An acquired high-risk chromosome instability phenotype in multiple myeloma: Jumping 1q Syndrome

Prognostic Significance of +1q Alterations in Relapsed/Refractory Multiple Myeloma Treated With Daratumumab-, Elotuzumab-, and Carfilzomib-Based Triplet Regimens: A Multicenter Real-World Analysis of 635 Patients

Relapsed/refractory multiple myeloma (RRMM) research on the impact of +1q abnormalities in real-world settings is limited. This study evaluated the prognostic and predictive significance of 1q gain [gain(1q)] and amplification [ampl(1q)] in 635 RRMM patients treated with daratumumab-, elotuzumab-, and carfilzomib-based triplet regimens. Patients with +1q abnormalities had lower deep response rates [≥ CR: 9.4% for gain(1q), 11.6% for ampl(1q)] versus 20.2% in +1q-negative patients. Multivariable ordinal logistic analysis showed significantly lower odds of achieving ≥ CR in patients with gain(1q) (OR = 0.49, p < 0.001) or ampl(1q) (OR = 0.58, p = 0.0037). Progression-free survival (PFS) was longer in +1q-negative patients (28 months) compared to those with gain(1q) (8 months) or ampl(1q) (7.4 months). Multivariable models identified gain(1q) (HR = 1.9, p < 0.001) and ampl(1q) (HR = 2.2, p < 0.001) as independent negative prognostic factors alongside del17p, t(4;14), creatinine clearance < 60 mL/min, and ISS Stages II and III. Similarly, overall survival (OS) was reduced for patients with gain(1q) (25 months) and ampl(1q) (19.5 months) versus 42.2 months in +1q-negative patients. Multivariable analysis showed gain(1q) (HR = 1.6, p = 0.007) and ampl(1q) (HR = 2.0, p = 0.002) as independent predictors of increased mortality. Ancillary +1q abnormalities associated with high-risk cytogenetic changes were linked to both shorter PFS and OS. Stratification into no-hit, single-hit, double-hit, and triple-hit groups showed significant survival differences, emphasizing the impact of cumulative cytogenetic abnormalities on outcomes. In conclusion, +1q abnormalities significantly impact prognosis in RRMM and should be considered in risk stratification. The study emphasizes the importance of comprehensive cytogenetic profiling in real-world settings and highlights the need for personalized treatment strategies to improve patient outcomes.

The role of 1q abnormalities in multiple myeloma: Genomic insights, clinical implications, and therapeutic challenges

Chromosome 1q copy number variations, collectively termed +1q, are 1 of the most common cytogenetic abnormalities in multiple myeloma. 1q abnormalities are associated with overexpression of a high-risk gene signature promoting cell proliferation, apoptosis resistance, genomic instability, and treatment resistance, and acquisition or expansion of +1q subclones mediate disease development and relapse. While there remains significant controversy as to whether the presence of +1q is itself an independent driver of poor prognosis or is simply a marker of other high-risk features, +1q has recently been incorporated into multiple prognostic scoring models as a new high-risk cytogenetic abnormality. In this review, we present possible underlying genetic mechanisms of high-risk disease in +1q myeloma, implications for subclonal development, its role in modifying the tumor microenvironment, current evidence for clinical significance in newly-diagnosed and relapsed patients, and current controversies in +1q classification and prognostication.

Locus-specific differential expression of human satellite sequences in the nuclei of cancer cells and heat-shocked cells

Human satellitess(HSats) are pericentric, tandemly repeating satellite DNA sequences in the human genome. While silent in normal cells, a subset of HSat2 noncoding RNA is expressed and accumulates in the nucleus of cancer cells. We developed a FISH-based approach for identification of the distribution of three subfamilies of HSat2 (A1, A2, B) sequences on individual human chromosomes. Further, using the HSat subfamily annotations in the T2T completed centromere satellite (CenSat) sequence, we isolated, defined and mapped differentially expressed sequence variants of nuclear-restricted HSat2 and HSat3 RNA from cancer cell lines and heat-shocked cells. We identified chromosome-specific and subfamily-specific expression of HSat2 and HSat3 and established a computational pipeline for differential expression analysis of tandemly repeated satellite sequences. Results suggest the differential expression of chromosome-specific HSat2 arrays in the human genome may underlie their accumulation in cancer cells and that specific HSat3 loci are upregulated upon heat shock.

High-risk cytogenetic abnormalities in multiple myeloma: PETHEMA-GEM experience

This study examines the impact of cytogenetic abnormalities and their co-segregation on the prognosis of newly diagnosed multiple myeloma patients. The analysis included 1304 patients from four different GEM-PETHEMA clinical trials. Genetic alterations, such as t(4;14), t(14;16), del(17p), +1q, and del(1p), were investigated using FISH on CD38 purified plasma cells. The frequency of genetic alterations detected were as follows: del(17p) in 8%, t(4;14) in 12%, t(14;16) in 3%, +1q in 43%, and del(1p) in 8%. The median follow-up was 61 months, and the median progression-free survival (PFS) and overall survival (OS) were 44 months and not reached, respectively. Consistent with previous reports, the presence of t(4;14) was associated with shorter PFS and OS. In our series, the presence of t(14;16) did not impact survival, maybe due to limitations in sample size. Del(17p) was linked to poor prognosis using a cut-off level of ≥20% positive cells, without any impact of higher cut-off in prognosis, except for patients with clonal fraction ≥80% who had a dismal outcome. Cosegregation of cytogenetic abnormalities patients worsened the prognosis in t(4;14) patients but not in patients with del(17p), which retained its adverse prognosis even as a solitary abnormality. Gain(1q) was associated with significantly shorter PFS and OS, while del(1p) affected PFS but not OS. Nevertheless, when co-segregation was eliminated, the detrimental effect of +1q or del(1p) was no longer observed. In conclusion, this study confirms the prognostic significance of high-risk cytogenetic abnormalities in MM and highlights the importance of considering co-occurrence for accurate prognosis assessment.

Epigenetic Modeling of Jumping Translocations of 1q Heterochromatin in Acute Myeloid Leukemia After 5'-Azacytidine Treatment

Jumping translocations (JT) are rare cytogenetic abnormalities associated with progression in myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML). Typically, a tri-tetra-somic 1q chromosome is translocated to two or more recipient chromosomes. In multiple myeloma JT were shown to originate after DNA demethylation and decondensation. Using epigenomics, we investigated sequential samples in an SRSF2-mutated MDS and AML cohort with normal karyotype at diagnosis and 1qJT at disease evolution after 5'-azacytidine (AZA). 1qJT breakpoints fell within repetitive DNA at both 1q12 and the translocation partners, namely acrocentrics n. 14, 15, 21, and 22, chromosome 16, and chromosome Y. The global methylome at diagnosis showed hypermethylation at 61% of the differentially methylated regions (DMRs), followed by hypomethylation at 80% of DMRs under AZA, mostly affecting pathways related to immune system, chromatin organization, chromosome condensation, telomere maintenance, rRNA, and DNA repair. At disease evolution, a shift toward hypermethylation, intronic enhancers enrichment and epigenetic involvement of the PI3K/AKT and MAPK signaling emerged. In particular, AKT1 phosphorylation behaved as a hallmark of the progression. Overall, we provided new insights on the characterization of 1qJT in SRSF2-mutated myeloid neoplasms and first showed that epigenetics is a powerful tool to investigate the molecular landscape of repetitive DNA rearrangements.

Spindle Cell Lesions with Oncogenic EGFR Kinase Domain Aberrations: Expanding the Spectrum of Protein Kinase-Related Mesenchymal Tumors

EGFR aberrations are reported in a subset of myofibroblastic lesions with kinase domain duplication (EGFR-KDD) and exon 20 mutations being assigned to infantile fibrosarcomas (IFS), mesoblastic nephroma, and fibrous hamartoma of infancy (FHI), respectively. In this retrospective study, we correlated molecular findings with the histomorphology of 14 myofibroblastic lesions harboring such genetic changes identified by NGS. We additionally performed DNA methylation profiling (DNAmp) and immunohistochemistry. Lesions were from 10 males and 4 females with a mean age of 3 years (range, 0.3-14) and occurred subcutaneously in the upper limbs (n = 5), lower limbs (n = 3), back/thorax (n = 5), and the nasal cavity (n = 1). Eleven were cured by surgery, including 1 relapsed case. Two patients were lost to follow-up. One case was very recent, and the patient was biopsied. Histologically, the lesions showed a wide spectrum varying from classic FHI (n = 9) to IFS (n = 1) or lipofibromatosis-like tumors (LFT-like) (n = 2) or dermatofibrosarcoma protuberans-like (DFSP-like) (n = 1) to a predominantly myxoid spindle cell lesion (n = 1). Immunohistochemically, all neoplasms stained with CD34, whereas S100 was positive in 2/14. EGFR expression was observed in 9/10 cases. Molecularly, the IFS and 1 LFT-like harbored EGFR-KDD, whereas an exon 20 mutation was identified in all FHI, 1 LFT-like, the DFSP-like, and in predominant myxoid spindle cell lesion. By DNAmp, all but 2 cases formed a well-defined cluster, demonstrating that these lesions are also epigenetically related. In conclusion, EGFR kinase domain aberrations found in FHI, IFS, LFT-like, DFSP-like, and a spindle cell lesion with a predominant myxoid stroma of children and adolescents showed that these neoplasms with a broad morphologic spectrum belong to the group of protein kinase-related lesions with a distinct epigenetic signature. Molecular analyses, including DNAmp, help to identify and characterize this emerging category and become mandatory when targeted treatment is considered.

High-risk multiple myeloma: Redefining genetic, clinical, and functional high-risk disease in the era of molecular medicine and immunotherapy

Multiple myeloma (MM) exhibits significant heterogeneity in its presentation, genetics, and treatment response. Despite therapeutic advances, some patients continue to relapse early (ER, <18-months) and rapidly cycle through therapies. Myriad prognostic factors have been identified and incorporated into risk stratification models; however, these produce discordant, often three-tiered outputs that fail to identify many patients destined for ER. Treatment strategies are increasingly focused on disease biology and trials enriched for high-risk (HR)MM, but consensus on the minimum required testing and a succinct, specific, and clinically meaningful definition for HRMM remains elusive. We review the risk-factors, definitions, and future directions for HRMM.

Additional copies of 1q negatively impact the outcome of multiple myeloma patients and induce transcriptomic deregulation in malignant plasma cells

Additional copies of chromosome 1 long arm (1q) are frequently found in multiple myeloma (MM) and predict high-risk disease. Available data suggest a different outcome and biology of patients with amplification (Amp1q, ≥4 copies of 1q) vs. gain (Gain1q, 3 copies of 1q) of 1q. We evaluated the impact of Amp1q/Gain1q on the outcome of newly diagnosed MM patients enrolled in the FORTE trial (NCT02203643). Among 400 patients with available 1q data, 52 (13%) had Amp1q and 129 (32%) Gain1q. After a median follow-up of 62 months, median progression-free survival (PFS) was 21.2 months in the Amp1q group, 54.9 months in Gain1q, and not reached (NR) in Normal 1q. PFS was significantly hampered by the presence of Amp1q (HR 3.34 vs. Normal 1q, P < 0.0001; HR 1.99 vs. Gain1q, P = 0.0008). Patients with Gain1q had also a significantly shorter PFS compared with Normal 1q (HR 1.68, P = 0.0031). Concomitant poor prognostic factors or the failure to achieve MRD negativity predicted a median PFS < 12 months in Amp1q patients. Carfilzomib-lenalidomide-dexamethasone plus autologous stem cell transplantation treatment improved the adverse effect of Gain1q but not Amp1q. Transcriptomic data showed that additional 1q copies were associated with deregulation in apoptosis signaling, p38 MAPK signaling, and Myc-related genes.

Navigating High-Risk and Ultrahigh-Risk Multiple Myeloma: Challenges and Emerging Strategies

Despite significant improvement in the outcomes of patients with newly diagnosed multiple myeloma (NDMM) with novel therapies, there is still an underserved high-risk (HR) population that experiences early disease progression and death. With the median survival crossing 10 years, we defined ultrahigh-risk (uHR)MM as MM leading to death within 24-36 months of diagnosis and HRMM as MM leading to death within 36-60 months. Several features have emerged as markers of uHRMM: the co-occurrence of two or more high-risk cytogenetic abnormalities, extramedullary disease, plasma cell leukemia and a high-risk gene expression profiling signature. The heterogeneous risk definition across trials, the few trials available designed for HR patients, and the small HR subgroups in all-comers trials make it difficult to generate recommendations with high levels of evidence. Nevertheless, regardless of treatment administered, several studies consistently showed that achieving and maintaining measurable residual disease negativity is now considered the main factor able to mitigate the adverse prognosis related to baseline features. For fit patients with HR transplant-eligible (TE) NDMM, quadruplet induction/consolidation treatment with anti-CD38 monoclonal antibodies, immunomodulatory agents, proteasome inhibitors and dexamethasone, and autologous stem-cell transplant and maintenance with, if available, at least a doublet combination could be considered the option of choice. For non-TE NDMM, considering the recent data generated and carefully reviewing those upcoming, quadruplet treatment consisting of anti-CD38 monoclonal antibodies, immunomodulatory agents, proteasome inhibitors, and dexamethasone should also be considered. Future trials integrating BCMA-directed novel generation immunotherapies hold great potential for further advancing the treatment landscape in all NDMM patients with HR disease.

Fluorescence in situ hybridization reveals the evolutionary biology of minor clone of gain/amp(1q) in multiple myeloma

Growing evidence suggests that gain or amplification [gain/amp(1q)] accumulates during disease progression of multiple myeloma (MM). Previous investigations have indicated that small gain/amp(1q) subclones present at the time of diagnosis may evolve into dominant clones upon MM relapse. However, the influence of a minor clone of gain/amp(1q) on MM survival, as well as the correlation between different clonal sizes of gain/amp(1q) and the chromosomal instability (CIN) of MM, remains poorly understood. In this study, we analyzed fluorescence in situ hybridization (FISH) results of 998 newly diagnosed MM (NDMM) patients. 513 patients were detected with gain/amp(1q) at diagnosis. Among these 513 patients, 55 had a minor clone (≤20%) of gain/amp(1q). Patients with a minor clone of gain/amp(1q) displayed similar survival outcomes compared to those without gain/amp(1q). Further analysis demonstrated patients with a minor clone of gain/amp(1q) exhibited a clonal architecture similar to those without gain/amp(1q). Lastly, our results showed a significant increase in the clonal size of the minor clone of gain/amp(1q), frequently observed in MM. These findings suggested that a minor clone of gain/amp(1q) might represent an earlier stage in the pathogenesis of gain/amp(1q) and propose a "two-step" process in the clonal size changes of gain/amp(1q) in MM.

The numerous facets of 1q21+ in multiple myeloma: Pathogenesis, clinicopathological features, prognosis and clinical progress (Review)

Multiple myeloma (MM) is a malignant neoplasm characterized by the clonal proliferation of abnormal plasma cells (PCs) in the bone marrow and recurrent cytogenetic abnormalities. The incidence of MM worldwide is on the rise. 1q21+ has been found in ~30-40% of newly diagnosed MM (NDMM) patients.1q21+ is associated with the pathophysiological mechanisms of disease progression and drug resistance in MM. In the present review, the pathogenesis and clinicopathological features of MM patients with 1q21+ were studied, the key data of 1q21+ on the prognosis of MM patients were summarized, and the clinical treatment significance of MM patients with 1q21+ was clarified, in order to provide reference for clinicians to develop treatment strategies targeting 1q21+.

Approach to High-Risk Multiple Myeloma

Improving the outcome of high-risk myeloma (HRMM) is a key therapeutic aim for the next decade. To achieve this aim, it is necessary to understand in detail the genetic drivers underlying this clinical behavior and to target its biology therapeutically. Advances have already been made, with a focus on consensus guidance and the application of novel immunotherapeutic approaches. Cases of HRMM are likely to have impaired prognosis even with novel strategies. However, if disease eradication and minimal disease states are achieved, then cure may be possible.

Chromosomal defects in multiple myeloma

Multiple myeloma is a plasma cell neoplasm driven by primary (e.g. hyperdiploidy; IGH translocations) and secondary (e.g. 1q21 gains/amplifications; del(17p); MYC translocations) chromosomal events. These are important to detect as they influence prognosis, therapeutic response and disease survival. Currently, cytogenetic testing is most commonly performed by interphase fluorescence in situ hybridisation (FISH) on aspirated bone marrow samples. A number of variations to FISH methodology are available, including prior plasma cell enrichment and incorporation of immunophenotypic plasma cell identification. Other molecular methods are increasingly being utilised to provide a genome-wide view at high resolution (e.g. single nucleotide polymorphism (SNP) microarray analysis) and these can detect abnormalities in most cases. Despite their wide application at diagnostic assessment, both FISH and SNP-array have relatively low sensitivity, limiting their use for identification of prognostically significant low-level sub-clones or for disease monitoring. Next-generation sequencing is increasingly being used to detect mutations and new FISH techniques such as by flow cytometry are in development and may address some of the current test limitations. Here we review the primary and secondary cytogenetic aberrations in myeloma and discuss the range of techniques available for their assessment.

Complex/cryptic EWSR1::FLI1/ERG Gene Fusions and 1q Jumping Translocation in Pediatric Ewing Sarcomas

Ewing sarcomas (ES) are rare small round cell sarcomas often affecting children and characterized by gene fusions involving one member of the FET family of genes (usually EWSR1) and a member of the ETS family of transcription factors (usually FLI1 or ERG). The detection of EWSR1 rearrangements has important diagnostic value. Here, we conducted a retrospective review of 218 consecutive pediatric ES at diagnosis and found eight patients having data from chromosome analysis, FISH/microarray, and gene-fusion assay. Three of these eight ES had novel complex/cryptic EWSR1 rearrangements/fusions by chromosome analysis. One case had a t(9;11;22)(q22;q24;q12) three-way translocation involving EWSR1::FLI1 fusion and 1q jumping translocation. Two cases had cryptic EWSR1 rearrangements/fusions, including one case with a cryptic t(4;11;22)(q35;q24;q12) three-way translocation involving EWSR1::FLI1 fusion, and the other had a cryptic EWSR1::ERG rearrangement/fusion on an abnormal chromosome 22. All patients in this study had various aneuploidies with a gain of chromosome 8 (75%), the most common, followed by a gain of chromosomes 20 (50%) and 4 (37.5%), respectively. Recognition of complex and/or cryptic EWSR1 gene rearrangements/fusions and other chromosome abnormalities (such as jumping translocation and aneuploidies) using a combination of various genetic methods is important for accurate diagnosis, prognosis, and treatment outcomes of pediatric ES.

Multiple Myeloma With Amplification of Chr1q: Therapeutic Opportunity and Challenges

Multiple myeloma (MM) is an incurable plasma cell malignancy with a heterogeneous genetic background. Each MM subtype may have its own therapeutic vulnerabilities, and tailored therapy could improve outcomes. However, the cumulative frequency of druggable targets across patients is very low, which has precluded the widespread adoption of precision therapy for patients with MM. Amplification of the long arm of chromosome 1 (Amp1q) is one of the most frequent genetic alterations observed in patients with MM, and its presence predicts inferior outcomes in the era of proteasome inhibitors and immunomodulatory agents. Therefore, establishing precision medicine for MM patients with Amp1q stands to benefit a large portion of patients who are otherwise at higher risk of relapse. In this article, we review the prevalence and clinical significance of Amp1q in patients with MM, its pathogenesis and therapeutic vulnerabilities, and discuss the opportunities and challenges for Amp1q-targeted therapy.

Chromosome 1 instability in multiple myeloma: Aberrant gene expression, pathogenesis, and potential therapeutic target

Multiple myeloma (MM), the terminally differentiated B cells malignancy, is widely considered to be incurable since many patients have either developed drug resistance or experienced an eventual relapse. To develop precise and efficient therapeutic strategies, we must understand the pathogenesis of MM. Thus, unveiling the driver events of MM and its further clonal evolution will help us understand this complicated disease. Chromosome 1 instabilities are the most common genomic alterations that participate in MM pathogenesis, and these aberrations of chromosome 1 mainly include copy number variations and structural changes. The chromosome 1q gains/amplifications and 1p deletions are the most frequent structural changes of chromosomes in MM. In this review, we intend to focus on the genes that are affected by chromosome 1 instability: some tumor suppressors were lost or down regulated in 1p deletions, and others that contributed to tumorigenesis were upregulated in 1q gains/amplifications. We have summarized their biological function as well as their roles in the MM pathogenesis, hoping to uncover potential novel therapeutical targets and promote the development of future therapeutic approaches.

Genome Instability in Multiple Myeloma: Facts and Factors

Multiple myeloma (MM) is a malignant neoplasm of terminally differentiated immunoglobulin-producing B lymphocytes called plasma cells. MM is the second most common hematologic malignancy, and it poses a heavy economic and social burden because it remains incurable and confers a profound disability to patients. Despite current progress in MM treatment, the disease invariably recurs, even after the transplantation of autologous hematopoietic stem cells (ASCT). Biological processes leading to a pathological myeloma clone and the mechanisms of further evolution of the disease are far from complete understanding. Genetically, MM is a complex disease that demonstrates a high level of heterogeneity. Myeloma genomes carry numerous genetic changes, including structural genome variations and chromosomal gains and losses, and these changes occur in combinations with point mutations affecting various cellular pathways, including genome maintenance. MM genome instability in its extreme is manifested in mutation kataegis and complex genomic rearrangements: chromothripsis, templated insertions, and chromoplexy. Chemotherapeutic agents used to treat MM add another level of complexity because many of them exacerbate genome instability. Genome abnormalities are driver events and deciphering their mechanisms will help understand the causes of MM and play a pivotal role in developing new therapies.

Patient similarity network of newly diagnosed multiple myeloma identifies patient subgroups with distinct genetic features and clinical implications

The remarkable genetic heterogeneity of multiple myeloma poses a substantial challenge for proper prognostication and clinical management of patients. Here, we introduce MM-PSN, the first multiomics patient similarity network of myeloma. MM-PSN enabled accurate dissection of the genetic and molecular landscape of the disease and determined 12 distinct subgroups defined by five data types generated from genomic and transcriptomic profiling of 655 patients. MM-PSN identified patient subgroups not previously described defined by specific patterns of alterations, enriched for specific gene vulnerabilities, and associated with potential therapeutic options. Our analysis revealed that co-occurrence of t(4;14) and 1q gain identified patients at significantly higher risk of relapse and shorter survival as compared to t(4;14) as a single lesion. Furthermore, our results show that 1q gain is the most important single lesion conferring high risk of relapse and that it can improve on the current International Staging Systems (ISS and R-ISS).

Chromosomal 1q21 abnormalities in multiple myeloma: a review of translational, clinical research, and therapeutic strategies

INTRODUCTION

Multiple myeloma (MM) remains an incurable disease with a median overall survival of approximately 5 years. Gain or amplification of 1q21 (1q21+) occurs in around 40% of patients with MM and generally portends a poor prognosis. Patients with MM who harbor 1q21+ are at increased risk of drug resistance, disease progression, and death. New pharmacotherapies with novel modes of action are required to overcome the negative prognostic impact of 1q21+. Areas covered: This review discusses the detection, biology, prognosis, and therapeutic targeting of 1q21+ in newly diagnosed and relapsed MM. Patients with MM and 1q21+ tend to present with higher tumor burden, greater end-organ damage, and more co-occurring high-risk cytogenetic abnormalities than patients without 1q21+. The chromosomal rearrangements associated with 1q21+ result in dysregulation of genes involved in oncogenesis. Identification and characterization of the 1q21+ molecular targets are needed to inform on prognosis and treatment strategy. Clinical trial data are emerging that addition of isatuximab to combination therapies may improve outcomes in patients with 1q21+ MM. Expert opinion: In the next 5 years, the results of ongoing research and trials are likely to focus on the therapeutic impact and treatment decisions associated with 1q21+ in MM.

Copy number evolution and its relationship with patient outcome-an analysis of 178 matched presentation-relapse tumor pairs from the Myeloma XI trial

Structural chromosomal changes including copy number aberrations (CNAs) are a major feature of multiple myeloma (MM), however their evolution in context of modern biological therapy is not well characterized. To investigate acquisition of CNAs and their prognostic relevance in context of first-line therapy, we profiled tumor diagnosis-relapse pairs from 178 NCRI Myeloma XI (ISRCTN49407852) trial patients using digital multiplex ligation-dependent probe amplification. CNA profiles acquired at relapse differed substantially between MM subtypes: hyperdiploid (HRD) tumors evolved predominantly in branching pattern vs. linear pattern in t(4;14) vs. stable pattern in t(11;14). CNA acquisition also differed between subtypes based on CCND expression, with a marked enrichment of acquired del(17p) in CCND2 over CCND1 tumors. Acquired CNAs were not influenced by high-dose melphalan or lenalidomide maintenance randomization. A branching evolution pattern was significantly associated with inferior overall survival (OS; hazard ratio (HR) 2.61, P = 0.0048). As an individual lesion, acquisition of gain(1q) at relapse was associated with shorter OS, independent of other risk markers or time of relapse (HR = 2.00; P = 0.021). There is an increasing need for rational therapy sequencing in MM. Our data supports the value of repeat molecular profiling to characterize disease evolution and inform management of MM relapse.

Chromothripsis as a pathogenic driver of multiple myeloma

Analysis of the genetic basis for multiple myeloma (MM) has informed many of our current concepts of the biology that underlies disease initiation and progression. Studying these events in further detail is predicted to deliver important insights into its pathogenesis, prognosis and treatment. Information from whole genome sequencing of structural variation is revealing the role of these events as drivers of MM. In particular, we discuss how the insights we have gained from studying chromothripsis suggest that it can be used to provide information on disease initiation and that, as a consequence, it can be used for the clinical classification of myeloma precursor diseases allowing for early intervention and prognostic determination. For newly diagnosed MM, the integration of information on the presence of chromothripsis has the potential to significantly enhance current risk prediction strategies and to better characterize patients with high-risk disease biology. In this article we summarize the genetic basis for MM and the role played by chromothripsis as a critical pathogenic factor active at early disease phases.

Chromosome 1q21 abnormalities in multiple myeloma

Gain of chromosome 1q (+1q) is one of the most common recurrent cytogenetic abnormalities in multiple myeloma (MM), occurring in approximately 40% of newly diagnosed cases. Although it is often considered a poor prognostic marker in MM, +1q has not been uniformly adopted as a high-risk cytogenetic abnormality in guidelines. Controversy exists regarding the importance of copy number, as well as whether +1q is itself a driver of poor outcomes or merely a common passenger genetic abnormality in biologically unstable disease. Although the identification of a clear pathogenic mechanism from +1q remains elusive, many genes at the 1q21 locus have been proposed to cause early progression and resistance to anti-myeloma therapy. The plethora of potential drivers suggests that +1q is not only a causative factor or poor outcomes in MM but may be targetable and/or predictive of response to novel therapies. This review will summarize our current understanding of the pathogenesis of +1q in plasma cell neoplasms, the impact of 1q copy number, identify potential genetic drivers of poor outcomes within this subset, and attempt to clarify its clinical significance and implications for the management of patients with multiple myeloma.

Interplay between genome organization and epigenomic alterations of pericentromeric DNA in cancer

In eukaryotic genome biology, the genomic organization inside the three-dimensional (3D) nucleus is highly complex, and whether this organization governs gene expression is poorly understood. Nuclear lamina (NL) is a filamentous meshwork of proteins present at the lining of inner nuclear membrane that serves as an anchoring platform for genome organization. Large chromatin domains termed as lamina-associated domains (LADs), play a major role in silencing genes at the nuclear periphery. The interaction of the NL and genome is dynamic and stochastic. Furthermore, many genes change their positions during developmental processes or under disease conditions such as cancer, to activate certain sorts of genes and/or silence others. Pericentromeric heterochromatin (PCH) is mostly in the silenced region within the genome, which localizes at the nuclear periphery. Studies show that several genes located at the PCH are aberrantly expressed in cancer. The interesting question is that despite being localized in the pericentromeric region, how these genes still manage to overcome pericentromeric repression. Although epigenetic mechanisms control the expression of the pericentromeric region, recent studies about genome organization and genome-nuclear lamina interaction have shed light on a new aspect of pericentromeric gene regulation through a complex and coordinated interplay between epigenomic remodeling and genomic organization in cancer.

How to Treat High-Risk Myeloma at Diagnosis and Relapse

Survival in multiple myeloma has improved greatly during the past 2 decades, but this change has primarily benefited patients who have standard-risk disease. Patients with high-risk disease remain a challenge to diagnose and treat. To improve their clinical outcomes, it is imperative to develop tools to readily identify them and to provide them with the most effective available treatments. The most widely used stratification system, the revised International Staging System, incorporates serum β-2 microglobulin, albumin, lactate dehydrogenase, and high-risk chromosomal abnormalities [del(17p), t(4;14), and t(14;16)]. Recent updates have included mutational status and chromosome 1q abnormalities. Plasma cell leukemia, extramedullary disease, circulating plasma cells, renal failure, and frailty are also associated with poor outcome. The treatment approach for a newly diagnosed patient with high-risk multiple myeloma should include induction therapy, autologous stem cell transplantation if appropriate, and maintenance therapy. Triplet therapy with a proteasome inhibitor, immunomodulatory drug, and steroid, with or without an anti-CD38 antibody, should be considered for induction, along with a proteasome inhibitor and/or immunomodulatory drug for maintenance. Aiming for a deep and sustained response is important. Similar principles apply at relapse, with close monitoring of response, especially extramedullary disease and active management of side effects, so that patients can continue therapy and benefit from treatment. Immune-based therapies, including autologous CAR T-cell-based therapies and bispecific antibodies, show promising activity in relapsed disease and are being actively explored in earlier disease settings. As the prognosis for high-risk disease remains poor, the future goal for this patient group is to develop specific clinical trials to explore novel approaches and therapies efficiently.

Gain/Amplification of Chromosome Arm 1q21 in Multiple Myeloma

Simple Summary

Multiple myeloma (MM), a plasma cell neoplasm, is an incurable hematological malignancy. Gain/amplification of chromosome arm 1q21 (1q21+) is the most common adverse genomic abnormality associated with disease progression and drug resistance. While possible mechanisms of 1q21+ occurrence and candidate genes in the 1q21 amplicon have been suggested, the precise pathogenesis of MM with 1q21+ is unknown. Herein, we review the current knowledge about the clinicopathological features of 1q21+ MM, which can assist in effective therapeutic approaches for MM patients with 1q21+.

Abstract

Multiple myeloma (MM), a plasma cell neoplasm, is an incurable hematological malignancy characterized by complex genetic and prognostic heterogeneity. Gain or amplification of chromosome arm 1q21 (1q21+) is the most frequent adverse chromosomal aberration in MM, occurring in 40% of patients at diagnosis. It occurs in a subclone of the tumor as a secondary genomic event and is more amplified as the tumor progresses and a risk factor for the progression from smoldering multiple myeloma to MM. It can be divided into either 1q21 gain (3 copies) or 1q21 amplification (≥4 copies), and it has been suggested that the prognosis is worse in cases of amplification than gain. Trisomy of chromosome 1, jumping whole-arm translocations of chromosome1q, and tandem duplications lead to 1q21+ suggesting that its occurrence is not consistent at the genomic level. Many studies have reported that genes associated with the malignant phenotype of MM are situated on the 1q21 amplicon, including CKS1B, PSMD4, MCL1, ANP32E, and others. In this paper, we review the current knowledge regarding the clinical features, prognostic implications, and the speculated pathology of 1q21+ in MM, which can provide clues for an effective treatment approach to MM patients with 1q21+.

A Journey Through Myeloma Evolution: From the Normal Plasma Cell to Disease Complexity

The knowledge of cancer origin and the subsequent tracking of disease evolution represent unmet needs that will soon be within clinical reach. This will provide the opportunity to improve patient's stratification and to personalize treatments based on cancer biology along its life history. In this review, we focus on the molecular pathogenesis of multiple myeloma (MM), a hematologic malignancy with a well-known multi-stage disease course, where such approach can sooner translate into a clinical benefit. We describe novel insights into modes and timing of disease initiation. We dissect the biology of the preclinical and pre-malignant phases, elucidating how knowledge of the genomics of the disease and the composition of the microenvironment allow stratification of patients based on risk of disease progression. Then, we explore cell-intrinsic and cell-extrinsic drivers of MM evolution to symptomatic disease. Finally, we discuss how this may relate to the development of refractory disease after treatment. By integrating an evolutionary view of myeloma biology with the recent acquisitions on its clonal heterogeneity, we envision a way to drive the clinical management of the disease based on its detailed biological features more than surrogates of disease burden.

Novel Insights Into Epigenetic Reprogramming and Destabilization of Pericentromeric Heterochromatin in Cancer

Pericentromeric heterochromatin is maintained in a condensed structure by repressive epigenetic control mechanisms and perturbation of these may cause diseases. The chromosome 1q12 region harbors the largest pericentromeric heterochromatin domain in the genome and is among the most common breakpoints in both solid and hematopoietic cancers. Furthermore, the 1q arm is frequently amplified in cancer and this may support tumorigenesis by increasing the dosage of the many oncogenes of this genomic region. Recent studies have provided insight into the mechanisms leading to loss of 1q12 stability and 1q amplification and DNA hypomethylation seems to play a prominent role. This may be the result of decreased activity of DNA methyltransferases and instrumental for 1q12 destabilization or arise secondary to perturbation of other important epigenetic mechanisms that control repression of pericentromeric heterochromatin. Polycomb proteins were recently demonstrated to epigenetically reprogram demethylated 1q12 pericentromeric heterochromatin in premalignant and malignant cells to form large subnuclear structures known as polycomb bodies. This may influence the regulation and stability of 1q12 pericentromeric heterochromatin and/or the distribution of polycomb factors to support tumorigenesis. This review will discuss recent insight into the epigenetic perturbations causing the destabilization of 1q12 pericentromeric heterochromatin and its possible implications for tumor biology.

Genomic Instability in Multiple Myeloma

Genomic instability (GIN), an increased tendency to acquire genomic alterations, is a cancer hallmark. However, its frequency, underlying causes, and disease relevance vary across different cancers. Multiple myeloma (MM), a plasma cell malignancy, evolves through premalignant phases characterized by genomic abnormalities. Next-generation sequencing (NGS) methods are deconstructing the genomic landscape of MM across the continuum of its development, inextricably linking malignant transformation and disease progression with increasing acquisition of genomic alterations, and illuminating the mechanisms that generate these alterations. Although GIN drives disease evolution, it also creates vulnerabilities such as dependencies on 'superfluous' repair mechanisms and the induction of tumor-specific antigens that can be targeted. We review the mechanisms of GIN in MM, the associated vulnerabilities, and therapeutic targeting strategies.

Drug Targeting of Genomic Instability in Multiple Myeloma

Genomic instability can be observed at both chromosomal and chromatin levels. Instability at the macro level includes centrosome abnormalities (CA) resulting in numerical as well as structural chromosomal changes, whereas instability at the micro level is characterized by defects in DNA repair pathways resulting in microsatellite instability (MIN) or mutations. Genomic instability occurs during carcinogenesis without impairing survival and growth, though the precise mechanisms remain unclear. Solid tumors arising from most cells of epithelial origin are characterized by genomic instability which renders them resistant to chemotherapy and radiotherapy. This instability is also observed in 25% of myeloma patients and has been shown to be highly prognostic, independently of the international staging system (ISS). However, a biomarker of aberrant DNA repair and loss of heterozygosity (LOH), was only observed at a frequency of 5% in newly diagnosed patients. Several new molecules targeting the pathways involved in genomic instability are under development and some have already entered clinical trials. Poly(ADP-ribose) polymerase-1 (PARP) inhibitors have been FDA-approved for the treatment of breast cancer type 1 susceptibility protein (BRCA1)-mutated metastatic breast cancer, as well as ovarian and lung cancer. Topoisomerase inhibitors and epigenetic histone modification-targeting inhibitors, such as HDAC (Histone Deacetylase) inhibitors which are novel agents that can target genomic instability. Several of the small molecule inhibitors targeting chromosomal level instability such as PARP, Akt, Aurora kinase, cyclin dependent kinase or spindle kinase inhibitors have been tested in mouse models and early phase I/II trials. ATM, ATR kinase inhibitors and DNA helicase inhibitors are also promising novel agents. However, most of these drugs are not effective as single agents but appear to act synergistically with DNA damaging agents such as radiotherapy, platinum derivatives, immunomodulators, and proteasome inhibitors. In this review, new drugs targeting genomic instability and their mechanisms of action will be discussed.

Jumping translocations of chromosome 1q occurring by a multi-stage process in an acute myeloid leukemia progressed from myelodysplastic syndrome with a TET2 mutation

Background

Jumping translocations (JTs) are rare chromosome rearrangements characterized by re-localization of one donor chromosome to multiple recipient chromosomes. Here, we describe an acute myeloid leukemia (AML) that progressed from myelodysplastic syndrome (MDS) in association with acquisition of 1q JTs. The sequence of molecular and cytogenetic changes in our patient may provide a mechanistic model for the generation of JTs in leukemia.

Case presentation

A 68-year-old man presented with pancytopenia. Bone marrow aspirate and biopsy showed a hypercellular marrow with multilineage dysplasia, consistent with MDS, with no increase in blasts. Karyotype and MDS fluorescence in situ hybridization (FISH) panel were normal. Repeat bone marrow aspirate and biopsy after 8 cycles of azacitidine, with persistent pancytopenia, showed no changes in morphology, and karyotype was again normal. Myeloid mutation panel showed mutations in RUNX1, SRSF2, ASXL1, and TET2. Three years after diagnosis, he developed AML with myelodysplasia-related changes. Karyotype was abnormal, with unbalanced 1q JTs to the short arms of acrocentric chromosomes 14 and 21, leading to gain of 1q.

Conclusions

Our patient had MDS with pathogenic mutations of the RUNX1, SRSF2, ASXL1, and TET2 genes and developed 1q JTs at the time of progression from MDS to AML. Our data suggest that the formation of 1q JTs involves multiple stages and may provide a mechanistic model for the generation of JTs in leukemia.