Incidence, presenting features and outcome of extramedullary disease in multiple myeloma: a longitudinal study on 1003 consecutive patients

Low circulating tumor cell levels correlate with favorable outcomes and distinct biological features in multiple myeloma

There is growing interest in multiple myeloma (MM) circulating tumor cells (CTCs), but their rareness in peripheral blood (PB) and inconsistency in cutoffs question their clinical utility. Herein, we applied next-generation flow cytometry in 550 bone marrow (BM) and matched PB samples to define an optimal CTC cutoff for both transplant-eligible and transplant-ineligible newly diagnosed MM (NDMM) patients. Deep phenotyping was performed to investigate unique microenvironmental features associated with CTC dissemination. CTCs were detected in 90% of patients (median 0.01%; range: 0.0002%-12.6%) and increased levels associated with adverse features. Correlations were observed between high CTC percentages and a diffused MRI pattern, a distinct BM composition characterized by altered B-cell differentiation together with an expansion of effector cells and tumor-associated macrophages, as well as a greater phenotypic dissimilarity between BM and PB clonal cells. Progression-free survival (PFS) and overall survival (OS) gradually worsened with each logarithmic increment of CTCs. Conversely, NDMM patients without CTCs showed unprecedented outcomes, with 5-year PFS and OS rates of 83% and 97%, respectively. A cutoff of 0.02% CTCs was independent of the ISS, LDH, and cytogenetics in a multivariate analysis of risk factors for PFS. The 0.02% CTC cutoff synergized with the MGUS-like phenotype and the R-ISS for improving the risk stratification systems. MRD negativity was less frequent if CTCs were ≥0.02% at diagnosis, but whenever achieved, the poor prognosis of these patients was abrogated. This study shows the clinical utility of CTC assessment in MM and provides evidence toward a consensus cutoff for risk stratification.

Beyond the marrow: insights from comprehensive next-generation sequencing of extramedullary multiple myeloma tumors

Extramedullary multiple myeloma (EMM) is an aggressive form of multiple myeloma (MM). This study represents the most comprehensive next-generation sequencing analysis of EMM tumors (N = 14) to date, uncovering key molecular features and describing the tumor microenvironment. We observed the co-occurrence of 1q21 gain/amplification and MAPK pathway mutations in 79% of EMM samples, suggesting that these are crucial mutational events in EMM development. We also demonstrated that patients with mutated KRAS and 1q21 gain/amplification at the time of diagnosis have a significantly higher risk of EMM development (HR = 2.4, p = 0.011) using data from a large CoMMpass dataset. We identified downregulation of CXCR4 and enhanced cell proliferation, along with reduced expression of therapeutic targets (CD38, SLAMF7, GPRC5D, FCRH5), potentially explaining diminished efficacy of immunotherapy. Conversely, we identified significantly upregulated EZH2 and CD70 as potential future therapeutic options. For the first time, we report on the tumor microenvironment of EMM, revealing CD8+ T cells and NK cells as predominant immune effector cells using single-cell sequencing. Finally, this is the first longitudinal study in EMM revealing the molecular changes from the time of diagnosis to EMM relapse.

Daratumumab-based regimens for patients with multiple myeloma plus extramedullary plasmacytomas or paraskeletal plasmacytomas: initial follow-up of an Italian multicenter observational clinical experience

Myeloma with extramedullary plasmacytomas not adjacent to bone (EMP) is associated with an extremely poor outcome compared with paraosseous plasmacytomas (PP) as current therapeutic approaches are unsatisfactory. The role of new molecules and in particular of monoclonal antibodies is under investigation. To determine whether daratumumab-based regimens are effective for myeloma with EMP, we report herein an initial multicenter observational analysis of 102 myeloma patients with EMP (n = 10) and PP (n = 25) at diagnosis and EMP (n = 28) and PP (n = 39) at relapse, treated with daratumumab-based regimens at 11 Haematological Centers in Italy.EMP and PP at diagnosis were associated with higher biochemical (90% vs. 96%, respectively) and instrumental ORR (86% vs. 83.3%, respectively), while at relapse, biochemical (74% vs. 73%) and instrumental (53% vs. 59%) ORR were lower. Median OS was inferior in EMP patients compared with patients with PP both at diagnosis (21.0 months vs. NR) (p = 0.005) and at relapse (32.0 vs. 40.0 months) (p = 0.428), although, during relapse, there was no statistically significant difference between the two groups. Surprisingly, at diagnosis, median TTP and median TTNT were not reached either in EMP patients or PP patients and during relapse there were no statistically significant differences in terms of median TTP (20 months for two groups), and median TTNT (24 months for PP patients vs. 22 months for EMP patients) between the two groups. Median TTR was 1 month in all populations.These promising results were documented even in the absence of local radiotherapy and in transplant-ineligible patients.

Megalosplenia as an initial manifestation of multiple myeloma with a novel CYLD gene mutation: A case report and literature review

INTRODUCTION

Megalosplenia in newly diagnosed multiple myeloma (MM) is extremely rare, posing diagnostic and therapeutic challenges due to its unusual location and clinical manifestations and lack of optimal therapeutic strategies.

CASE PRESENTATION

A 65-year-old female who was previously healthy presented with a history of ecchymosis on her right leg accompanied by progressive fatigue for 2 weeks. She was admitted to our center in July 2019 due to thrombocytopenia. The patient presented with megalosplenia, anemia, monoclonal protein (λ-light chain type) in the serum and urine, and 45.6% malignant plasma cells in the bone marrow. Splenectomy was performed due to persistent splenomegaly after 3 cycles of the bortezomib plus dexamethasone regimen, and immunohistochemistry results indicated λ-plasmacytoma of the spleen. The same cytogenetic and molecular abnormalities, including t(14;16), 14q32 amplification, 16q32 amplification, 20q12 amplification, and a novel CYLD gene mutation, were identified using fluorescence in situ hybridization and next-generation sequencing in both bone marrow and spleen samples. Therefore, a diagnosis of MM (λ-light chain type, DS III, ISS III, R-ISS III, high-risk) with spleen infiltration was proposed. The patient did not achieve remission after induction treatment with bortezomib plus lenalidomide and dexamethasone or salvage therapy with daratumumab plus ixazomib and dexamethasone. However, she ultimately did achieve very good partial remission with a regimen of bendamustine plus lenalidomide and dexamethasone. Unfortunately, she died of pneumonia associated with chemotherapy.

CONCLUSION

To our knowledge, only 8 cases of spleen plasmacytoma at MM diagnosis have been described previously. Extramedullary myeloma patients with spleen involvement at diagnosis are younger and that the condition is usually accompanied by splenic rupture with aggressive clinical features and poor prognosis. Further studies are needed to explore pathogenesis and effective therapies to prolong the survival of such patients.

Doxorubicin-loaded PEG-CdTe QDs conjugated with anti-CXCR4 mAbs: a novel delivery system for extramedullary multiple myeloma treatment

Extramedullary multiple myeloma (EMM) is defined as the presence of plasma cells outside the bone marrow of multiple myeloma patients, and its prognosis is poor. High-dose chemotherapy with autologous stem cell transplantation, as a good option on early lines of therapy, has retained the survival benefit of youny EMM patients, but is intolerant for the majority of old patients because of drug cytotoxicity. To essentially address the intolerance above, we designed a CXCR4-PEG-CdTe-DOX (where CXCR4: chemokine receptor 4; PEG-CdTe: polyethylene glycol-modified cadmium telluride; DOX:doxorubicin) nanoplatform. First, CXCR4 is highly expressed in extramedullary plasma cells. Second, PEG-CdTe a drug carrier that controls drug release, can reduce adverse reactions, prolong drug (e.g, DOX) circulation time in the body, and form a targeting carrier after connecting antibodies. In vitro experiments showed CXCR4-PEG-CdTe-DOX facilitated intracellular drug accumulation through active CXCR4 targeting and released DOX into the microenvironment in a pH-controlled manner, enhancing the therapeutic efficacy and apoptosis rate of myeloma cells (U266). Therefore, targeted chemotherapy mediated by CXCR4-PEG-CdTe-DOX is a promising option for EMM treatment.

Imaging of Multiple Myeloma: Present and Future

Multiple myeloma (MM) is the second most common adult hematologic malignancy, and early intervention increases survival in asymptomatic high-risk patients. Imaging is crucial for the diagnosis and follow-up of MM, as the detection of bone and bone marrow lesions often dictates the decision to start treatment. Low-dose whole-body computed tomography (CT) is the modality of choice for the initial assessment, and dual-energy CT is a developing technique with the potential for detecting non-lytic marrow infiltration and evaluating the response to treatment. Magnetic resonance imaging (MRI) is more sensitive and specific than 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) for the detection of small focal lesions and diffuse marrow infiltration. However, FDG-PET/CT is recommended as the modality of choice for follow-up. Recently, diffusion-weighted MRI has become a new technique for the quantitative assessment of disease burden and therapy response. Although not widespread, we address current proposals for structured reporting to promote standardization and diminish variations. This review provides an up-to-date overview of MM imaging, indications, advantages, limitations, and recommended reporting of each technique. We also cover the main differential diagnosis and pitfalls and discuss the ongoing controversies and future directions, such as PET-MRI and artificial intelligence.

Survival trends and prognostic factors of patients with newly diagnosed multiple myeloma accompanied with extramedullary disease

Background: Extramedullary disease (EMD) is an unusual event in patients with MM. This study aimed to assess the prognostic impact of EMD and develop an EMD-based risk model to estimate the survival of patients with newly diagnosed multiple myeloma (NDMM).Methods: A total of 518 patients were enrolled in this study, of which 121 presented with EMD at the initial diagnosis. Patients were divided into non-EMD, extramedullary-bone-related (EM-B) and extramedullary-extraosseous (EM-E) groups. Clinical characteristics were compared using the chi-squared test or Fisher's exact test. Survival curves were plotted using the Kaplan-Meier method, and a nomogram was constructed based on the Cox proportional hazards model.Results: Compared to patients without EMDs, patients with EM-E were younger (p = 0.028), and those with EM-B had less renal damage (p < 0.001). The EM-E group had the worst progression-free survival (PFS) and overall survival (OS). In addition, patients with multiple sites of EMD invasion or high Ki67 expression had poor OS. Lenalidomide-based treatment showed the worst outcome, and autologous stem cell transplantation (ASCT) remarkably improved the survival of patients with EMD. A prognostic model (MM prognostic index, MM-PI) comprising lactate dehydrogenase (LDH), circulating plasma cells (CPC), del(17p), and type of extramedullary involvement was developed, and a 4-factor nomogram.Conclusions: We established a risk model incorporating extramedullary disease that provides accurate and individualized survival estimates for patients with NDMM.

Imaging findings in a case of leptomeningeal myelomatosis, a rare but critical central nervous system complication of multiple myeloma

Leptomeningeal myelomatosis is a rare complication of multiple myeloma (<1% of the patients). There was an increase in the incidence of leptomeningeal myelomatosis during the last decade; the prognosis of leptomeningeal myelomatosis remains poor, (overall median survival from the time of diagnosis of 2 months). We discuss a rare case of a monoclonal gammopathy evolving into multiple myeloma and finally into a rapidly progressing leptomeningeal disease. A 76 year-old woman in hematologic follow-up for advanced stage multiple myeloma in sixth-line treatment had an episode of generalized tonic-clonic seizure with sphincter release followed by altered state of consciousness. The unenhanced head CT scan showed a mild enlargement of the ventricular system without intra-axial or extra-axial hemorrhages nor significant changes in brain parenchyma. The subsequent contrast-enhanced brain MRI revealed a widespread nodular leptomeningeal enhancement characterized by contrast-enhancement of the pia mater extended into the subarachnoid spaces of the sulci and cisterns, involving supra- and sub-tentorial regions and the statoacoustic nerve in the inner ear canal bilaterally. The fluid-attenuated inversion recovery MRI images demonstrated an abnormally elevated signal within the sulci in the parieto-occipital regions. The radiological diagnosis of leptomeningeal myelomatosis was made. The patient died 4 days after the examination. In patients with long-lasting multiple myeloma and onset of neurological signs or symptoms, a contrast-enhanced brain MRI should be performed to assess the actual burden of central nervous system involvement in leptomeningeal myelomatosis; CT may provide a clue to the diagnosis when progressive enlargement of the ventricles over time is noted.

Natural history, predictors of development of extramedullary disease, and treatment outcomes for patients with extramedullary multiple myeloma

Extramedullary multiple myeloma (EMM) can present either at initial diagnosis (de novo) or at disease relapse (secondary) and confers an aggressive clinical course. Limited data exist for choosing the optimal therapy for EMM and this remains an area of unmet clinical need. After excluding paraskeletal multiple myeloma and primary plasma cell leukemia, we identified 204 (68%) patients with secondary EMM and 95 (32%) with de novo EMM between January 01, 2000 and 31 December, 2021. The median overall survival (OS) was 0.7 (95% CI: 0.6-0.9) years for secondary EMM and 3.6 (95%CI: 2.4-5.6) years for de novo EMM. The median progression-free survival (PFS) with initial therapy was 2.9 months (95% CI: 2.4-3.2 months) for secondary EMM and 12.9 months (95% CI: 6.7-18 months) for de novo EMM. Patients with secondary EMM treated with CAR-T therapy (n = 20) achieved a partial response (PR) or better in 75% with a median PFS of 4.9 months (3.1 months-not reached; NR). Patients with EMM treated with bispecific antibodies (n = 12) achieved a ≥ PR in 33%, with a median PFS of 2.9 months (95%CI: 2.2 months-NR). In a matched cohort, multivariate logistic regression analysis demonstrated younger age at diagnosis, 1q duplication, and t(4;14) at diagnosis of MM to be independent predictors of development of secondary EMM. Presence of EMM was independently associated with inferior OS in the matched cohorts for both de novo (HR 2.9 [95% CI: 1.6-5.4], p = .0007) and secondary EMM (HR 1.5 [95% CI: 1.1-2], p = .001).

Molecular and immunological mechanisms of clonal evolution in multiple myeloma

Multiple myeloma (MM) is a hematologic malignancy characterized by the proliferation of clonal plasma cells in the bone marrow (BM). It is known that early genetic mutations in post-germinal center B/plasma cells are the cause of myelomagenesis. The acquisition of additional chromosomal abnormalities and distinct mutations further promote the outgrowth of malignant plasma cell populations that are resistant to conventional treatments, finally resulting in relapsed and therapy-refractory terminal stages of MM. In addition, myeloma cells are supported by autocrine signaling pathways and the tumor microenvironment (TME), which consists of diverse cell types such as stromal cells, immune cells, and components of the extracellular matrix. The TME provides essential signals and stimuli that induce proliferation and/or prevent apoptosis. In particular, the molecular pathways by which MM cells interact with the TME are crucial for the development of MM. To generate successful therapies and prevent MM recurrence, a thorough understanding of the molecular mechanisms that drive MM progression and therapy resistance is essential. In this review, we summarize key mechanisms that promote myelomagenesis and drive the clonal expansion in the course of MM progression such as autocrine signaling cascades, as well as direct and indirect interactions between the TME and malignant plasma cells. In addition, we highlight drug-resistance mechanisms and emerging therapies that are currently tested in clinical trials to overcome therapy-refractory MM stages.

Identification of evolutionary mechanisms of myelomatous effusion by single-cell RNA sequencing

Myelomatous effusion (ME) is a rare manifestation of extramedullary multiple myeloma (MM) with limited therapeutic options and poor outcomes. The molecular mechanisms underlying ME are incompletely understood. We profiled transcriptomes of bone marrow, peripheral blood (PB), and pleural effusion/ascites from 3 patients with ME using single-cell RNA sequencing analysis. We found that ME contained a higher percentage of cytotoxic T cells, whereas PB contained a higher proportion of naive T cells. Malignant cells varied within and between sites and patients in their expression of signatures. We identified a gene module highly expressed in intramedullary and extramedullary plasma cell clusters and defined cell clusters expressing this gene set as extramedullary-initiating cells (EMICs). This gene set was associated with increased cellular proliferation, involved in p53 signaling, and related to poor prognosis in MM. The transcriptional regulators E2F1, YY1, and SMAD1 were activated in EMICs. Leukocyte immunoglobulin-like receptor subfamily B4 (LILRB4) was upregulated in extramedullary EMICs. We confirmed that LILRB4 promoted MM cell migration in vitro. This study provided insight into the evolutionary mechanisms of ME and defined EMICs and LILRB4 associated with extramedullary development.

Cyclophosphamide etoposide dexamethasone as salvage and bridging therapy in relapsed refractory and extramedullary multiple myeloma

Patients with relapsed refractory multiple myeloma (RRMM) that are triple-exposed to immunomodulatory drugs, proteasome inhibitors, and anti-CD38 monoclonal antibodies have a poor prognosis. Standard treatment for these patients has not been established. Patients with extramedullary disease or secondary plasma cell leukemia often display high tumor cell proliferation and might therefore be susceptible to chemotherapy. While current regimens are often platinum-based, we present single-center data on 70 patients with RRMM who were treated with cyclophosphamide, etoposide, and dexamethasone (CED) after a median of four lines of therapy. An overall response rate of 52% was achieved after 1-6 cycles, with 23% of patients having a very good partial response. Comparable response rates and survival were observed in patients with extramedullary disease and high-risk cytogenetics. Treatment resulted in non-hematological °III-IV adverse events in 31% of patients. No treatment-related deaths occurred. The median progression-free and overall survival were 6.2 and 10.9 months, respectively. 23% of patients were bridged to autologous stem cell transplantation (ASCT) or chimeric antigen receptor (CAR) T cell therapy. In summary, CED is an effective treatment regimen for RRMM cases with a tolerable safety profile and suitable as bridging therapy to CAR T cell treatment and ASCT.

Massive Myelomatous Pleural Effusion With Contralateral Mediastinal Shift: A Unique Presentation of Extramedullary Myeloma

Multiple myeloma (MM) is a relatively common malignancy that primarily affects the bone marrow, while extramedullary disease (EMD) occurs in the skin and muscle, lung pleura, lymph nodes, liver, and CNS. Myelomatous pleural effusion (MPE) is a rare extramedullary manifestation of MM in which pleural fluid is composed almost entirely of abnormal plasma cells. MPE and other types of EMD are associated with poor prognosis, and MPE can present emergently due to tension physiology. We report a case of a patient with massive MPE presenting with contralateral midline shift. There are exceedingly few such cases and this report highlights a unique presentation of this rare clinical entity. Epidemiology, radiographic features, diagnosis, treatment, and implications for the prognosis of the disease are discussed.

Paraskeletal plasmacytoma presenting as a chest wall mass

Extramedullary involvement in multiple myeloma is uncommon. It can present as a plasma cell mass in the soft tissue surrounding the bony structures through direct extension or in various other organs via hematogenous spread. Here, we report a case of paraskeletal plasmacytoma that manifested as a chest wall mass in a 60-year-old man.

Efficacy and Safety Analysis of VRD-PDCE in Treatment-Native Patients with Multiple Extramedullary Plasmacytomas or Plasma Cell Leukemia

The prognosis of multiple extramedullary plasmacytomas (MEP) and plasma cell leukemia (PCL) is extremely poor, with the median overall survival (OS) of only 8 months with standard chemotherapy. Innovative treatment approaches incorporating various strategies are required to improve outcome. From November 2019 to September 2021, a total of 12 newly diagnosed MEP or PCL patients were enrolled in our department. An intensive chemotherapy treatment as VRD-PDCE consisted of bortezomib, lenalidomide, dexamethasone plus cisplatin, pegylated liposomal doxorubicin, cyclophosphamide and etoposide was first proposed. Disease activity and toxicity were evaluated after each cycle. Of the patients receiving therapy achieved a rapid and sustained response, and the overall response rate (ORR) was up to 75%. Nine patients achieved partial response (PR) or better, the response was the best response and the median time to best response was 4 cycles. Median overall survival (OS) and progression-free survival (PFS) were 24 (5-30) months and 18 (2-23) months. The toxicities were acceptable and there was no treatment related mortality. Our intensive treatment showed encouraging results in terms of disease control and improving survival, VRD-PDCE may be a novel regimen which is feasible and generally well-tolerated in MEP or PCL patients.

The utility of serum amylase as a prognostic marker in multiple myeloma

Background

Ectopic production of amylase by tumor cells is known since 1951. Elevated amylase in multiple myeloma (MM) was first described in 1988. It has been postulated that translocation of chromosome 1, where amylase gene is situated, is responsible for ectopic production from the malignant plasma cells. Anecdotal reports have shown hyperamylasemia in MM to be associated with extensive bone disease, rapid progression, and shorter survival. Serum amylase estimation is a ubiquitous test. This prospective study was conducted to ascertain the degree of elevated amylase, its clinical utility, and implications in MM patients.

Materials and Methods

In an 18-month period, all consenting patients with newly diagnosed or relapsed MM were tested for serum amylase levels. The study excluded patients with elevated lipase, abnormal creatinine clearance, and evidence of intestinal obstruction or perforation. Patients with amylase value >100 U/L were designated to have "elevated amylase level" for the purpose of this study.

Results

We enrolled 58 patients with MM, of which 29.3% (n = 17) were found to have elevated serum amylase levels. The median age of patients with elevated amylase was 65 years. The male-to-female ratio was 1.9:1. There was no statistical association between age, gender, type of heavy chain class, light chain, or high-risk cytogenetics. Among patients with the International Staging System (ISS), Stages I, II, and III, 20.8% (n = 5), 31.3% (n = 5), and 41.2% (n = 7) were noted to have elevated amylase levels. A statistically significant association was noted between the presence of extramedullary disease (EMD) and elevated amylase level (P = 0.028). Higher mortality (29.4% versus 17%) and shorter mean survival of (30.2 ± 3.3 months versus 51.7 + 4.9 months) were recorded in patients with elevated amylase levels in comparison to those with normal levels.

Conclusions

Elevated serum amylase level in MM is indicative of advanced ISS stage, the presence of EMD, higher risk of mortality, and shorter survival. Serum amylase can be used as a cost-effective tool in myeloma management.

Isolated Progression of Multiple Myeloma into the Extramedullary Plasmacytoma of Dura Mater: A Case Report and Review of the Literature

Multiple myeloma (MM) is a disease caused by the uncontrolled proliferation of clonal plasma cells in bone marrow. Extramedullary plasma cell infiltrations may occur at the time of diagnosis but usually arise during systemic disease progression. Central nervous system (CNS) plasmacytomas are extremely rare (less than 1% of patients with MM) and usually occur as a result of systemic disease progression. The frequency of extramedullary progression to CNS without simultaneous systemic progression is not known. Here, we present a challenging case in which local disease progression to CNS occurred without any signs of systemic progression. The extramedullary plasmacytoma originated from the dura mater of the brain mimicking a brain tumor. We review and discuss further treatment options that are available in such rare clinical scenarios in relation to the treatment already undertaken.

Comparison of clinical characteristics, treatment efficacy and survival in patients with newly diagnosed multiple myeloma with single- versus multi-site extramedullary invasion

PURPOSE

We aimed to compare the clinical characteristics, treatment efficacy and survival in patients with newly diagnosed multiple myeloma with single- versus multi-site extramedullary invasion.

METHODS

A total of 90 extramedullary multiple myeloma (EMM) patients were included. We compared the characteristics, overall remission rates (ORRs) and survival among patients with single-site and multi-site invasions. Comparison was also done regarding extramedullary-bone-related (EM-B) and extramedullary-extraosseous (EM-E) multiple myeloma patients.

RESULTS

Patients with multi-site invasion had higher LDH (179.0 U/L) than single-site invasion (P = 0.016). Significantly higher LDH was also showed in patients with EM-E (189.4 U/L) than EM-B (P = 0.025). The ORR of patients with single-site invasion (72.1%) was not significantly higher than multi-site invasion (68.2%) (P = 0.690). But the ORR of patients with EM-B was significantly higher than EM-E (78.2 vs. 56.3%, P = 0.031). Among patients with single-site invasion, the multivariate survival analysis showed that PI plus IMiD regimen significantly improved the PFS (P < 0.05). Among patients with multi-site invasion or with EM-B, the multivariate survival analysis confirmed the associations of rISS III with poor PFS and OS (P < 0.05). Among patients with EM-E, plasma cell percentage ≥ 20% was associated with significantly poor PFS and OS (P < 0.05).

CONCLUSION

rISS stage III was possibly associated with poor survival of EMM patients with multi-site invasion or with EM-B. Plasma cell percentage ≥ 20% was associated with poor survival of EMM patients with EM-E. Comparison should not only be done between single- and multi-site invasions, but also between EM-B and EM-E.

The evolving diagnosis and treatment paradigms of multiple myeloma in China: 15 years' experience of 1256 patients in a national medical center

BACKGROUND

Significant advances in multiple myeloma (MM) over the past 15 years led to exciting changes in the management of MM patients in China, which in turn brought about the early diagnoses, precise risk stratifications, and improved prognoses.

METHODS

We summarized the dynamic changes in the management of newly diagnosed (ND) MM in a national medical center, crossing the old and novel drug era. Demographics, clinical characteristics, first-line treatment, response rate, and survival were retrospectively collected among NDMMs diagnosed in Zhongshan Hospital Fudan University from January 2007 to October 2021.

RESULTS

Of the 1256 individuals, median age was 64 (range 31-89) with 45.1% patients >65 years. About 63.5% were male, 43.1% were at ISS stage III and 9.9% had light-chain amyloidosis. Patients with abnormal ratio of free light chain (80.4%), extramedullary disease (EMD, 22.0%), and high-risk cytogenetic abnormalities (HRCA, 26.8%) were detected by novel detection techniques. The best confirmed ORR was 86.5%, including 39.4% with CR. Short- and long-term PFS and OS rates persistently increased each year along with increasing novel drug applications. Median PFS and OS were 30.9 and 64.7 months. Advanced ISS stage, HRCA, light-chain amyloidosis and EMD independently predicted an inferior PFS. First-line ASCT indicated a superior PFS. Advanced ISS stage, elevated serum LDH, HRCA, light-chain amyloidosis, and receiving PI/IMiD-based regimen versus PI+IMiD-based regimen independently indicated a poorer OS.

CONCLUSIONS

In brief, we illustrated a dynamic landscape of MM patients in a national medical center. Chinese MM patients evidently benefited from newly introduced techniques and drugs in this field.

Unusual Extramedullary Manifestation in Multiple Myeloma: Bilateral Synchronous Testicular Infiltration

ABSTRACT

A 73-year-old man with multiple myeloma (initial diagnosis 21 months earlier) was referred to our center for a whole-body 18 F-FDG PET/CT. We detected a bilateral synchronous testicular manifestation, which was confirmed by histopathology after orchiectomy. Besides hypermetabolic lesions in the spine and ribs (most likely old fractures), known osteolysis showed no uptake. Extramedullary manifestation occurs in 13% to 20% of cases, among these 4% demonstrate testicular manifestation, which is associated with poor survival rates. Optimal therapy management is still unclear, due to limited data. To the authors' knowledge, so far only 3 comparable cases have been described.

Multiple myeloma presenting as a cervical intraforaminal tumor: A case report and review of literature

Multiple myeloma (MM) is a hematological malignancy with characteristic clonal plasma cell proliferation and production of monoclonal immunoglobulins. Although it can often metastasize to the bony spine, completely extravertebral and extra-/intradural manifestations are exceedingly rare. In this case report, we describe a 51-year-old male patient with cervical extradural and intraforaminal MM who was surgically treated in our department. Clinical findings and radiological images were retrieved from medical records and an imaging system. This unusual localization of MM and similar cases in the literature are reviewed in detail. The patient underwent tumor resection via a ventral approach, and postoperative MRI demonstrated a sufficient decompression of neural structures. No new neurological deficits were observed at subsequent follow-ups. Although 7 cases of extramedullary extradural manifestations of multiple myeloma have been described in the literature so far, this is the first case of intraforaminal extramedullary multiple myeloma located in the cervical spine and treated by surgery.

Analysis of High-Risk Extramedullary Relapse Factors in Newly Diagnosed MM Patients

Extramedullary relapse of multiple myeloma (MM) is often resistant to existing treatments, and has an extremely poor prognosis, but our understanding of extramedullary relapse is still limited. The incidence, clinical characteristics, impact on the prognosis of extramedullary relapse, and the risk factors for extramedullary relapse in NDMM patients were analyzed. Among the 471 NDMM patients, a total of 267 patients had disease relapse during follow-up, including 64 (24.0%) patients with extramedullary relapse. Extramedullary relapse was more common in patients with younger age, IgD subtype, elevated LDH, extensive osteolytic lesions, extramedullary involvement, and spleen enlargement at the time of MM diagnosis. Survival analysis showed that extramedullary relapse patients had significantly worse median OS than patients with relapse but without extramedullary involvement (30.8 months vs. 53.6 months, p = 0.012). Multivariate analysis confirmed that elevated LDH (OR = 2.09, p = 0.023), >2 osteolytic lesions (OR = 3.70, p < 0.001), extramedullary involvement (OR = 3.48, p < 0.001) and spleen enlargement (OR = 2.27, p = 0.011) at the time of MM diagnosis were independent risk factors for extramedullary relapse in NDMM patients. Each of the above four factors was assigned a value of 1 to form the extramedullary relapse prediction score, and the 3-year extramedullary relapse rates of patients in the 0−2 and 3−4 score groups were 9.0 % and 76.7 %, respectively. This study suggested that extramedullary relapse was associated with poor clinical characteristics and poor prognosis in NDMM patients. The extramedullary relapse prediction score model composed of LDH, osteolytic lesions, extramedullary involvement and spleen enlargement has a better ability to predict extramedullary relapse than the existing ISS and R-ISS stages.

Five-year remission without disease progression in a patient with relapsed/refractory multiple myeloma with extramedullary disease treated with LCAR-B38M chimeric antigen receptor T cells in the LEGEND-2 study: a case report

BACKGROUND

Multiple myeloma remains incurable despite treatment advancements over the last 20 years. LCAR-B38M Cells in Treating Relapsed/Refractory Multiple Myeloma was a phase 1, first-in-human, investigator-initiated study in relapsed/refractory multiple myeloma conducted at four sites in China. The study used LCAR-B38M chimeric antigen receptor-T cells expressing two B-cell maturation antigen-targeting single-domain antibodies designed to confer avidity, and a CD3ζ signaling domain with a 4-1BB costimulatory domain to optimize T-cell activation and proliferation. This chimeric antigen receptor construct is identical to ciltacabtagene autoleucel. In the LEGEND-2 study (n = 57, Xi'an site), overall response rate was 88%; median (95% CI) progression-free survival and overall survival were 19.9 (9.6-31.0) and 36.1 (26.4-not evaluable) months, respectively; and median follow-up was 25 months. This case study reports on a patient with relapsed/refractory multiple myeloma (λ light chain type) who was treated with LCAR-B38M chimeric antigen receptor T cells in the LEGEND-2 study (Xi'an site); he had received five prior lines of treatment and had extensive extramedullary lesions.

CASE PRESENTATION

The patient, a 56-year-old Asian male, received cyclophosphamide (500 mg daily × 3 days) as lymphodepletion therapy and a total dose of 0.5 × 10⁶ chimeric antigen receptor + T cells/kg split into three infusions (days 1, 24, and 84 from June to August 2016). He experienced grade 2 cytokine release syndrome after the first infusion; all symptoms resolved with treatment. No cytokine release syndrome occurred following the second and third infusions. His λ light chain levels decreased and normalized 20 days after the first infusion, and extramedullary lesions were healed as of January 2018. He has sustained remission for 5 years and received no other multiple myeloma treatments after LCAR-B38M chimeric antigen receptor T cell infusion. As of 30 October 2020, the patient is still progression-free and has maintained minimal residual disease-negative (10^-4) complete response status for 52 months.

CONCLUSIONS

This case provides support that treatment with LCAR-B38M chimeric antigen receptor T cells can result in long-term disease remission of 5 or more years without disease progression in a heavily pretreated patient with extensive extramedullary disease and no other treatment options.

Clinical features and prognosis of multiple myeloma and orbital extramedullary disease: Seven cases report and review of literature

BACKGROUND

Multiple myeloma (MM) complicated with extramedullary disease (EMD) has a poor prognosis and is a limiting factor in the treatment of MM, and no standard treatment is recommended in international guidelines. Few studies have reported MM with periorbital EMD.

CASE SUMMARY

In this paper, the clinical characteristics and survival of seven patients with multiple myeloma and orbital are described and analyzed. The common ocular symptoms were blurred vision, proptosis and/or eye movement disorders, IgG type MM may be a risk factor for orbital involvement. Of them, six patients were treated with bortezomib-based regimens. The median overall survival (OS) and progression free survival for the entire cohort were 48 and 33 mo, respectively, which was much worse than the OS reported for MM patients without orbital EMD.

CONCLUSION

Orbital MM may have significantly shortened survival for the entire cohort, so multidisciplinary collaboration is emphasized and recommended in the diagnosis and treatment of these difficult cases.

A prognostic model for patients with primary extramedullary multiple myeloma

Background: Extramedullary disease is a manifestation of multiple myeloma, the prognosis of which remains poor even in the era of novel drugs. Therefore, we aimed to develop a predictive model for patients with primary extramedullary multiple myeloma (EMM). Methods: Clinical and laboratory data of patients diagnosed with primary EMM between July 2007 and July 2021 were collected and analyzed. Univariate and least absolute shrinkage and selection operation Cox regression analyses (LASSO) were used to select prognostic factors for overall survival (OS) to establish a nomogram prognostic model. The performance of the model was evaluated using concordance index which was internally validated by bootstraps with 1,000 resample, area under the curve (AUCs), and calibration curves. Results: 217 patients were included in this retrospective study. Patients with EMM had a higher rate of belonging to the male sex, age >50 years, advanced Durie-Salmon stage III, hypercalcemia, and low hemoglobin level. Compared with patients with bone-related extramedullary disease, those with extraosseous-related extramedullary disease had a higher frequency of advanced Durie-Salmon stage III, lower rate of hypercalcemia, and elevated prothrombin time. The OS and progression-free survival (PFS) of patients with bone-related extramedullary disease were significantly higher than those of patients with extraosseous-related extramedullary disease. After the univariate and LASSO analyses, six prognostic factors, including performance status, number of extramedullary involved sites, β2-microglobulin, lactate dehydrogenase, monocyte-lymphocyte ratio, and prothrombin time, were integrated to establish a nomogram. The model showed robust discrimination with a concordance index (C-index) of 0.775 (95% confidence interval [CI], 0.713-0.836), internally validated with the corrected C-index of 0.756, and excellent performance in time-dependent AUCs compared with other staging systems. The AUCs for 1-, 3-, and 5-year OS were 0.814, 0.744, and 0.832, respectively. The calibration curves exhibited good consistency between the observed and nomogram-predicted OS. The 5-year OS of patients in the high-risk group (23.3%; 95% CI, 13.9%-39.3%) was much worse than that in the low-risk group (73.0%; 95% CI, 62.5%-85.4%; p < 0.001). Conclusion: The nomogram predictive model based on six clinical variables showed good prognostic performance and could better predict individual survival in patients with EMM.

Involvement of Small Non-Coding RNA and Cell Antigens in Pathogenesis of Extramedullary Multiple Myeloma

Extramedullary multiple myeloma (EMD) is an aggressive disease; malignant plasma cells lose their dependence in the bone marrow microenvironment and migrate into tissues. EMD is a negative prognostic factor of survival. Using flow cytometry and next-generation sequencing, we aimed to identify antigens and microRNAs (miRNAs) involved in EMD pathogenesis. Flow cytometry analysis revealed significant differences in the level of clonal plasma cells between MM and EMD patients, while the expression of CD markers was comparable between these two groups. Further, miR-26a-5p and miR-30e-5p were found to be significantly down-regulated in EMD compared to MM. Based on the expression of miR-26a-5p, we were able to distinguish these two groups of patients with high sensitivity and specificity. In addition, the involvement of deregulated miRNAs in cell cycle regulation, ubiquitin-mediated proteolysis and signaling pathways associated with infections or neurological disorders was observed using GO and KEGG pathways enrichment analysis. Subsequently, a correlation between the expression of analyzed miRNAs and the levels of CD molecules was observed. Finally, clinicopathological characteristics as well as CD antigens associated with the prognosis of MM and EMD patients were identified. Altogether, we identified several molecules possibly involved in the transformation of MM into EMD.

Multiple myeloma with extramedullary plasmacytoma: pathogenesis and clinical case

Background. Multiple myeloma complicated by extramedullary plasmacytoma is an unfavorable variant of the disease. It remains unknown what triggers tumor transformation. The review presents literature data on the pathogenesis of extramedullary disease, as well as a clinical example of a comprehensive study of the tumor substrate.

Aim. To study the molecular and biological characteristics of the tumor substrate of the bone marrow and extramedullary plasmacytoma using various research methods.

Materials and methods. A 55-year-old patient was admitted to National Medical Research Center for Hematology with a diagnosis of multiple myeloma occurring with extramedullary plasmacytoma of the retroperitoneal space. dNA was isolated from samples of different localization (blood plasma, Cd138+ bone marrow cells, plasmacytoma and buccal epithelial cells). The profile of short tandem dNA repeats (STR) from the obtained samples was studied by multiplex polymerase chain reaction followed by fragment analysis. fluorescent in situ hybridization (fISH) of bone marrow Cd138+ cells was performed using various dNA probes. Comparative genomic hybridization on a microarray (arrayCGH) plasmacytoma dNA was also performed. The mutation profile of the KRAS, NRAS, BRAF genes was studied by Sanger sequencing in tumor samples of various localizations.

Results. The induction therapy (vCd (bortezomib + cyclophosphamide + dexamethasone), vRd (bortezomib + lenalidomide + dexamethasone), daratumumab therapy) was ineffective, death occurred 4 months after the first clinical manifestations appeared. Comparison of STR markers of circulating cell-free tumor dNA (cfdNA), Cd138+ bone marrow cells, and plasmacytoma revealed the largest number of involved loci exactly in plasmacytoma’ dNA. A mutation in the NRAS gene was found only in plasmacytoma’ dNA. This indicates the presence of another clone of tumor cells in the extra-medullary plasmacytoma. Molecular karyotyping of plasmacytoma using the arrayCGH method revealed rearrangements of many chromosomes. 1p32.3 bi-allelic deletion, amplification of 1q21, 8q24/MyC rearrangements and del17p13 were confirmed by arrayCGH molecular karyotyping and fISH studies in bone marrow and plasmacytoma.

Conclusion. A comprehensive molecular genetic study of the extramedullary plasmacytoma’ substrate is necessary to understand the pathogenesis mechanisms and, on this basis, to develop differentiated therapeutic approaches.

Clinical Characteristics and Prognosis of Multiple Myeloma With Myelomatous Pleural Effusion: A Retrospective Single-Center Study

Objectives: Myelomatous pleural effusion is a rare presentation of extramedullary disease in multiple myeloma, which has been reported with dismal prognosis. We aimed to explore whether it has distinctive clinical characteristics and outcomes compared to other anatomic locations of extramedullary involvements. Methods: Multiple myeloma patients diagnosed at our institution from 2010 to 2020 were retrieved retrospectively. In total, 42 pairs of patients with and without extramedullary disease were enrolled, including 13 with myelomatous pleural effusion. The clinical and laboratory parameters were collected and compared between different groups. Prognostic effect of myelomatous pleural effusion was assessed in cox regression model and Kaplan-Meier curves. Results: Myelomatous pleural effusion patients presented a higher level of β2-microglobulin (P = .041), greater prevalence of multisites extramedullary lesions (69.2% vs 38.0%, P = .036) and International Staging System stage III (76.9% vs 44.8%, P = .016). Median overall survival was 60.6 months in patients without extramedullary disease versus 35.0 months in patients with extramedullary disease (P = .045). Notably, median overall survival was 13.0 months in myelomatous pleural effusion patients versus 37.0 months in other extramedullary disease patients with a significant difference (P = .029). Furtherly, multivariate analysis recognized myelomatous pleural effusion as an independent prognostic indicator (Hazard ratio: 2.669, 95% CI [1.132-6.293], P = .025). Conclusion: Myelomatous pleural effusion patients presented heavier tumor burden and worse outcomes than other extramedullary diseases.

Unexpected Heterogeneity of Newly Diagnosed Multiple Myeloma Patients with Plasmacytomas

In multiple myeloma (MM), malignant plasma cells infiltrate the bone marrow. In some cases, plasma cells migrate out of the bone marrow creating either para-skeletal plasmacytomas (PS) or infiltrating soft tissues as extramedullary plasmacytomas (EMD). The aim of this study was to define risk groups in newly diagnosed MM (NDMM) patients with PS and EMD plasmacytomas. In total, 523 NDMM patients with PS plasmacytomas and 196 NDMM patients with EMD plasmacytomas were diagnosed in the Czech Republic between 2004 and 2021 using modern imaging methods. Patients’ data were analyzed from the Registry of Monoclonal Gammopathies of the Czech Myeloma Group. In NDMM patients with PS plasmacytomas, we found a subgroup with <5% of bone-marrow plasma cells to have the best prognosis (mPFS: 58.3 months (95% CI: 33.0−NA); mOS: not reached). The subgroup with >5% of bone-marrow plasma cells and ≥3 plasmacytomas had the worst prognosis (mPFS: 19.3 months (95% CI: 13.4−28.8), p < 0.001; mOS: 27.9 months (95% CI: 19.3−67.8), p < 0.001). Our results show association between tumor burden and prognosis of NDMM patients with plasmacytomas. In the case of PS plasmacytomas, NDMM patients with low BM PC infiltration have an excellent prognosis.

Extramedullary Multiple Myeloma: A Patient-Focused Review of the Pathogenesis of Bone Marrow Escape

Multiple myeloma (MM) is a neoplastic clonal proliferation of plasma cells, predominantly in the bone marrow. The presentation of MM in extramedullary tissue, particularly the liver, is uncommon with only a few reported cases in literature. We report a rare and unusual presentation of kappa light chain restricted MM with progression of disease to involve the liver. MM was initially diagnosed on bone marrow biopsy, initially treated with carfilzomib, lenalidomide and dexamethasone, later changed to bortezomib, daratumumab and dexamethasone. There was subsequent progression with a new biopsy-proven myelomatous liver lesion. The patient could not receive high-dose chemotherapy due to multiple co-morbidities and extent of disease and eventually succumbed to her disease rapidly. This article emphasizes the poor prognosis of extramedullary involvement in MM and the pathogenic mechanisms by which it develops. Based on a review of the literature of other cases and case series of solitary or diffuse myeloma involvement in the liver, high-dose chemotherapy in combination with proteasome inhibitors and immunomodulators has the best success rate with less relapse and progressive disease in extramedullary myeloma. Our analysis concluded that the gain of CD44, loss of CD56, loss of very late antigen-4 (VLA-4), imbalance of the chemokine receptor-4-chemokine ligand-12 (CXCR4-CXCL12) axis, metastasis-associated lung adenocarcinoma 1 (MALAT1) upregulation, RAS pathway activation as well as 13q and 17p deletions show an increased propensity of malignant plasma cells to leave the bone marrow and hone in extramedullary sites giving rise to more aggressive extramedullary diseases. Targeted therapeutics such as CD44v-directed therapy and reactivation of p53 to wild-type conformation could potentially be evaluated as treatment options in the future to improve outcomes in this aggressive form of MM, especially in patients with advanced disease and limited treatment options.

Paraskeletal and extramedullary plasmacytomas in multiple myeloma at diagnosis and at first relapse: 50-years of experience from an academic institution

From January 1970 to December 2018, 1304 patients were diagnosed with multiple myeloma (MM) at our institution and 256 (19.6%) had plasmacytomas (Ps) (paraskeletal –PPs- 17.6%, extramedullary –EMPs-1.9%). Patients with Ps had lower serum M-protein and less advanced ISS stage than those without. At first relapse, 192 out of 967 patients (19.8%) developed Ps (PPs 14.6%, EMPs 5.1%). The only factor associated with Ps at relapse was the presence of Ps at diagnosis (46% vs 13%, p < 0.00001) with no impact with exposure to novel drugs or previous autologous stem-cell transplantation (ASCT). The median overall survival (OS) was 45, 44 and 20 months for patients without Ps, PPs and EMPs, respectively (p = 0.013). Patients with PPs who underwent ASCT had similar OS than those without Ps (98 vs. 113 months) and significantly longer than those with EMPs (98 vs 47 months, p = 0.006). In patients non-eligible for ASCT the presence of PPs or EMPs was associated with shorter OS compared with patients without Ps (32 vs. 24 vs. 6 months, p = 0.009). In the relapsed setting, a significant survival benefit was observed beyond the year 2000, but still with significant differences among patients without Ps, PPs and EMPs (37 vs 22 vs 16 months, p = 0.003). Importantly, rescue therapy with combinations of proteasome-inhibitors plus immunomodulatory drugs was associated with prolonged OS from first relapse (over 6 years), even in patients with EMPs.

Advanced Imaging in Multiple Myeloma: New Frontiers for MRI

Plasma cell dyscrasias are estimated to newly affect almost 40,000 people in 2022. They fall on a spectrum of diseases ranging from relatively benign to malignant, the malignant end of the spectrum being multiple myeloma (MM). The International Myeloma Working Group (IMWG) has traditionally outlined the diagnostic criteria and therapeutic management of MM. In the last two decades, novel imaging techniques have been employed for MM to provide more information that can guide not only diagnosis and staging, but also treatment efficacy. These imaging techniques, due to their low invasiveness and high reliability, have gained significant clinical attention and have already changed the clinical practice. The development of functional MRI sequences such as diffusion weighted imaging (DWI) or intravoxel incoherent motion (IVIM) has made the functional assessment of lesions feasible. Moreover, the growing availability of positron emission tomography (PET)–magnetic resonance imaging (MRI) scanners is leading to the potential combination of sensitive anatomical and functional information in a single step. This paper provides an organized framework for evaluating the benefits and challenges of novel and more functional imaging techniques used for the management of patients with plasma cell dyscrasias, notably MM.

Apical lung mass—A rare presentation of multiple myeloma

Multiple myeloma is a neoplastic proliferation of immunoglobulin-producing plasma cells with clinical features resulting from infiltration of plasma cells into bones and other organs. Multiple myeloma manifesting as an apical lung mass is less common and very few cases have been reported. We report the case of a 50-year-old female who presented with an apical lung mass which happened to be multiple myeloma arising from the upper ribs into the lung. At the time of diagnosis, patient had axillary lymph node metastasis with extensive bony involvement. This case report and literature review provides insight to a rare but significant presentation of multiple myeloma and highlights the need to consider multiple myeloma as a possible differential for Pancoast tumor in the appropriate clinical setting as this could potentially affect management options and patient outcome.

Cutaneous involvement in relapsed multiple myeloma

Cutaneous involvement in multiple myeloma with extramedullary disease is rare. We report the case of a refractory multiple myeloma patient who developed a cutaneous lesion. Histopathology revealed dermal immature plasma cell infiltrate with a lack of CD138 expression. This cutaneous location was associated with an aggressive clinical course and short survival.

Plasmablastic lymphoma: An update

Plasmablastic lymphoma (PBL) is a highly aggressive B cell non-Hodgkin lymphoma frequently associated with immunosuppression, particularly human immunodeficiency virus (HIV) infection. Although PBL is rare globally, South Africa has a high burden of HIV infection leading to a higher incidence of PBL in the region. Laboratory features in PBL may overlap with plasmablastic myeloma and other large B cell lymphomas with plasmablastic or immunoblastic morphology leading to diagnostic dilemmas. There are, however, pertinent distinguishing laboratory features in PBL such as a plasma cell immunophenotype with MYC overexpression, expression of Epstein-Barr virus-encoded small RNAs and lack of anaplastic lymphoma kinase (ALK) expression. This review aims to provide a summary of current knowledge in PBL, focusing on the epidemiology, pathophysiology, laboratory diagnosis and clinical management.

Multiple Myeloma Therapy: Emerging Trends and Challenges

Multiple myeloma (MM) is a complex hematologic malignancy characterized by the uncontrolled proliferation of clonal plasma cells in the bone marrow that secrete large amounts of immunoglobulins and other non-functional proteins. Despite decades of progress and several landmark therapeutic advancements, MM remains incurable in most cases. Standard of care frontline therapies have limited durable efficacy, with the majority of patients eventually relapsing, either early or later. Induced drug resistance via up-modulations of signaling cascades that circumvent the effect of drugs and the emergence of genetically heterogeneous sub-clones are the major causes of the relapsed-refractory state of MM. Cytopenias from cumulative treatment toxicity and disease refractoriness limit therapeutic options, hence creating an urgent need for innovative approaches effective against highly heterogeneous myeloma cell populations. Here, we present a comprehensive overview of the current and future treatment paradigm of MM, and highlight the gaps in therapeutic translations of recent advances in targeted therapy and immunotherapy. We also discuss the therapeutic potential of emerging preclinical research in multiple myeloma.

Minimal residual disease detection by next-generation sequencing in multiple myeloma: Promise and challenges for response-adapted therapy

Assessment of minimal residual disease (MRD) is becoming a standard diagnostic tool for curable hematological malignancies such as chronic and acute myeloid leukemia. Multiple myeloma (MM) remains an incurable disease, as a major portion of patients even in complete response eventually relapse, suggesting that residual disease remains. Over the past decade, the treatment landscape of MM has radically changed with the introduction of new effective drugs and the availability of immunotherapy, including targeted antibodies and adoptive cell therapy. Therefore, conventional serological and morphological techniques have become suboptimal for the evaluation of depth of response. Recently, the International Myeloma Working Group (IMWG) introduced the definition of MRD negativity as the absence of clonal Plasma cells (PC) with a minimum sensitivity of <10⁻⁵ either by next-generation sequencing (NGS) using the LymphoSIGHT platform (Sequenta/Adaptative) or by next-generation flow cytometry (NGF) using EuroFlow approaches as the reference methods. While the definition of the LymphoSIGHT platform (Sequenta/Adaptive) as the standard method derives from its large use and validation in clinical studies on the prognostic value of NGS-based MRD, other commercially available options exist. Recently, the LymphoTrack assay has been evaluated in MM, demonstrating a sensitivity level of 10⁻⁵, hence qualifying as an alternative effective tool for MRD monitoring in MM. Here, we will review state-of-the-art methods for MRD assessment by NGS. We will summarize how MRD testing supports clinical trials as a useful tool in dynamic risk-adapted therapy. Finally, we will also discuss future promise and challenges of NGS-based MRD determination for clinical decision-making. In addition, we will present our real-life single-center experience with the commercially available NGS strategy LymphoTrack-MiSeq. Even with the limitation of a limited number of patients, our results confirm the LymphoTrack-MiSeq platform as a cost-effective, readily available, and standardized workflow with a sensitivity of 10⁻⁵. Our real-life data also confirm that achieving MRD negativity is an important prognostic factor in MM.

Advances in the treatment of extramedullary disease in multiple myeloma

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Extramedullary multiple myeloma results in an adverse prognosis.

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Novel agents such as bortezomib, lenalidomide, pomalidomide, isatuximab and selinexor showed efficacy and were recommended to treat EMD.

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For EMD at special sites, marizomib has advantages in the treatment of CNS-MM; Daratumumab combining with intrapleural bortezomib administration is active in treating myelomatous pleural effusion.

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Based on treatment experience of EMD in our department, we summarized treatment approach for EMD.

Extramedullary disease (EMD) is characterized by plasma cells outside of bone marrow in multiple myeloma (MM) patients, which results in an adverse prognosis. The cornerstone of treatment consists of combination therapy including proteasome inhibitors, immunomodulatory agents, steroids, followed by consolidative autologous hematopoietic stem cell transplantation in eligible patients. This review summarized the recent advances in the treatment of EMD. Bortezomib based therapy showed efficacy and was recommended to treat EMD. Marizomib had advantages in the treatment of central nervous system-multiple myeloma (CNS-MM) because of its good central nervous system penetrability. Immunomodulatory drugs such as lenalidomide and pomalidomide have been reported to be effective. Isatuximab and selinexor were also active. Based on the treatment experience of EMD in our department, we summarized treatment approach for EMD. However, the benefits of patients with EMD from the new era of novel drugs were limited. Novel drugs combination, monoclonal antibody, molecular targeted therapy, cellular immunotherapy and autologous stem cell transplantation (ASCT) are under investigation. Therapeutic studies and clinical trials specifically target EMD should be conducted. Hopefully, these treatment options for EMD will be demonstrated efficacy in the future.

Solitary Extramedullary Plasmacytoma of the Larynx and Secondary Laryngeal Involvement in Plasma Cell Myeloma: Single-Centre Retrospective Analysis and Systematic Literature Review

The involvement of the larynx in plasma cell myeloma (PCM) may manifest as solitary extramedullary plasmacytoma of the larynx (sEMP-L) or as infiltration of the larynx during newly diagnosed or relapsed systemic disease with bone marrow involvement (plasma cell myeloma with laryngeal involvement, PCM-L). To increase knowledge about these rare conditions, we performed a retrospective analysis along with a comprehensive literature review of cases of sEMP-L or PCM-L. Six patients (two sEMP-L and four PCM-L) were identified in our tertiary laryngological centre from 2009 to 2021, constituting 0.88% of all malignant laryngeal tumours. The literature search yielded 187 cases, including 152 sEMP-L and 35 sPCM-L. A comparison of baseline characteristics between sEMP-L and PCM-L performed in the combined cohort of cases from literature review and retrospective analysis revealed that patients with sEMP-L were younger (56 vs. 64 years, p ≤ 0.001) and presented less commonly with thyroid or cricoid cartilage involvement (2.2% vs. 30.8%, p ≤ 0.001). The prognosis of sEMP-L was better than PCM-L (overall survival 86% vs. 55% at 5 years, p = 0.002). Analysis of potential factors that could influence progression-free survival (PFS) in the group of sEMP-L revealed that male sex and cartilage involvement negatively affected PFS in univariate analyses, while only cartilage involvement retained statistical significance in multivariate analysis (HR = 19.94, p = 0.024). In conclusion, PCM with laryngeal involvement is sporadic. Secondary involvement of the larynx during PCM might be more common than sEMP-L and is associated with worse survival. The involvement of cartilage adversely influences the outcome of sEMP-L.

Bone-Related Extramedullary Disease in Newly Diagnosed Myeloma Patients is an Independent Poor Prognostic Predictor

Background

Bone-related extramedullary disease (EMD-B) is mass of clonal plasma cells derived from adjacent bone lesions and has obvious heterogeneities in clinical outcomes. This retrospective study aims to evaluate the treatment outcomes and long-term prognosis of newly diagnosed myeloma patients with EMD-B.

Methods

This was a retrospective study conducted in Beijing Chaoyang Hospital from January 1, 2010 to December 31, 2019. Seventy-seven newly diagnosed multiple myeloma patients with EMD-B were selected. Propensity score matching (1:2) was used to match patients with and without EMD-B. After matching, 132 patients without extramedullary disease (non-EMD) were included in the study. All patients received bortezomib-based regimens as induction therapy.

Results

After matching, baseline data of the 2 groups were comparable. The Cox regression analysis of patients with EMD-B showed that age, paravertebral lesions, and immunoglobulin D (IgD) type may have adverse effects on survival. Bone-related extramedullary disease at new diagnosis was a risk predictor of survival (hazard ration [HR] = 1.80, 95% confidence interval [CI]: 1.09-2.98, P = .022). The median survival time of the EMD-B group was significantly shorter than that of the non-EMD group (52 months vs 96 months, P = .043). Induction therapy did not show any significant differences in effectiveness between the 2 groups. Autologous stem cell transplantation (ASCT) significantly increased complete remission rate of patients with EMD-B (EMD-B vs non-EMD: no ASCT 15.7% vs 31.9%, P = .035; ASCT 42.3% vs 48.8%, P = .626) and improved their median overall survival rate (EMD-B vs non-EMD: no ASCT 49 months vs 75 months, P = .003; ASCT not reached vs 96 months, P = .505).

Conclusions

This study demonstrated that newly diagnosed myeloma patients with EMD-B had poor outcomes, which could be improved by ASCT.

Central Nervous System Myeloma and Unusual Extramedullary Localizations: Real Life Practical Guidance

Central nervous system localization of multiple myeloma (CNS-MM) accounts for about 1% of all MM during disease course or even rarer at diagnosis. A difference in the origin, i.e., osteodural or primary dural vs leptomeningeal/intraparenchymal, seems to define two distinct types of intracranial myeloma, with different clinical behavior. CNS-MM may occur also as a presentation of MM. Treatment is still unsatisfactory and many treatments have been reported: chemotherapy, intrathecal therapy, and radiotherapy, with dismal prognosis. Other sites of myeloma localization could be also of interest and deserve description. Because of the rarity and aggressiveness of the disease clinicians are often doubtful on how to treat it since there is no general agreement. Moreover, recent drugs such as the anti CD38 monoclonal antibody, immunomodulatory drugs, and proteasome inhibitors have changed the treatment of patients with MM with a significant improvement in overall response and survival. The role of novel agents in CNS MM management and unusual presentations will be discussed as well as the potential role of other new immunomodulatory drugs and proteasome inhibitors that seem to cross the blood-brain barrier. The purpose of this review is to increase awareness of the clinical unusual presentation and neuroradiological findings, give practical diagnostic advice and treatment options algorithm.

Molecular Impact of the Tumor Microenvironment on Multiple Myeloma Dissemination and Extramedullary Disease

Multiple myeloma (MM) is the most common malignant monoclonal disease of plasma cells. Aside from classical chemotherapy and glucocorticoids, proteasome inhibitors, immunomodulatory agents and monoclonal antibodies are used in the current treatment scheme of MM. The tumor microenvironment (TME) plays a fundamental role in the development and progression of numerous solid and non-solid cancer entities. In MM, the survival and expansion of malignant plasma cell clones heavily depends on various direct and indirect signaling pathways provided by the surrounding bone marrow (BM) niche. In a number of MM patients, single plasma cell clones lose their BM dependency and are capable to engraft at distant body sites or organs. The resulting condition is defined as an extramedullary myeloma (EMM). EMMs are highly aggressive disease stages linked to a dismal prognosis. Emerging literature demonstrates that the dynamic interactions between the TME and malignant plasma cells affect myeloma dissemination. In this review, we aim to summarize how the cellular and non-cellular BM compartments can promote plasma cells to exit their BM niche and metastasize to distant intra-or extramedullary locations. In addition, we list selected therapy concepts that directly target the TME with the potential to prevent myeloma spread.