Extramedullary Myeloma Research Articles

Challenges in the treatment of soft-tissue plasmacytoma: a retrospective analysis of 120 patients with extramedullary multiple myeloma

PurposeDespite the development of novel drugs and the widespread use of hematopoietic cell transplantation, the prognosis of patients (pts) with multiple myeloma and extramedullary involvement (soft-tissue plasmacytoma, STP) is rather unfavorable.MethodsA retrospective analysis of 120 pts with STP treated between 2007 and 2022 was performed. The effects of demographic and clinical characteristics on treatment response, progression-free survival (PFS), and overall survival (OS) were evaluated.ResultsThe rate of serological response to first-line STP treatment (at least partial remission) was 67%, and the rate of imaging response was 59%. With a median follow-up of 84.2 months, the median PFS was 10.5 months (primary STP: 20.2 months; secondary STP: 5.8 months), and the median OS was 24.5 months (primary STP: 34.5 months; secondary STP: 12.4 months). Based on the multivariate regression analysis, secondary STP (HRPFS 2.75; HROS 2.63) and organ involvement (HRPFS 1.45; HROS 1.68) were found to be negative prognostic factors of both PFS and OS. In a prognostic model, pts with at least one of these factors had a significantly worse PFS (HRPFS 3.31) and OS (HROS 3.45) than those with none risk factor.ConclusionIn pts with STP, risk-adapted treatment strategies including immunotherapies and cell therapies are urgently required.

Leukocyte immunoglobulin-like receptor B4: A keystone in immune modulation and therapeutic target in cancer and beyond.

Leukocyte immunoglobulin-like receptor B4 (LILRB4) significantly impacts immune regulation and the pathogenesis and progression of various cancers. This review discusses LILRB4's structural attributes, expression patterns in immune cells, and molecular mechanisms in modulating immune responses. We describe the influence of LILRB4 on T cells, dendritic cells, NK cells, and macrophages, and its dual role in stimulating and suppressing immune activities. The review discusses the current research on LILRB4's involvement in acute myeloid leukemia, chronic lymphocytic leukemia, and solid tumors, such as colorectal cancer, pancreatic cancer, non-small cell lung cancer, hepatocellular carcinoma, and extramedullary multiple myeloma. The review also describes LILRB4's role in autoimmune disorders, infectious diseases, and other conditions. We evaluate the recent advancements in targeting LILRB4 using monoclonal antibodies and peptide inhibitors and their therapeutic potential in cancer treatment. Together, these studies underscore the need for further research on LILRB4's interactions in the tumor microenvironment and highlight its importance as a therapeutic target in oncology and for future clinical innovations.

Extramedullary Pulmonary Manifestations of Relapsed/Refractory Multiple Myeloma: A Case Series and Brief Review of the Literature

Extramedullary myeloma with pulmonary and pleural involvement is rare and can present in different ways. Here we present two cases of extramedullary pulmonary disease in relapsed/refractory multiple myeloma. Background: Multiple myeloma remains an incurable disease with unmet need for new treatments for high-risk disease such as extramedullary plasmacytoma. Relapses can occur at different stages due to the heterogeneity of the disease. While relapsed/refractory disease can be challenging to treat, progression can also lead to extramedullary disease which indicates an aggressive form with poor outcomes. Pulmonary extramedullary disease can present in various ways, such as a lung mass, parenchymal infiltrates, pleural mass, or pleural effusion. Objective: Our case series highlights two different presentations of pulmonary extramedullary disease and a review of the treatment of relapsed/refractory myeloma. Our patients highlight the progression of their multiple myeloma due to the aggressive nature of their extramedullary disease. Their cases emphasize the importance of new targeted treatments to treat extramedullary disease and penta-refractory disease as there is no currently accepted standard regimen for this difficult to treat condition.

Spatial transcriptomics reveals profound subclonal heterogeneity and T-cell dysfunction in extramedullary myeloma

AbstractExtramedullary disease (EMD) is a high-risk feature of multiple myeloma (MM) and remains a poor prognostic factor, even in the era of novel immunotherapies. Here, we applied spatial transcriptomics (RNA tomography for spatially resolved transcriptomics [tomo-seq] [n = 2] and 10x Visium [n = 12]) and single-cell RNA sequencing (n = 3) to a set of 14 EMD biopsies to dissect the 3-dimensional architecture of tumor cells and their microenvironment. Overall, infiltrating immune and stromal cells showed both intrapatient and interpatient variations, with no uniform distribution over the lesion. We observed substantial heterogeneity at the copy number level within plasma cells, including the emergence of new subclones in circumscribed areas of the tumor, which is consistent with genomic instability. We further identified the spatial expression differences between GPRC5D and TNFRSF17, 2 important antigens for bispecific antibody therapy. EMD masses were infiltrated by various immune cells, including T cells. Notably, exhausted TIM3+/PD-1+ T cells diffusely colocalized with MM cells, whereas functional and activated CD8+ T cells showed a focal infiltration pattern along with M1 macrophages in tumor-free regions. This segregation of fit and exhausted T cells was resolved in the case of response to T-cell–engaging bispecific antibodies. MM and microenvironment cells were embedded in a complex network that influenced immune activation and angiogenesis, and oxidative phosphorylation represented the major metabolic program within EMD lesions. In summary, spatial transcriptomics has revealed a multicellular ecosystem in EMD with checkpoint inhibition and dual targeting as potential new therapeutic avenues.

Extraosseous Plasmacytomas: A Radiologist's Perspective-A Narrative Review of the Literature.

Extraosseous plasmacytomas (EPs) are rare neoplasms originating from plasma cells, often associated with multiple myeloma. EPs are classified into three subtypes: extramedullary myeloma, solitary extramedullary plasmacytoma (SEP), and multiple solitary plasmacytomas. They can manifest in various anatomical sites, including the lung, mediastinum, breast, liver, pancreas, stomach, mesentery, kidney, small and large bowel, testis, and soft tissue. Despite their rarity, EPs present a diagnostic challenge due to their non-specific imaging appearances, which can mimic other neoplastic and inflammatory conditions. This review aims to describe the radiographic features of EPs in the chest, abdomen, and pelvis based on a thorough analysis of the existing literature. While imaging plays a crucial role in the detection and characterization of EPs, histological confirmation is necessary to differentiate them from other neoplastic entities. The review underscores the importance of considering EPs in the differential diagnosis, particularly in patients with a history of multiple myeloma. Understanding the imaging characteristics of EPs is essential for accurate diagnosis and appropriate management. Early imaging is crucial in these patients to exclude the possibility of EP, as timely diagnosis can significantly impact patient outcomes.

Impact of extramedullary multiple myeloma on outcomes with idecabtagene vicleucel

Idecabtagene vicleucel (Ide-cel) has demonstrated excellent efficacy and durable responses in patients with relapsed/refractory multiple myeloma (RRMM). However, the outcomes with ide-cel in patients with extramedullary disease (EMD) remain incompletely characterized. We included patients with RRMM treated with ide-cel between May 2021 and April 2023 across 11 US academic institutions. Visceral or soft tissue lesions non-contiguous from bone was classified as EMD. Time-to-event analyses were performed from date of ide-cel infusion. Among 351 patients, 84 (24%) had EMD prior to infusion. The median follow-up from ide-cel infusion was 18.2 months (95% CI: 17-19.3). The day 90 overall response rates (ORR) were 52% vs. 82% for the EMD and non-EMD cohorts, respectively (p < 0.001). The median progression-free survival (PFS) was 5.3 months (95% CI: 4.1–6.9) for the EMD cohort vs. 11.1 months (95% CI: 9.2–12.6; p < 0.0001) for the non-EMD cohort. In a multivariable analysis, EMD was an independent predictor of inferior PFS [hazard ratio 1.5 (1.1–2.2), p = 0.02]. The median overall survival was 14.8 months [95% CI: 9-Not reached (NR)] vs. 26.9 months (26.3 vs. NR, p = 0.006) for the EMD and non-EMD cohorts, respectively. Extramedullary disease represents an independent predictor of inferior day 90 ORR and PFS among patients treated with ide-cel.

Real world outcomes of high dose melphalan conditioning prior to autologous stem cell transplant in extramedullary multiple myeloma vs. multiple myeloma without extramedullary involvement: A single center experience.

7550 Background: Extramedullary multiple myeloma (EMM) is defined as the presence of multiple myeloma plasma cells, which develop outside of the bone marrow. It is an aggressive form of multiple myeloma that is associated with a poor prognosis. The current standard of care for multiple myeloma consists of induction, high dose melphalan autologous stem cell transplant (ASCT), followed by maintenance. However, there is limited data on the outcome of patients with extramedullary multiple myeloma who undergo ASCT. Therefore, we examined the outcomes of high dose melphalan conditioning prior to ASCT in EMM patients compared to multiple myeloma patients without extramedullary involvement (non-EMM) at an academic institution in Los Angeles. Methods: We retrospectively reviewed 246 multiple myeloma patients who underwent ASCT after receiving high dose melphalan conditioning at USC Norris Comprehensive Cancer Center from Jan 2017 to Dec 2022. The cohort was subdivided into 70 EMM patients and 176 non-EMM patients. Outcomes were measured as the status of disease response, which was evaluated at 100 days (D+100) and 365 days (D+365) after the date of transplant. Results: In the EMM group, 1.43% (n=1) was found to have progression at D+100 and 12.86% (n=9) at D+365. In the non-EMM group, 0.57% (n=1) was found to have progression at D+100 and 11.93% (n=21) at D+365. There was no statistical significance between the EMM and non-EMM groups for progression free survival at D+100 (p-0.50) and D+365 (p-0.75). Regarding overall survival, there were 0 deaths observed at D+100 in both the EMM and non-EMM groups. For D+365, the overall survival was 98.57% (n=69) for the EMM group and 99.43% (n=175) for the non-EMM group. There was no statistical significance between the overall survival at D+365 (p-0.14). Conclusions: The EMM cohort exhibited similar rates of progression free survival (87.14% vs. 88.07%) and overall survival (98.57% vs. 99.43%) compared to the non-EMM cohort at one year post ASCT after receiving high dose melphalan conditioning. We observed that there was no significant statistical difference between the EMM and non-EMM cohorts regarding progression-free survival (p-0.75) and overall survival (p-0.14) on day 365. According to our data, high dose melphalan conditioning prior to autologous stem cell transplant is equally as effective for patients with multiple myeloma with or without extramedullary involvement. Future studies with long-term follow-up are recommended to further explore these findings. [Table: see text]

Impact of extramedullary multiple myeloma on outcomes with idecabtagene vicleucel.

7508 Background: Idecabtagene vicleucel (Ide-cel) has demonstrated excellent efficacy in patients with relapsed/refractory multiple myeloma (RRMM). However, outcomes in patients with extramedullary disease (EMD) remain to be better characterized. Methods: We included patients from 11 US academic centers, who were evaluated for EMD and were infused with ide-cel between May 2021 and April 2023. Patients with soft tissue or visceral lesions non-contiguous from bony lesions were classified as having true EMD, with paraskeletal disease classified as non-EMD. Disease responses were evaluated using the IMWG criteria. Time-to-event analyses were performed from the date of ide-cel infusion. Results: Among 351 patients with RRMM treated with ide-cel, 84 (24%) had EMD prior to infusion. Median follow-up for the entire cohort was 18.2 months (95% CI: 17-19.3). Baseline characteristics at ide-cel infusion for EMD and non-EMD cohorts are depicted in the table. For the EMD and non-EMD cohorts, the Day 30 objective response rates (ORR) were 58% vs. 69% (p=0.1), Day 30 ≥complete response rates were 16% vs 24% (p=0.11), the Day 90 ORR were 52% vs 82% (p&lt;0.001), and best ORR were 58% vs 82%, respectively. The median progression-free survival (PFS) was 5.3 months (95% CI: 4.1-6.9) for the EMD cohort vs. 11.1 months (95% CI: 9.2-12.6; p&lt;0.0001) for the non-EMD cohort. The median duration of response for EMD among day 30 responders was 6.4 months (95% CI: 5.1-8.4). In a multivariable analysis, EMD was an independent predictor of inferior PFS [hazard ratio 1.8 (95% CI: 1.2-2.5), p&lt;0.001] after adjusting for ECOG status, revised ISS stage, penta-drug refractoriness, elevated ferritin, prior BCMA-directed therapy and use of bridging therapy. Pattern of progression in the EMD cohort (n=68/84) included EMD site only (21%), hematologic only (22%), or both (57%), with comparable PFS for type of progression (p=0.19). The median overall survival (OS) was 14.8 months [95% CI: 9-Not reached (NR)] for EMD and 26.9 months [95% CI: 26.3 vs NR, p=0.006)] for the non-EMD group. Rates of Grade ≥2 cytokine release syndrome or neurotoxicity syndrome were comparable between the two cohorts. Conclusions: Patients with EMD demonstrate significantly inferior Day 90 ORR and presence of EMD is an independent risk factor for inferior PFS. [Table: see text]

Multiple Myeloma

The second most common hematologic malignancy is the clonal proliferation of neoplastic plasma cells within the bone marrow. There is the presence of monoclonal immunoglobulins in the serum and/or urine. This results in anemia, myelosuppression, bone destruction, and clinical consequences of para-proteinemia on kidney function and other organ systems. The disease manifests through the acronym CRAB (hypercalcemia, renal impairment, anemia, and bone lesions). Less frequent manifestations of multiple myeloma are of extramedullary localizations. Myeloma cells can become independent of the bone marrow microenvironment, circulate freely in the blood, and infiltrate organs. This results in a high-risk state characterized by increased proliferation, evasion of apoptosis, and treatment resistance. It can affect any area of tissue. Most commonly it involves the pleura, lymph nodes, chest wall, liver, skin/soft tissue, lungs, CNS, genitourinary system, breast and pancreas. In patients with confirmed multiple myeloma, the diagnosis of extramedullary involvement is typically established by the presence of pathological soft tissue masses using radiological methods such as computed tomography (CT) scan, positron emission tomography/CT (PET/CT), magnetic resonance imaging (MRI), or ultrasound, along with biopsy or physical examination. The molecular mechanisms underlying the development of extramedullary multiple myeloma (EMM) have not been fully defined. Various cytogenetic abnormalities are observed, and some studies have generated genomic sequencing profiles that distinguish EMM from classic multiple myeloma. While plasma cell leukemia (PCL) and central nervous system (CNS) EMM indicate a poor prognosis, outcomes for other manifestations can be highly heterogeneous. Sensitive imaging modalities including PET/CT and MRI (Fig.1) are integral components of diagnosis and response assessment. Patients with extramedullary multiple myeloma (EMM) have a clear survival disadvantage.

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.

Primary multifocal extramedullary multiple myeloma with a rare cytogentic abnormality

Primary multifocal extramedullary multiple myeloma with a rare cytogentic abnormality

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.Graphical abstractFigure 1 Action mechanism of drug delivery pathway: CXCR4-PEG-CdTe-DOX nanocomplex can be targeted and close to MM cell membranes, effectively transport DOX into MM cells, and promote MM cell apoptosis.

Refractory Myeloma Developed with Multiple Extramedullary Tumors and Myelofibrosis

The use of novel drugs has improved prognosis in multiple myeloma (MM). However, as the pathophysiology of primary Extramedullary Myeloma (EM) is not well defined due to its rarity, effective treatment for EM is not yet established. We report the case of a 63-year-old man with MM who presented with back pain and fever following the development of extramedullary disease, including subcutaneous tumors accompanied by marrow fibrosis. CT at presentation revealed subcutaneous tumors, mediastinal lymphadenopathy, and pleural involvement with pleural effusion. Peripheral blood exhibited leukoerythroblastosis. Bone marrow biopsy showed diffuse fibrosis and infiltration of large or small atypical cells with high N/C ratio that did not resemble plasma cells, and were positive for CD138 and cytoplasmic IgG/κ immunoglobulin. Biopsy of subcutaneous tumors showed an infiltration of small atypical cells similar to those of bone marrow. The diagnosis was MM with primary EM that was refractory to chemotherapy with bortezomib and progressed with multiple subcutaneous tumors. Intriguingly, molecules related to proliferation including p53, cyclin D1, and Ki-67 were differentially expressed between bone marrow tumor cells and soft tissue tumor cells. In addition, the simultaneous occurrence of primary EM and diffuse myelofibrosis at diagnosis is peculiar

CDK6 protein expression is associated with disease progression and treatment resistance in multiple myeloma.

Multiple myeloma (MM) is a heterogeneous malignancy of plasma cells. Despite improvement in the prognosis of MM patients after the introduction of many new drugs in the past decades, MM remains incurable since most patients become treatment-resistant. Cyclin-dependent kinase 6 (CDK6) is activated in many types of cancer and has been associated with drug resistance in MM. However, its association with disease stage, genetic alterations, and outcomehas not been systematically investigated in large cohorts. Here, we analyzed CDK6 expression using immunohistochemistry in 203 formalin-fixed paraffin-embeddedsamples of 146 patients and four healthy individuals. We found that 61.5% of all MM specimens express CDK6 at various levels. CDK6 expression increased with the progression of disease with a median of 0% of CDK6-positive plasma cells in monoclonal gammopathy of undetermined significance (MGUS) (n = 10) to 30% in newly diagnosed MM (n = 78)and up to 70% in relapsed cases (n = 55). The highest median CDK6 was observed in extramedullary myeloma (n = 12), a highly aggressive manifestation of MM. Longitudinal analyses revealed that CDK6 is significantly increased in lenalidomide-treated patients but not in those who did not receive lenalidomide. Furthermore, we observed that patients who underwent lenalidomide-comprising induction therapy had significantly shorter progression-free survival when their samples were CDK6 positive. These data support that CDK6 protein expression is a marker for aggressive and drug-resistant disease and describes a potential drug target in MM.

Immune checkpoint receptors and their ligands on CD8 T cells and myeloma cells in extramedullary multiple myeloma

Immune checkpoint receptors and their ligands on CD8 T cells and myeloma cells in extramedullary multiple myeloma

Unveiling complexity: Chest wall swelling manifestation of extramedullary myeloma

There are two forms of myeloma: Solitary plasmacytoma and multiple myeloma. Both are malignant tumors and develop from bone marrow plasma cells, which secrete immunoglobulins. Pleural effusion secondary to myeloma is extremely rare, with an incidence of 1–2%. A 58-year-old man presented to the emergency department with a chief complaint of swelling and pain over the left side of his chest, breathlessness, generalized weakness, abdominal pain, and blood in his stool for 15 days. The chest X-ray posteroanterior view showed well-defined homogenous opacity in the left hemithorax. The patient underwent ultrasound-guided left-sided thoracocentesis. Pleural fluid was exudative, and cytology showed the presence of malignant cells. Contrast-enhanced computed tomography of the thorax and abdomen showed a well-defined soft-tissue density lesion involving the left posteriolateral chest wall with underlying rib erosion. For confirmation of malignant etiology, a USG-guided transthoracic needle biopsy was performed. A biopsy revealed a malignant round cell tumor in a histopathological review. For confirmation, a tissue sample was sent for immunohistochemistry markers, which had positivity for CD 138 and MUM 1, consistent with myeloma. Rarely, MM can present as chest wall swelling. Ultrasound is an easily available diagnostic modality that can be used for chest wall biopsy with a minimal incidence of complications.

Isolated Abducens Nerve Palsy: A Rare Manifestation of Recurrent Extramedullary Myeloma

Isolated Abducens Nerve Palsy: A Rare Manifestation of Recurrent Extramedullary Myeloma

The Unfortunate Event - Extramedullary Myeloma Of The Urinary Tract

Extramedullary disease is an uncommon manifestation of multiple myeloma (MM). It can present de-novo or develop as a result of disease progression or relapse. We present a rare case of extramedullary myeloma (EMM) of the urinary tract in a 65-year-old gentleman. The incidence of EMM is ~13% of the MM population with a higher predilection for males in the fifth decade. The common sites for EMM were lymph nodes, skin, and soft tissue, however, involvement of the urinary tract is exceedingly rare. Despite the combination of chemotherapy, radiotherapy, the novel agents of immunomodulators, proteosome inhibitors, and consolidative autologous hematopoietic stem cell transplantation, the relapse rate is relatively high. In conclusion, the prognosis of patients with EMM is poor and currently, the optimal treatment strategy for this subset of patients is still debatable.

Extramedullary plasmacytoma in the head and neck region – presentation of two cases

&lt;b&gt;&lt;br&gt;Introduction:&lt;/b&gt; Plasma cell tumors might be present in two types: as solitary lesions (plasmacytoma) or disseminated throughout the body – multiple myeloma. The former most commonly develops in the bones containing bone marrow, rarer in different soft tissues (extramedullary plasmacytoma).&lt;/br&gt; &lt;b&gt;&lt;br&gt;Case report:&lt;/b&gt; The first case is a 53-year-old man with a tumor of the left side of the larynx. The CT scan revealed a tumor on the left side of the larynx causing destruction of the thyroid cartilage. Oligobiopsy results – differential diagnosis included lymphoma and plasmacytoma. Based on histopathological examination and additional tests, the diagnosis was made: extramedullary myeloma. The patient was referred for further treatment to the hematology department, where he was qualified for chemotherapy and radiotherapy. The second case is a 27-year-old man with chronic rhinitis that does not respond to antiinflammatory treatment. The MRI examination revealed a pathological mass of a hyperplastic nature with enhancement after contrast administration. An endoscopic tumor biopsy was performed. Histopathological examination revealed a plasma cell tumor. The correlation of the performed tests allowed for the diagnosis of extramedullary ameloblastoma of the maxillary sinus. The patient was referred for IGRT radiotherapy treatment.&lt;/br&gt; &lt;b&gt;&lt;br&gt;Discussion:&lt;/b&gt; Extramedullary plasmacytoma (EMP) accounts for about 3% of all plasma cell neoplasms. It is a locally invasive submucosal tumor presenting a tendency for recurrences; however, in about 16% of cases it may progress to multiple myeloma. The treatment of choice in case of EMP is radiotherapy or chemo-radiotherapy. Pan-London Haemato-Oncology Clinical Guidelines for Plasma Cell Disorder (2020) defined diagnostic criteria for extramedullary myeloma, which are also presented in the paper.&lt;/br&gt;

Helical Tomotherapy and Melphalan As the Conditioning Regimen in Autologous Stem Cell Transplantation for Multiple Myeloma with Extramedullary Plasmacytoma: A Single Center Clinical Research

Background Multiple myeloma(MM) is the second hematologic malignancy. Extramedullary myeloma indicates a poorer prognosis and survival. High dose Melphalan is the most widely used conditioning regimen. Helical tomotherapy(TOMO) is one of the most advanced intensity-modulated conformal radiotherapy technologies. We applied the combination of TOMO and Melphalan as the conditioning regimen in MM patients, and analyzed its efficacy and safety. Methods Clinical data were collected and compared between TOMO combined with melphalan group and non-TOMO group. SPSS V.25.0 was used for statistical analysis. Results Two methods were not significant difference by statistics analysis. The complete response rate of 100d in non-TOMO group significantly decreased compared to 1 month after transplantation (P=0.001). The 1-year PFS rate in the TOMO group was 86%, while non-TOMO group was 91%. There was no myeloma related death in the two groups within one year. TOMO group showed earlier enter platelet count below 20x109/L (P=0.003) and granulocyte deficiency (P=0.000). In terms of platelet implantation time,TOMO group was superior in platelet implantation time (P=0.041). No atrial fibrillation, heart failure, hepatic small vein occlusion, or transplant related death occurred during the transplantation period. Conclusion: The combination of TOMO and reduced dose Melphalan conditioning regimen is clinically feasible in terms of safety and efficacy evaluation. This scheme could improve the long-term survival of MM patients with extramedullary plasmacytoma.