Prognostic value of angiogenesis in solitary bone plasmacytoma

Impact of cytogenetic abnormalities on the risk of disease progression in solitary bone plasmacytomas

Most patients with solitary bone plasmacytomas (SBP) progress to multiple myeloma (MM) after definitive radiation therapy as their primary treatment. Whether the presence of high-risk (HR) cytogenetic abnormalities by fluorescence in situ hybridization (FISH) in the clonal plasma cells, obtained either directly from the diagnostic SBP tissue or the corresponding bone marrow examination at the time of diagnosis, is associated with a shorter time to progression (TTP) to MM is unknown. This study evaluated all patients diagnosed with SBP at the Mayo Clinic from January 2012 to July 2022. The presence of del(17p), t(14;16), t(4;14), or +1q (gain or amplification) by FISH in clonal plasma cells was defined as HR. A total of 114 patients were included in this cohort, and baseline FISH was available for 55 patients (48%), of which 22 were classified as HR (40%). The median TTP to MM for patients with SBP and HR FISH was 8 months (95% confidence interval [CI], 6.3-26) compared with 42 months (95% CI, 25-not reached [NR]) in patients with SBP without HR FISH (P < .001). In a multivariate analysis, only HR FISH was a significant predictor for shorter TTP to MM, independent of minimal marrow involvement and an abnormal serum free light chain ratio at diagnosis. Deletion (17p) and gain 1q abnormalities were the most common FISH abnormalities responsible for the short TTP to MM. Thus, assessing for HR FISH abnormalities in clonal plasma cells derived from either the diagnostic SBP tissue or the staging bone marrow examination of patients with newly diagnosed SBP is feasible and prognostic for a shorter TTP to MM.

A Case of Recurrent Multiple Myeloma as Testicular Plasmacytoma Without Systemic Disease

Plasma cell neoplasms include various conditions ranging from indolent conditions such as monoclonal gammopathy of undetermined significance (MGUS) to more aggressive forms such as multiple myeloma (MM). The World Health Organization classifies plasmacytomas into two types: solitary osseous plasmacytoma (SOP) and extramedullary plasmacytoma (EMP). Most primary EMPs occur in the upper gastrointestinal tract, head and neck, upper respiratory system, central nervous system, lungs, liver, spleen, and kidneys. However, the occurrence of EMP involving the testis site is quite rare. Given the rarity of testicular plasmacytoma, there is no consensus on the standard of treatment for this diagnosis. Most EMP is radiosensitive, with few localized types responding to surgical intervention. Tumor recurrence and disseminated infiltration are treated with adjuvant chemotherapy after radiation or surgery. Our patient has a unique presentation of an individual who developed recurrent myeloma of the testis 12 years after his initial diagnosis of myeloma.

Solitary Plasmacytoma in the Calcaneus

Solitary plasmacytomas (SPs) are tumors characterized by local monoclonal plasma cell proliferation, presenting without systemic manifestations. It mainly affects the axial skeleton, with calcaneal involvement being extremely rare. We report a case of a 48-year-old patient with a history of gunshot injury to his foot who presented with worsening heel pain and a calcaneal cyst. Biopsy revealed plasmacytoma, and subsequent 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) scan further supported the diagnosis of solitary plasmacytoma of the bone (SPB). Management included lesion excision, bone cement placement, and radiotherapy. However, due to recurrent osteomyelitis following cement placement, the patient eventually required total calcanectomy. SPB usually affects older adults, and developing the disease at a young age and in the calcaneus is exceedingly uncommon. Trauma is implicated as a possible inciting trigger in the pathogenesis of SPB without a clear association. This case highlights the importance of developing our current understanding of the clinical presentation and manifestations of SPB, beyond the conventional assumption that it only affects the axial skeleton of older individuals.

Anti-Angiogenic Activity of Drugs in Multiple Myeloma

Angiogenesis represents a pivotal hallmark of multiple myeloma (MM) that correlates to patients’ prognosis, overall survival, and drug resistance. Hence, several anti-angiogenic drugs that directly target angiogenic cytokines (i.e., monoclonal antibodies, recombinant molecules) or their cognate receptors (i.e., tyrosine kinase inhibitors) have been developed. Additionally, many standard antimyeloma drugs currently used in clinical practice (i.e., immunomodulatory drugs, bisphosphonates, proteasome inhibitors, alkylating agents, glucocorticoids) show anti-angiogenic effects further supporting the importance of inhibiting angiogenesis from potentiating the antimyeloma activity. Here, we review the most important anti-angiogenic therapies used for the management of MM patients with a particular focus on their pharmacological profile and on their anti-angiogenic effect in vitro and in vivo. Despite the promising perspective, the direct targeting of angiogenic cytokines/receptors did not show a great efficacy in MM patients, suggesting the need to a deeper knowledge of the BM angiogenic niche for the design of novel multi-targeting anti-angiogenic therapies.

What's Old is New: The Past, Present and Future Role of Thalidomide in the Modern-Day Management of Multiple Myeloma

Immunomodulatory drugs (IMiDs) have become an integral part of therapy for both newly diagnosed and relapsed/refractory multiple myeloma (RRMM). IMiDs bind to cereblon, leading to the degradation of proteins involved in B-cell survival and proliferation. Thalidomide, a first-generation IMiD, has little to no myelosuppressive potential, negligible renal clearance, and long-proven anti-myeloma activity. However, thalidomide's adverse effects (e.g., somnolence, constipation, and peripheral neuropathy) and the advent of more potent therapeutic options has led to the drug being less frequently used in many countries, including the US and Canada. Newer-generation IMiDs, such as lenalidomide and pomalidomide, are utilized far more frequently. In numerous previous trials, salvage therapy with thalidomide (50-200 mg/day) plus corticosteroids (with or without selected cytotoxic or targeted agents) has been shown to be effective and well-tolerated in the RRMM setting. Hence, thalidomide-based regimens remain important alternatives for heavily pretreated patients, especially for those who have no access to novel therapies and/or are not eligible for their use (due to renal failure, high-grade myelosuppression, or significant comorbidities). Ongoing and future trials may provide further insights into the current role of thalidomide, especially by comparing thalidomide-containing regimens with protocols based on newer-generation IMiDs and by investigating thalidomide's association with novel therapies (e.g., antibody-drug conjugates, bispecific antibodies, and chimeric antigen receptor T cells).

Prediction of Solitary Plasmacytoma of Bone in Elderly Patients: A Nomogram and a Risk Classification System for Overall Survival

Background

Solitary plasmacytoma of bone (SPB) is an isolated plasmacytoma of bone origin, most commonly seen in the elderly, with a poor prognosis. So far, there is no precise nomogram to predict the overall survival (OS) of elderly patients with SPB. Our goal is to construct and validate a nomogram for elderly patients with SPB.

Methods

This study collected all elderly patients with SPB in the Surveillance, Epidemiology and End Results (SEER) database from 2000 to 2018, and the variables included were age, sex, race, marital status, primary site, grade, stage, surgery, chemotherapy, and radiotherapy. Independent prognostic factors were identified using univariate and multivariate Cox analysis. The nomogram was constructed to predict 1-, 2-, and 3-year OS of elderly patients with SPB. The receiver-operating characteristic (ROC) and the calibration curves were used to differentiate and calibrate the nomogram. The clinical validity of the nomogram was evaluated by decision curve analysis (DCA). The total OS scores of all elderly SPB patients were calculated and divided into two risk subgroups for comparison.

Results

A total of 1837 patients diagnosed with SPB were screened from the SEER database, with a final inclusion of 1180 patients (age ≥ 60 years). Age, radiotherapy, and marital status were significantly correlated with OS. These characteristics were further incorporated into the creation of the nomogram for predicting 1-, 2-, and 3-year OS of elderly patients with SPB. For this predictive model, the area under the ROC curves, calibration curves, and DCA have good performance in terms of differentiation, consistency, and validity, respectively. In addition, patients in the high-risk group (≥96) had a worse prognosis than those in the low-risk group (<96).

Conclusion

We constructed a nomogram and a risk classification system that could provide an intuitive and effective tool for clinicians to better predict the OS of elderly SPB patients.

A Rare Case of Solitary Plasmacytoma Arising From the Sternum

Solitary plasmacytoma (SP) is characterized by an accumulation of neoplastic monoclonal plasma cells in a localized fashion, without evidence of multiple myeloma. It makes up <5% of all plasma cell neoplasms and is typically found in regions like the pelvis, ribs, vertebra, and spine. SP is classified into extramedullary plasmacytoma (EMP), which primarily affects soft tissues, and solitary bone plasmacytoma (SBP), which primarily affects the pelvis, ribs, vertebrae, and spine. We report a case of a 66-year-old man with sternal plasmacytoma presenting as chest pain. He was treated with radiation therapy. Here, we aim to describe the clinical features, diagnostic methods, treatment, and potential outcome in a patient with SBP.

Radiotherapy alleviates spinal cord compression caused by solitary bone plasmacytoma: A case report

INTRODUCTION AND IMPORTANCE

Solitary bone plasmacytoma (SBP) is a hematopoietic malignancy occurring in bone tissue, which often causes bone destruction at the site of the lesion. When the lesion occurs in the spine and causes spinal stenosis and compression of the spinal cord, surgery is performed as an adjuvant treatment before radiotherapy.

CASE PRESENTATION

A 36-year-old patient suffered from neck, shoulder and upper limbs pain for 3 weeks and the symptom worsened for 3 days after exercise. CT and MRI examination of the neck after emergency admission revealed C5 vertebral pathological fracture with associated spinal stenosis and spinal cord compression. PET-CT indicated a hypermetabolic soft tissue mass in the C5-6 vertebral body. Granulomatous lesions (tuberculosis) were considered, but neoplastic lesions were not ruled out. The primary diagnosis was cervical fracture caused by tuberculosis. Finally, a needle biopsy was performed at the lesion site and a diagnosis of SBP was made. Radiotherapy was immediately followed and the spinal cord compression was relieved a month later. After 6 months of follow-up, she is now in stable condition with no neck pain or neurological impairment.

CONCLUSION

For patients with SPB resulting in pathological fracture of the cervical vertebra with spinal stenosis and compression of the spinal cord, forgoing surgery and undergoing radiation therapy alone may be an option.

Potential of a sphingosine 1‑phosphate receptor antagonist and sphingosine kinase inhibitors as targets for multiple myeloma treatment

Sphingosine 1-phosphate (S1P) is a bioactive lipid involved in cancer progression through its binding to S1P receptors (S1PRs). However, the association between multiple myeloma (MM) and S1P is unclear. The current study aimed to investigate the potential anti-cancer effects of fingolimod and sphingosine kinase (SK) inhibitors in myeloma cells and the effects of S1P-induced chemoresistance and neovascularization on MM cell proliferation. MM cell lines were treated with the S1PR1 antagonist fingolimod and the SK inhibitors ABC294640 and SK1-I, after which cell proliferation was measured. Protein expression was also assessed under each condition using immunoblotting. Serum S1P levels in patients with MM, monoclonal gammopathy of undetermined significance and healthy volunteers were assessed. Human umbilical vessel cells (HUVECs) were co-cultured with anti-S1P agents to assess the effect on cell migration. All treatments suppressed myeloma cell proliferation and caspase-3-mediated apoptosis by suppressing S1P activity. These findings suggest that S1P activation is associated with proliferation and survival for MM cells. S1P attenuated the proteosome inhibitor (PI) effect, while the anti-S1P agents recovered the effect. In addition, S1P promoted the migration and proliferation of HUVECs, whereas the S1P inhibitors reduced the influence of S1P. This study highlights the therapeutic potential of anti-S1P agents for MM treatment. Inhibition of S1P function may overcome resistance to PI developed by myeloma cells and inhibit the changes to the bone marrow microenvironment via neovascularization.

Extramedullary plasmacytoma of the ureter

INTRODUCTION

We report a rare case of an extramedullary plasmacytoma of the ureter.

CASE PRESENTATION

A 77-year-old man was referred to our hospital because of left hydronephrosis. Computed tomography showed a tumor in the left ureter, and tumor invasion into the periureteric fat was suspected. Urine cytology showed Eatypical cells whose nuclei were hyperchromatic (class IIIb). The left ureteral tumor was diagnosed as urothelial carcinoma (cT3N0M0) preoperatively. Subsequently, we performed laparoscopic radical nephroureterectomy with bladder cuff excision. The tumor was pathologically diagnosed as a plasmacytoma. Postoperative positron emission tomography did not reveal abnormal uptake, and bone marrow aspiration findings were normal. Consequently, the left ureter tumor was diagnosed as an extramedullary plasmacytoma of the ureter.

CONCLUSION

Extramedullary plasmacytoma commonly occurs in the upper respiratory tract or upper gastrointestinal tract. Extramedullary plasmacytoma of the ureter is rare. This is only the fourth reported case of extramedullary plasmacytoma of the ureter.

Can Targeting Hypoxia-Mediated Acidification of the Bone Marrow Microenvironment Kill Myeloma Tumor Cells?

Multiple myeloma (MM) is an incurable cancer arising from malignant plasma cells that engraft in the bone marrow (BM). The physiology of these cancer cells within the BM microenvironment (TME) plays a critical role in MM development. These processes may be similar to what has been observed in the TME of other (non-hematological) solid tumors. It has been long reported that within the BM, vascular endothelial growth factor (VEGF), increased angiogenesis and microvessel density, and activation of hypoxia-induced transcription factors (HIF) are correlated with MM progression but despite a great deal of effort and some modest preclinical success the overall clinical efficacy of using anti-angiogenic and hypoxia-targeting strategies, has been limited. This review will explore the hypothesis that the TME of MM engrafted in the BM is distinctly different from non-hematological-derived solid tumors calling into question how effective these strategies may be against MM. We further identify other hypoxia-mediated effectors, such as hypoxia-mediated acidification of the TME, oxygen-dependent metabolic changes, and the generation of reactive oxygen species (ROS), that may prove to be more effective targets against MM.

Solitary plasmacytoma of jaw bone: A case report and systematic review of fifty cases from literature

Solitary plasmacytoma of bone (SPB) is a localized form of plasma cell neoplasm where jaw involvement is rare. Distinguishing SPB from other plasma cell neoplasms is critical for treatment and survival. Here, a case of SPB of mandible in an elderly female is reported. Histopathological diagnosis of plasma cell neoplasm was confirmed immunohistochemically with MUM1 and CD138 positivity and multiple myeloma (MM) was ruled out on performing systemic workup. Prognosis of SPB worsens when it transforms into MM. A systematic review was undertaken with the objective to determine the factors affecting conversion of SPB to MM. An electronic search was undertaken with PubMed/MEDLINE, Web of Science and Science Direct. Fifty cases of SPB of jaw from 29 publications were reviewed. SPB commonly presents as a painless swelling. Radiographically, it is commonly seen as multilocular radiolucency with well-defined borders. Follow-up data showed that nine cases turned into MM in a mean duration of 1 year 9 months and 12 patients died after median disease-free survival of 6 years 9 months. Prognosis of SPB is found to be affected by tumor size (≥5 cm), anaplasia of tumor cells, Ki-67 labeling index, vascularity of the tumor, presence of clonal bone marrow plasma cells, serum immune globulin level, dose of radiotherapy and persistence of M protein after treatment. There is a need to identify prognostic subgroups in SPB based on these factors. Furthermore, studies are necessary for standardization of treatment protocol to halt or prolong the progression of SPB to MM.

Evaluation of Angiogenesis in Multiple Myeloma by VEGF Immunoexpression and Microvessel Density

Background  Multiple myeloma (MM) is a plasma cell disorder characterized by monoclonal proliferation of plasma cells in bone marrow. Plasmablastic MM is a morphologic subset of MM, containing ≥2% plasmablasts of all plasma cells.

Methods  The study included 30 consecutively diagnosed patients of MM (6 plasmablastic, 24 nonplasmablastic) over a span of 2 years. Angiogenesis in MM was assessed by analysis of vascular endothelial growth factor (VEGF) immunoexpression by plasma cells and microvessel density (MVD) using anti-CD34 antibody. CD34 and VEGF immunohistochemical staining was performed in all the 30 cases. Angiogenesis was studied in relation to plasmablastic morphology and clinical profile to determine if any correlation exists between these.

Results  The mean VEGF expression of 80.83 ± 7.36 in plasmablastic myeloma cases was significantly higher compared with a mean VEGF of 53.54 ±17.09 in nonplasmablastic cases. Most of the cases (66.6%) of plasmablastic myeloma exhibited strong (3+) VEGF expression. The difference in mean VEGF expression between plasmablastic and nonplasmablastic cases was found to be statistically significant ( p = 0.001). The mean MVD in plasmablastic cases was 44.8 ± 3.69, while in the nonplasmablastic category, the mean MVD was 23.7 ± 5.14, difference being statistically significant ( p < 0.05). Also, a positive correlation was found between VEGF expression and MVD.

Conclusion  A moderate/strong VEGF intensity and higher MVD were found in cases of plasmablastic MM, suggesting that a more aggressive histological disease may be associated with increased production of VEGF. This finding might be helpful to identify a subset of patients with adverse prognosis and to provide antiangiogenic therapy to improve their survival. However, studies comprising larger number of patients are required to bring out a statistical significance to further substantiate these findings.

Solitary Plasmacytoma of Frontal Bone: A Case Report

A 42 years old male presenting with complaints of swelling on the left supraorbital region since-5 months. Swelling was gradual in onset and progressive in nature. On examination it was a single swelling 5 × 6 cm, with diffuse margins, skin over the swelling was red and stretched, swelling is firm in consistency, fixed, tender on touch, non pulsatile with diffuse irregular margin. FNAC. Smears are positive for malignancy. Bone marrow examination was normal. Excision of the mass from the left frontal sinus, orbit and supraorbital region under GA and sent for HPR. Definitive treatment of choice is: radiotherary 45-50 Gy/4-5 weeks, chemotherapy and surgery. Prognosis is good with local recurrence (< 10%).

Primary extramedullary plasmacytoma with diffuse lymph node involvement: a case report and review of the literature

Background

Primary plasmacytomas are localized proliferations of clonal plasma cells occurring in the absence of a systemic plasma cell dyscrasia such as multiple myeloma. Primary plasmacytomas most commonly manifest as solitary lesions of the bone or of the upper aerodigestive tract. Presentation in a lymph node is very uncommon and can often be initially mistaken for lymphoma. Because they are local phenomena, primary plasmacytomas are managed with local therapies such as radiation or, less commonly, excision. Multifocal presentations are rare and are often not amenable to local treatment modalities, thus requiring systemic therapies. Because of their rarity, standardized treatment guidelines are not established, and treatment paradigms borrow heavily from those employed in multiple myeloma. Multifocal presentation in lymph nodes is nearly unheard of with only seven such cases reported in the existing literature, only four of which were diffuse enough to require systemic therapy. Here we describe the most diffuse and widely distributed instance of primary lymph node plasmacytoma yet reported and present a description of its successful treatment with systemic therapy.

Case presentation

A 71-year-old Asian man presented with progressive fatigue in the setting of diffuse hypermetabolic lymphadenopathy throughout his chest, abdomen, and pelvis. A diagnosis of lymphoma was initially suspected; however, a lymph node biopsy was consistent with plasmacytoma. A bone marrow biopsy was unremarkable, and no monoclonal protein was identified, establishing a diagnosis of primary extramedullary plasmacytomas of the lymph nodes. He was treated with a myeloma-like regimen consisting of four cycles of bortezomib/dexamethasone followed by two cycles of thalidomide/prednisone with improvement in symptoms and near complete resolution of prior hypermetabolic lymphadenopathy. He remains in remission over 18 months following completion of therapy.

Conclusion

This case report and accompanying literature review highlight the exceedingly rare and easily misclassified entity of primary plasmacytoma of diffuse lymph nodes. Importantly, we demonstrate that this entity may be treated with, and demonstrate excellent response to, systemic therapies often employed in multiple myeloma.

Mast Cells and Angiogenesis in Human Plasma Cell Malignancies

Bone marrow angiogenesis plays an important role in the pathogenesis and progression of hematological malignancies. It is well known that tumor microenvironment promotes tumor angiogenesis, proliferation, invasion, and metastasis, and also mediates mechanisms of therapeutic resistance. An increased number of mast cells has been demonstrated in angiogenesis associated with hematological tumors. In this review we focused on the role of mast cells in angiogenesis in human plasma cell malignancies. In this context, mast cells might act as a new target for the adjuvant treatment of these tumors through the selective inhibition of angiogenesis, tissue remodeling and tumor-promoting molecules, permitting the secretion of cytotoxic cytokines and preventing mast cell-mediated immune suppression.

Copanlisib, a novel phosphoinositide 3-kinase inhibitor, combined with carfilzomib inhibits multiple myeloma cell proliferation

Multiple myeloma (MM) is a uniformly fatal disorder of B cells characterized by the accumulation of abnormal plasma cells. Phosphoinositide 3-kinase (PI3K) signaling pathways play a critical regulatory role in MM pathology. Copanlisib, also known as BAY80-6946, is a potent PI3Kα and δ inhibitor. In this study, we investigated the efficacy of copanlisib and a proteasome inhibitor using MM cell lines and primary samples. The p110α and δ catalytic subunits of the class PI3K increased, and carfilzomib activity reduced in the presence of a supernatant from the feeder cell line, HS-5. Phosphorylation of Akt and activation of caspase 3 and poly (ADP-ribose) polymerase (PARP) partially reduced upon carfilzomib treatment in the presence of HS-5. Apoptosis also decreased. Copanlisib treatment for 72 h inhibited growth in MM cell lines and induced apoptosis. Combination treatment of MM cells with carfilzomib and copanlisib caused greater cytotoxicity than that caused by either drug alone and increased apoptosis. Caspase 3 activity increased while that of Akt decreased after combination treatment with copanlisib and carfilzomib. Further, copanlisib inhibited vascular endothelial growth factor (VEGF)-mediated angiogenesis in vitro and in vivo. It also inhibited C-X-C motif chemokine 12 (CXCL12)-mediated chemotaxis. The data suggest that administration of the PI3K inhibitor, copanlisib, may be a powerful strategy against stroma-associated drug resistance of MM cells and can enhance the cytotoxic effects of proteasome inhibitors in such residual MM cells.

Differential Diagnosis and Treatment Modality of Parasellar Plasmacytoma: Clinical Series and Literature Review

BACKGROUND

Parasellar plasmacytomas are rare tumors arising from the sellar region that should be considered in the differential diagnosis of lesions involving the sella and clivus. Before surgical pathologic examination, parasellar plasmacytomas have often been misdiagnosed as invasive pituitary adenomas or chordomas owing to the similarity of the clinical presentation and imaging findings.

METHODS

We retrospectively reviewed the data from 5 patients with parasellar plasmacytoma who underwent endonasal endoscopic tumor resection in Beijing Tiantan Hospital from January 2008 to January 2018. Their clinical symptoms, radiological features, and treatment modalities and outcomes were summarized.

RESULTS

We enrolled a total of 5 patients (3 men and 2 women; median age at diagnosis, 54 years; range, 47-61) with parasellar plasmacytoma in the present clinical series. The presenting symptoms mainly included diplopia, headache, and blurred vision. All the patients had undergone endonasal endoscopic surgery combined with adjuvant therapy. After postoperative radiotherapy, complete remission was achieved within a median follow-up period of 41 months (range, 15-120).

CONCLUSIONS

The differential diagnosis of parasellar plasmacytoma with pituitary adenoma and chordoma should include a thorough endocrine workup, neurological examination, and radiological assessment. Our findings support radiotherapy as the main treatment of choice for parasellar plasmacytoma, given its typical feature of relatively high radiosensitivity. Tumor resection through the endonasal endoscopic approach combined with adjuvant radiotherapy could be the optimal initial treatment strategy in long-term control of the lesion and alleviation of neurological symptoms.

Nasal plasmacytoma: a rare cause of persistent epistaxis

Extramedullary plasmacytoma (EP) is a rare neoplasm characterized by monoclonal proliferation of plasma cells without features of multiple myeloma. EP constitutes 3% of all plasma cell tumors. Most of the cases of EP occur in the head and neck regions, especially in the aerodigestive tract. We present a case of recurrent epistaxis for 6 months and extensive workup revealed EP of the right nasal cavity. Primary care physicians and otolaryngologists should be aware of this very rare but a plausible cause of epistaxis and keep EP in the differential diagnosis of recurrent epistaxis.

Diagnosis, treatment, and response assessment in solitary plasmacytoma: updated recommendations from a European Expert Panel

Solitary plasmacytoma is an infrequent form of plasma cell dyscrasia that presents as a single mass of monoclonal plasma cells, located either extramedullary or intraosseous. In some patients, a bone marrow aspiration can detect a low monoclonal plasma cell infiltration which indicates a high risk of early progression to an overt myeloma disease. Before treatment initiation, whole body positron emission tomography-computed tomography or magnetic resonance imaging should be performed to exclude the presence of additional malignant lesions. For decades, treatment has been based on high-dose radiation, but studies exploring the potential benefit of systemic therapies for high-risk patients are urgently needed. In this review, a panel of expert European hematologists updates the recommendations on the diagnosis and management of patients with solitary plasmacytoma.

Asymptomatic solitary bladder plasmocytoma: A case report and literature review

RATIONALE

Solitary extramedullary plasmocytoma may arise in any organ, either as a primary tumor or as part of a systemic myeloma; if it rarely affects bladder, it presents with urinary symptoms. We describe the first case of asymptomatic BP occasionally diagnosed in a patient with ascites.

PATIENT CONCERNS

A 74-year-old woman with hepatitis C virus (HCV)-related liver cirrhosis presented with ascites and no urinary or other symptoms.

DIAGNOSES

Routine blood tests were within normal ranges, except for mild elevation of transaminases due to chronic hepatitis. Abdominal ultrasound and computed tomography (CT) scanning showed multiple liver nodules suspected for carcinomas and, incidentally, a 18 mm solid lesion of right bladder wall.

OUTCOMES

She underwent transurethral resection of the bladder tumor and percutaneous liver biopsies; final diagnosis was solitary bladder plasmocytoma (BP) and hepatocellular carcinoma (HCC), respectively. She was given chemoembolization of the main HCC nodule but no adjuvant treatment for BP. At 3-month follow-up, total-body CT showed no signs of bladder disease nor distant metastases; unfortunately, she died one month later due to liver failure.

LESSONS

This is the first reported case of asymptomatic BP. This rare neoplasm may pose difficulties in differential diagnosis with both bladder metastases and the plasmocytoid variant of bladder transitional cell carcinoma. We also highlighted lack of factors predicting disease outcome as well as response to potential adjuvant treatments.

Solitary Extramedullary Plasmacytoma of the Cricoid Cartilage-Case Report

Solitary plasmacytoma (SP) is an extremely rare form of hematologic malignancy that can be classified as solitary bone plasmacytoma or solitary extramedullary plasmacytoma. Here, we report a patient who presented with progressive shortness of breath and foreign body sensation in his throat. Fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG-PET/CT) demonstrated an abnormal FDG-avid soft tissue mass arising from the larynx involving the cricoid cartilage without additional suspicious lesions. Histology revealed an abundance of plasma cells; immunohistochemistry was positive for CD138 expression and lambda chains, and negative for CD20. Comprehensive imaging studies and panendoscopy of the ENT tract confirmed solitary disease involvement. Following additional systemic work-up, a diagnosis of extramedullary plasmacytoma was rendered. The patient underwent definitive radiotherapy using intensity-modulated radiation therapy (total dose of 46 Gy, divided in 23 fractions of 200 cGy). Serial PET/CT showed the stepwise resolution of abnormal FDG uptake and resolution of the cricoid cartilage lesion. With 22 months of follow-up, the patient remains free of disease. We describe the rare case of SP presenting as a FDG-avid hypermetabolic soft tissue mass in the cricoid cartilage, which should be considered in the differential diagnosis of laryngeal tumors. Of note, SP is radiosensitive; favorable outcome can be expected once treated with doses of 40–50 Gy. FDG PET/CT is helpful in diagnosis and response assessment for this disease.

Metachronous solitary plasmacytoma

Solitary plasmacytoma is a rare disorder comprising 5%-10% of all plasma cell neoplasms. Progression to multiple myeloma is the most common pattern of relapse. Appearance of new lesions without any systemic disease is the most unusual pattern of relapse seen in <2% cases. We present a case of a 46-year-old female who presented with features of third and seventh cranial nerve palsy, diagnosed with solitary plasmacytoma, with no evidence of any systemic disease. As per standard recommendations, the patient received radiotherapy to the local site. The patient developed relapse twice, at three sites, during the follow-up period. Investigations revealed no evidence of any systemic disease. In view of repeat relapses, the patient was started on immune modulatory agent. Two and half years after the last radiotherapy, the patient is symptom free with no evidence of any new lesion.

Bone Marrow Stroma and Vascular Contributions to Myeloma Bone Homing

PURPOSE OF THE REVIEW

Herein we dissect mechanisms behind the dissemination of cancer cells from primary tumor site to the bone marrow, which are necessary for metastasis development, with a specific focus on multiple myeloma.

RECENT FINDINGS

The ability of tumor cells to invade vessels and reach the systemic circulation is a fundamental process for metastasis development; however, the interaction between clonal cells and the surrounding microenvironment is equally important for supporting colonization, survival, and growth in the secondary sites of dissemination. The intrinsic propensity of tumor cells to recognize a favorable milieu where to establish secondary growth is the basis of the "seed and soil" theory. This theory assumes that certain tumor cells (the "seeds") have a specific affinity for the milieu of certain organs (the "soil"). Recent literature has highlighted the important contributions of the vascular niche to the hospitable "soil" within the bone marrow. In this review, we discuss the crucial role of stromal cells and endothelial cells in supporting primary growth, homing, and metastasis to the bone marrow, in the context of multiple myeloma, a plasma cell malignancy with the unique propensity to primarily grow and metastasize to the bone marrow.

Management of Patients With Hepatitis C Virus, Monoclonal Gammopathy of Undetermined Significance, and Multiple Myeloma

Background and Aim: The vast majority of the 2.7 million individuals in the United States who are currently infected with hepatitis C virus (HCV) were born between 1945 and 1965. The median age of these patients in this particular generation at the time of this writing was 55 years. In the general population, older age is a risk factor for multiple myeloma (MM) and other monogammopathies. As the baby boomer population ages, HCV providers are increasingly likely to encounter HCV-infected patients with a monoclonal gammopathy. Guidelines for managing these patients are needed. Methods: We conducted a detailed case series investigation of 4 HCV-positive patients with MM or a monoclonal gammopathy disorder. Patients were followed at the Mount Sinai Faculty Practice liver clinic. We also performed a detailed review of the literature exploring if there is any known association between HCV, MM, and monoclonal gammopathy. Results and Conclusions: There is no convincing evidence of a causal association between HCV and MM. HCV is linked to type II and type III cryoglobulinemia, specific kinds of monoclonal gammopathies of determinable significance. Whether a link exists between HCV and MM or monoclonal gammopathy of undetermined significance is unclear. Our case series provides the first evidence that modern HCV treatments with direct-acting antivirals can be safely and effectively co-administered with MM chemotherapy.

Solitary plasmacytoma: population-based analysis of survival trends and effect of various treatment modalities in the USA

Background

Solitary plasmacytoma (SP) is a localized neoplastic plasma cell disorder with an annual incidence of less than 450 cases. Given the rarity of this disorder, it is difficult to conduct large-scale population studies. Consequently, very limited information on the disorder is available, making it difficult to estimate the incidence and survival rates. Furthermore, limited information is available on the efficacy of various treatment modalities in relation to primary tumor sites.

Methods

The data for this retrospective study were drawn from the Surveillance, Epidemiology and End Results (SEER) database, which comprises 18 registries; patient demographics, treatment modalities and survival rates were obtained for those diagnosed with SP from 1998 to 2007. Various prognostic factors were analyzed via Kaplan-Meier analysis and log-rank test, with 5-year relative survival rate defined as the primary outcome of interest. Cox regression analysis was employed in the multivariate analysis.

Results

The SEER search from 1998 to 2007 yielded records for 1691 SP patients. The median age at diagnosis was 63 years. The patient cohort was 62.4% male, 37.6% female, 80% Caucasian, 14.6% African American and 5.4% other races. Additionally, 57.8% had osseous plasmacytoma, and 31.9% had extraosseous involvement. Unspecified plasmacytoma was noted in 10.2% of patients. The most common treatment modalities were radiotherapy (RT) (48.8%), followed by combination surgery with RT (21.2%) and surgery alone (11.6%). Univariate analysis of prognostic factors revealed that the survival outcomes were better for younger male patients who received RT with surgery (p < 0.05). Additionally, patients who received neoadjuvant RT had increased survival rates compared to those receiving adjuvant RT (86% vs 73%, p < 0.05). Furthermore, the analyses revealed that 5-year survival rates for patients with axial plasmacytoma were superior when RT was combined with surgery (p < 0.05). In the multivariate analysis, age <60 years and treatment with either RT or surgery showed superior survival rates. Progression to multiple myeloma (MM) was noted in 551 patients. Age >60 years was associated with a lower 5-year survival in patients who progressed to MM compared to those who were diagnosed initially with MM (15.1 vs 16.6%). Finally, those who received RT and progressed to MM still had a higher chance of survival than those who were diagnosed with MM initially and treated with RT/surgery (21.8% vs 15.9%, p < 0.05).

Conclusions

A review of the pertinent literature indicates that we provided the most comprehensive population-based analysis of SP to date. Moreover, our study contributes to the establishment of the optimal SP treatment modality, as RT is the favored option in frontline settings. Consensus is currently lacking regarding the benefits of combined treatment including surgery. Thus, the findings reported here elucidate the role of primary treatment modalities while also demonstrating the quantifiable benefits of combining RT with surgery in relation to different primary tumor sites. While our results are promising, they should be confirmed through further large-scale randomized studies.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-3015-5) contains supplementary material, which is available to authorized users.

Solitary Plasmacytoma of Bone Involving Spine in a 12-year-old Boy: Report of a Rare Case and Review of Literature

Solitary plasmacytoma of the bone (SPB) is a rare plasma cell neoplasm representing only about 5% of plasma cell neoplasia. It usually presents as a lytic lesion mainly localized within the axial skeleton. SPB is exceedingly rare in young individuals, and only few cases have been reported so far in patients younger than 20 years of age. In view of rarity of disease, definitive treatment guidelines have not been established. We hereby report a case of SPB involving of lumbar vertebra (L5) in a 12-year-old boy. He was initially treated with antilymphoma therapy and curative radiotherapy considering as primary bone lymphoma. However, he had local recurrence with paraparesis after 9 months which was diagnosed as solitary bone plasmacytoma for which he was treated with decompressive laminectomy and chemotherapy (bortezomib, lenalidomide, and dexamethasone). The purpose of this article is to report a rare case of SPB in a pediatric patient and to review the available literature and treatment options. SPB should be considered in the differential diagnosis of osteolytic bone lesions even in young patients.

Progression of a solitary plasmacytoma to multiple myeloma. A population-based registry of the northern Netherlands

Plasmacytoma is characterized by a local accumulation of monoclonal plasma cells without criteria for multiple myeloma (MM). The current treatment regimen is local radiotherapy. However, more than 50% of patients develop MM within 2 years after treatment. A population-based registry was consulted for the diagnosis of solitary plasmacytoma between 1988 and 2011. Progression to MM and prognostic features for progression to MM were scored, including hypoxia inducible factors (HIF), vascular endothelial growth factor (VEGF, also termed VEGFA) and micro-vessel density (MVD) expression in biopsy material. A total of 76 patients were included, 34% having extramedullary plasmacytoma (EMP) while 66% had a solitary plasmacytoma of the bone (SBP). Median follow-up was 89 months, (7-293 months). In Seventy per cent of SBP patients developed MM with a median time to progression of 19 months (5-293). Three patients (12%) with EMP developed MM. High expression of VEGF and HIF-2α (also termed EPAS1) was demonstrated in conjunction with an increased MVD in 66% of the patients. No association could be shown between angiogenesis parameters and progression to MM. In conclusion, this population-based study demonstrates that SBP patients have a higher risk of developing MM following local radiotherapy, indicating that this group might benefit from added systemic chemotherapy.

Clinical features, outcome, and prognostic factors for survival and evolution to multiple myeloma of solitary plasmacytomas: a report of the Greek myeloma study group in 97 patients

Solitary plasmacytoma (SP) is a rare plasma cell dyscrasia characterized by the presence of bone or extramedullary plasma cell tumors. The treatment of choice is local radiotherapy (R/T) ± surgical excision. The role of adjuvant chemotherapy (C/T) or novel agents (NA) is uncertain. Data related to prognostic factors are inconclusive. Herein, we describe the clinical features, survival and prognosis of 97 consecutive patients, 65 with bone SP (SBP), and 32 with extramedullary SP (SEP), diagnosed and treated in 12 Greek Myeloma Centers. Objective response rate (≥PR) and complete response (CR) was 91.8% and 61.9%, respectively, and did not differ between the 2 groups. Overall, 38 patients relapsed or progressed to multiple myeloma (MM). After a median follow-up of 60 months, 5 and 10-year overall survival (OS) probability was 92% and 89% in SEP and 86% and 69% in SBP, respectively (P = 0.2). The 5- and 10-year MM-free survival (MMFS) probability was 90% and 70% for patients with SEP vs. 59% and 50% for patients with SBP, respectively (P = 0.054). Overall, the 5- and 10-year OS probability, plasmacytoma relapse-free survival (PRFS), progression-free survival and MMFS was 84% and 78%, 72% and 58%, 58% and 43%, and 70% and 59%, respectively. In the multivariate analysis, prolonged PRFS and young age were positive predictors of OS. Achievement of CR was the only positive predictor of PRFS. Immunoparesis was the only negative predictor of progression to MM. The addition of C/T or NA-based treatment increased toxicity without offering any survival advantage over R/T.

Rapid progression of solitary plasmacytoma to multiple myeloma in lumbar vertebra

The prognosis of solitary plasmacytoma varies greatly, with some patients recovering after surgical removal or local fractional radiation therapy, and others progressing to multiple myeloma years later. Primary detection of progression to multiple myeloma is important in the treatment of solitary plasmacytoma. There have been several analyses of the risk factors involved in the early progression to multiple myeloma. We describe one case of solitary plasmacytoma of the lumbar vertebra that was treated with surgical decompression with stabilization and additional radiotherapy. The patient had no factors associated with rapid progression to multiple myeloma such as age, size, immunologic results, pathological findings, and serum free light chain ratio at the time of diagnosis. However, his condition progressed to multiple myeloma less than two months after the initial diagnosis of solitary plasmacytoma. We suggest that surgeons should be vigilant in watching for rapid progression to multiple myeloma even in case that the patient with solitary plasmacytoma has no risk factors for rapid progression to multiple myeloma.

Durable responses after donor lymphocyte infusion for patients with residual multiple myeloma following non-myeloablative allogeneic stem cell transplant

The role of donor lymphocyte infusion (DLI) in mediating the graft-versus-myeloma (GvM) effect after allogeneic hematopoietic stem cell transplant (allo-HCT) is not clearly defined. We evaluated the safety and utility of DLI in patients with either persistent or recurrent multiple myeloma (MM) after allo-HCT. Twenty-three patients with MM received DLI after allo-HCT at the University of Texas M. D. Anderson Cancer Center between July 1996 and June 2008. Eight patients received preemptive DLI for residual disease (RD) while 15 patients received DLI for the treatment of recurrent or progressive disease (PD). We evaluated the response to DLI and the factors that may predict a response. Median DLI dose was 3.3 × 10(7) CD3 + cells (range 0.5-14.8 × 10(7)). Grade II-IV acute graft-versus-host disease (GvHD) was seen in five patients (22%). Median follow-up in surviving patients was 24 months. Five of 23 patients (22%) achieved a complete or a very good partial response (two CR, three VGPR), while eight patients (34%) had stable disease (SD) after the DLI. Patients who received DLI for RD had a higher response rate (≥ VGPR 50% vs. 7%, p = 0.03), a longer overall survival (28.3 vs. 7.6 months, p = 0.03) and a trend toward longer progression-free survival (11.9 vs. 5.2 months, p = 0.1). In this largest single institution study, we conclude that the use of preemptive, non-manipulated DLI for RD after reduced-intensity conditioning allo-HCT is encouraging, and it was associated with a higher response rate and a longer overall survival when given preemptively. The role of DLI needs to be further explored in prospective clinical trials.

A review for solitary plasmacytoma of bone and extramedullary plasmacytoma

Solitary plasmacytoma (SP) is characterized by a mass of neoplastic monoclonal plasma cells in either bone (SBP) or soft tissue without evidence of systemic disease attributing to myeloma. Biopsy confirmation of a monoclonal plasma cell infiltration from a single site is required for diagnosis. The common presentation of SBP is in the axial skeleton, whereas the extramedullary plasmacytoma (EMP) is usually seen in the head and neck. The ratio of SP seen at males to females is 2 : 1 and the median age of patients is 55 years. The incidence rate of SP in black race is approximately 30% higher than the white race. Incidence rate increases exponentially by advancing age. SBP has a significant higher risk for progression to myeloma, and the choice of treatment is radiotherapy (RT) that is applied with curative intent at min. 4000 cGy. By only RT application, long-term disease-free survival (DFS) is possible for approximately 30% of patients with SBP and 65% of patients with EMP.

Myeloma as a model for the process of metastasis: implications for therapy

Multiple myeloma (MM) is a plasma cell dyscrasia characterized by the presence of multiple myelomatous "omas" throughout the skeleton, indicating that there is continuous trafficking of tumor cells to multiple areas in the bone marrow niches. MM may therefore represent one of the best models to study cell trafficking or cell metastasis. The process of cell metastasis is described as a multistep process, the invasion-metastasis cascade. This involves cell invasion, intravasation into nearby blood vessels, passage into the circulation, followed by homing into predetermined distant tissues, the formation of new foci of micrometastases, and finally the growth of micrometastasis into macroscopic tumors. This review discusses the significant advances that have been discovered in the complex process of invasion-metastasis in epithelial carcinomas and cell trafficking in hematopoietic stem cells and how this process relates to progression in MM. This progression is mediated by clonal intrinsic factors that mediate tumor invasiveness as well as factors present in the tumor microenvironment that are permissive to oncogenic proliferation. Therapeutic agents that target the different steps of cell dissemination and progression are discussed. Despite the significant advances in the treatment of MM, better therapeutic agents that target this metastatic cascade are urgently needed.

Angiogenesis and multiple myeloma

The bone marrow microenvironment in multiple myeloma is characterized by an increased microvessel density. The production of pro-angiogenic molecules is increased and the production of angiogenic inhibitors is suppressed, leading to an "angiogenic switch". Here we present an overview of the role of angiogenesis in multiple myeloma, the pro-angiogenic factors produced by myeloma cells and the microenvironment, and the mechanisms involved in the myeloma-induced angiogenic switch. Current data suggest that the increased bone marrow angiogenesis in multiple myeloma is due to the aberrant expression of angiogenic factors by myeloma cells, the subsequent increase in pro-angiogenic activity of normal plasma cells as a result of myeloma cell angiogenic activity, and the increased number of plasma cells overall. Hypoxia also contributes to the angiogenic properties of the myeloma marrow microenvironment. The transcription factor hypoxia-inducible factor-1α is overexpressed by myeloma cells and affects their transcriptional and angiogenic profiles. In addition, potential roles of the tumor suppressor gene inhibitor of growth family member 4 and homeobox B7 have also been recently highlighted as repressors of angiogenesis and pro-angiogenic related genes, respectively. This complex pathogenetic model of myeloma-induced angiogenesis suggests that several pro-angiogenic molecules and related genes in myeloma cells and the microenvironment are potential therapeutic targets.

Solitary plasmacytoma of the proximal tibia in an adolescent

This is the case report of a 14-year young female who was diagnosed with solitary bone plasmacytoma (SBP) of proximal tibia and was treated by local involved field radiotherapy. We present the clinical, radiological and pathological findings of the case and review of the available treatment options and prognosis of this rare site presentation of plasmacytoma in an adolescent female.

Update on the Diagnosis and Classification of the Plasma Cell Neoplasms

The plasma cell neoplasms are malignancies of the most terminally differentiated cells in B-cell ontogeny and are usually associated with the production of a monoclonal immunoglobulin molecule or M protein. These malignancies include tumors whose clinical manifestations are directly attributable to the end-organ damage induced by the dysregulated proliferation of neoplastic plasma cells. In contrast, disorders, such as primary amyloidosis, have a paradoxically low burden of neoplastic plasma cells, rendered highly pathogenic by the end-organ damage induced by deposition of the secreted paraprotein. In this article, discussion focuses on plasma cell myeloma. The molecular pathogenesis of plasma cell myeloma is reviewed and the diagnosis of the plasma cell neoplasms discussed.

Thalidomide decreases gelatinase production by malignant B lymphoid cell lines through disruption of multiple integrin-mediated signaling pathways

BACKGROUND

Thalidomide and its analogs are effective agents in the treatment of multiple myeloma. Since gelatinases (matrix metalloproteinases-2 and -9) play a crucial role in tumor progression, we explored the effect of thalidomide on gelatinase production by malignant B lymphoid cell lines.

DESIGN AND METHODS

We investigated the effect of therapeutic doses of thalidomide on integrin-mediated production of gelatinases by malignant B lymphoid cell lines by gelatin zymography, western-blot, reverse transcriptase polymerase chain reaction and invasive capacity through Matrigel-coated Boyden chambers. We also explored the effect of thalidomide on the activation status of the main signaling pathways involved in this process.

RESULTS

Thalidomide strongly inhibited gelatinase production by B-cell lines and primary myeloma cells in response to fibronectin, the most efficient gelatinase inducer identified in lymphoid cells. Thalidomide disrupted integrin-mediated signaling pathways involved in gelatinase induction and release, such as Src and MAP-kinase ERK activation, resulting in decreased cell motility and invasiveness. Unexpectedly, treatment with thalidomide elicited an increase in fibronectin-induced Akt phosphorylation through phosphoinositide 3-kinase-independent pathways since thalidomide decreased fibronectin-induced phosphoinositide 3-kinase phosphorylation and reversed the inhibition of Akt phosphorylation achieved by the phosphoinositide 3-kinase inhibitors wortmannin and LY294002.

CONCLUSIONS

Disruption of integrin-mediated signaling may be an important mechanism through which thalidomide and its analogs impair tumor cell interactions with the microenvironment. The unexpected effects of thalidomide on Akt activation indicate the need for further studies to elucidate whether the interference with Akt downstream effects would synergize with the anti-tumor activity of thalidomide.

Patients with plasma cell disorders examined at whole-body dynamic contrast-enhanced MR imaging: initial experience

This study was approved by the institutional review board, and informed consent was obtained from all subjects. The authors prospectively evaluated the feasibility of multistation whole-body dynamic contrast material-enhanced magnetic resonance (MR) imaging performed in patients with plasma cell disorders to assess disease extension and the time-signal intensity curves of diffuse and focal bone marrow infiltration. Three healthy adult male volunteers (age range, 29-31 years) and 21 patients (12 men, nine women; age range, 34-79 years) underwent whole-body dynamic unenhanced (volunteers) and contrast-enhanced MR imaging, which was performed by using an 18-channel 1.5-T MR system. A five-station (three sagittal and two coronal planes) fat-saturated three-dimensional gradient-echo sequence (3.3-3.6/1.3 [repetition time msec/echo time msec], 20 degrees flip angle, voxel size of 2 x 2.6 x [3-5] mm) was performed seven times. The temporal resolution of the five-station dynamic contrast-enhanced examination was 60 seconds with use of parallel imaging. Time-signal intensity curves for the bone marrow and the focal lesions were successfully obtained in all patients.

SUPPLEMENTAL MATERIAL

http://radiology.rsnajnls.org/cgi/content/full/250/3/905/DC1http://radiology.rsnajnls.org/cgi/content/full/250/3/905/DC2http://radiology.rsnajnls.org/cgi/content/full/250/3/905/DC3.

Clinical and prognostic features of plasmacytomas: a multicenter study of Turkish Oncology Group-Sarcoma Working Party

To identify the outcomes of prognostic factors of solitary plasmacytoma mainly treated with local radiotherapy (RT). The data were collected from 80 patients with solitary plasmacytoma (SP). Forty patients (50.0%) received radiotherapy (RT) alone while 38 of them (47.5%) were treated with surgery (S) and RT. The median radiation dose was 46 Gy (range 30-64). The median follow up was 2.41 years (range 0.33-12.33). Ten-year overall survival (OS) and local relapse-free survival (LRFS) were 73% and 94%, respectively. The median progression-free survival (PFS) and multiple myeloma-free survival (MMFS) were 3.5 years and 4.8 years, respectively. On multivariate analyses, the favorable factors were radiotherapy dose of > or =50 Gy and RT + S for PFS and younger age for MMFS. For the patients with medullary plasmacytoma, the favorable factor was younger age for MMFS. RT at > or =50 Gy and RT + S may be favorable prognostic factors on PFS. Younger patients, especially with head-neck lesion and without pre-RT macroscopic tumor, seem to have the best outcome when treated with RT +/- S. Progression to MM remains as the main problem especially for older patients.

Bone marrow angiogenesis and angiogenic factors in multiple myeloma treated with novel agents

INTRODUCTION

An increased bone marrow (BM) angiogenesis is associated with poor outcome in multiple myeloma (MM).

OBJECTIVE

Angiogenesis study in MM treated with novel antimyeloma agents: thalidomide, lenalidomide, bortezomib, and with dexamethasone.

PATIENTS AND METHODS

Forty-four patients with MM (14 newly diagnosed, 30 refractory/relapsed) were treated with novel agents at our institution. A BM biopsy was obtained before the initiation of therapy in 19. Angiogenesis was assessed by microvessel density (MVD) estimation in BM biopsies stained with the monoclonal anti-CD34 antibody, and by serum levels of angiogenic factors (VEGF, bFGF, and HGF) and cytokines (IL-6 and TNF-alpha).

RESULTS

A positive correlation was found between BM plasma cell involvement and MVD estimation (p=0.01). However, MVD was not significantly correlated with either disease phase (p=0.065) or response to therapy (p=0.79). Neither baseline serum levels of angiogenic cytokines correlated to response to treatment. No significant correlation was found between BM MVD and serum levels of angiogenic cytokines. Serum levels of angiogenic cytokines before and after therapy showed a significant increase of bFGF (p=0.008).

CONCLUSION

There is no relationship between MVD estimation and baseline serum levels of angiogenic cytokines, neither between each of them and response to therapy.

Targeting the vascular endothelial growth factor pathway in the treatment of multiple myeloma

Multiple myeloma is a clonal plasma cell malignancy within the bone marrow associated with bone loss, renal disease and immunodeficiency. Despite new insights into the pathogenesis of multiple myeloma and novel targeted therapies, the median survival remains 3-5 years. It is now well established that the intimate relation between the tumor cells and components of the microenvironment plays a key role in multiple myeloma pathogenesis. Specifically, tumor cells impact the bone marrow and thereby cause immune suppression and lytic bone lesions; conversely, components of the bone marrow provide signals that influence the behavior of multiple myeloma cells, including tumor cell growth, survival, migration and drug resistance. Important contributing effectors are tumor cell-stroma cell and cell-extracellular matrix contacts, the bone marrow vasculature, and a variety of cytokines and growth factors in the bone marrow milieu.

Monoclonal gammopathy of undetermined significance and smoldering multiple myeloma

Monoclonal gammopathy of undetermined significance (MGUS) and smoldering multiple myeloma (SMM) are asymptomatic disorders characterized by monoclonal plasma cell proliferation in the bone marrow in the absence of end-organ damage. Updated diagnostic criteria for these disorders, risk-stratification models to determine prognosis, and the current management of these two entities are discussed in this review.

AKT activity regulates the ability of mTOR inhibitors to prevent angiogenesis and VEGF expression in multiple myeloma cells

We recently demonstrated that the mammalian target of rapamycin (mTOR) inhibitor, CCI-779, curtailed the growth of a subcutaneous challenge of multiple myeloma (MM) cells in immunodeficient mice. This antitumor effect was associated with prevention of cell proliferation, induction of apoptosis and inhibition of angiogenesis. Interestingly, myeloma tumors with heightened AKT activation were particularly sensitive to a CCI-779-induced antitumor response. To investigate whether part of the differential sensitivity was due to an AKT-regulated effect on angiogenesis, we compared the effects of mTOR inhibitors against isogenic MM cell lines that only differ by their degree of AKT activity. In this model, heightened AKT activity significantly sensitized MM cells to the following inhibitory effects of mTOR inhibition: angiogenesis in vivo, vascular endothelial growth factor (VEGF) expression in vitro and in vivo and VEGF translation (but not transcription). Assessment of p70S6 kinase activity indicated that rapamycin induced comparable mTOR inhibition in both cell lines suggesting that an adverse effect on VEGF cap-dependent translation would be comparable. Internal ribosome entry site (IRES)-mediated cap-independent translation is a salvage pathway for protein expression when mTOR is inhibited, so we analyzed a possible regulatory role of AKT on VEGF IRES activity. We found that elevated AKT activity inhibited VEGF IRES function. These results support a mechanism whereby AKT prevents VEGF IRES activity in myeloma cells during mTOR inhibition resulting in a more complete abrogation of VEGF translation, and ultimately, angiogenesis.