Multiple myeloma: diagnosis and treatment

The proteasome inhibitor carfilzomib exerts anti-inflammatory and antithrombotic effects on the endothelium

BACKGROUND

Carfilzomib (CFZ) is a second-generation proteasome inhibitor used to treat multiple myeloma. Potent inhibition of the proteasome results in chronic proteotoxic endoplasmic reticulum (ER) stress, leading to apoptosis. While CFZ has improved survival rates in multiple myeloma, it is associated with an increased risk of cardiovascular adverse effects. While this has been putatively linked to cardiotoxicity, CFZ could potentially also exhibit adverse effects on the endothelium.

OBJECTIVES

To investigate the effects of CFZ on the endothelium.

METHODS

Human umbilical vein endothelial cells (HUVECs) were treated with CFZ, and expression of relevant markers of ER stress, inflammation, and thrombosis was measured and functionally assessed.

RESULTS

CFZ failed to induce ER stress in HUVECs but induced the expression of Kruppel-like factor 4, endothelial nitric oxide synthase, tissue plasminogen activator, and thrombomodulin and reduced tumor necrosis factor alpha (TNFα)-mediated intercellular adhesion molecule 1 and tissue factor expression, suggesting a potential protective effect on the endothelium. Consistent with these observations, CFZ reduced leukocyte adhesion under shear stress and reduced factor Xa generation and fibrin clot formation on the endothelium following TNFα treatment and inhibited von Willebrand factor (VWF) and angiopoietin-2 exocytosis from Weibel-Palade bodies. Subsequently, CFZ inhibited the formation of VWF-platelet strings, and moreover, media derived from myeloma cell lines induced VWF release, a process also inhibited by CFZ.

CONCLUSION

These data demonstrate that CFZ is unable to induce ER stress in confluent resting endothelial cells and can conversely attenuate the prothrombotic effects of TNFα on the endothelium. This study suggests that CFZ does not negatively alter HUVECs, and proteasome inhibition of the endothelium may offer a potential way to prevent thrombosis.

The Combinatorial Effect of Ad-IL-24 and Ad-HSV-tk/GCV on Tumor Size, Autophagy, and UPR Mechanisms in Multiple Myeloma Mouse Model

Multiple myeloma is a type of malignant neoplasia whose treatment has changed over the past decade. This study aimed to investigate the effects of combination of Adenovector-carrying interleukin-24 and herpes simplex virus 1 thymidine kinase/ganciclovir on tumor growth, autophagy, and unfolded protein response mechanisms in mouse model of multiple myeloma. Six groups of mice, including Ad-HSV-tk/GCV, Ad-IL-24, Ad-HSV-tk/IL-24, Ad-GFP, and positive and negative controls, were investigated, and each group was injected every 72 h. The tumor size was measured several times. The expression of LC3B evaluated through western blotting and ASK-1, CHOP, Caspase-3, and ATF-6 genes in the UPR and apoptosis pathways were also analyzed by the quantitative polymerase chain reaction (qPCR) method. The present results showed that the injection of Ad-HSV-tk/GCV, Ad-HSV-tk/IL-24, and metformin reduced the tumor size. The expression of LC3B was significantly higher in the treatment groups and positive control groups compared to the negative control group. The expression of CHOP, caspase-3, and ATF-6 genes was significantly higher in the Ad-IL-24 group compared to the other treatment groups. Besides, the ASK-1 expression was significantly lower in the Ad-IL-24 group as compared to the other groups. Overall, the results indicated that the presence of the HSV-tk gene in the adenovectors reduced the size of tumors and induced autophagy by triggering the expression of LC3B protein. The presence of the IL-24 might affect tumor growth but not as much the therapeutic effect of HSV-tk. Furthermore, the results indicated that co-administration of IL-24 and HSV-tk had no synergistic effect on tumor size control.

Discovery of imidazo[1,2-b]pyridazine-containing TAK1 kinase inhibitors with excellent activities against multiple myeloma

Current treatment options for patients with multiple myeloma (MM) include proteasome inhibitors, anti-CD38 antibodies, and immunomodulatory agents. However, if patients have continued disease progression after administration of these treatments, there are limited options. There is a need for effective targeted therapies of MM. Recent studies have shown that the transforming growth factor-β activated kinase (TAK1) is upregulated and overexpressed in MM. We have discovered that 6-substituted morpholine or piperazine imidazo[1,2-b]pyridazines, with an appropriate aryl substituent at position-3, inhibit TAK1 at nanomolar concentrations. The lead compound, 26, inhibits the enzymatic activity of TAK1 with an IC50 of 55 nM. Under similar conditions, the known TAK1 inhibitor, takinib, inhibits the kinase with an IC50 of 187 nM. Compound 26 and analogs thereof inhibit the growth of multiple myeloma cell lines MPC-11 and H929 with GI50 values as low as 30 nM. These compounds have the potential to be translated into anti-MM therapeutics.

Immune-epigenetic crosstalk in haematological malignancies

Haematological malignancies comprise a diverse set of lymphoid and myeloid neoplasms which can arise during any stage of haematopoiesis in the bone marrow. Accumulating evidence suggests that chronic inflammation generated by inflammatory cytokines secreted by tumour and the tumour-associated cells within the bone marrow microenvironment initiates signalling pathways in malignant cells, resulting in activation of master transcription factors including Smads, STAT3, and NF-κB which confer cancer stem cell phenotypes and drive disease progression. Deciphering the molecular mechanisms for how immune cells interact with malignant cells to induce such epigenetic modifications, specifically DNA methylation, histone modification, expression of miRNAs and lnRNAs to perturbate haematopoiesis could provide new avenues for developing novel targeted therapies for haematological malignancies. Here, the complex positive and negative feedback loops involved in inflammatory cytokine-induced cancer stem cell generation and drug resistance are reviewed to highlight the clinical importance of immune-epigenetic crosstalk in haematological malignancies.

Antitumor activity and mechanisms of dual EGFR/DNA-targeting strategy for the treatment of lung cancer with EGFRL858R/T790M mutation

Dual- or multi-targeted EGFR inhibitors as single drugs can overcome EGFR inhibitor resistance and circumvent many disadvantages of combination therapy. In this work, fifteen 4-anilinoquinazoline derivatives bearing nitrogen mustard or hemi mustard moieties were designed and synthesized as dual EGFR-DNA targeting anticancer agents. Structures of target molecules were confirmed by ¹H NMR, ¹³C NMR and HR-MS, and evaluated for their in vitro anti-proliferative activities using MTT assay. Compound 6g emerged as the most potent derivative against mutant-type H1975 cells with IC₅₀ value of 1.45 μM, which exhibited 4-fold stronger potency than Chl/Gef (equimolar combination of chlorambucil and gefitinib). Kinase inhibition studies indicated that 6g showed excellent inhibitory effect on EGFR^L858R/T790M enzyme, which was 8.6 times more effective than gefitinib. Mechanistic studies indicated that 6g induced apoptosis of H1975 cells in a dose-dependent manner and caused DNA damage. Importantly, 6g could significantly inhibit the expression of p-EGFR and its downstream p-AKT and p-ERK in H1975 cells. Molecular docking was also performed to gain insights into the ligand-binding interactions of 6g inside EGFR^WT and EGFR^L858R/T790M binding sites. Moreover, 6g efficiently inhibited tumor growth in the H1975 xenograft model without side effects.

Gossypol and Its Natural Derivatives: Multitargeted Phytochemicals as Potential Drug Candidates for Oncologic Diseases

Despite the vast amounts of research and remarkable discoveries that have been made in recent decades, cancer remains a leading cause of death and a major public health concern worldwide. Gossypol, a natural polyphenolic compound derived from the seeds, roots, and stems of cotton (Gossypium hirsutum L.), was first used as a male contraceptive agent. Due to its diverse biological properties, including antifertility, antiviral, antioxidant, antibacterial, antimalarial, and most notably antitumor activities, gossypol has been the subject of numerous studies. Nevertheless, no systematic review has been performed that analyzes the antineoplastic potential of gossypol and related natural compounds in an organ-specific manner while delineating the molecular mechanisms of action. Hence, we have performed an extensive literature search for anticancer properties of gossypol and their natural derivatives against various types of cancer cells utilizing PubMed, ScienceDirect, Google Scholar, and Scopus. The sources, distribution, chemical structure, and toxicity of gossypol and its constituents are briefly reviewed. Based on emerging evidence, gossypol and related compounds exhibit significant antineoplastic effects against various cancer types through the modulation of different cancer hallmarks and signaling pathways. Additionally, the synergistic activity of gossypol and its derivatives with chemotherapeutic agents has been observed. Our evaluation of the current literature suggests the potential of gossypol and its derivatives as multitargeting drug candidates to combat multiple human malignancies.

Light Chain Glomerulopathy Causing Kidney Failure in Renal Cell Carcinoma

Light chain deposition disease (LCDD) is a rare cause of kidney failure. It is associated with multiple myeloma and is diagnosed by the evaluation of serum and urine free light chains. Patients who are diagnosed with this disease often develop rapidly progressive renal failure. To our knowledge, it does not have any association with other malignancies aside from multiple myeloma. We present a case that highlights a novel association between renal cell carcinoma and light chain-mediated renal disease. Our patient was admitted due to acute renal failure and underwent a comprehensive diagnostic evaluation with an eventual diagnosis of light chain glomerulopathy in the setting of metastatic renal cell carcinoma.

Bone marrow-derived mesenchymal stem cells inhibit CD8+ T cell immune responses via PD-1/PD-L1 pathway in multiple myeloma

High expression of the inhibitory receptor programmed cell death ligand 1 (PD-L1) on tumor cells and tumor stromal cells have been found to play a key role in tumor immune evasion in several human malignancies. However, the expression of PD-L1 on bone marrow mesenchymal stem cells (BMSCs) and whether the programmed cell death 1 (PD-1)/PD-L1 signal pathway is involved in the BMSCs versus T cell immune response in multiple myeloma (MM) remains poorly defined. In this study, we explored the expression of PD-L1 on BMSCs from newly diagnosed MM (NDMM) patients and the role of PD-1/PD-L1 pathway in BMSC-mediated regulation of CD8⁺ T cells. The data showed that the expression of PD-L1 on BMSCs in NDMM patients was significantly increased compared to that in normal controls (NC) (18·81 ± 1·61 versus 2·78± 0·70%; P < 0·001). Furthermore, the PD-1 expression on CD8⁺ T cells with NDMM patients was significantly higher than that in normal controls (43·22 ± 2·98 versus 20·71 ± 1·08%; P < 0·001). However, there was no significant difference in PD-1 expression of CD4⁺ T cells and natural killer (NK) cells between the NDMM and NC groups. Additionally, the co-culture assays revealed that BMSCs significantly suppressed CD8⁺ T cell function. However, the PD-L1 inhibitor effectively reversed BMSC-mediated suppression in CD8⁺ T cells. We also found that the combination of PD-L1 inhibitor and pomalidomide can further enhance the killing effect of CD8⁺ T cells on MM cells. In summary, our findings demonstrated that BMSCs in patients with MM may induce apoptosis of CD8⁺ T cells through the PD-1/PD-L1 axis and inhibit the release of perforin and granzyme B from CD8⁺ T cells to promote the immune escape of MM.

Characteristics and outcomes of patients with multiple myeloma at the Uganda Cancer Institute

PURPOSE

Data on multiple myeloma (MM) in sub-Sahara Africa is scarce. In Uganda, there is a progressively increasing incidence of MM over the years.

METHODS

We performed a retrospective study on 217 patients with MM at the UCI using purposive sampling method. The objectives of the study were to determine the clinical characteristics, treatment outcomes, 5 year overall survival and predictors of survival of patients with MM at the UCI from 01 January 2008 to 31 December 2012.

RESULTS

There were 119 (54.8%) males; the mean(SD) age of the study population at presentation was 59(12.8) years; 183(84.3%) patients presented with bone pain, and 135 (61.9%) had skeletal pathology; 186(85.3%) were HIV negative, and 152(70%) had Durie-Salmon stage III. The median overall survival was 2.5 years, (95% CI, 0.393-0.595); factors significantly associated with worse survival were Durie-Salmon stage III disease, HR=5.9, 95% CI (1.61 - 21.74; P=0.007) and LDH >225 U/L HR=3.3, 95% CI (0.57 - 5.92; P=0.029).

CONCLUSION

Most patients with multiple myeloma at the UCI were diagnosed at a relatively young age, presented with late stage disease and bone pain, and had a shorter survival time. Factors associated with worse survival were Durie-Salmon stage III and LDH >225 U/L.

Antimyeloma Potential of Caffeic Acid Phenethyl Ester and Its Analogues through Sp1 Mediated Downregulation of IKZF1-IRF4-MYC Axis

Caffeic acid phenethyl ester (CAPE, 2), a natural compound from propolis, is a well-documented antitumor agent with nuclear factor kappa B (NF-κB) inhibitory activity. Key transcription factors regulated by NF-κB, namely, interferon regulatory factor-4 (IRF4) and octameric binding protein-2 (OCT2), are implicated in the tumorigenesis of multiple myeloma (MM), an incurable bone marrow cancer. Adverse effects and resistance to current chemotherapeutics pose a great challenge for MM treatment. Hence, the structure-activity relationships of CAPE (2) and 21 of its analogues were evaluated for their antimyeloma potential. Preclinical evaluation revealed that CAPE (2) and the 3-phenylpropyl (4), 2,5-dihydroxycinnamic acid 3-phenylpropyl ester (17), and 3,4-dihydroxycinnamic ether (22) analogues inhibited human myeloma cell growth. Analogue 4 surpassed CAPE (2) and lenalidomide in showing strong apoptotic effects with a remarkable decrease in IRF4 levels. The analogue 17 exhibited the most potent anti-MM activity. The downregulation of specificity protein 1 (Sp1) and the IKZF1-IRF4-MYC axis by CAPE (2) analogues 4 and 17 revealed their novel mechanism of action. The analogues showed no adverse cytotoxic effects on normal human cells and exhibited appropriate in silico pharmacokinetic properties and drug-likeness. These findings suggest the promising application of CAPE (2) analogues to target Ikaros (IKZF1)/IRF4 addiction, the so-called Achilles heel of myeloma, for better treatment outcomes.

T-Cell Large Granular Lymphocytic Leukemia with Extremely Rare Immunophenotype (CD4/CD8 Double-Positive) Followed by Multiple Myeloma Diagnosis

T-cell large granular lymphocytic leukemia is characterized by clonal expansion of a CD3⁺/CD57⁺ subpopulation, which are typically CD8⁺ positive cytotoxic T- cells, and can only be diagnosed if there is a persistent, greater than 6 months, elevation of LGL in the blood (usually 2–20 × 10⁹/L), in the absence of an identifiable cause. T-LGLL has been associated with reactive conditions such as autoimmune diseases and viral infections and has also been reported in association with hematologic and non-hematologic malignancies. We report a case of asymptomatic CD4/CD8 double-positive T-LGLL. Flow cytometry on peripheral blood revealed a subpopulation of CD4/CD8 double-positive T cells expressing CD57 and cTIA. Clonality was established by flow cytometric analysis of T-cell receptor V(â) region repertoire which showed that >70% of the cells failed to express any of the tested V(â) regions. Clonality was further confirmed by PCR with the detection of clonal TCR beta and TCR gamma gene rearrangements. Six months later, she presented with persistent lower back pain and diagnosed with IgG kappa multiple myeloma. CD4/CD8 double-positive T-large granular leukemia is the first case reported in the literature. This rare phenotype is either underreported or a truly rare clinical entity. More studies are warranted to characterize the pathogenesis and clinical characteristics of this group of patients and to further assess the relationship between multiple myeloma and T-LGLL as a cause-and-effect relationship or simply related to the time at which diagnosis has been made.

Identification and Characterization of Tumor-Initiating Cells in Multiple Myeloma

BACKGROUND

Treatment failures in cancers, including multiple myeloma (MM), are most likely due to the persistence of a minor population of tumor-initiating cells (TICs), which are noncycling or slowly cycling and very drug resistant.

METHODS

Gene expression profiling and real-time quantitative reverse transcription polymerase chain reaction were employed to define genes differentially expressed between the side-population cells, which contain the TICs, and the main population of MM cells derived from 11 MM patient samples. Self-renewal potential was analyzed by clonogenicity and drug resistance of CD24+ MM cells. Flow cytometry (n = 60) and immunofluorescence (n = 66) were applied on MM patient samples to determine CD24 expression. Therapeutic effects of CD24 antibodies were tested in xenograft MM mouse models containing three to six mice per group.

RESULTS

CD24 was highly expressed in the side-population cells, and CD24+ MM cells exhibited high expression of induced pluripotent or embryonic stem cell genes. CD24+ MM cells showed increased clonogenicity, drug resistance, and tumorigenicity. Only 10 CD24+ MM cells were required to develop plasmacytomas in mice (n = three of five mice after 27 days). The frequency of CD24+ MM cells was highly variable in primary MM samples, but the average of CD24+ MM cells was 8.3% after chemotherapy and in complete-remission MM samples with persistent minimal residual disease compared with 1.0% CD24+ MM cells in newly diagnosed MM samples (n = 26). MM patients with a high initial percentage of CD24+ MM cells had inferior progression-free survival (hazard ratio [HR] = 3.81, 95% confidence interval [CI] = 5.66 to 18.34, P < .001) and overall survival (HR = 3.87, 95% CI = 16.61 to 34.39, P = .002). A CD24 antibody inhibited MM cell growth and prevented tumor progression in vivo.

CONCLUSION

Our studies demonstrate that CD24+ MM cells maintain the TIC features of self-renewal and drug resistance and provide a target for myeloma therapy.

The Effect of Ras Homolog C/Rho-Associated Coiled-Protein Kinase (Rho/ROCK) Signaling Pathways on Proliferation and Apoptosis of Human Myeloma Cells

BACKGROUND The aim of this study was to explore the impact of Ras homolog C/Rho-associated coiled-protein kinase (Rho/ROCK) signaling pathways intervention on biological characteristics of the human multiple myeloma cell lines RPMI-8226 and U266 cells, and to investigate the expression of RhoC, ROCK1, and ROCK2 in RPMI-8226 and U266 cells. MATERIAL AND METHODS RPMI8226 and U266 cell lines were treated by 5-aza-2-deoxycytidine (5-Aza-Dc), trichostatin A (TSA), RhoA inhibitor CCG-1423, Rac1 inhibitor NSC23766, and ROCK inhibitor fasudil. Cell proliferation was examined by Cell Counting Kit-8 (CCK-8) assay and clone formation. Cell apoptosis was examined by flow cytometry and TUNEL assay. The mRNA and protein expressions of RhoC, ROCK1, and ROCK2 were detected by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and western blot, respectively. RESULTS CCG-1423, NSC23766, and fasudil could significantly inhibit the proliferation of RPMI8226 and U266 cells. The inhibitory effect was dose- and time-dependent within a certain concentration range (P<0.05). After treatment with CCG-1423, NSC23766, and fasudil for 24 hours, the apoptosis rates of RPMI8226 and U266 cells were significantly higher than those of the control group, which were dose-dependent (P<0.05). Compared with the control group, the mRNA and protein expressions of RhoC, ROCK1, and ROCK2 in RPMI8226 and U266 cells were significantly decreased with single 5-Aza-Dc or TSA treatment. However, the effects were obviously stronger after combined treatment of 5-Aza-CdR and TSA (P<0.05). CONCLUSIONS We found that 5-Aza-Dc and TSA can effectively decrease the mRNA and protein expressions of RhoC, ROCK1, and ROCK2. Furthermore, Rho and ROCK inhibitors significantly inhibit cell growth and induce cell apoptosis in the human multiple myeloma cell lines RPMI-8226 and U266.

Development of a prognostic model for overall survival in multiple myeloma using the Connect® MM Patient Registry

Median overall survival (OS) has improved for patients with newly diagnosed multiple myeloma (NDMM), but prognosis varies depending on baseline patient characteristics. Current models use data from selected clinical trial populations, which prevent application to patients in an unselected community setting that reflects routine clinical practice. Using data from the Connect^® MM Registry, a large, US, multicentre, prospective observational cohort study (Cohort 1: 2009-2011; Cohort 2: 2012-2016) of 3011 patients with NDMM, we identified prognostic variables for OS via the multivariable analysis of baseline patient characteristics in Cohort 1 (n = 1493) and developed a tool to examine individual outcomes. Factors associated with OS (n = 1450 treated patients; P < 0·05) were age, del(17p), triplet therapy use, EQ-5D mobility, International Staging System stage, solitary plasmacytoma, history of diabetes, platelet count, Eastern Cooperative Oncology Group performance status and serum creatinine, which were used to create survival matrices for 3- and 5-year OS. The model was internally and externally validated using Connect MM Cohort 2 (Harrell's concordance index, 0·698), MM-015 (0·649), and the phase 3 FIRST (0·647) clinical trials. This novel prognostic tool may help inform outcomes for NDMM in the era of triplet therapy use with novel agents.

Pre-ESRD Care and Mortality in Incident ESRD Patients With Multiple Myeloma

OBJECTIVES

The relationship between mortality and pre-ESRD (end-stage renal disease) nephrology care in incident ESRD patients with multiple myeloma (MM) as the primary cause of renal failure has not been examined.

MATERIALS AND METHODS

Among 439,206 incident US hemodialysis patients with MM as the primary cause of ESRD (June 1, 2005 to May 31, 2009) identified using the US Renal Data System, adjusted odds ratios (OR) for reported pre-ESRD nephrology care for ESRD due to MM (n=4561) versus other causes (n=434,645) were calculated. The association of pre-ESRD nephrology care with subsequent mortality in MM-ESRD patients was examined.

RESULTS

MM-ESRD patients were less likely to have any predialysis nephrology care in the year before initiation of dialysis (34.8% vs. 58.5%; OR=0.38; 95% confidence interval [CI], 0.34-0.43) compared with patients with ESRD due to other causes. MM-ESRD patients compared with others were more likely to have catheters on first dialysis (91.8% vs. 75.6%; OR=4.15; 95% CI, 3.54-4.86). Incident MM-ESRD patients receiving predialysis care for ≥6 months had significantly lower 1-year mortality (hazard ratio 0.89; 95% CI, 0.82-0.97 and 0.88; 95% CI, 0.80-0.96, respectively), relative to those without this care. A catheter for dialysis access was associated with a 1.6-fold increase in 1-year mortality in incident MM-ESRD (hazard ratio 1.55; 95% CI, 1.32-1.83).

CONCLUSIONS

MM-ESRD patients were less likely to have predialysis nephrology care and more likely to use catheters on first dialysis. However, predialysis care is independently associated with lower mortality in MM-ESRD patients. Predialysis care should be prioritized in MM patients approaching ESRD.

Downregulation of DCC sensitizes multiple myeloma cells to bortezomib treatment

Multiple myeloma (MM) is an incurable disease; a better understanding of the molecular aspects of this hematological malignancy could contribute to the development of new treatment strategies and help to improve the survival rates of patients with MM. Previously, the methylation status of the deleted in colorectal cancer (DCC) gene was correlated with the survival rate of patients with MM, thus the main goal of this study was to understand DCC contribution to MM tumorigenesis, and to assess the impact of DCC inhibition in the MM response to treatment with bortezomib. Our results demonstrated that hypermethylation of the DCC promoter inhibits gene expression, and DCC silencing is significantly correlated with a reduction in cell viability and an increase in cell death induced by bortezomib. In conclusion, our results suggested that hypermethylation is an important mechanism of DCC expression regulation in MM and that the absence of DCC contributes to the enhanced sensitivity to treatment with bortezomib.

Epidemiology of multiple myeloma in 17 Latin American countries: an update

The objective of this study was to describe incidence, mortality rates, and trends for multiple myeloma (MM) in Latin America (LA), contributing to better knowledge on the epidemiology of MM in this continent. Incidence data were extracted from the International Agency for Research on Cancer (IARC), for the period 1990-2007. Mortality data were obtained for 17 countries from the World Health Organization, for the period 1995-2013. Annual average percentage change (AAPC) and 95% confidence interval (95% CI) were calculated for incidence and mortality. The average incidence rate of MM was higher in Cali (Colombia). For the age-group over 60 years old, rates were 14.2 and 12.8 per 100,000 inhabitants for men and women, respectively. Increasing incidence trends were verified for Cali (Colombia). Mortality rates were higher among men; most countries presented increasing trends, and the highest increments were observed in Guatemala (12.5% [95% CI: 10.6; 14.5] in men; 8.8% [95% CI: 7.8; 9.8] in women), Ecuador (5.5% [95% CI: 5.0; 6.0] in men; 3.7 [95% CI: 3.1; 4.3] in women), Paraguay (2.9% [95% CI: 2.3; 3.5] in men; 3.2% [95% CI: 2.1; 4.3] in women), and Brazil (1.4% [95% CI: 1.3; 1.5] in men; 0.9% [95% CI: 0.8; 1.0] in women). Multiple myeloma presented heterogeneous incidence patterns in Cali (Colombia), Quito (Ecuador), and Costa Rica. Increasing mortality trends were verified for most Latin American countries and could be related to limited access to diagnosis and new therapies.

Synergistic inhibition effect of TNIK inhibitor KY-05009 and receptor tyrosine kinase inhibitor dovitinib on IL-6-induced proliferation and Wnt signaling pathway in human multiple myeloma cells

Multiple myeloma is a fetal form of plasma cell malignancy characterized by abnormal clonal proliferation of plasma cells. Especially, the canonical Wnt signaling pathway mediated by β-catenin is activated in multiple myeloma cells, stimulating their proliferation. Here, we investigated the relationship between interleukin-6-induced proliferation of multiple myeloma cells and Traf2- and Nck-interacting kinase (TNIK) expression in Wnt signaling. Interleukin-6 increased the proliferation of multiple myeloma cells and TNIK mRNA and protein expression. In addition, we examined the effect on TNIK of TNIK inhibitor KY-05009 and receptor tyrosine kinase inhibitor dovitinib and whether inhibition of TNIK suppresses the interleukin-6-induced proliferation of multiple myeloma cells. KY-05009 and dovitinib synergistically inhibited interleukin-6-stimulated proliferation and induced apoptosis through the inhibition of Wnt signaling in MM cells. Our results provide crucial information that TNIK is involved in the interleukin-6-dependent proliferation of multiple myeloma cells and inhibition of Wnt signaling involving TNIK could be a therapeutic strategy for the treatment of interleukin-6-dependent multiple myeloma.

Minimal residual disease in multiple myeloma: Benefits of flow cytometry

Over the last 20 years, the approaches to the treatment of multiple myeloma (MM) have changed considerably, which led to an increase in remission rate. Using new diagnostic methods has made it possible to assess the response to treatment more reliably and forecast disease recurrence: allele-specific polymerase chain reaction, new-generation sequencing and multicolor flow cytometry enable minimal residual disease (MRD) detection of with sensitivity of 10^-5 to 10^-6 . MRD assessment with flow cytometry using is a rapidly developing area of research. The goal of multicenter groups that use flow cytometry as a tool to detect MRD in patients with MM is achieving standardization and increasing sensitivity and specificity of this method. This article provides data about the methods used for MRD monitoring and describes the advances in the field of flow cytometry.

The effect of marrow stromal cells on TRAF6 expression levels in myeloma cells

Tumor necrosis factor receptor-associated factor 6 (TRAF6) is an important E3 ubiquitin ligase, which is key to immunity. TRAF6 has been implicated in the invasive growth and metastasis of various types of cancer, including squamous cell carcinoma, gastric cancer, myelodysplastic syndromes and acute myeloid leukemia. In the present study, associations between multiple myeloma (MM) and TRAF6, its downstream component nuclear factor-κB (NF-κB) and bone marrow stromal cells (MSC) were investigated. The TRAF6 protein expression levels of 18 patients were positively correlated with the protein levels of β-2 microglobulin (r²=0.3472; P=0.01) and negatively correlated with albumin protein levels (r²=0.5494; P=0.0004). In vitro expression of the TRAF6 protein, phosphorylated transcription factor p65 and phosphorylated p100 in myeloma cell lines was induced by MSCs from patients with MM. In addition, the in vitro expression of TRAF6 was associated with an enhanced proliferation rate of myeloma cells, which was blocked by silencing TRAF6 using small interfering RNA. Due to the association between the TRAF6-NF-κB signaling pathway in myeloma cells and MSCs, this signaling pathway may be a useful prognostic and therapeutic target in myeloma.

Multiple myeloma in Niger Delta, Nigeria: complications and the outcome of palliative interventions

Background

Multiple myeloma (MM) is one of the hematological malignancies that require palliative care. This is because of the life-threatening nature and the suffering associated with the illness. The aim of this study is to bring to the fore the complications experienced by people living with MM in the Niger-Delta region of Nigeria and the outcome of various palliative interventions.

Methods

This was a 10-year multi-center retrospective study of 26 patients diagnosed and managed in three major centers in the Niger-Delta region of Nigeria from January 2003 to December 2012. Information on the clinical, laboratory, radiological data, and palliative treatment was obtained at presentation and subsequently at intervals of 3 months until the patient was lost to follow-up.

Result

The mean duration from onset of symptoms to diagnosis was 13.12 months (95% CI, 6.65–19.58). A total of 16 (61.5%), eight (30.8%), and two subjects (7.7%) presented in Durie–Salmon (DS) stages III, II, and I, respectively. The complications presented by patients at diagnoses included bone pain (84.6%), anemia (61.5%), nephropathy (23.1%), and hemiplegia (35%). All the patients received analgesics, while 50.0% received blood transfusion, 56.7% had surgery performed, 19% had hemodialysis, and 3.8% received radiotherapy. A total of 10 (38%) patients benefited from bisphosphonates (BPs). A total of 57.6% of patients were on melphalan–prednisone (MP) double regimen, while 19% and 8% patients were on MP–thalidomide and MP–bortezomib triple regimens, respectively. A total of 3.8% of patients at DS stage IIIB disease had autologous stem-cell transplantation (ASCT). Only 7.6% of the myeloma patients survived up to 5 years post diagnosis. The overall mean survival interval was 39.7 months (95% CI, 32.1–47.2).

Conclusion

Late diagnosis and inadequate palliative care account for major complications encountered by MM patients in the Niger-Delta region of Nigeria. This could be responsible for the poor prognostic outcome and low survival interval of MM individuals in this region. There is, therefore, a need to improve the quality of palliative care received by myeloma patients in this region. This is achievable via provision of relevant and affordable health care facilities for diagnosis and treatment of the disease.

Diagnosis and management of neuropathies associated with plasma cell dyscrasias

Neuropathies associated with plasma cell dyscrasias are a major cause of morbidity for patients managed by medical oncologists. Because of similarities in clinical presentation and on nerve conduction studies, identifying the underlying disease leading to a paraproteinemic neuropathy can often be difficult. In addition, the degree of neurologic deficit does not strictly correlate with the extent of abnormalities on common clinical laboratory testing. Fortunately, with increasing understanding into the biologic mechanisms of underlying hematologic diseases, additional biomarkers have recently been developed, thus improving our diagnostic capacity. Neuropathies associated with plasma cells dyscrasias are seen with Monoclonal gammopathy of undetermined significance (MGUS) particularly IgM subtype, followed by IgG and IgA MGUS, multiple myeloma, Waldenström's macroglobulinemia, amyloid, Castleman's disease, and POEMS syndrome. The mechanisms of neuronal injury associated with plasma cell dyscrasia vary based on underlying diagnosis and include malignant infiltration, immune-mediated antibody deposition, or local compression of nerve roots. The polyneuropathies are frequently demyelinating, although axonal and mixed neuropathies can also be seen. As demonstrated by the cases included in this review, patients frequently present with symmetric sensory disturbance, followed by progressive motor weakness. Unfortunately, because of the complexity of diagnostic testing, patients are frequently examined late, often after receiving several ineffective therapies. The aim of this case-based review is to provide clinicians with insight on how to properly recognize these atypical neuropathies and send the appropriate diagnostic work, increasing the likelihood of accurately classify the patient's underlying hematologic disorder.

Novel Induction Regimens in Multiple Myeloma

Multiple myeloma is the second most common hematologic malignancy and predominantly affects the elderly. The introduction of novel agents such as thalidomide, lenalidomide, and bortezomib has improved progression-free survival, overall survival, and quality of life in myeloma patients. Next generation agents such as carfilzomib hold further promise for increased depth and length of remission. Autologous stem cell transplant remains a useful tool in the treatment of multiple myeloma, but not all patients are eligible for this procedure. As therapy becomes more effective, determination of the right therapy in the right patient becomes paramount. The focus of this review is a critical analysis of combinations of the novel agents in the treatment of newly diagnosed multiple myeloma in both transplant eligible and ineligible patients.

Monoclonal antibody therapy in multiple myeloma: where do we stand and where are we going?

Multiple myeloma is a plasma cell malignancy that is characterized by refractory and relapsing course of disease. Despite the introduction of high-dose chemotherapy in combination with autologous stem cell transplantation and innovative agents such as proteasome inhibitors and immunomodulatory drugs, achieving cure in multiple myeloma is a challenging endeavor. In the last couple of years, enormous advances were made in implementing monoclonal antibody therapy in multiple myeloma. A large number of preclinical and clinical studies have been introduced successfully, demonstrating a safe and efficient administration of monoclonal antibodies in multiple myeloma. In particular, the application of monoclonal antibodies in combination with immunomodulatory drugs, proteasome inhibitors, corticosteroids or conventional chemotherapy seem to be promising and will expand the treatment arsenal for patients with multiple myeloma.

Infectious complications in patients with newly diagnosed multiple myeloma: A complication from the past?

Infectious complications are an important risk factor for early mortality in patients with multiple myeloma. However, data about the impact and severity of infections in these patients in the era of new therapies have not been properly analyzed. This review has reviewed the incidence and severity of infections complications and infection-related mortality during induction treatment in patients with newly diagnosed myeloma receiving regimens with new drugs within randomized trials. The results show that infections are still a major cause of morbidity, especially among elderly patients receiving immunomodulatory drugs seen in up to 28% of patients in some trials vs less than 10% among transplant-eligible patients. Overall infection-related mortality ranged from 0-7% in transplant-ineligible patients, with no infection-related deaths in the majority of the trials including younger patients. Strategies directed to further reduce these complications and a better knowledge of their impact in patients treated outside clinical trials are needed.

CD4+CD25+ cells in multiple myeloma related renal impairment

CD4⁺CD25⁺ cells are critical regulators in almost all of the animal models of human organ-specific autoimmune diseases, transplant rejection and allergic diseases. We aimed to explore the role of CD4⁺CD25⁺ cells in the pathogenesis of multiple myeloma (MM) related renal impairment (RI). Thirty patients with MM related RI and 30 healthy volunteers were studied. The number of CD4⁺CD25⁺ cells was examined by flow cytometry. Clinical and laboratory data were collected from each subject. Glomerular injury was assessed by histopathology. Serum IL-2, IL-4 and IL-6 were analyzed by ELISA. CD4⁺CD25⁺ cells significantly decreased in MM related RI patients compared to the controls (P<0.05). CD4⁺CD25⁺ cell number was negatively associated with blood urea nitrogen (BUN), supernatant IL-4, serum IL-6, monoclonal immunoglobulin and β2-microglobulin, as well as bone marrow plasma cell percentage and proteinuria; whereas positively associated with estimated glomerular filtration rate (eGFR) (all P < 0.05). CD4⁺CD25⁺ cells gradually decreased as the Clinic Stage increased. The number of CD4⁺CD25⁺ cells reduced in MM related RI patients, and was correlated with disease severity. CD4⁺CD25⁺ cells may play an important role in the pathogenesis of MM related RI.

Circulating Serum MicroRNA-130a as a Novel Putative Marker of Extramedullary Myeloma

Poor outcome of extramedullary disease in multiple myeloma patients and lack of outcome predictors prompt continued search for new markers of the disease. In this report, we show circulating microRNA distinguishing multiple myeloma patients with extramedullary disease from myeloma patients without such manifestation and from healthy donors. MicroRNA-130a was identified by TaqMan Low Density Arrays and verified by quantitative PCR on 144 serum samples (59 multiple myeloma, 55 myeloma with extramedullary disease, 30 healthy donors) in test and validation cohorts as being down-regulated in myeloma patients with extramedullary disease. Circulating microRNA-130a distinguished myeloma patients with extramedullary disease from healthy donors with specificity of 90.0% and sensitivity of 77.1%, patients with extramedullary disease from newly diagnosed multiple myeloma patients with specificity of 77.1% and sensitivity of 34.3% in the test cohort and with specificity of 91.7% and sensitivity of 30.0% in the validation cohort of patients. Circulating microRNA-130a in patients with extramedullary myeloma was associated with bone marrow plasma cells infiltration. Further, microRNA-130a was decreased in bone marrow plasma cells obtained from patients with extramedullary myeloma in comparison to bone marrow plasma cells of myeloma patients without such manifestation, but it was increased in tumor site plasma cells of patients with extramedullary disease compared to bone marrow plasma cells of such patients (p<0.0001). Together, our data suggest connection between lower level of microRNA-130a and extramedullary disease and prompt further work to evaluate this miRNA as a marker of extramedullary disease in multiple myeloma.

IgD multiple myeloma: Clinical, biological features and prognostic value of the serum free light chain assay

IgD multiple myeloma (MM) is a rare subtype of myeloma, it affects less than 2% of patients with MM. To evaluate the clinical and prognostic attributes of serum free light chains (sFLCs) analysis, we examined 17 cases of IgD MM. From 1998 to 2012, we obtained 1250 monoclonal gammapathies including 590 multiple myeloma and 17 patients had IgD MM. With preponderance of men patients with a mean age at diagnosis of: 59±12years. Patients with IgD MM have a short survival (Median survival=9months). The presenting features included: bone pain (75%), lymphadenopathy (16%), hepatomegaly (25%), splenomegaly (8%), associated AL amyloidosis (6%), renal impairment function (82%), infections (47%), hypercalcemia (37%) and anemia (93%). Serum electrophoresis showed a subtle M-spike (Mean=13.22±10g/L) in all patients associated to a hypogammaglobulinemia. There was an over-representation of Lambda light chain (65%); high serum β2-microglobulin in 91% and Bence Jones proteinuria was identified in 71%. The median rate of sFLCs κ was 19.05mg/L and 296.75mg/L for sFLCs λ. sFLCR was abnormal in 93% of patients and it showed concordance between baseline sFLCR and the survival (P=0.034). The contribution of FLC assay is crucial for the prognosis of patients with IgD MM.

Paraproteinemic neuropathies

PURPOSE OF REVIEW

Monoclonal gammopathies are common in the general population and occur in 10% of patients with peripheral neuropathy. It is important for the clinician to be able to determine whether an association exists between the paraprotein and the neuropathy. The clinical phenotype of the neuropathy, as well as the type of monoclonal protein, provides clues for the diagnosis. Optimal management of paraproteinemic neuropathies requires appropriate evaluation of the monoclonal protein for an underlying hematologic disorder.

RECENT FINDINGS

Clinical studies in paraproteinemic neuropathies have provided a better understanding of these disorders, but much is still unknown regarding the pathophysiologic mechanisms. Recent clinical trials in immunoglobulin M (IgM) neuropathy have shown that better outcome measures and treatment approaches are needed. Peripheral blood stem cell transplantation has shown promising improvements in the treatment of polyneuropathy, organomegaly, endocrinopathy, monoclonal plasma cell disorder, and skin changes (POEMS) syndrome and immunoglobulin light chain (AL) amyloidosis.

SUMMARY

Recognizing the frequent association of neuropathy with monoclonal proteins and evaluating for a hematologic malignancy should enable physicians to find better treatments and ultimately improve neuropathy outcome.

New prognostic tools for myeloma

In this issue of Blood, Palumbo et al show, in a study performed with the cooperation of the International Myeloma Working Group (IMWG), that detailed systematic geriatric assessment of elderly myeloma patients might be a useful tool for identifying fit and frail individuals. Like most malignancies, multiple myeloma mainly affects elderly patients. Even so, in daily clinical practice, we usually only consider chronological age (i.e., is the patient under or above 65 years of age?). However, it is quite obvious that there is a huge difference between a 70-year-old fit patient and a frail patient above the age of 80.

Design, synthesis and biological evaluation of novel sesquiterpene mustards as potential anticancer agents

Several novel series of sesquiterpene mustards (SMs) bearing nitrogen mustard and glutathione (GSH)-reactive α-methylene-γ-butyrolactone groups were successfully prepared for the first time and showed excellent antiproliferative activities in vitro. Among them, compounds 2e and 2g displayed the highest antiproliferative properties with IC50 values ranging from 2.5 to 8.7 μM. The selectivity of these two compounds was evaluated by SRB method against human cancer and normal hepatic cells (HepG2 and L02). The induction of apoptosis and effects on the cell cycle distribution with compounds 2e and 2g were investigated by Hoechst 33,258 staining and flow cytometry, which exhibited that they could induce selective cell apoptosis and cell cycle arrest in HepG2 and L02 cells. In addition, further investigation showed that compounds 2e and 2g could obviously inhibit the proliferation of HepG2 cells by inducing significant DNA cross-linking and depleting GSH in cell media. The good cytotoxicity and selectivity of compounds 2e and 2g pointed them as promising leads for anticancer drug design.

Synthesis and biological studies of the thiols-triggered anticancer prodrug for a more effective cancer therapy

Thiols-triggered anticancer prodrug1produces an active DNA alkylating agent mechlorethamine leading to DNA damage and finally cell death.

Staging and prognostication of multiple myeloma

Multiple myeloma (MM) is a heterogeneous disease that, over the past 15 years, has seen an increased understanding of its biology and of novel therapeutic options. Distinctive subtypes of the disease have been described, each with different outcomes and clinic-pathological features. Even though a detailed classification of MM into at least seven or eight major subtypes is possible, a more practical clinical approach can classify the disease into high-risk and non-high-risk MM. Such classification has permitted a more personalized approach to the management of the disease. Additionally, risk stratification should be included in outcome discussions with patients, as survival differs significantly by high-risk status. Nowadays, test for risk stratification are widely available and can be routinely used in the clinic. A greater understanding of the genetic abnormalities underlying the biology of MM will allow for the development of novel targeted therapies and better prognostic markers of the disease.

A quantitative method for the characterization of lytic metastases of the bone from radiographic images

The aim of our study was to assess the diagnostic usefulness of the gray level parameters to distinguish osteolytic lesions using radiological images. Materials and Methods. A retrospective study was carried out. A total of 76 skeletal radiographs of osteolytic metastases and 67 radiographs of multiple myeloma were used. The cases were classified into nonflat (MM1 and OL1) and flat bones (MM2 and OL2). These radiological images were analyzed by using a computerized method. The parameters calculated were mean, standard deviation, and coefficient of variation (MGL, SDGL, and CVGL) based on gray level histogram analysis of a region-of-interest. Diagnostic utility was quantified by measurement of parameters on osteolytic metastases and multiple myeloma, yielding quantification of area under the receiver operating characteristic (ROC) curve (AUC). Results. Flat bone groups (MM2 and OL2) showed significant differences in mean values of MGL (P = 0.048) and SDGL (P = 0.003). Their corresponding values of AUC were 0.758 for MGL and 0.883 for SDGL in flat bones. In nonflat bones these gray level parameters do not show diagnostic ability. Conclusion. The gray level parameters MGL and SDGL show a good discriminatory diagnostic ability to distinguish between multiple myeloma and lytic metastases in flat bones.

A single nucleotide polymorphism in SLC7A5 is associated with gastrointestinal toxicity after high-dose melphalan and autologous stem cell transplantation for multiple myeloma

Multiple myeloma is the most frequent indication for high-dose melphalan (HDM) chemotherapy with autologous stem cell transplantation (ASCT). Gastrointestinal symptoms represent the most significant nonhematological toxicity of HDM. However, specific, especially genetic, predictors of their incidence or clinical severity are lacking. The amino acid transporters LAT1 and LAT2 encoded by the SLC7A5 and SLC7A8 genes, respectively, are the principal mediators of melphalan uptake into cells. To determine whether genetic variability at these loci contributed to interindividual differences in the development of gastrointestinal complications of HDM, we analyzed single nucleotide polymorphisms (SNPs) in these genes in 135 patients with multiple myeloma treated with HDM and ASCT and correlated these with the need for total parenteral nutrition (TPN). Seven SNPs in SLC7A5 and 20 in SLC7A8 were genotyped. Multiple analyses indicated that 1 SNP in the first intron of SLC7A5, rs4240803, was significantly associated with TPN use (odds ratio = .45, 95% confidence interval, .25 to .79; P = .007). Further, every haplotype that correlated with TPN requirement included this SNP. These results suggest that variability in melphalan transport affects mucosal injury after HDM. This finding could help in individualizing the dose of this effective and widely used chemotherapeutic agent for multiple myeloma.

Gene set enrichment analysis of the NF-κB/Snail/YY1/RKIP circuitry in multiple myeloma

The presence of a dysregulated NF-κB/Snail/YY1/RKIP loop was recently established in metastatic prostate cancer cells and non-Hodgkin's lymphoma; however, its involvement in multiple myeloma (MM) has yet to be investigated. Aim of the study was to investigate the role of the NF-κB/Snail/YY1/RKIP circuitry in MM and how each gene is correlated with the remaining genes of the loop. Using gene set enrichment analysis and gene neighbours analysis in data received from four datasets included in the Multiple Myeloma Genomics Portal of the Multiple Myeloma Research Consortium, we identified various enriched gene sets associated with each member of the NF-κB/Snail/YY1/RKIP circuitry. In each dataset, the 20 most co-expressed genes with the circuitry genes were isolated subjected to Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment. Among many, we highlighted on FNDC3B, TPD52, BBX, MBNL1 and MFAP2. Many co-expressed genes participated in the regulation of metabolic processes and nucleic acid binding, or were transcription factor binding genes and genes with metallopeptidase activity. The transcription factors FOXO4, GATA binding factor, Sp1 and AP4 most likely affect the expression of the NF-κB/Snail/YY1/RKIP circuitry genes. Computational analysis of various GEO datasets revealed elevated YY1 and RKIP levels in MM vs. the normal plasma cells, as well as elevated RKIP levels in MM vs. normal B lymphocytes. The present study highlights the relationships of the NF-κB/Snail/YY1/RKIP circuitry genes with specific cancer-related gene sets in multiple myeloma.

Therapeutic use of immunomodulatory drugs in the treatment of multiple myeloma

Immunomodulatory drugs, such as thalidomide, lenalidomide (Revlimid, CC-5013) and actimid (CC-4047), have a broad spectrum of activity and have shown remarkable responses in patients with multiple myeloma and related hematological diseases, such as myelodysplastic syndrome. They are currently being tested in other cancer types. This review will focus on the preclinical and clinical activity of thalidomide and its more potent immunomodulatory derivatives that are used to treat multiple myeloma. They represent a new class of antitumor agents that not only target the tumor cell directly, but also have significant activity within the bone marrow milieu. These agents have shown high responses in all phases of multiple myeloma, including the upfront setting, relapsed refractory stage and also as maintenance therapy for the disease. They have been used in combination with dexamethasone, chemotherapy and, more recently, with other novel agents, such as proteasome inhibitors. Thalidomide and lenalidomide in combination with dexamethasone have recently been approved by the US FDA for the treatment of multiple myeloma.

Nestin expression throughout multistep pathogenesis of multiple myeloma

The stem cell marker nestin (NES) is found in dividing cells of developing and regenerating tissues. Upon terminal differentiation, NES expression is diminished but may be re-expressed following injury or in cancer. Surprisingly, we recently confirmed NES as a tumour-specific marker for mature CD138(+) 38(+) plasma cells (PC) in multiple myeloma (MM). The present study analysed NES expression throughout the spectrum of MM developmental stages, starting with individuals with no haematological malignancy, through monoclonal gammopathy of undetermined significance (MGUS) and MM to plasma cell leukaemia (PCL) and MM cell lines. NES was analysed in bone marrow PC of 163 MM, four PCL and nine MGUS patients, 10 individuals with no haematological malignancy and 6 myeloma cell lines (OPM-2, RPMI-8226, MOLP-8, U-266, EJM, NCI-H929) by flow cytometry and/or real-time polymerase chain reaction or immunochemistry. We observed a tendency of increased NES expression in parallel with disease progression. NES was evaluated as a reliable marker for accurate discrimination between MM patients and the control group. High NES levels were strongly associated with the presence of 1q21 gain. For the first time, NES was demonstrated to predict worse response to conventional therapy/novel agents. These results suggest that NES might become a useful clinical parameter with an important role in MM pathogenesis.

(11)C-acetate as a new biomarker for PET/CT in patients with multiple myeloma: initial staging and postinduction response assessment

PURPOSE

We investigated the potential value of (11)C-acetate (ACT) PET/CT in characterizing multiple myeloma (MM) compared with (18)F-FDG PET/CT. Bone marrow histological and whole-body (WB) MRI findings served as the reference standards.

METHODS

In this prospective study, 15 untreated MM patients (10 men and 5 women, age range 48-69 years) underwent dual-tracer (11)C-ACT and (18)F-FDG PET/CT and WB MRI for pretreatment staging, and 13 of them had repeated examinations after induction therapy. Diffuse and focal bone marrow uptake was assessed by visual and quantitative analyses, including measurement of the maximum standardized uptake value (SUVmax). Between-group differences and correlations were assessed with the Mann-Whitney U test and the Pearson test.

RESULTS

At staging, all 15 patients had diffuse myeloma involvement upon bone marrow examination with 30-90 % of plasma cell infiltrates. Diffuse infiltration was detected in all of them (100 %) using (11)C-ACT with a positive correlation between bone marrow uptake values and percentages of plasma cell infiltrates (r = +0.63, p=0.01). In contrast, a diagnosis of diffuse infiltration could be established using (18)F-FDG in only six patients (40 %). Focal lesions were shown in 13 patients on both (11)C-ACT PET/CT and WB MRI, and in 10 patients on (18)F-FDG PET/CT. Focal lesions demonstrated (11)C-ACT uptake with a mean SUVmax of 11.4 ± 3.3 (range 4.6-19.6, n=59), which was significantly higher than the (18)F-FDG uptake (mean SUVmax 6.6 ± 3.1, range 2.3-13.7, n=29; p<0.0001). After treatment, the diffuse bone marrow (11)C-ACT uptake showed a mean SUVmax reduction of 66 % in patients with at least a very good partial response versus 34 % in those with at most a partial response only (p=0.01).

CONCLUSION

PET/CT using (11)C-ACT as a biomarker showed a higher detection rate for both diffuse and focal myeloma lesions at diagnosis than using (18)F-FDG, and may be valuable for response assessment.

Clinical challenges: Myeloma and concomitant type 2 diabetes

Multiple myeloma is a malignant plasma cell disorder that accounts for approximately 10% of all hematological cancers. It is characterized by accumulation of clonal plasma cells, predominantly in the bone marrow. The prevalence of type 2 diabetes is increasing; therefore, it is expected that there will be an increase in the diagnosis of multiple myeloma with concomitant diabetes mellitus. The treatment of multiple myeloma and diabetes mellitus is multifaceted. The coexistence of the two conditions in a patient forms a major challenge for physicians.

Myeloma plasma cells alter the bone marrow microenvironment by stimulating the proliferation of mesenchymal stromal cells

Multiple myeloma is an incurable hematologic cancer characterized by the clonal proliferation of malignant plasma cells within the bone marrow. Numerous studies suggest that the myeloma plasma cells occupy and alter the stromal tissue of the bone marrow as a means of enhancing their survival and growth. However, the nature and magnitude of the changes to the stromal cell tissue remain to be determined. In this study, we used mesenchymal stromal cell and osteoblast-related cell surface marker expression (STRO-1 and alkaline phosphatase, respectively) and flow cytometry to enumerate mesenchymal stromal cell and osteoblast numbers in bone marrow recovered from myeloma patients at the time of diagnosis. Using this approach, we identified an increase in the number of STRO-1 positive colony forming mesenchymal stromal cells and a concomitant decrease in alkaline phophatase osteoblasts. Notably, this increase in mesenchymal stromal cell numbers correlated closely with plasma cell burden at the time of diagnosis. In addition, in comparison with the osteoblast population, the STRO-1+ mesenchymal stromal cell population was found to express higher levels of plasma cell- and osteoclast-activating factors, including RANKL and IL-6, providing a mechanism by which an increase in mesenchymal stromal cells may promote and aid the progression of myeloma. Importantly, these findings were faithfully replicated in the C57BL/KaLwRij murine model of myeloma, suggesting that this model may present a unique and clinically relevant system in which to identify and therapeutically modulate the bone microenvironment and, in turn, alter the progression of myeloma disease.

Radiofrequency-targeted vertebral augmentation for the treatment of vertebral compression fractures as a result of multiple myeloma

STUDY DESIGN

A retrospective review of a consecutive population of patients treated with radiofrequency-targeted vertebral augmentation (RF-TVA) for malignant vertebral compression fractures (VCFs).

OBJECTIVE

To investigate the safety and efficacy of RF-TVA in patients with malignant VCFs.

SUMMARY OF BACKGROUND DATA

The use of polymethylmethacrylate (PMMA) in vertebroplasty and balloon kyphoplasty for patients with recalcitrant pain after acute VCFs is shown to be safe, successful in stabilizing the VCF, and effective for the relief of pain after osteoporotic and malignant VCFs. RF-TVA using targeted cavity creation and ultrahigh viscosity PMMA delivery with a long handling time was developed to address the potential adverse issues that arise with vertebroplasty and balloon kyphoplasty.

METHODS

Between December 2008 and May 2009, a consecutive series of 66 RF-TVA procedures were performed by the authors for VCF secondary to multiple myeloma. Pre- and postoperatively, a standard 10-point visual analogue scale was used to assess back pain. Pain medication use and activity categories were defined and monitored for changes before and after RF-TVA. All patients were followed for 6 months postoperatively.

RESULTS

At 6 months postoperatively, significant improvement in pain, activity, and narcotic use was observed. There were no pulmonary or neurological complications, and one patient had radiographical evidence of asymptomatic leakage of PMMA into the vertebral disc space.

CONCLUSION

We report optimum safety and efficacy results in the treatment of malignant VCFs with a novel RF-TVA technique in which controlled delivery of an ultrahigh viscosity PMMA is used for fracture stabilization. The deposition of PMMA with RF-TVA is predictable and uniform, and can be performed without the PMMA handling constraints that may be encountered with vertebroplasty and balloon kyphoplasty. The safety and efficacy we report with RF-TVA achieved equivalency with other methods of treatment for VCF stabilization.