting the influence of length bias. To better understand the implications of hematopoietic clonality independent of mutational function, we evaluated a set of silent synonymous and noncoding mutations. We found that silent CH, particularly when multiple variants were present or VAF was high, was associated with increased risk of hematologic malignancy. We tracked expansion of CH mutations in 26 hematologic malignancies sequenced with the same platform. JAK2 and TP53 VAF consistently expanded at disease onset, whereas DNMT3A and silent CH VAFs mostly decreased. These data inform the clinical and biological interpretation of CH in the context of nonhematologic cancer.

Acute Myeloid Leukemia Post Cytotoxic Therapy in Breast Cancer Survivors-Over 23 Years of Single Center Analysis

Background: Acute myeloid leukemia post cytotoxic therapy (AML-pCT) among breast cancer (BC) survivors represents a life-threatening complication. This study aims to assess the clinical outcomes of AML-pCT post BC. Methods: An analysis of all AML patients treated at a single hematology center (2000-2023) was performed to select patients with AML-pCT post BC. We applied the 2022 ELN criteria to define the genetic risk. Results: Among 847 AML patients, 28 were diagnosed with AML-pCT following BC. Complex karyotype (CK) occurred in 23.8% of patients. The median overall survival (OS) was 40 months. The survival outcomes were better after allogenic hematopoietic stem cell transplantation (alloHCT) treatment compared to chemotherapy alone (median OS: 47 versus 7 months, p = 0.008). Patients demonstrating CK showed lower survival compared to those without CK (2-year OS: 25.0% versus 66.2%, p = 0.0048). The multivariable Cox proportional hazards regression model indicated that treatment with alloHCT emerged as a significant factor associated with improved OS. The treatment was associated with superior OS (HR = 0.07, 95% CI = 0.01-0.86, p = 0.04). Conclusions: Patients with AML-pCT following BC were characterized with the highest frequency of adverse genetic risk profiles and demonstrated worse survival rates. AlloHCT should be performed as early as possible in such patients. The growing need for studies on inherited cancer susceptibility underscores the importance of close AML-pCT development monitoring in BC survivors.

The crossroads of cancer therapies and clonal hematopoiesis

The intricate interplay between Clonal Hematopoiesis (CH) and the repercussions of cancer therapies has garnered significant research focus in recent years. Previously perceived as an age-related phenomenon, CH is now closely linked to inflammation ("Inflammaging") and cancer, impacting leukemogenesis, cancer progression, and treatment responses. This review explores the complex interplay between CH and diverse cancer therapies, including chemotherapy, targeted treatments, radiation, stem cell transplants, CAR-T cell therapy, and immunotherapy, like immune checkpoint inhibitors. Notably, knowledge about post-chemotherapy CH mutation/acquisition has evolved from a de novo incident to more of a clonal selection process. Chemotherapy and radiation exposure, whether therapeutic or environmental, increases CH risk, particularly in genes like TP53 and PPM1D. Environmental toxins, especially in high-risk environments like post-disaster sites or space exploration, are associated with CH. CH affects clinical outcomes in stem cell transplant scenarios, including engraftment, survival, and t-MN development. The presence of CH also alters CAR-T cell therapy responses and impacts the efficacy and toxicity of immunotherapies. Furthermore, specific mutations like DNMT3A and TET2 thrive under inflammatory stress, influencing therapy outcomes and justifying the ongoing tailored interventions in clinical trials. This review underscores the critical need to integrate CH analysis into personalized medicine, enhancing risk assessments and refining treatment strategies. As we progress, multidisciplinary collaboration and comprehensive studies are imperative. Understanding CH's impact, especially concerning genotoxic stressors, will inform screening, surveillance, and early detection strategies, decreasing the risk of therapy-related myeloid neoplasms and revolutionizing cancer treatment paradigms.

TET2 mutation as prototypic clonal hematopoiesis lesion

Loss of function TET2 mutation (TET2MT) is one of the most frequently observed lesions in clonal hematopoiesis (CH). TET2 a member TET-dioxygenase family of enzymes that along with TET1 and TET3, progressively oxidize 5-methyl cytosine (mC) resulting in regulated demethylation of promoter, enhancer and silencer elements of the genome. This process is critical for efficient transcription that determine cell lineage fate, proliferation and survival and the maintenance of the genomic fidelity with aging of the organism. Partial or complete loss-of-function TET2 mutations create regional and contextual DNA hypermethylation leading to gene silencing or activation that result in skewed myeloid differentiation and clonal expansion. In addition to myeloid skewing, loss of TET2 creates differentiation block and provides proliferative advantage to hematopoietic stem and progenitor cells (HSPCs). TET2MT is a prototypical lesion in CH, since the mutant clones dominate during stress hematopoiesis and often associates with evolution of myeloid malignancies. TET2MT clones has unique privilege to create and persist in pro-inflammatory milieu. Despite extensive knowledge regarding biochemical mechanisms underlying distorted myeloid differentiation, and enhanced self-replication of TET2MT HSPC, the mechanistic link of various pathogenesis associated with TET2 loss in CHIP is less understood. Here we review the recent development in TET2 biology and its probable mechanistic link in CH with aging and inflammation. We also explored the therapeutic strategies of targeting TET2MT associated CHIP and the utility of targeting TET2 in normal hematopoiesis and somatic cell reprograming. We explore the biochemical mechanisms and candidate therapies that emerged in last decade of research.

Prognostic relevance of clonal hematopoiesis in myeloid neoplastic transformation in patients with follicular lymphoma treated with radioimmunotherapy

While novel radioisotope therapies continue to advance cancer care, reports of therapy-related myeloid neoplasms (t-MN) have generated concern. The prevalence and role of clonal hematopoiesis (CH) in this process remain to be defined. We hypothesized that: (i) CH is prevalent in relapsed follicular lymphoma and is associated with t-MN transformation, and (ii) radiation in the form of radioimmunotherapy (RIT) plays a role in clonal progression. In this retrospective cohort study, we evaluated the prevalence and prognostic impact of CH on clinical outcomes in 58 heavily pre-treated follicular lymphoma patients who received RIT. Patients had been given a median of four lines of therapy before RIT. The prevalence of CH prior to RIT was 46%, while it was 67% (P=0.15) during the course of RIT and subsequent therapies in the paired samples. Fourteen (24%) patients developed t-MN. Patients with t-MN had a higher variant allele fraction (38% vs. 15%; P=0.02) and clonal complexity (P=0.03) than those without. The spectrum of CH differed from that in age-related CH, with a high prevalence of DNA damage repair and response pathway mutations, absence of spliceosome mutations, and a paucity of signaling mutations. While there were no clear clinical associations between RIT and t-MN, or overall survival, patients with t-MN had a higher mutant clonal burden, along with extensive chromosomal abnormalities (median survival, afer t-MN diagnosis, 0.9 months). The baseline prevalence of CH was high, with an increase in prevalence on exposure to RIT and subsequent therapies. The high rates of t-MN with marked clonal complexities and extensive chromosomal damage underscore the importance of better identifying and studying genotoxic stressors accentuated by therapeutic modalities.

Clonal Hematopoiesis, Inflammation, and Hematologic Malignancy

Somatic or acquired mutations are postzygotic genetic variations that can occur within any tissue. These mutations accumulate during aging and have classically been linked to malignant processes. Tremendous advancements over the past years have led to a deeper understanding of the role of somatic mutations in benign and malignant age-related diseases. Here, we review the somatic mutations that accumulate in the blood and their connection to disease states, with a particular focus on inflammatory diseases and myelodysplastic syndrome. We include a definition of clonal hematopoiesis (CH) and an overview of the origins and implications of these mutations. In addition, we emphasize somatic disorders with overlapping inflammation and hematologic disease beyond CH, including paroxysmal nocturnal hemoglobinuria and aplastic anemia, focusing on VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome. Finally, we provide a practical view of the implications of somatic mutations in clinical hematology, pathology, and beyond.

Cord blood transplantation for AML: Comparable LFS in patients with de novo versus secondary AML in CR1, an ALWP/EBMT study

We investigated whether secondary versus de novo acute myeloid leukaemia (AML) would be associated with poor outcomes in adult acute AML patients in first complete remission (CR1) receiving unrelated cord blood transplantation (CBT). This is a retrospective study from the acute leukaemia working party of the European Society for Blood and Marrow Transplantation. Inclusion criteria included adult at first allogeneic haematopoietic cell transplantation between 2000 and 2021, unrelated single or double unit CBT, AML in CR1, no ex vivo T-cell depletion and no post-transplant cyclophosphamide. The primary end-point of the study was leukaemia-free survival (LFS). A total of 879 patients with de novo (n = 696) or secondary (n = 183) AML met the inclusion criteria. In multivariable analyses, sAML patients had non-significantly different LFS (HR = 0.98, p = 0.86), overall survival (HR = 1.07, p = 0.58), relapse incidence (HR = 0.74, p = 0.09) and non-relapse mortality (HR = 1.26, p = 0.13) than those with de novo AML. Our results demonstrate non-significantly different LFS following CBT in adult patients with secondary versus de novo AML.

Clinical Outcomes and Evolution of Clonal Hematopoiesis in Patients with Newly Diagnosed Multiple Myeloma

Clonal hematopoiesis (CH) at time of autologous stem cell transplant (ASCT) has been shown to be associated with decreased overall survival (OS) and progression-free survival (PFS) in patients with multiple myeloma not receiving immunomodulatory drugs (IMiD). However, the significance of CH in newly diagnosed patients, including transplant ineligible patients, and its effect on clonal evolution during multiple myeloma therapy in the era of novel agents, has not been well studied. Using our new algorithm to differentiate tumor and germline mutations from CH, we detected CH in approximately 10% of 986 patients with multiple myeloma from the Clinical Outcomes in MM to Personal Assessment of Genetic Profile (CoMMpass) cohort (40/529 transplanted and 59/457 non-transplanted patients). CH was associated with increased age, risk of recurrent bacterial infections and cardiovascular disease. CH at time of multiple myeloma diagnosis was not associated with inferior OS or PFS regardless of undergoing ASCT, and all patients benefited from IMiD-based therapies, irrespective of the presence of CH. Serial sampling of 52 patients revealed the emergence of CH over a median of 3 years of treatment, increasing its prevalence to 25%, mostly with DNMT3A mutations.

SIGNIFICANCE

Using our algorithm to differentiate tumor and germline mutations from CH mutations, we detected CH in approximately 10% of patients with newly diagnosed myeloma, including both transplant eligible and ineligible patients. Receiving IMiDs improved outcomes irrespective of CH status, but the prevalence of CH significantly rose throughout myeloma-directed therapy.