European Myeloma Network recommendations on tools for the diagnosis and monitoring of multiple myeloma: what to use and when

Optimal cut-off values and diagnostic significance of clinical laboratory indicators in newly diagnosed multiple myeloma

OBJECTIVE

This study aims to identify clinical laboratory parameters for the diagnosis of newly diagnosed multiple myeloma (NDMM), establish optimal cutoffs for early screening, and develop a diagnostic model for precise diagnosis.

METHODS

The study conducted a retrospective analysis of 279 NDMM patients and 553 healthy subjects at Zhejiang Province People's Hospital between January 2008 and June 2023. Multifactor LR was employed to explore clinical laboratory indicators with diagnostic value for NDMM, determine optimal cutoff values and contract a diagnostic model. The diagnostic efficacy and clinical utility were evaluated using receiver operating characteristic curves (ROC), sensitivity, specificity, and other indicators.

RESULTS

Multifactor analysis revealed that hemoglobin (Hb), albumin (Alb), and platelet distribution width (PDW) were significant diagnostic factors for NDMM. Optimal cutoff values for Hb, Alb, and PDW in MM diagnosis were determined, and the results showed a significant increase in the probability of NDMM diagnosis when Alb was below 39.3 g/L, Hb was below 11.6 g/dL, and PDW was below 14.1 fL. The diagnostic model constructed from the development cohort demonstrated a high area under the ROC curve of 0.960 (95% CI 0.942-0.978) and exhibited good sensitivity (0.860), specificity (0.957). The area under the curve (AUC) value of the diagnostic model in the external validation cohort was 0.979, confirming its good diagnostic efficacy and generalization.

CONCLUSIONS

The optimal cutoff values for Hb, Alb, and PDW and the diagnostic model designed in the study provided good accuracy and sensitivity for the initial screening and diagnosis of NDMM.

EANM guidelines on the use of [18F]FDG PET/CT in diagnosis, staging, prognostication, therapy assessment, and restaging of plasma cell disorders

We provide updated guidance and standards for the indication, acquisition, and interpretation of [18F]FDG PET/CT for plasma cell disorders. Procedures and characteristics are reported and different scenarios for the clinical use of [18F]FDG PET/CT are discussed. This document provides clinicians and technicians with the best available evidence to support the implementation of [18F]FDG PET/CT imaging in routine practice and future research.

Detection of myeloma-associated osteolytic bone lesions with energy-integrating and photon-counting detector CT

BACKGROUND

A recent innovation in computed tomography (CT) imaging has been the introduction of photon-counting detector CT (PCD-CT) systems, which are able to register the number and the energy level of incoming x‑ray photons and have smaller detector elements compared with conventional CT scanners that operate with energy-integrating detectors (EID-CT).

OBJECTIVES

The study aimed to evaluate the potential benefits of a novel, non-CE certified PCD-CT in detecting myeloma-associated osteolytic bone lesions (OL) compared with a state-of-the-art EID-CT.

MATERIALS AND METHODS

Nine patients with multiple myeloma stage III (according to Durie and Salmon) underwent magnetic resonance imaging (MRI), EID-CT, and PCD-CT of the lower lumbar spine and pelvis. The PCD-CT and EID-CT images of all myeloma lesions that were visible in clinical MRI scans were reviewed by three radiologists for corresponding OL. Additionally, the visualization of destructions to cancellous or cortical bone, and trabecular structures, was compared between PCD-CT and EID-CT.

RESULTS

Readers detected 21% more OL in PCD-CT than in EID-CT images (138 vs. 109; p < 0.0001). The sensitivity advantage of PCD-CT in lesion detection increased with decreasing lesion size. The visualization quality of cancellous and cortical destructions as well as of trabecular structures was rated higher by all three readers in PCD-CT images (mean image quality improvements for PCD-CT over EID-CT were +0.45 for cancellous and +0.13 for cortical destructions).

CONCLUSIONS

For myeloma-associated OL, PCD-CT demonstrated significantly higher sensitivity, especially with small size. Visualization of bone tissue and lesions was considered significantly better in PCD-CT than in EID-CT. This implies that PCD-CT scanners could potentially be used in the early detection of myeloma-associated bone lesions.

Isatuximab-Specific Immunofixation Electrophoresis Assay to Remove Interference in Serum M-Protein Measurement in Patients with Multiple Myeloma

BACKGROUND

Isatuximab, an IgG-kappa (IgGκ) anti-cluster of differentiation 38 (CD38) monoclonal antibody approved for use in patients with relapsed or refractory multiple myeloma (MM), can potentially interfere with the visualization of endogenous monoclonal protein (M-protein) on standard immunofixation electrophoresis (IFE) and lead to inaccurate classification of a patient's response to therapy. The Hydrashift 2/4 isatuximab IFE assay (Hydrashift isatuximab assay) removes isatuximab interference from IFE. Using samples from patients enrolled in clinical trials of isatuximab-based therapy for MM, we demonstrate how the Hydrashift isatuximab assay improves the ability to detect residual M-protein and offer recommendations for when the assay is most useful.

METHODS

Samples from 141 patients with a variety of known M-protein isotypes were selected and analyzed by standard IFE and the Hydrashift isatuximab assay. A positive control containing isatuximab was run on every standard IFE and Hydrashift gel.

RESULTS

The Hydrashift isatuximab assay reliably shifted the migration of isatuximab in patient samples. Standard IFE was adequate for determining 104 patients' M-protein status, and the Hydrashift isatuximab assay confirmed these results. In samples from 37 patients with a history of IgGκ MM and a single IgGκ band visible on standard IFE near the isatuximab migration site, the Hydrashift isatuximab assay was able to separate isatuximab from endogenous M-protein, identifying residual M-protein in 17 samples and preventing false-positive interpretations of standard IFE in 20 samples.

CONCLUSIONS

The Hydrashift isatuximab assay is most useful in patients with known IgGκ MM when a single IgGκ band appears near the isatuximab migration site on standard IFE during isatuximab-based therapy.

CLINICALTRIALS.GOV REGISTRATION NUMBERS

NCT03275285 and NCT03319667.

A Combined Cyto- and Histopathological Diagnostic Approach Reduces Time to Diagnosis and Time to Therapy in First Manifestation of Metastatic Spinal Disease: A Cohort Study

Malignant spinal lesions (MSLs) are frequently the first manifestation of malignant disease. Spinal care, diagnostic evaluation, and the initiation of systemic therapy are crucial for outcomes in patients (pts) with advanced cancer. However, histopathology (HP) may be time consuming. The additional evaluation of spinal lesions using cytopathology (CP) has the potential to reduce the time to diagnosis (TTD) and time to therapy (TTT). CP and HP specimens from spinal lesions were evaluated in parallel in 61 pts (CP/HP group). Furthermore, 139 pts in whom only HP was performed were analyzed (HP group). We analyzed the TTD of CP and HP within the CP/HP group. Furthermore, we compared the TTD and TTT between the groups. The mean TTD in CP was 1.7 ± 1.7 days (d) and 8.4 ± 3.6 d in HP (p < 0.001). In 13 pts in the CP/HP group (24.1%), specific therapy was initiated based on the CP findings in combination with imaging and biomarker results before completion of HP. The mean TTT in the CP/HP group was 21.0 ± 15.8 d and was significantly shorter compared to the HP group (28.6 ± 23.3 d) (p = 0.034). Concurrent CP for MSLs significantly reduces the TTD and TTT. As a result, incorporating concurrent CP for analyzing spinal lesions suspected of malignancy might have the potential to enhance pts' quality of life and prognosis in advanced cancer. Therefore, we recommend implementing CP as a standard procedure for the evaluation of MSLs.

Prognostic Implications of Circulating Plasma Cell Percentage in Multiple Myeloma and Primary Plasma Cell Leukemia Defined by New Criteria

INTRODUCTION

The definition of primary plasma cell leukemia (pPCL) has been revised from ≥20% to ≥5% circulating plasma cells (CPC). However, the precise prognosis associated with CPC remains controversial. This study aimed to investigate prognostic biomarkers for myeloma patients based on CPC presence.

METHODS

A comprehensive analysis was conducted on 309 consecutive patients diagnosed with either multiple myeloma or pPCL, utilizing peripheral blood smears stained with Wright-Giemsa.

RESULTS

Patients were grouped by CPC percentage: 0% (221, 71.5%), 1-4% (49, 15.9%), 5-19% (16, 5.2%), ≥20% (23, 7.4%). CPC >5% correlated with unfavorable characteristics, including anemia, renal dysfunction, and advanced International Staging System. Common cytogenetic abnormalities such as 1q21 amplification, 17p deletion, and Myc rearrangement were prevalent among CPC-positive patients. Median progression-free survival (PFS) and overall survival (OS) were shorter in patients with CPC ≥5% (29.47 vs. 10.03 months; 64.10 vs. 12.30 months). Additionally, PFS and OS were shorter in CPC-positive patients without autologous hematopoietic stem cell transplantation (ASCT) and those with response < partial remission to the first-line regimen. Furthermore, an association emerged between soft tissue-related extramedullary disease and inferior PFS, while Myc rearrangement correlated with abbreviated OS.

CONCLUSION

Biological characteristics displayed greater aggressiveness in patients with positive CPC, leading to significantly shorter PFS and OS. The presence of CPC, ASCT, and overall response rate were independent prognostic factors. While no new threshold for pPCL with CPCs is proposed, Myc rearrangements and CPC positivity could serve as ultra-high-risk factors for multiple myeloma.

Effect of multidisciplinary cooperative continuous nursing and psychological nursing on multiple myeloma with a peripherally inserted central catheter

Objective: This study was conducted to analyze the effectiveness of multidisciplinary cooperative continuous nursing combined with psychological nursing intervention in multiple myeloma (MM) patients undergoing peripherally inserted central catheter (PICC). Methods: The Numerical Pain Rating Scale (NPRS), Anxiety Self-Assessment Scale (SAS), Depression Self-Assessment Scale (SDS) and Revised Piper Fatigue Scale (PFS-R), Self-Care Ability Scale (ESCA), Quality of Life Core Questionnaire (QLQ-C30), incidence of unplanned extubation of PICC, total incidence of catheter-related complications and satisfaction with nursing were compared between the two groups of patients in a prospective study. Results: Patients in the observation group had reduced NPRS, SAS, SDS and PFS-R scores, total incidence of unplanned extubation of PICC and the total incidence of catheter-related complications, and a higher nursing satisfaction rate in comparison to those in the control group. Conclusion: Multidisciplinary cooperative continuous nursing combined with psychological nursing interventions can relieve pain in MM patients.

Rheological properties of blood in multiple myeloma patients

Multiple myeloma (MM) is considered to be one of the hematological malignancies formed by excessive and abnormal proliferation of plasmocytes. Among other parameters, several blood tests are used to diagnose multiple myeloma. The hemorheological profile in multiple myeloma is not widely studied. Hemorheology includes the study of measuring the deformability and aggregation of erythrocytes, blood viscosity, and sedimentation rate. The degree of deformability of blood cells is necessary to maintain proper vital functions. Proper deformability of red blood cells ensures proper blood circulation, tissue oxidation and carbon dioxide uptake. The aim of the study was to compare morphology and blood rheology parameters in patients with MM and healthy individuals. The study included 33 patients with MM, and 33 healthy subjects of the same age. The hematological blood parameters were evaluated using ABX MICROS 60 hematology analyzer. The LORCA Analyzer to study erythrocyte aggregation and deformability. Patients with MM had lower red blood cells count (RBC) (9.11%) (p < 0.001) and half time of total aggregation (T1/2) (94.29%) (p < 0.001) values and higher mean corpuscular volume (MCV) (5.50%) (p < 0.001), aggregation index (AI) (68.60%) (p < 0.001), total extent of aggregation (AMP) (87.92%) (p < 0.001) values than the healthy control group. Aggregation in patients with MM is different compared to healthy individuals. It was observed that the percentage of cell aggregation is almost 50% higher than in the control group. The study of morphology, aggregation and deformability of erythrocytes in patients with suspected MM may be helpful in making clinical decisions.

Exploring the causal relationship between gut microbiota and multiple myeloma risk based on Mendelian randomization and biological annotation

Introduction

The microbial genome-wide association studies (mbGWAS) have highlighted significant host-microbiome interactions based on microbiome heritability. However, establishing causal relationships between particular microbiota and multiple myeloma (MM) remains challenging due to limited sample sizes.

Methods

Gut microbiota data from a GWAS with 18,340 participants and MM summary statistics from 456,348 individuals. The inverse variance-weighted (IVW) method was used as the main bidirectional Mendelian randomization (MR) analysis. To assess the robustness of our results, we further performed supplementary analyses, including MR pleiotropy residual sum and outlier (MR-PRESSO) test, MR-Egger, Weighted median, Simple mode, and Weighted mode. Moreover, a backward MR analysis was conducted to investigate the potential for reverse causation. Finally, gene and gene-set-based analyses were then conducted to explore the common biological factors connecting gut microbiota and MM.

Results

We discovered that 10 gut microbial taxa were causally related to MM risk. Among them, family Acidaminococcaceae, Bacteroidales family S24-7, family Porphyromonadaceae, genus Eubacterium ruminantium group, genus Parabacteroides, and genus Turicibacter were positively correlated with MM. Conversely, class Verrucomicrobia, family Verrucomicrobiaceae, genus Akkermansia, and order Verrucomicrobiales were negatively correlated with MM. The heterogeneity test revealed no Heterogeneity. MR-Egger and MR-PRESSO tests showed no significant horizontal pleiotropy. Importantly, leave-one-out analysis confirmed the robustness of MR results. In the backward MR analysis, no statistically significant associations were discovered between MM and 10 gut microbiota taxa. Lastly, we identified novel host-microbiome shared genes (AUTS2, CDK2, ERBB3, IKZF4, PMEL, SUOX, and RAB5B) that are associated with immunoregulation and prognosis in MM through biological annotation.

Discussion

Overall, this study provides evidence supporting a potential causal relationship between gut microbiota and MM risk, while also revealing novel host-microbiome shared genes relevant to MM immunoregulation and clinical prognosis.

Laboratory practice is central to earlier myeloma diagnosis: Utilizing a primary care diagnostic tool and laboratory guidelines integrated into haematology services

Treatment advances have greatly improved survival, but myeloma is among the worst of all cancers for delayed diagnosis, causing serious morbidities and early deaths. This delay is largely because the symptom profile of myeloma has very low specificity, and in primary care, myeloma is rare. However, initiating the journey to diagnosis simply requires considering myeloma and sending blood to test for monoclonal immunoglobulin. Laboratory tests reliably detect monoclonal immunoglobulin, which is present in 99% of myeloma cases, so why do health care systems have such a problem with delayed diagnosis? The Myeloma UK early diagnosis programme has brought together diverse expertise to investigate this problem, and this article was prepared by the programme's working group for laboratory best practice. It reviews evidence for test requesting, analysis and reporting, for which there is large variation in practice across the United Kingdom. It presents a 'GP Myeloma diagnostic tool' and how it can be integrated into laboratory practice alongside a laboratory best practice tool. It proposes improved requesting and integration with haematology services for reporting and interpretation. Here the laboratory has a central role in creating efficient and cost-effective pathways for appropriate and timely bone marrow examination for myeloma diagnosis.

IGH::NSD2 Fusion Gene Transcript as Measurable Residual Disease Marker in Multiple Myeloma

Multiple myeloma (MM) is the second most common hematological malignancy. Approximately 15% of MM patients are affected by the t(4;14) translocation resulting in the IGH::NSD2 fusion transcript. Breakage occurs in three major breakpoint regions within the NSD2 gene (MB4-1, MB4-2, and MB4-3), where MB4-1 leads to the production of full-length protein, while truncated proteins are expressed in the other two cases. Measurable residual disease (MRD) has been conclusively established as a crucial prognostic factor in MM. The IGH::NSD2 fusion transcript can serve as a sensitive MRD marker. Using bone marrow (BM) and peripheral blood (PB) samples from 111 patients, we developed a highly sensitive quantitative real-time PCR (qPCR) and digital PCR (dPCR) system capable of detecting fusion mRNAs with a sensitivity of up to 1:100,000. PB samples exhibited sensitivity three orders of magnitude lower compared to BM samples. Patients with an MB4-2 breakpoint demonstrated significantly reduced overall survival (p = 0.003). Our novel method offers a simple and sensitive means for detecting MRD in a substantial proportion of MM patients. Monitoring may be carried out even from PB samples. The literature lacks consensus regarding survival outcomes among patients with different NSD2 breakpoints. Our data align with previous findings indicating that patients with the MB4-2 breakpoint type tend to exhibit unfavorable overall survival.

Exploring the molecular biomarker utility of circCCT3 in multiple myeloma: A favorable prognostic indicator, particularly for R-ISS II patients

Circular RNAs (circRNAs) are associated with the pathobiology of multiple myeloma (MM). Recent findings regarding circCCT3 support its involvement in the development and progression of MM, through microRNA sponging. Thus, we aimed to examine the expression of circCCT3 in smoldering and symptomatic MM and to assess its clinical importance. Three cell lines from plasma cell neoplasms were cultured and bone marrow aspirate (BMA) samples were collected from 145 patients with MM or smoldering MM. Next, CD138+ enrichment was performed in BMA samples, followed by total RNA extraction and reverse transcription. Preamplification of circCCT3 and GAPDH cDNA was performed. Finally, a sensitive assay for the relative quantification of circCCT3 using nested real-time quantitative polymerase chain reaction was developed, optimized, and implemented in the patients' samples and cell lines. MM patients exhibited significantly higher intracellular circCCT3 expression in their CD138+ plasma cells, compared to those from SMM patients. In addition, MM patients overexpressing circCCT3 had longer progression-free and overall survival intervals. The favorable prognostic significance of high circCCT3 expression in MM was independent of disease stage (either International Staging System [ISS] or revised ISS [R-ISS]) and age of MM patients. Interestingly, circCCT3 expression could serve as a surrogate molecular biomarker of prognosis in MM patients, especially those of R-ISS stage II. In conclusion, our study sheds new light on the significance of circCCT3 as a promising molecular marker for predicting MM patients' prognosis.

Resolution of dysglycaemia after treatment of monoclonal gammopathy of endocrine significance

In very rare cases of monoclonal gammopathy, insulin-binding paraprotein can cause disabling hypoglycaemia. We report a 67-year-old man re-evaluated for hyperinsulinaemic hypoglycaemia that persisted despite distal pancreatectomy. He had no medical history of diabetes mellitus or autoimmune disease but was being monitored for an IgG kappa monoclonal gammopathy of undetermined significance. On glucose tolerance testing, hyperglycaemia occurred at 60 min (glucose 216 mg/dL) and hypoglycaemia at 300 min (52 mg/dL) concurrent with an apparent plasma insulin concentration of 52 850 pmol/L on immunoassay. Laboratory investigation revealed an IgG2 kappa with very high binding capacity but low affinity (Kd 1.43 × 10-6 mol/L) for insulin. The monoclonal gammopathy was restaged as smouldering myeloma not warranting plasma cell-directed therapy from a haematological standpoint. Plasma exchange reduced paraprotein levels and improved fasting capillary glucose concentrations. Lenalidomide was used to treat disabling hypoglycaemia, successfully depleting paraprotein and leading to resolution of symptoms.

Lymphomas and Amyloid in the Gastrointestinal Tract

Lymphoproliferative disorders are a heterogeneous group of neoplasms with varying clinical, morphologic, immunophenotypic, and genetic characteristics. A subset of lymphomas have a proclivity for the gastrointestinal tract, although this region may also be involved by systemic lymphomas. In addition, a number of indolent lymphoproliferative disorders of the gastrointestinal tract have been defined over the past decade, and it is important to accurately differentiate these neoplasms to ensure that patients receive the proper management. Here, the authors review lymphoid neoplasms that show frequent gastrointestinal involvement and provide updates from the recent hematolymphoid neoplasm classification systems.

Impact of Photon-Counting Detector Computed Tomography on Image Quality and Radiation Dose in Patients With Multiple Myeloma

OBJECTIVE

Computed tomography (CT) is an established method for the diagnosis, staging, and treatment of multiple myeloma. Here, we investigated the potential of photon-counting detector computed tomography (PCD-CT) in terms of image quality, diagnostic confidence, and radiation dose compared with energy-integrating detector CT (EID-CT).

MATERIALS AND METHODS

In this prospective study, patients with known multiple myeloma underwent clinically indicated whole-body PCD-CT. The image quality of PCD-CT was assessed qualitatively by three independent radiologists for overall image quality, edge sharpness, image noise, lesion conspicuity, and diagnostic confidence using a 5-point Likert scale (5 = excellent), and quantitatively for signal homogeneity using the coefficient of variation (CV) of Hounsfield Units (HU) values and modulation transfer function (MTF) via the full width at half maximum (FWHM) in the frequency space. The results were compared with those of the current clinical standard EID-CT protocols as controls. Additionally, the radiation dose (CTDIvol) was determined.

RESULTS

We enrolled 35 patients with multiple myeloma (mean age 69.8 ± 9.1 years; 18 [51%] males). Qualitative image analysis revealed superior scores (median [interquartile range]) for PCD-CT regarding overall image quality (4.0 [4.0-5.0] vs. 4.0 [3.0-4.0]), edge sharpness (4.0 [4.0-5.0] vs. 4.0 [3.0-4.0]), image noise (4.0 [4.0-4.0] vs. 3.0 [3.0-4.0]), lesion conspicuity (4.0 [4.0-5.0] vs. 4.0 [3.0-4.0]), and diagnostic confidence (4.0 [4.0-5.0] vs. 4.0 [3.0-4.0]) compared with EID-CT (P ≤ 0.004). In quantitative image analyses, PCD-CT compared with EID-CT revealed a substantially lower FWHM (2.89 vs. 25.68 cy/pixel) and a significantly more homogeneous signal (mean CV ± standard deviation [SD], 0.99 ± 0.65 vs. 1.66 ± 0.5; P < 0.001) at a significantly lower radiation dose (mean CTDIvol ± SD, 3.33 ± 0.82 vs. 7.19 ± 3.57 mGy; P < 0.001).

CONCLUSION

Whole-body PCD-CT provides significantly higher subjective and objective image quality at significantly reduced radiation doses than the current clinical standard EID-CT protocols, along with readily available multi-spectral data, facilitating the potential for further advanced post-processing.

Identifying novel mechanisms of biallelic TP53 loss refines poor outcome for patients with multiple myeloma

Biallelic TP53 inactivation is the most important high-risk factor associated with poor survival in multiple myeloma. Classical biallelic TP53 inactivation has been defined as simultaneous mutation and copy number loss in most studies; however, numerous studies have demonstrated that other factors could lead to the inactivation of TP53. Here, we hypothesized that novel biallelic TP53 inactivated samples existed in the multiple myeloma population. A random forest regression model that exploited an expression signature of 16 differentially expressed genes between classical biallelic TP53 and TP53 wild-type samples was subsequently established and used to identify novel biallelic TP53 samples from monoallelic TP53 groups. The model reflected high accuracy and robust performance in newly diagnosed relapsed and refractory populations. Patient survival of classical and novel biallelic TP53 samples was consistently much worse than those with mono-allelic or wild-type TP53 status. We also demonstrated that some predicted biallelic TP53 samples simultaneously had copy number loss and aberrant splicing, resulting in overexpression of high-risk transcript variants, leading to biallelic inactivation. We discovered that splice site mutation and overexpression of the splicing factor MED18 were reasons for aberrant splicing. Taken together, our study unveiled the complex transcriptome of TP53, some of which might benefit future studies targeting abnormal TP53.

Identification of druggable genes for multiple myeloma based on genomic information

Multiple myeloma (MM) is a hematological malignancy. It is widely believed that genetic factors play a significant role in the development of MM, as investigated in numerous studies. However, the application of genomic information for clinical purposes, including diagnostic and prognostic biomarkers, remains largely confined to research. In this study, we utilized genetic information from the Genomic-Driven Clinical Implementation for Multiple Myeloma database, which is dedicated to clinical trial studies on MM. This genetic information was sourced from the genome-wide association studies catalog database. We prioritized genes with the potential to cause MM based on established annotations, as well as biological risk genes for MM, as potential drug target candidates. The DrugBank database was employed to identify drug candidates targeting these genes. Our research led to the discovery of 14 MM biological risk genes and the identification of 10 drugs that target three of these genes. Notably, only one of these 10 drugs, panobinostat, has been approved for use in MM. The two most promising genes, calcium signal-modulating cyclophilin ligand (CAMLG) and histone deacetylase 2 (HDAC2), were targeted by four drugs (cyclosporine, belinostat, vorinostat, and romidepsin), all of which have clinical evidence supporting their use in the treatment of MM. Interestingly, five of the 10 drugs have been approved for other indications than MM, but they may also be effective in treating MM. Therefore, this study aimed to clarify the genomic variants involved in the pathogenesis of MM and highlight the potential benefits of these genomic variants in drug discovery.

Proteasome inhibition in combination with immunotherapies: State-of-the-Art in multiple myeloma

Multiple myeloma (MM) is a malignant plasma cell disorder accounting for around 1.8% of all neoplastic diseases. Nowadays, clinicians have a broad arsenal of drugs at their disposal for the treatment of MM, such as proteasome inhibitors, immunomodulatory drugs, monoclonal antibodies, bispecific antibodies, CAR T-cell therapies and antibody-drug conjugates. In this paper we briefly highlight essential clinical elements relating to proteasome inhibitors, such as bortezomib, carfilzomib and ixazomib. Studies suggest that the early use of immunotherapy may improve outcomes significantly. Therefore, in our review we specifically focus on the combination therapy of proteasome inhibitors with novel immunotherapies and/or transplant. A high number of patients develop PI resistance. Thus, we also review new generation PIs, such as marizomib, oprozomib (ONX0912) and delanzomib (CEP-18770) and their combinations with immunotherapies.

Consensus for Flow Cytometry Clinical Report on Multiple Myeloma: A Multicenter Harmonization Process Merging Laboratory Experience and Clinical Needs

Flow cytometry is a highly sensitive and specific approach for discriminating between normal and clonal plasma cells in multiple myeloma. Uniform response criteria after treatment have been established by the International Myeloma Working Group and the EuroFlow Group; however, the way in which flow cytometry data are reported has suffered from no collaborative or multicentre efforts. This study, involving 8 expert laboratories and 12 clinical hematology units of the Lazio region in Italy, aims to produce a uniform and shared report among the various Centres. From the pre-analytical phase to sample processing, data acquisition, analysis, and evaluation of the potential limitations and pitfalls of the entire process, the study reaches a final conclusion shared by laboratories and clinicians according to the most updated principles and recommendations. The aim was to identify the necessary data to be included in the clinical report by using multiple-choice questionnaires at every single stage of the process. An agreement of more than 75% of the laboratories was considered mandatory for the data to be included in the report. By ensuring the operational autonomy of each laboratory, this study provides a clear report that limits subjective interpretations and highlights possible bias in the process, better supporting clinical decision-making.

Elkourahy Omar S. Treatment of Multiple Myeloma in the First Relapse

The treatment scope for relapsed myeloma has been expanded considerably in the last few years, by virtue of the advent of numerous novel agents with new mechanisms of actions. This has resulted in increasing responses and prolonging survival even in advanced diseases. The wealth of novel regimens comes with the challenges of balancing toxicities and aligning a regimen with the biology of myeloma and the nature of relapse in conjunction with the patient’s treatment history, comorbidities, and personal preference. The second-line treatment in myeloma includes new generation of proteasome inhibitors and immunomodulators, CD38 monoclonal antibodies, Panobinostat, and Elotuzumab. Recent randomized trials have shown that triplet combinations incorporating CD38 monoclonal antibodies, dexamethasone along with either proteasome inhibitor or immunomodulator were superior to doublet combinations in terms of response rate and progression-free survival. The choice of the second-line therapy is determined by lenalidomide/bortezomib exposure and resistance and access to new agents. Furthermore, autologous transplantation should be considered in selected cases. Here, we will be discussing the optimal management of multiple myeloma in the first relapse.

Amp(1q) and tetraploidy are commonly acquired chromosomal abnormalities in relapsed multiple myeloma

Long-term disease control in multiple myeloma (MM) is typically an unmet medical need, and most patients experience multiple relapses. Fluorescence in situ hybridization (FISH) is the standard technique to detect chromosomal abnormalities (CAs), which are important to estimate the prognosis of MM and the allocation of risk adapted therapies. In advanced stages, the importance of CAs needs further investigation. From 148 MM patients, two or more paired samples, at least one of which was collected at relapse, were analyzed by FISH. Using targeted next-generation sequencing, we molecularly investigated samples harboring relapse-associated CAs. Sixty-one percent of the patients showed a change in the cytogenetic profile during the disease course, including 10% who acquired high-risk cytogenetics. Amp(1q) (≥4 copies of 1q21), driven by an additional increase in copy number in patients who already had 3 copies of 1q21, was the most common acquired CA with 16% affected patients. Tetraploidy, found in 10% of the samples collected at the last time-point, was unstable over the course of the disease and was associated with TP53 lesions. Our results indicate that cytogenetic progression is common in relapsed patients. The relatively high frequency of amp(1q) suggests an active role for this CA in disease progression.

High-risk multiple myeloma predicted by circulating plasma cells and its genetic characteristics

Introduction

Circulating plasma cells (CPC) have been reported to be one of the indicators of high-risk multiple myeloma (MM), yet the prognostic significance of CPC in Chinese population and the genetic mechanisms underlying CPC formation have not been fully elucidated.

Methods

Patients with newly diagnosed MM were included in this study. We used multi-parameter flow cytometry (MFC) for CPC quantification and next-generation sequencing (NGS) technology for mutational landscape mapping to identify the correlation of CPC level with clinical characteristics and the mutations.

Results

A total of 301 patients were enrolled in this investigation. We demonstrated that CPC quantification could effectively mirror the tumor load, and CPC ≥ 0.105% at diagnosis or detectable CPC after therapy indicates poor treatment response and adverse outcome, and the introduction of CPC into the R-ISS enables a more accurate risk stratification. Interestingly, we noticed an elevated percentage of light-chain MM in patients with higher CPC. Mutational landscape revealed that patients harboring mutations in TP53, BRAF, DNMT3A, TENT5C, and IL-6/JAK/STAT3 pathway-related genes tended to have higher CPC levels. Gene enrichment analysis demonstrated that pathways involving chromosome regulation and adhesion may be potential mechanisms accounting for CPC formation.

Discussion

Accordingly, quantification of CPC may provide a less-invasive and reliable approach for identifying high-risk MM in Chinese population.

Combining Deep Learning and Radiomics for Automated, Objective, Comprehensive Bone Marrow Characterization From Whole-Body MRI: A Multicentric Feasibility Study

OBJECTIVES

Disseminated bone marrow (BM) involvement is frequent in multiple myeloma (MM). Whole-body magnetic resonance imaging (wb-MRI) enables to evaluate the whole BM. Reading of such whole-body scans is time-consuming, and yet radiologists can transfer only a small fraction of the information of the imaging data set to the report. This limits the influence that imaging can have on clinical decision-making and in research toward precision oncology. The objective of this feasibility study was to implement a concept for automatic, comprehensive characterization of the BM from wb-MRI, by automatic BM segmentation and subsequent radiomics analysis of 30 different BM spaces (BMS).

MATERIALS AND METHODS

This retrospective multicentric pilot study used a total of 106 wb-MRI from 102 patients with (smoldering) MM from 8 centers. Fifty wb-MRI from center 1 were used for training of segmentation algorithms (nnU-Nets) and radiomics algorithms. Fifty-six wb-MRI from 8 centers, acquired with a variety of different MRI scanners and protocols, were used for independent testing. Manual segmentations of 2700 BMS from 90 wb-MRI were performed for training and testing of the segmentation algorithms. For each BMS, 296 radiomics features were calculated individually. Dice score was used to assess similarity between automatic segmentations and manual reference segmentations.

RESULTS

The "multilabel nnU-Net" segmentation algorithm, which performs segmentation of 30 BMS and labels them individually, reached mean dice scores of 0.88 ± 0.06/0.87 ± 0.06/0.83 ± 0.11 in independent test sets from center 1/center 2/center 3-8 (interrater variability between radiologists, 0.88 ± 0.01). The subset from the multicenter, multivendor test set (center 3-8) that was of high imaging quality was segmented with high precision (mean dice score, 0.87), comparable to the internal test data from center 1. The radiomic BM phenotype consisting of 8880 descriptive parameters per patient, which result from calculation of 296 radiomics features for each of the 30 BMS, was calculated for all patients. Exemplary cases demonstrated connections between typical BM patterns in MM and radiomic signatures of the respective BMS. In plausibility tests, predicted size and weight based on radiomics models of the radiomic BM phenotype significantly correlated with patients' actual size and weight ( P = 0.002 and P = 0.003, respectively).

CONCLUSIONS

This pilot study demonstrates the feasibility of automatic, objective, comprehensive BM characterization from wb-MRI in multicentric data sets. This concept allows the extraction of high-dimensional phenotypes to capture the complexity of disseminated BM disorders from imaging. Further studies need to assess the clinical potential of this method for automatic staging, therapy response assessment, or prediction of biopsy results.

A Novel Integrated Approach for Cytogenomic Evaluation of Plasma Cell Neoplasms

Plasma cell neoplasm (PCN) is associated with characteristic chromosomal aberrations of diagnostic and prognostic significance. The presence of a small percentage of neoplastic cells is a drawback in the application of karyotyping and fluorescence in situ hybridization for the evaluation of bone marrow aspirate. The analysis of samples enriched for CD138⁺ cells has improved the detection rate. However, fluorescence in situ hybridization requires several probes and may not be completed due to a limited number of isolated cells. To address the issues experienced with the conventional approach, a novel integrated protocol that consists of whole-genome amplification of DNA isolated from CD138⁺ cells, followed by microarray as well as one fluorescence in situ hybridization assay for balanced IGH gene rearrangements, has been developed. In the present study in a cohort of 56 patients with clinical suspicion for PCN, compared to conventional cytogenetic analysis, this approach provided higher yield in the detection of PCN-related abnormalities, irrespective of the initial percentage of plasma cells. Whole-genome profiling uncovered recurrent chromosomal abnormalities of prognostic value, including unbalanced alterations within the MYC locus, 16q loss, and hypodiploidy, that were not otherwise detectable by conventional methods. The proposed approach is cost-efficient and provides a superior detection rate, required for proper risk stratification and differential diagnosis of PCN regardless of initial plasma cell percentage.

The role of the bone microenvironment in regulating myeloma residual disease and treatment

Multiple myeloma is an incurable haematological cancer. The increase in targeted therapies has improved the number of myeloma patients achieving a complete response and improved progression-free survival following therapy. However, a low level of disease or minimal residual disease (MRD) still persists which contributes to the inevitable relapse in myeloma patients. MRD has been attributed to the presence of dormant myeloma cells and their subsequent reactivation, which is controlled by the microenvironment and specialised niches within the bone marrow. This contributes to the evasion of the immune system and chemotherapy, eventually leading to relapse. The growth of myeloma tumours are heavily dependent on environmental stimuli from the bone marrow microenvironment, and this plays a key role in myeloma progression. The bone microenvironment also plays a critical role in myeloma bone disease and the development of skeletal-related events. This review focuses on the bone marrow microenvironment in relation to myeloma pathogenesis and cancer dormancy. Moreover, it reviews the current therapies targeting the bone microenvironment to treat myeloma and myeloma bone disease. Lastly, it identifies novel therapeutic targets for myeloma treatment and the associated bone disease.

LTβR overexpression promotes plasma cell accumulation

Multiple myeloma (MM), a malignancy of plasma cells (PCs), has diverse genetic underpinnings and in rare cases these include amplification of the lymphotoxin b receptor (Ltbr) locus. LTβR has well defined roles in supporting lymphoid tissue development and function through actions in stromal and myeloid cells, but whether it is functional in PCs is unknown. Here we showed that Ltbr mRNA was upregulated in mouse PCs compared to follicular B cells, but deficiency in the receptor did not cause a reduction in PC responses to a T-dependent or T-independent immunogen. However, LTβR overexpression (OE) enhanced PC formation in vitro after LPS or anti-CD40 stimulation. In vivo, LTβR OE led to increased antigen-specific splenic and bone marrow (BM) plasma cells responses. LTβR OE PCs had increased expression of Nfkb2 and of the NF-kB target genes Bcl2 and Mcl1, factors involved in the formation of long-lived BM PCs. Our findings suggest a pathway by which Ltbr gene amplifications may contribute to MM development through increased NF-kB activity and induction of an anti-apoptotic transcriptional program.

Prognostic Value of Association of Copy Number Alterations and Cell-Surface Expression Markers in Newly Diagnosed Multiple Myeloma Patients

Multiple myeloma results from the clonal proliferation of abnormal plasma cells (PCs) in the bone marrow (BM). In this study, the cell surface expression markers (CD) on atypical PCs (detected by multiparametric flow cytometry (MFC)) were correlated with copy number alterations (CNAs) in the genome (detected by multiplex ligation-dependent probe amplification (MLPA)) to assess their impact on prognosis in newly diagnosed MM patients. Statistically significant results were obtained when different stages of PC maturation (classified based on CD19 and CD81 expression) were associated with CD117 expression and identified CNAs. In the intermediately differentiated PC group (CD19(-) CD81(+)), patients who didn't express CD117 had a lower median progression free survival (PFS) (p = 0.024). Moreover, within this group, patients with less than three adverse CNAs, which harbor CD117, had a better outcome with a PFS of more than 48 months compared with 19 months (p = 0.008). Considering all the results, our study suggested the need to integrate both the CD markers and copy number alterations to evaluate the prognosis of newly diagnosed multiple myeloma patients.

Serum free light chain analysis: persisting limitations with new kids on the block

OBJECTIVES

Serum free light chain (sFLC) measurements have inherent analytical limitations impacting sFLC clinical interpretation. We evaluated analytical and diagnostic performance of three polyclonal sFLC assays on four analytical platforms.

METHODS

sFLC concentration was measured using Diazyme FLC assays (Diazyme) on cobas c501/c503 analyzer (Roche); Freelite assays (The Binding Site) on Optilite analyzer (The Binding Site) and cobas c501 analyzer and Sebia FLC ELISA assays (Sebia) on AP22 ELITE analyzer (DAS). Imprecision, linearity, method comparison vs. Freelite/Optilite, antigen excess detection and reference value verification were assessed. Diagnostic performance was compared on 120 serum samples and on follow-up samples of five patients with κ and λ monoclonal gammopathy.

RESULTS

Method comparison showed excellent correlation with Freelite/Optilite method for all assays. A large proportional negative bias was shown for both Sebia κ and λ ELISA and a significant positive proportional bias for λ in the low (<10 mg/L) Freelite/cobas c501 method. Clinically relevant underestimation of κ sFLC levels due to antigen excess was shown for 7% of each Diazyme/cobas application and for 11 and 32.1% of λ sFLC assay of respectively Diazyme/cobas and Sebia/AP22. sFLC reference values revealed application specific. Cohen's κ values were (very) good for κ sFLC but only moderate to good for λ sFLC. In 4/10 follow-up patients, significant differences in clinical interpretation between sFLC assays were noticed.

CONCLUSIONS

Important analytical limitations remain for all sFLC applications. Differences in reference values and diagnostic performance hamper interchangeability of sFLC assays. Assay specific sFLC decision guidelines are warranted.

Whole-body magnetic resonance imaging plus serological follow-up for early identification of progression in smouldering myeloma patients to prevent development of end-organ damage

The definition of multiple myeloma (MM) was updated in 2014, with the intent to enable earlier treatment and thereby avoid appearance of end-organ damage at progression from smouldering multiple myeloma (SMM) to MM. The purpose of this study was to investigate to which extent the development of end-organ damage at progression to MM was reduced under the updated guidelines. In this prospective observational cohort study (ClinicalTrials.gov Identifier: NCT01374412), between 2014 and 2020, 96 SMM patients prospectively underwent whole-body magnetic resonance imaging (wb-MRI) and serological follow-up at baseline and every 6 months thereafter. A total of 22 patients progressed into MM during follow-up, of which seven (32%) showed SLiM-criteria only but no end-organ damage. Four (57%) of the seven patients who progressed by SLiM-criteria only progressed with >1 focal lesion (FL) or a growing FL, and three (43%) due to serum free light-chain-ratio ≥100. Fifteen (68%) out of 22 patients who progressed still suffered from end-organ damage at progression. The updated disease definition reduced the proportion of SMM patients suffering from end-organ damage at progression to MM by one third. wb-MRI is an important tool for detection of SMM patients who progress to MM without end-organ damage.

CD24 Is a Prognostic Marker for Multiple Myeloma Progression and Survival

Surface antigens are commonly used in flow cytometry assays for the diagnosis of multiple myeloma (MM). Some of these are directly involved in MM pathogenesis or interactions with the microenvironment, but most are used for either diagnostic or prognostic purposes. In a previous study, we showed that in-vitro, CD24-positive plasma cells exhibit a less tumorigenic phenotype. Here, we assessed the prognostic importance of CD24 expression in patients newly diagnosed with MM as it correlates to their clinical course. Immunophenotyping by flow cytometry of 124 patients uniformly treated by a bortezomib-based protocol was performed. The expression of CD24, CD117, CD19, CD45, and CD56 in bone marrow PCs was tested for correlations to clinical parameters. None of the CD markers correlated with the response rates to first-line therapy. However, patients with elevated CD24+ expression on their PCs at diagnosis had a significantly longer PFS (p = 0.002) and OS (p = 0.044). In contrast, the expression of CD117, CD56, or CD45 was found to have no prognostic value; CD19 expression was inversely correlated with PFS alone (p < 0.001) and not with OS. Thus, elevated CD24 expression on PCs appears to be strongly correlated with survival and can be used as a single-surface antigenic prognostic factor in MM.

Defects and countermeasures in laboratory diagnosis of rare IgE multiple myeloma

BACKGROUND

IgE multiple myeloma (MM) is a rare subtype of MM that is easily misdiagnosed. We report a rare case of IgE-MM and investigate the application of the SLiM-CRAB criteria to screen for high-risk smoldering MM (SMM) patients, so as to summarize the causes and methods used to prevent missed diagnosis or misdiagnosis in IgE-MM.

METHODS

The serum monoclonal protein (M-protein) classification and IgE quantification was performed and sent to several individual institutions. The results were collected and the causes of IgE detection defects were analyzed.

RESULTS

Upon admission to our hospital, the patient's serum free kappa light chain was 1,069.9 mg/L, free lambda light chain was 9.2 mg/L, and free kappa/lambda ratio was 115.9, which met the SLiM criteria, but without CRAB features. Immunofixation electrophoresis (IF) showed "M-like protein aggregation bands" in all lanes. After pretreatment with 1% β-mercaptoethanol to depolymerize the aggregation of monoclonal protein, the "M-like protein aggregation bands disappeared. The other five institutions did not provide the correct typing results. The quantification of serum IgE was as high as 2.06×10⁷ IU/mL, whereas 7 other testing institutions reported IgE levels ranging from 1.0 to 1100 IU/mL.

CONCLUSION

High-risk biomarkers in SLiM criteria can achieve good therapeutic effects in rare IgE-MM patients. Serum immunofixation performed without antisera against IgE, insufficient identification of the lytic bands produced by high macromolecule aggregation in IF, and the absence of a prozone effect avoidance procedure during IgE quantitative detection are the primary causes of missed diagnosis or misdiagnosis in patients with IgE-MM.

A prospective study of Skeletal survey versus Low-dose whole-body CT for Osteolytic lesions in Multiple Myeloma

Whole-body low-dose CT (WBLDCT) is recommended over classical skeletal surveys (CSS) for investigating bone disease in multiple myeloma (MM) based on retrospective studies. No prospective studies with serial follow-up scans exist.

OBJECTIVE

To compare WBLDCT to CSS for identifying progressive bone disease in MM in a prospective setting.

METHODS

Ninety-six patients with MM at Odense University Hospital and Stavanger Hospital were followed for up to four years. Patients were scanned with WBLDCT and CSS every year for the first two years and every six months thereafter or at suspicion of progression.

RESULTS

Nineteen cases of progressive bone disease were found using WBLDCT vs eight cases using CSS (p < 0.001). All cases of progressive bone disease using CSS were also identified by WBLDCT. Progression not found by CSS was primarily in the spine, sternum, and pelvis. Of the 19 cases, five patients had progressive bone disease only without other criteria for clinical progression. WBLDCT consistently identified more bone lesions per patient, 8.2 CI(6.8;9.6) vs CSS, 3.6 CI(2.7;4.5).

CONCLUSION

WBLDCT outperformed CSS for finding progressive bone disease and osteolytic lesions. More new lesions were found during follow-up by WBLDCT than CSS. Using CSS for lytic lesions will underestimate progression rates. Our data offer prospective evidence for the current recommendation using WBLDCT for skeletal evaluations in patients with multiple myeloma.

Evaluation of Diffuse Bone Marrow Infiltration Pattern in Monoclonal Plasma Cell Diseases by Quantitative Whole-body Magnetic Resonance Imaging

RATIONALE AND OBJECTIVES

To analyze diffuse infiltration pattern in monoclonal plasma cell diseases by diffusion-weighted whole-body imaging with background body signal suppression (DWIBS) and quantitative chemical-shift encoded MRI.

MATERIALS AND METHODS

Ninety-nine patients with monoclonal plasma cell diseases and 15 healthy control subjects were retrospectively analyzed. All patients underwent whole-body MRI (including DWIBS and mDIXON Quant) and were divided into three groups: monoclonal gammopathy of undetermined significance (MGUS), smoldering multiple myeloma (SMM), and multiple myeloma (MM). Apparent diffusion coefficient (ADC), fat fraction (FF), and T2* values for each group were calculated then analyzed by one-way ANOVA and receiver operating characteristic curve. Correlations of ADC, FF, and T2* with clinical indices were analyzed with Spearman correlation test.

RESULTS

The ADC and T2* values of MM were significantly higher than those of the healthy control, MGUS and SMM (ADC: p = 0.003, p = 0.003, and p = 0.042; T2*: all with p < 0.001). The FF values of MM were significantly lower than those of the healthy control, MGUS and SMM (p < 0.001, p < 0.001 and p = 0.034). The ADC, FF, and T2* thresholds for recognizing MM and MGUS+SMM were 0.51 × 10^-3 mm²/s, 31.14%, and 10.53 ms, respectively. The ADC, FF, and T2* values were identified to be significantly associated with bone marrow plasma cells and hemoglobin in patients (all with p < 0.001).

CONCLUSION

ADC, FF, and T2* were significantly correlated with clinical indices related to monoclonal plasma cell diseases. MM with the diffuse infiltration pattern can be distinguished more objectively from MGUS and SMM by quantitative functional MRI parameters.

Understanding the Bioactivity and Prognostic Implication of Commonly Used Surface Antigens in Multiple Myeloma

Multiple myeloma (MM) progression is dependent on its interaction with the bone marrow microenvironment and the immune system and is mediated by key surface antigens. Some antigens promote adhesion to the bone marrow matrix and stromal cells, while others are involved in intercellular interactions that result in differentiation of B-cells to plasma cells (PC). These interactions are also involved in malignant transformation of the normal PC to MM PC as well as disease progression. Here, we review selected surface antigens that are commonly used in the flow cytometry analysis of MM for identification of plasma cells (PC) and the discrimination between normal and malignant PC as well as prognostication. These include the markers: CD38, CD138, CD45, CD19, CD117, CD56, CD81, CD27, and CD28. Furthermore, we will discuss the novel marker CD24 and its involvement in MM. The bioactivity of each antigen is reviewed, as well as its expression on normal vs. malignant PC, prognostic implications, and therapeutic utility. Understanding the role of these specific surface antigens, as well as complex co-expressions of combinations of antigens, may allow for a more personalized prognostic monitoring and treatment of MM patients.

18 F-FDG PET/CT and MRI in the Management of Multiple Myeloma: A Comparative Review

During the last two decades, the imaging landscape of multiple myeloma (MM) has evolved with whole-body imaging techniques such as fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET/CT) and MRI replacing X-ray skeletal survey. Both imaging modalities have high diagnostic performance at the initial diagnosis of MM and are key players in the identification of patients needing treatment. Diffusion-weighted MRI has a high sensitivity for bone involvement, while 18F-FDG PET/CT baseline parameters carry a strong prognostic value. The advent of more efficient therapeutics, such as immunomodulatory drugs and proteasome inhibitors, has called for the use of sensitive imaging techniques for monitoring response to treatment. Diffusion-weighted MRI could improve the specificity of MRI for tumor response evaluation, but questions remain regarding its role as a prognostic factor. Performed at key time points of treatment in newly diagnosed MM patients, 18F-FDG PET/CT showed a strong association with relapse risk and survival. The deployment of minimal residual disease detection at the cellular or the molecular level may raise questions on the role of these imaging techniques, which will be addressed. This review summarizes and outlines the specificities and respective roles of MRI and 18F-FDG PET/CT in the management of MM.

The Dynamics of Nucleotide Variants in the Progression from Low-Intermediate Myeloma Precursor Conditions to Multiple Myeloma: Studying Serial Samples with a Targeted Sequencing Approach

Simple Summary

Multiple myeloma (MM), characterized by the expansion of plasma cells in the bone marrow, is the second most common hematological malignancy. This incurable cancer is consistently preceded by non-malignant asymptomatic precursor conditions known as monoclonal gammopathy of undetermined significance (MGUS) and/or smoldering multiple myeloma (SMM). These pre-stages are relatively frequent, but only a select percentage of them will progress to MM. However, it is still not possible to individually predict when and which patients will develop MM. Therefore, this study aimed to investigate the mutational profile in the progression in serial bone marrow samples with a custom targeted sequencing panel, designed to detect variants in myeloma-related genes. Remarkably, almost all variants identified in the MM samples were also already present in the pre-stages, sometimes even many years before the progression. These results provide new important insights into the molecular mechanisms of the precursor conditions and progression to MM.

Abstract

Multiple myeloma (MM), or Kahler’s disease, is an incurable plasma cell (PC) cancer in the bone marrow (BM). This malignancy is preceded by one or more asymptomatic precursor conditions, monoclonal gammopathy of undetermined significance (MGUS) and/or smoldering multiple myeloma (SMM). The molecular mechanisms and exact cause of this progression are still not completely understood. In this study, the mutational profile underlying the progression from low–intermediate risk myeloma precursor conditions to MM was studied in serial BM smears. A custom capture-based sequencing platform was developed, including 81 myeloma-related genes. The clonal evolution of single nucleotide variants and short insertions and deletions was studied in serial BM smears from 21 progressed precursor patients with a median time of progression of six years. From the 21 patients, four patients had no variation in one of the 81 studied genes. Interestingly, in 16 of the 17 other patients, at least one variant present in MM was also detected in its precursor BM, even years before progression. Here, the variants were present in the pre-stage at a median of 62 months before progression to MM. Studying these paired BM samples contributes to the knowledge of the evolutionary genetic landscape and provides additional insight into the mutational behavior of mutant clones over time throughout progression.

Application of diffusion-weighted whole-body MRI for response monitoring in multiple myeloma after chemotherapy: a systematic review and meta-analysis

OBJECTIVE

Myeloma Response Assessment and Diagnosis System recently published provides a framework for the standardised interpretation of DW-WBMRI in response assessment of multiple myeloma (MM) based on expert opinion. However, there is a lack of meta-analysis providing higher-level evidence to support the recommendations. In addition, some disagreement exists in the literature regarding the effect of timing and lesion subtypes on apparent diffusion coefficient (ADC) value changes post-treatment.

METHOD

Medline, Cochrane and Embase were searched from inception to 20th July 2021, using terms reflecting multiple myeloma and DW-WBMRI. Using PRISMA reporting guidelines, data were extracted by two investigators. Quality was assessed by the Quality Assessment of Diagnostic Accuracy Studies-2 method.

RESULTS

Of the 74 papers screened, 10 studies were included comprising 259 patients (127 males and 102 females) and 1744 reported lesions. Responders showed a significant absolute ADC change of 0.21×10^-3 mm/s² (95% CI, 0.01-0.41) with little evidence of heterogeneity (Cochran Q, p = 0.12, I² = 45%) or publication bias (p = 0.737). Non-responders did not show a significant absolute difference in ADC (0.06 ×10^-3 mm/s², 95% CI, -0.07 to 0.19). A percentage ADC increase of 34.78% (95% CI, 10.75-58.81) was observed in responders. Meta-regression showed an inverse trend between ADC increases and time since chemotherapy initiation which did not reach statistical significance (R² = 20.46, p = 0.282).

CONCLUSIONS

This meta-analysis supports the use of the DW-WBMRI as an imaging biomarker for response assessment. More evidence is needed to further characterise ADC changes by lesion subtypes over time.

KEY POINTS

• In multiple myeloma patients who received chemotherapy, responders have a significant absolute increase in ADC values that is not seen in non-responders. • A 35% increase in ADC from baseline values is found to classify response post-induction chemotherapy which corroborates with expert opinion from the Myeloma Response Assessment and Diagnosis System. • More evidence is needed to further characterise ADC changes by lesion subtypes over time after induction of therapy.

Gene Expression Analysis of the Bone Marrow Microenvironment Reveals Distinct Immunotypes in Smoldering Multiple Myeloma Associated to Progression to Symptomatic Disease

Background

We previously reported algorithms based on clinical parameters and plasma cell characteristics to identify patients with smoldering multiple myeloma (SMM) with higher risk of progressing who could benefit from early treatment. In this work, we analyzed differences in the immune bone marrow (BM) microenvironment in SMM to better understand the role of immune surveillance in disease progression and to identify immune biomarkers associated to higher risk of progression.

Methods

Gene expression analysis of BM cells from 28 patients with SMM, 22 patients with monoclonal gammopathy of undetermined significance (MGUS) and 22 patients with symptomatic MM was performed by using Nanostring Technology.

Results

BM cells in SMM compared to both MGUS and symptomatic MM showed upregulation of genes encoding for key molecules in cytotoxicity. However, some of these cytotoxic molecules positively correlated with inhibitory immune checkpoints, which may impair the effector function of BM cytotoxic cells. Analysis of 28 patients with SMM revealed 4 distinct clusters based on immune composition and activation markers. Patients in cluster 2 showed a significant increase in expression of cytotoxic molecules but also inhibitory immune checkpoints compared to cluster 3, suggesting the presence of cytotoxic cells with an exhausted phenotype. Accordingly, patients in cluster 3 had a significantly longer progression free survival. Finally, individual gene expression analysis showed that higher expression of TNF superfamily members (TNF, TNFAIP3, TNFRSF14) was associated with shorter progression free survival.

Conclusions

Our results suggest that exhausted cytotoxic cells are associated to high-risk patients with SMM. Biomarkers overexpressed in patients with this immune gene profile in combination with clinical parameters and PC characterization may be useful to identify SMM patients with higher risk of progression.

18F FDG imaging - response criteria in tumors

With the progress of medical oncology, it became apparent that anatomical imaging is oftentimes insufficient for therapy response evaluation. Hybrid imaging, namely ¹⁸F-FDG PET/CT has helped to overcome these limitations. The aim of this paper is to emphasize the utility and impact in clinical use of ¹⁸F-FDG PET/CT, and to give an overview of the most important ¹⁸F-FDG PET/CT tumor response criteria. We also focus on standardization of hybrid imaging techniques as this is of outmost importance to provide reliable imaging evaluation.

Role of Serum Free Light Chain Assay in Relapsed/Refractory Multiple Myeloma. A Real-Life Unicentric Retrospective Study

BACKGROUND

In the era of novel drugs a growing number of multiple myeloma (MM) patients are treated until disease progression. Serum free light chain (sFLC) assay is recommended for disease monitoring in oligo-secretory and micromolecular MM.

METHODS

In this real-life survey, a total of 130 relapsed/refractory MM patients treated at our center with at least three lines were investigated as a retrospective cohort.

RESULTS

The median age at diagnosis was 64 years and more than half of patients were male. A total of 24 patients (18%) had oligo-secretory/micromolecular disease at diagnosis. More than 20% of 106 normo-secretory patients had oligo-secretory/micromolecular escape. In order to evaluate potential role of sFLC assay before ("pre") and after ("post") every treatment line, involved serum free light chain values (iFLC) less than 138 mg/mL and serum free light chain ratios (FLCr) <25 were identified by using ROC curve analysis. The analysis of the entire cohort throughout four treatment lines demonstrated a statistically significant negative impact on progression-free survival (PFS) for both involved pre-sFLC and its ratio (respectively p = 0.0086 and p = 0.0065). Furthermore, both post-iFLC and post-FLCr greater than the pre-established values had a negative impact on PFS of the study cohort; respectively, p = 0.014 and p = 0.0079. Odds ratio analysis evidenced that patients with both involved post-sFLC greater than 138 mg/mL and post-FLCr above 25 at disease relapse had a higher probability of having clinical relapse (respectively p = 0.026 and p = 0.006).

CONCLUSIONS

Alterations of sFLC values, namely iFLC and FLCr, both prior to treatment initiation and in the course of therapy at every treatment line, could be of aid in relapse evaluation and treatment outcome. We therefore suggest close periodical monitoring of sFLC assay, independently from secretory status.

Dual Targeting of Multiple Myeloma Stem Cells and Myeloid-Derived Suppressor Cells for Treatment of Chemotherapy-Resistant Multiple Myeloma

Here we review the insights and lessons learned from early clinical trials of T-cell engaging bispecific antibodies (BsABs) as a new class of biotherapeutic drug candidates with clinical impact potential for the treatment of multiple myeloma (MM). BsABs are capable of redirecting host T-cell cytotoxicity in an MHC-independent manner to malignant MM clones as well as immunosuppressive myeloid-derived suppressor cells (MDSC). T-cell engaging BsAB targeting the BCMA antigen may help delay disease progression in MM by destroying the MM cells. T-cell engaging BsAB targeting the CD38 antigen may help delay disease progression in MM by depleting both the malignant MM clones and the MDSC in the bone marrow microenvironment (BMME). BsABs may facilitate the development of a new therapeutic paradigm for achieving improved survival in MM by altering the immunosuppressive BMME. T-cell engaging BsiABs targeting the CD123 antigen may help delay disease progression in MM by depleting the MDSC in the BMME and destroying the MM stem cells that also carry the CD123 antigen on their surface.

S100 Calcium Binding Protein Family Members Associate With Poor Patient Outcome and Response to Proteasome Inhibition in Multiple Myeloma

Despite several new therapeutic options, multiple myeloma (MM) patients experience multiple relapses and inevitably become refractory to treatment. Insights into drug resistance mechanisms may lead to the development of novel treatment strategies. The S100 family is comprised of 21 calcium binding protein members with 17 S100 genes located in the 1q21 region, which is commonly amplified in MM. Dysregulated expression of S100 family members is associated with tumor initiation, progression and inflammation. However, the relationship between the S100 family and MM pathogenesis and drug response is unknown. In this study, the roles of S100 members were systematically studied at the copy number, transcriptional and protein level with patients’ survival and drug response. Copy number analysis revealed a predominant pattern of gains occurring in S100 genes clustering in the 1q21 locus. In general, gains of genes encoding S100 family members associated with worse patient survival. However, S100 gene copy number and S100 gene expression did not necessarily correlate, and high expression of S100A4 associated with poor patient survival. Furthermore, integrated analysis of S100 gene expression and ex vivo drug sensitivity data showed significant negative correlation between expression of S100 family members (S100A8, S100A9, and S100A12) and sensitivity to some drugs used in current MM treatment, including proteasome inhibitors (bortezomib, carfilzomib, and ixazomib) and histone deacetylase inhibitor panobinostat. Combined proteomic and pharmacological data exhibited significant negative association of S100 members (S100A4, S100A8, and S100A9) with proteasome inhibitors and panobinostat. Clinically, the higher expression of S100A4 and S100A10 were significantly linked to shorter progression free survival in patients receiving carfilzomib-based therapy. The results indicate an association and highlight the potential functional importance of S100 members on chromosome 1q21 in the development of MM and resistance to established myeloma drugs, including proteasome inhibitors.

Choosing the Right Therapy for Patients with Relapsed/Refractory Multiple Myeloma (RRMM) in Consideration of Patient-, Disease- and Treatment-Related Factors

Treatment of relapsed/refractory multiple myeloma (RRMM) is more complex today due to the availability of novel therapeutic options, mostly applied as combination regimens. immunotherapy options have especially increased substantially, likewise the understanding that patient-, disease- and treatment-related factors should be considered at all stages of the disease. RRMM is based on definitions of the international myeloma working group (IMWG) and includes biochemical progression, such as paraprotein increase, or symptomatic relapse with CRAB criteria (hypercalcemia, renal impairment, anemia, bone lesions). When choosing RRMM-treatment, the biochemical markers for progression and severity of the disease, dynamic of disease relapse, type and number of prior therapy lines, including toxicity and underlying health status, need to be considered, and shared decision making should be pursued. Objectively characterizing health status via geriatric assessment (GA) at each multiple myeloma (MM) treatment decision point has been shown to be a better estimate than via age and comorbidities alone. The well-established national comprehensive cancer network, IMWG, European myeloma network and other national treatment algorithms consider these issues. Ideally, GA-based clinical trials should be supported in the future to choose wisely and efficaciously from available intervention and treatment options in often-older MM adults in order to further improve morbidity and mortality.

Clonal Evolution of Multiple Myeloma-Clinical and Diagnostic Implications

Plasma cell dyscrasias are a heterogeneous group of diseases characterized by the expansion of bone marrow plasma cells. Malignant transformation of plasma cells depends on the continuity of events resulting in a sequence of well-defined disease stages, from monoclonal gammopathy of undetermined significance (MGUS) through smoldering myeloma (SMM) to symptomatic multiple myeloma (MM). Evolution of a pre-malignant cell into a malignant cell, as well as further tumor progression, dissemination, and relapse, require development of multiple driver lesions conferring selective advantage of the dominant clone and allowing subsequent evolution under selective pressure of microenvironment and treatment. This process of natural selection facilitates tumor plasticity leading to the formation of genetically complex and heterogenous tumors that are notoriously difficult to treat. Better understanding of the mechanisms underlying tumor evolution in MM and identification of lesions driving the evolution from the premalignant clone is therefore a key to development of effective treatment and long-term disease control. Here, we review recent advances in clonal evolution patterns and genomic landscape dynamics of MM, focusing on their clinical implications.

Identification of three immune molecular subtypes associated with immune profiles, immune checkpoints, and clinical outcome in multiple myeloma

Purpose

To identify the immune molecular subtype for MM to help achieve individualized and precise targeted therapy.

Methods

The GDC API was used to download the TCGA‐MM profile dataset, which contains 859 samples in total, all of which were anterior to the standard treatment after diagnosis. Moreover, 282, 298, and 258 samples were stage I, stage II, and stage III separately. We used the immune gene expression profile for consistent clustering; and used the R software package ConsensusClusterPlus to sort the immune molecular subtypes. Correlation between subtypes and clinical features, immunity, and prognosis was then analyzed.

Results

A total of 859 tumor samples were separated into these three subtypes, which were not meaningfully related to age or sex but showed a remarkable association with stage. The results suggested that obvious differences in immune metagene expression and expression of 10 immune checkpoint genes appeared among the three subtypes.

Conclusion

The three subtypes are distinctly different in terms of immune metagenes, immune checkpoint molecules, and clinical prognosis. The discovery of the immune microenvironment of MM could further reveal the strategy for immunotherapy in MM and provide a promising candidate prognostic tool for survival.

Whole genome sequencing demonstrates substantial pathophysiological differences of MYC rearrangements in patients with plasma cell myeloma and B-cell lymphoma

MYC rearrangements (MYCr) occur in several B-cell neoplasms and impact disease progression and overall survival. We used whole genome sequencing (WGS) and whole transcriptome sequencing (WTS) to analyze and compare MYCr in different B-cell neoplasms. The MYCr features of cases with plasma cell myeloma (PCM) (n = 88) showed distinct characteristics compared to cases with mature B-cell lymphomas (n = 62, including Burkitt lymphoma (BL), diffuse large B-cell lymphoma (DLBCL) and high grade lymphoma with MYC and BCL2 and/or BCL6 rearrangements (HGBL)): they were more complex and showed a wider variety of translocation partners and breakpoints. Additionally, unlike B-cell lymphomas, they showed no evidence of activation-induced deaminase (AID) involvement in the formation of MYCr with immunoglobolin heavy chain (IGH), indicating a different mechanism of origin. The different MYCr characteristics resulted in poor MYCr detection rates by fluorescence in situ hybridization of only 50% in PCM, compared to 94% in lymphoma.