Central nervous system multiple myeloma - potential roles for intrathecal therapy and measurement of cerebrospinal fluid light chains

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

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

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

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

Relapsed/Refractory Multiple Myeloma: A Review of Available Therapies and Clinical Scenarios Encountered in Myeloma Relapse

Multiple myeloma remains an incurable disease with the usual disease course requiring induction therapy, autologous stem cell transplantation for eligible patients, and long-term maintenance. Risk stratification tools and cytogenetic alterations help inform individualized therapeutic choices for patients in hopes of achieving long-term remissions with preserved quality of life. Unfortunately, relapses occur at different stages of the course of the disease owing to the biological heterogeneity of the disease. Addressing relapse can be complex and challenging as there are both therapy- and patient-related factors to consider. In this broad scoping review of available therapies in relapsed/refractory multiple myeloma (RRMM), we cover the pharmacologic mechanisms underlying active therapies such as immunomodulatory agents (IMiDs), proteasome inhibitors (PIs), monoclonal antibodies (mAbs), traditional chemotherapy, and Venetoclax. We then review the clinical data supporting the use of these therapies, organized based on drug resistance/refractoriness, and the role of autologous stem cell transplant (ASCT). Approaches to special situations during relapse such as renal impairment and extramedullary disease are also covered. Lastly, we look towards the future by briefly reviewing the clinical data supporting the use of chimeric antigen receptor (CAR-T) therapy, bispecific T cell engagers (BITE), and Cereblon E3 Ligase Modulators (CELMoDs).

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

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

Central Nervous System Involvement of Multiple Myeloma Presenting as Short-lasting Unilateral Neuralgiform Headache with Conjunctival Injection and Tearing: A Case Report

Short-lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT) and short-lasting unilateral neuralgiform headache attacks with cranial autonomic symptoms (SUNA) are part of the trigeminal autonomic cephalalgia (TAC) group of headache disorders. Attacks present with repeated, severe, sharp, stabbing, or throbbing pain. Patients may experience a single attack, recurrent attacks with pain-free interictal periods, or a sawtooth pattern background pain with superimposed stabs. 1 , 2

Although SUNCT typically presents as a primary headache disorder, it may be secondary to an underlying pathology, such as pituitary tumors or posterior fossa lesions, both intra and extra-axial (vascular lesion, tumor, or bony abnormalities). Multiple Myeloma (MM) with central nervous system involvement (CNS MM) most commonly presents with visual changes (36%), radiculopathy (27%), headache (25%), confusion (21%), dizziness (7%) and seizures (6%). 3 , 4 Secondary SUNCT cases have been sparsely described (less than 60), and CNS MM presenting as SUNCT has not been previously described in the literature. 2 , 5

Our case describes a previously unreported clinical presentation of CNS MM. The report highlights the need for a timely and thorough diagnostic work-up of headache in patients with risk factors for a secondary etiology, which in this case included new-onset, autonomic features, older age, and history of malignancy. A misdiagnosis will preclude a potentially life-extending or saving targeted therapy for the underlying illness. We also aim to remind practitioners of the variability in the clinical symptoms of SUNCT, which are known to occur in a significant number of cases, including migrainous features and dull interictal pain.

Extramedullary disease in multiple myeloma: a systematic literature review

Extramedullary involvement (or extramedullary disease, EMD) represents an aggressive form of multiple myeloma (MM), characterized by the ability of a clone and/or subclone to thrive and grow independent of the bone marrow microenvironment. Several different definitions of EMD have been used in the published literature. We advocate that true EMD is restricted to soft-tissue plasmacytomas that arise due to hematogenous spread and have no contact with bony structures. Typical sites of EMD vary according to the phase of MM. At diagnosis, EMD is typically found in skin and soft tissues; at relapse, typical sites involved include liver, kidneys, lymph nodes, central nervous system (CNS), breast, pleura, and pericardium. The reported incidence of EMD varies considerably, and differences in diagnostic approach between studies are likely to contribute to this variability. In patients with newly diagnosed MM, the reported incidence ranges from 0.5% to 4.8%, while in relapsed/refractory MM the reported incidence is 3.4 to 14%. Available data demonstrate that the prognosis is poor, and considerably worse than for MM without soft-tissue plasmacytomas. Among patients with plasmacytomas, those with EMD have poorer outcomes than those with paraskeletal involvement. CNS involvement is rare, but prognosis is even more dismal than for EMD in other locations, particularly if there is leptomeningeal involvement. Available data on treatment outcomes for EMD are derived almost entirely from retrospective studies. Some agents and combinations have shown a degree of efficacy but, as would be expected, this is less than in MM patients with no extramedullary involvement. The paucity of prospective studies makes it difficult to justify strong recommendations for any treatment approach. Prospective data from patients with clearly defined EMD are important for the optimal evaluation of treatment outcomes.

Secondary CNS myeloma with remission after systemic CNS-penetrating agents

Background

CNS myeloma is a rare manifestation of multiple myeloma and is often associated with a dismal prognosis; however, cases are increasing in frequency as overall survival improves for MM. There is currently no standardized treatment for CNS myeloma; however, different chemotherapy and radiotherapy regimens have been described.

Methods

We had previously reported on the efficacy of proton-based craniospinal irradiation in a patient with CNS myeloma; here we present a patient with a history of extramedullary plasmacytoma, 10 years in remission status post standard systemic chemotherapy, with biopsy-proven CNS myeloma successfully treated with systemic chemotherapy as a first-line treatment.

Results

The patient achieved clinical and radiographic remission on 2 separate occasions with systemic chemotherapy alone.

Conclusions

This case demonstrates that systemically administered agents may have activity in CNS myeloma. Further investigations are necessary to establish the optimal combination of agents and treatment schedules.

A Rare Case of Epidural Myeloma Presenting as Recurrent Subdural Bleeding

Multiple myeloma (MM) is an incurable clonal B-cell malignancy that usually presents with neoplastic monoclonal plasma cells in either bone or soft tissues. Central nervous system involvement of the myeloma (CNS-MM), such as dural myeloma or intraparenchymal infiltration, or diffuse leptomeningeal involvement, is uncommon. Dural involvement of myeloma without parenchymal or leptomeningeal disease is even rarer, with only seven cases reported previously. We present a case of epidural myeloma in a 50-year-old man with known kappa light chain MM, presenting with multiple episodes of subdural hemorrhage and progressive neurological deficits. He initially presented with severe back pain, hypercalcemia, and acute kidney injury (AKI). Further evaluation showed lytic bone lesions and elevated kappa light chains, and bone marrow biopsy showed 32% of clonal plasma cells. He was initially treated with bortezomib, lenalidomide, and dexamethasone combination, followed by pomalidomide and daratumumab. Eventually, he developed two episodes of subdural hemorrhage and left-sided seventh cranial nerve palsy, which was treated conservatively and monitored by computed tomography (CT) of the head. However, he gradually developed multiple cranial nerve palsies, weakness, and urinary incontinence. Cerebrospinal fluid (CSF) analysis showed elevated protein without any aberrant immunophenotype. Magnetic resonance imaging (MRI) of the brain showed diffuse smooth dural enhancement with extensive calvarial and skull base marrow replacement; MRI of the spine showed diffuse epidural enhancement in thoracic and lumbar regions, findings consistent with epidural myeloma. The patient received three doses of cranial irradiation but, unfortunately, could not tolerate further treatment and opted for hospice care. Intracranial hemorrhage is common in MM patients, and it is important to consider CNS involvement in patients presenting with recurrent subdural hemorrhage and to perform imaging (preferably MRI) earlier in the disease course. Due to its rarity, the treatment of CNS-MM is very heterogeneous. Thus, case reporting is important to accumulate data on this rare presentation.

Intracranial plasmacytoma arising from dura mater secondary to multiple myeloma and presenting with sudden lethal intracerebral hemorrhage: A case report and literature review

Background

Intracranial and central nervous system's involvement with multiple myeloma (MM) is a clinically rare manifestation. Furthermore, the development of intracranial plasmacytoma without bone involvement is much rarer. Herein, we report the case of massive intracerebral hemorrhage form intracranial plasmacytoma that arose from the dura mater without bone involvement.

Case Description

A 71-year-old woman, who had been diagnosed as MM and treated 2 years prior, developed sudden lethal intracerebral hemorrhage from the intracranial plasmacytoma. Massive hemorrhage was observed after a rapid tumor growth in the middle fossa. Immediate hematoma evacuation and tumor resection allowed the patient to avoid severe neurological deficits and lethal conditions.

Conclusion

A close follow-up by neuroimaging studies is essential in cases of intracranial plasmacytoma in MM patients and early intervention with surgical resection or radiotherapy should be considered.

Multiple Myeloma with Central Nervous System Relapse Early after Autologous Stem Cell Transplantation: A Case Report and Literature Review

Few reports have so far described central nervous system (CNS) involvement in multiple myeloma (MM), which shows a poor prognosis owing to its resistance to several treatments. We herein describe a 45-year-old woman who had MM (diagnosed with IgA-κ type) with CNS relapse early after undergoing autologous hematopoietic stem cell transplantation. Because no standard treatment for CNS lesions of MM has been established, we conducted a literature review on the cerebrospinal fluid (CSF) transferability of drugs for MM, since it was considered to be a useful tool for CNS involvement. Immunomodulatory-drugs including pomalidomide exhibit a good CSF transfer ability, and, therefore, may be beneficial against the CNS involvement of MM.

Multiple myeloma with central nervous system relapse

Central nervous system involvement in multiple myeloma is a rare complication but carries a very poor prognosis. We provide a review of current literature, including presentation, treatment and survival data, and describe our experience in a regional hematologic malignancy diagnosis center where, over a 15-year period, ten cases were identified. Although the median age of onset, frequently between 50-60 years, is comparatively young, those diagnosed usually have a preceding diagnosis of multiple myeloma and often have had several lines of treatment. We discuss putative underlying factors such as prior treatment and associations including possible risk factors and features suggestive of a distinct biology. Central nervous system involvement may be challenging to diagnose in myeloma, displaying heterogeneous symptoms that can be confounded by neurological symptoms caused by the typical features of myeloma or treatment side-effects. We discuss the clinical features, imaging and laboratory methods used in diagnosis, and highlight the importance of considering this rare complication when neurological symptoms occur at presentation or, more commonly, during the disease pathway. In the absence of clinical trial data to inform an evidence-based approach to treatment, we discuss current and novel treatment options. Finally, we propose the establishment of an International Registry of such cases as the best way to collect and subsequently disseminate presentation, diagnostic and treatment outcome data on this rare complication of multiple myeloma.

Intracranial Involvement in Multiple Myeloma Presenting as a Cranial Nerve Palsy

Multiple myeloma (MM) is characterized by the neoplastic proliferation of plasma cells producing a monoclonal immunoglobulin. Neurological complications in MM most frequently occur due to spinal cord compression by bony lesions, paraprotein-related neuropathy, hypercalcemia, hyperviscosity, or amyloidosis. Intracranial involvement is a rare complication of MM occurring in only 1% of patients. It can manifest as a solitary cerebral lesion, intra-parenchymal infiltration, or diffuse leptomeningeal disease. We present a case of a leptomeningeal myeloma in a 71-year-old woman with known relapsed MM presenting with a right sixth nerve palsy. Our patient was receiving spinal irradiation for a paraspinal plasmacytoma when she complained of double vision. Clinical exam revealed a right sixth nerve palsy. MRI revealed diffuse abnormal leptomeningeal thickening and enhancement typical for diffuse leptomeningeal infiltration. She was treated with whole brain irradiation and intrathecal methotrexate combined with a lenalidomide and dexamethasone chemotherapeutic regimen but unfortunately she passed away 5 weeks after onset of visual symptoms. MM involving the central nervous system (CNS) is a rare complication of MM and carries a poor prognosis with an average survival of 3 months. Due to its rarity, treatment of CNS MM is very heterogeneous. Thus case reporting is important to accumulate data on this rare presentation.

Aggressive Central Nervous System Relapse after Autologous Stem Cell Transplant in Multiple Myeloma: Case Reports and Literature Review

Extramedullary disease is an aggressive presentation at diagnosis and relapse for multiple myeloma (MM) patients. Central nervous system (CNS) is a very rare manifestation of the extramedullary disease, accounting for less than 1% of MM on diagnosis and relapse. Neurological symptoms are unspecific and usually attributed to other causes. We present two patients with CNS-MM at relapse after autologous stem cell transplant highlighting the importance of clinical suspicion and interdisciplinarity at diagnostic workup as well as the need for intensive therapeutic options on such rare and aggressive cases. The presence of neurological abnormalities in anamnesis and physical examination on a patient with MM should always prompt to suspect of a CNS involvement, and active investigation must be undertaken. MRI is the standard radiological method to detect CNS-MM, with histopathological corroboration by stereotactic biopsy and CSF evaluation alongside. Treatment of CNS-MM should include two essential approaches—be able to cross the BBB and treat the systemic disease. There is no standard therapy for this extramedullary relapse, and a tailored and multiple therapy should be promptly started—intrathecal therapy, radiotherapy, and systemic therapy, including an immunomodulator.

Multiple myeloma with dural mater involvement

Multiple myeloma is an incurable clonal B-cell malignancy which may present with neoplastic monoclonal plasma cells in either bone or soft tissues. Central nervous system (CNS) involvement such as dural myeloma or intraparenchymal infiltration, or with diffuse leptomeningeal involvement, is uncommon. Dural involvement of myeloma without parenchymal or leptomeningeal disease is an even rarer occurrence; therefore there are no established treatment guidelines for CNS myelomatosis. Here we reported a refractory MM patient progressed to dura mater involvement after the induction therapy but showed good response to lenalidomide treatment.

Durable treatment response of relapsing CNS plasmacytoma using intrathecal chemotherapy, radiotherapy, and Daratumumab

CNS myelomatous involvement is a rare complication of multiple myeloma with dismal outcome. This disease's optimal treatment is unclear. Combined approach of systemic therapy, radiotherapy, and intrathecal injections chemotherapy should be considered and autologous stem cell transplant consolidation is offered to eligible patients. The role of Daratumumab in this disease deserves further evaluation.

Multiple myeloma and central nervous system involvement: experience of a Brazilian center

INTRODUCTION

The estimated involvement of the central nervous system in patients with multiple myeloma is rare at about 1%. The infiltration can be identified at the time multiple myeloma is diagnosed or during its progression. However, it is more common in refractory disease or during relapse.

METHODS

This retrospective cohort study reviewed data from medical records of patients followed up at the Gammopathy Outpatient Clinic of Santa Casa de Misericórdia de São Paulo from January 2008 to December 2016.

RESULTS

Twenty patients were included, with a median follow-up of 33.5 months after central nervous system infiltration. The prevalence was 7%. The median age at diagnosis of multiple myeloma was 56.1 years, with 70% of participants being female. Sixteen patients had central nervous system infiltration at diagnosis of multiple myeloma. Seventeen patients had exclusive osteodural lesions and three had infiltrations of the leptomeninge, of which one had exclusive involvement and two had associated osteodural lesions. The median overall survival was 40.3 months after central nervous system involvement. The median overall survival in the group with central nervous system infiltration at relapse was 7.4 months. The patients with leptomeningeal involvement had a median overall survival of 5.8 months.

CONCLUSION

Central nervous system infiltration is a rare condition, but it should be considered as a possibility in patients with multiple myeloma and neurological symptoms. The best treatment regimen for this condition remains unknown and, in most cases, the prognosis is unfavorable.

Case Report of Bone Marrow-Sparing Proton Therapy Craniospinal Irradiation for Central Nervous System Myelomatosis

Central nervous system (CNS) involvement is rare but it is an increasingly recognized complication of the multiple myeloma. The craniospinal radiotherapy is a standard treatment option, however, it may be challenging to deliver due to hematologic toxicity in the patients with multiple prior systemic therapies. We report a case of CNS myelomatosis in a patient with prior stem cell transplant multiple systemic therapies treated with bone marrow-sparing proton therapy craniospinal irradiation, with the dramatic clinical response and minimal hematologic toxicity.

Bortezomib-related neuropathy may mask CNS relapse in multiple myeloma: A call for diligence

Background: Neuropathy is a common adverse effect of bortezomib. Isolated central nervous system (CNS) relapse in MM remains exceedingly rare and carries a dismal prognosis. We present an unusual case of bortezomib related neuropathy masking a CNS relapse of MM. Case presentation: A 57-year-old female was diagnosed with standard-risk MM with clinical and cytogenetic features not typically associated with CNS involvement. She was treated with 4 cycles of bortezomib/cyclophosphamide/dexamethasone (VCD) and achieved a VGPR, after which she underwent an autologous stem cell transplant (ASCT) followed by bortezomib maintenance. Six months after ASCT she developed symptoms suggestive of peripheral neuropathy which was attributed to bortezomib. However the symptoms persisted despite discontinuation of bortezomib. Imaging and cerebrospinal fluid analysis subsequently confirmed a CNS relapse. Discussion: CNS involvement in MM (CNS-MM) is uncommon and is considered an aggressive disease. Recently published literature has reported biomarkers with prognostic potential. However, isolated CNS relapse is even less common; an event which carries a very poor prognosis. Given the heterogeneous neurologic manifestations associated with MM, clinical suspicion may be masked by confounding factors such as bortezomib-based therapy. The disease may further remain incognito if the patient does not exhibit any of the high risk features and biomarkers associated with CNS involvement. Conclusion: In the era of proteasome inhibitor (PtdIns)/immunomodulator (IMID)-based therapy for MM which carries neurologic adverse effects, it is prudent to consider CNS relapse early. This case further highlights the need for more robust biomarkers to predict CNS relapse and use of newer novel agents which demonstrate potential for CNS penetration.

Central nervous system involvement by multiple myeloma: A multi-institutional retrospective study of 172 patients in daily clinical practice

The multicenter retrospective study conducted in 38 centers from 20 countries including 172 adult patients with CNS MM aimed to describe the clinical and pathological characteristics and outcomes of patients with multiple myeloma (MM) involving the central nervous system (CNS). Univariate and multivariate analyses were performed to identify prognostic factors for survival. The median time from MM diagnosis to CNS MM diagnosis was 3 years. Thirty-eight patients (22%) were diagnosed with CNS involvement at the time of initial MM diagnosis and 134 (78%) at relapse/progression. Upon diagnosis of CNS MM, 97% patients received initial therapy for CNS disease, of which 76% received systemic therapy, 36% radiotherapy and 32% intrathecal therapy. After a median follow-up of 3.5 years, the median overall survival (OS) from the onset of CNS involvement for the entire group was 7 months. Untreated and treated patients had median OS of 2 and 8 months, respectively (P < 0.001). At least one previous line of therapy for MM before the diagnosis of CNS disease and >1 cytogenetic abnormality detected by FISH were independently associated with worse OS. The median OS for patients with 0, 1 and 2 of these risk factors were 25 months, 5.5 months and 2 months, respectively (P < 0.001). Neurological manifestations, not considered chemotherapy-related, observed at any time after initial diagnosis of MM should raise a suspicion of CNS involvement. Although prognosis is generally poor, the survival of previously untreated patients and patients with favorable cytogenetic profile might be prolonged due to systemic treatment and/or radiotherapy. Am. J. Hematol. 91:575-580, 2016. © 2016 Wiley Periodicals, Inc.

How I treat extramedullary myeloma

Extramedullary myeloma (EMM) is defined by the presence of plasma cells (PCs) outside the bone marrow in a patient with multiple myeloma (MM). Using sensitive imaging techniques including magnetic resonance imaging and positron emission tomography/computed tomography, EMM may be found in up to 30% of MM patients across the overall disease course. The molecular mechanisms underlying the hematogenous spread of PCs outside the bone marrow are only partially known and involve hypoxia and an altered expression of adhesion molecules. Extramedullary disease is associated with adverse prognostic factors (ie, high lactate dehydrogenase level, 17p deletion, and high-risk gene expression profile). The prognosis of EMM is poor, and the median overall survival of patients who experience an extramedullary relapse is <6 months. The adverse prognosis is less pronounced in patients with bone-related plasmacytomas than in those with hematogenous EMM. EMM patients should be considered as having high-risk myeloma and treated accordingly. However, EMM clinical situations are extraordinarily heterogeneous, and their management is particularly challenging. In the present review, a case-and-comment format is used to describe our approach to the management of EMM.

17P deleted multiple myeloma presenting with intracranial disease: durable remission after tailored management

In multiple myeloma (MM), del(17p) is associated with a poor outcome if present in greater than half the tumour cells. Similarly, intracranial involvement, often seen in the context of advanced disease, also heralds short survival. We present a rare case of MM presenting with intracranial disease and carrying del(17p) in 100% of tumour cells. This patient was successfully treated with combination chemotherapy employing central nervous system directed agents and bortezomib, followed by autologous stem cell transplant and consolidation with radiotherapy, bortezomib and thalidomide. We also present the outcomes of our single-centre experience of MM patients presenting with del(17p) disease. Copyright © 2015 John Wiley & Sons, Ltd.

Quantitative measures of physical functioning after autologous hematopoietic stem cell transplantation in multiple myeloma: a feasibility study

BACKGROUND

The safety and feasibility of the symptom-limited cardiopulmonary exercise test (CPET) and the 6-minute walk test (6MWT) has not been rigorously tested in patients with multiple myeloma (MM) after high-dose chemotherapy with autologous stem cell transplantation (ASCT), nor have correlations with patient-reported outcomes (PROs) been explored.

PATIENTS AND METHODS

We undertook CPET, 6MWT, and PRO assessments using standardized measurements and questionnaires in patients with MM in remission after ASCT.

RESULTS

A total of 22 patients who were a median of 17 months after ASCT underwent assessment. No severe adverse events were observed. Exercise capacity, measured during CPET as the peak oxygen consumption, was 17.5 ± 5.9 mL/kg/min, the equivalent of 38% ± 18% less than that for age- and sex-predicted sedentary normative values. During the 6MWT, the mean 6-minute walk distance was 500 m, or 25% ± 13% less than the predicted values. Additional analysis using Pearson's correlation revealed no significant univariate associations between exercise or functional capacity and any PROs.

CONCLUSION

Patients with MM have marked and significant reductions in quantitative measures of physical function for years after the initial therapy, although that did not correlate with PROs in the present pilot study. Larger prospective studies are required to determine the clinical ramifications of these findings and to mechanistically dissect them, as well to test interventions aimed at mitigating them.