Improving quality of life in patients with advanced cancer: Targeting metastatic bone pain

Assessment of the benefits of bone modifying agents in the management of advanced breast, prostate, and lung cancers

PURPOSE OF REVIEW

Skeletal metastases occur in approximately 80% of advanced breast, 70% of advanced prostate, and 30% of lung cancers, and place patients at increased risk of skeletal related events (SRE). Bone modifying agents (BMAs) have been shown to prevent or delay SRE development. Our objective was to summarize the role of these agents in the management of these three cancers.

RECENT FINDINGS

Total 52 studies met our inclusion criteria. These highlighted the benefit of BMAs in reducing SREs in metastatic breast and castrate resistant prostate cancer (mCRPC), with less clear impact on reducing SRE in lung cancer, or on improving progression-free and overall survival due to significant heterogeneity in trial design and outcomes. Benefits in SRE reduction occurred with bisphosphonates and denosumab, however when compared, denosumab was superior. Denosumab however is not more cost effective, and multiple trials support potential de-escalation to either 12 weekly dosing or other reduced duration.

SUMMARY

There is a large body of evidence to support the role of BMAs in reducing SREs in metastatic breast and mCRPC. Impact on survival outcomes is heterogeneous, and future large database trials would be helpful in identifying which subgroups of patients truly have survival benefit from BMAs.

GPR37 Activation Alleviates Bone Cancer Pain via the Inhibition of Osteoclastogenesis and Neuronal Hyperexcitability

Osteolytic bone cancer pain is a primary concern for cancer patients with bone metastasis, and current therapies offer inadequate pain relief. The present study demonstrates that activation of the G protein-coupled receptor 37 (GPR37) by neuroprotectin D1 (NPD1) or artesunate (ARU) alleviates both acute and persistent pain in multiple mouse models of bone cancer. GPR37 agonists also protect against cancer-induced bone destruction. Mechanistically, NPD1 or ARU binding to GPR37 in macrophages promotes the release of IL-10, which further inhibits cancer-induced osteoclastogenesis. Moreover, direct activation of GPR37 in dorsal root ganglion (DRG) neurons and the spinal dorsal horn reduces action potential firing and the frequency of spontaneous excitatory postsynaptic currents (sEPSCs), thereby suppressing cancer-induced neuronal hyperexcitability. Importantly, the analgesic and protective effects of NPD1 and ARU are abolished in Gpr37-/- mice, and β-arrestin 2 is identified as a key mediator in IL-10 release and neuronal inhibition. In patients with bone metastases, plasma levels of endogenous NPD1 are negatively correlated with both pain intensity and the bone resorption marker CTX-I. Collectively, these findings highlight GPR37 activation as a potential therapeutic strategy for alleviating bone cancer pain through direct and synergistic inhibition of osteoclastogenesis and neuronal hyperexcitability.

Efficacy and Safety of Olaparib Plus Abiraterone Versus Placebo Plus Abiraterone in the First-line Treatment of Patients with Asymptomatic/Mildly Symptomatic and Symptomatic Metastatic Castration-resistant Prostate Cancer: Analyses from the Phase 3 PROpel Trial

BACKGROUND AND OBJECTIVE

In PROpel (NCT03732820), olaparib + abiraterone resulted in a statistically significant radiographic progression-free survival (rPFS) benefit and numerically prolonged overall survival (OS) versus placebo + abiraterone in first-line (1L) metastatic castration-resistant prostate cancer (mCRPC) patients. Here, we report post hoc exploratory subgroup analyses in patients with asymptomatic/mildly symptomatic or symptomatic disease at baseline.

METHODS

Patients were randomised 1:1 to olaparib (300 mg b.i.d.) or placebo with abiraterone (1000 mg o.d.) + prednisone/prednisolone (5 mg b.i.d.). For this post hoc exploratory analysis, patients with a Brief Pain Inventory-Short Form (BPI-SF) item 3 score of <4 and no opiate use were classified as asymptomatic/mildly symptomatic; those with a BPI-SF item 3 score of ≥4 and/or opiate use were classified as symptomatic. Subgroup analyses included investigator-assessed rPFS, OS, objective response rate, time to second progression or death, health-related quality of life, and safety.

KEY FINDINGS AND LIMITATIONS

The median rPFS in asymptomatic/mildly symptomatic patients (n = 560) was 27.6 mo for olaparib + abiraterone versus 19.1 mo for placebo + abiraterone (hazard ratio [HR], 0.59; 95% confidence interval [CI], 0.46-0.76). For symptomatic patients (n = 183), equivalent values were 14.1 versus 13.8 mo (HR, 0.78; 95% CI, 0.54-1.13). At the final planned OS analysis, the median OS in asymptomatic/mildly symptomatic patients was not reached for olaparib + abiraterone versus 39.5 mo for placebo + abiraterone (HR, 0.77; 95% CI, 0.59-1.00). For symptomatic patients, equivalent values were 22.9 versus 22.8 mo (HR, 0.82; 95% CI, 0.58-1.16). Other outcomes showed no meaningful differences between the subgroups.

CONCLUSIONS AND CLINICAL IMPLICATIONS

Olaparib + abiraterone provided efficacy benefits in 1L mCRPC patients with either asymptomatic/mildly symptomatic or symptomatic disease. A larger benefit occurred in asymptomatic/mildly symptomatic patients.

PATIENT SUMMARY

PROpel, a phase 3 clinical trial, looked at whether combining olaparib with abiraterone delays the progression of patients' cancer compared with placebo plus abiraterone. Patients with or without pain symptoms associated with metastatic castration-resistant prostate cancer were eligible for enrolment into the trial. Results showed that olaparib plus abiraterone reduced the risk of disease progression and death, with a larger benefit observed in patients without or with mild pain symptoms than in those with pain symptoms.

Defining Spine Cancer Pain Syndromes: A Systematic Review and Proposed Terminology

STUDY DESIGN

Systematic Review.

OBJECTIVES

Formalized terminology for pain experienced by spine cancer patients is lacking. The common descriptors of spine cancer pain as mechanical or non-mechanical is not exhaustive. Misdiagnosed spinal pain may lead to ineffective treatment recommendations for cancer patients.

METHODS

We conducted a systematic review of pain terminology that may be relevant to spinal oncology patients. We provide a comprehensive and unbiased summary of the existing evidence, not limited to the spine surgery literature, and subsequently consolidate these data into a practical, clinically relevant nomenclature for spine oncologists.

RESULTS

Our literature search identified 3515 unique citations. Through title and abstract screening, 3407 citations were excluded, resulting in 54 full-text citations for review. Pain in cancer patients is typically described as nociceptive pain (somatic vs visceral), neurologic pain and treatment related pain.

CONCLUSIONS

We consolidate the terminology used in the literature and consolidated into clinically relevant nomenclature of biologic tumor pain, mechanical pain, radicular pain, neuropathic pain, and treatment related pain. This review helps standardize terminology for cancer-related pain which may help clinicians identify pain generators.

Impacts of radiation therapy on quality of life and pain relief in patients with bone metastases

Bone metastases (BM) are a common complication in advanced cancer patients, significantly contributing to morbidity and mortality due to their ability to cause pain, fractures, and spinal cord compression. Radiation therapy (RT) is vital in managing these complications by targeting metastatic lesions to ease pain, improve mobility, and reduce the risk of skeletal-related events such as fractures. Evidence supports the effectiveness of RT in pain relief, showing its ability to provide significant palliation and lessen the need for opioid painkillers, thereby enhancing the overall quality of life (QoL) for patients with BM. However, optimizing RT outcomes involves considerations such as the choice of radiation technique, dose fractionation schedules, and the integration of supportive care measures to mitigate treatment-related side effects like fatigue and skin reactions. These factors highlight the importance of personalized treatment planning tailored to individual patient needs and tumor characteristics. This mini-review aims to provide comprehensive insights into the multifaceted impacts of RT on pain management and QoL enhancement in BM patients, with implications for refining clinical practices and advancing patient care through the synthesis of findings from various studies.

Management of Metastatic Spinal Disease - A Practical Approach

STUDY DESIGN

Narrative review.

OBJECTIVE

This review presents a comprehensive approach to the management of spinal metastases.

METHODS

N/A.

RESULTS

The wide spectrum of clinical presentation in spinal metastases necessitates a personalized approach to treatment planning. This includes a comprehensive diagnostic workup, oncological management, palliation of symptoms, and surgical intervention if appropriate. A systematic and multidisciplinary approach allows optimal shared decision making to reach an evidence-informed and value-congruent treatment plan for the patient. We highlight how advances in stereotactic body radiotherapy (SBRT) and separation surgery may be incorporated into clinical management from a spine surgeon's perspective.

CONCLUSION

This review summarizes the approach and management of spinal metastases, its outcomes and complications.

Content validation of the National Comprehensive Cancer Network/Functional Assessment of Cancer Therapy Lymphoma Symptom Index-18 (NFLymSI-18) in indolent B-cell non-Hodgkin's lymphoma

BACKGROUND

The NFLymSI-18 is a patient-reported outcome measure comprised of the highest priority symptoms, emotional concerns, treatment side effects, and other concerns identified by lymphoma patients and oncologists. This study assessed the content validity of the NFLymSI-18 for patients with indolent B-cell non-Hodgkin's lymphoma (iNHL), with a focus on the Disease-Related Symptoms Physical (DRS-P) subscale.

METHODS

Patients with a confirmed iNHL diagnosis who had received one or more lines of treatment were recruited during clinic visits. Patients described their symptoms, treatment side effects, and emotional concerns related to iNHL in a semi-structured interview. Qualitative data were analyzed using NVivo10.

RESULTS

Data saturation was obtained by the 18th interview. Most participants (67%) had follicular lymphoma. 28% of participants had marginal zone lymphoma, and one participant had lymphoplasmacytoid lymphoma/Waldenström macroglobulinemia. Mean age of the 18 participants was 67 years. 56% of the sample was male. Most participants (67%) had a college or advanced degree. When asked to describe their iNHL symptoms, patients most often discussed swelling (n = 14), fatigue (n = 11), and pain (n = 8). The following symptoms were mentioned by three patients each: anxiety, appetite loss, rash, sleep disruption, trouble breathing, and malaise. Mapping of NFLymSI-18 content to these concerns showed the instrument includes all those most frequently mentioned symptoms.

CONCLUSIONS

This study supports the content validity of the NFLymSI-18, including its DRS-P Subscale, for patients with iNHL. The instrument shows strong validity for the most referenced symptoms of swelling, fatigue, and pain. The diversity of additional symptoms reported by patients is consistent with the heterogeneous symptomology of iNHL.

Biodistribution and dosimetry of 177Lu-DOTA-IBA for therapy of bone metastases

BACKGROUND

We designed and synthesized a novel bisphosphonate radiopharmaceutical (68 Ga- or 177Lu-labeled DOTA-ibandronate [68 Ga/177Lu-DOTA-IBA]) for the targeted diagnosis and treatment of bone metastases. The biodistribution and internal dosimetry of a single therapeutic dose of 177Lu-DOTA-IBA were evaluated using a series of single-photon emission computerized tomography (SPECT) images and blood samples. Five patients with multiple bone metastases were included in this prospective study. After receiving 1110 MBq 177Lu-DOTA-IBA, patients underwent whole-body planar, SPECT/CT imaging and venous blood sampling over 7 days. Dosimetric evaluation was performed for the main organs and tumor lesions. Safety was assessed using blood biomarkers.

RESULTS

177Lu-DOTA-IBA showed fast uptake, high retention in bone lesions, and rapid clearance from the bloodstream in all patients. In this cohort, the average absorbed doses (ADs) in the bone tumor lesions, kidneys, liver, spleen, red marrow, bladder-wall, and osteogenic cells were 5.740, 0.114, 0.095, 0.121, 0.095, and 0.333 Gy/GBq, respectively. Although no patient reached the predetermined dose thresholds, the red marrow will be the dose-limiting organ. There were no adverse reactions recorded after the administration of 1110 MBq 177Lu-DOTA-IBA.

CONCLUSION

Dosimetric results show that the ADs for critical organs and total body are within the safety limit and with high bone retention. It is a promising radiopharmaceutical alternative for the targeted treatment of bone metastases, controlling its progression, and improving the survival and quality of life of patients with advanced bone metastasis.

The role of bone modifying agents for secondary osteoporosis prevention and pain control in post-menopausal osteopenic breast cancer patients undergoing adjuvant aromatase inhibitors

Introduction

Hormonal therapy (HT) blocks the hormone-mediated growth signal dramatically reducing estrogenic levels with aromatase inhibitors (AIs) becoming a crucial component of the treatment mainstay in patients with early breast cancer (BC). Postmenopausal BC patients receiving HT present with a significant risk of secondary osteoporosis with AIs further reducing estrogen levels and ultimately leading to an accelerated rate of bone resorption and thus decreased bone mineral density (BMD). This was an observational retrospective clinical study that consecutively enrolled early BC patients with osteopenia to compare the impact of alendronate versus denosumab on secondary osteoporosis prevention and pain control.

Methods

We identified two groups of patients treated with denosumab 60 mg by subcutaneous injection once every six months or alendronate 70 mg orally once a week. All the patients underwent a baseline physiatric evaluation (T0) and underwent a follow-up visit after 18 months (T1) together with femoral and vertebral Dual-Energy X-ray Absorptiometry (DEXA) exam evaluating T-Score marks. From September 2015 to December 2019 a total of 50 early (stage I-III) BC patients were considered eligible and consecutively enrolled in our study if they met pre-specified inclusion criteria.

Results

In the entire observed population, the addition of treatment with alendronate or denosumab led to a significant T-score improvement at the lumbar spine level (-1.92 vs -1.52, p=0.03), with a comparable contribution from alendronate (-1.60 vs -1.45, p=0.07) and denosumab (-2.26 vs -1.58, p=0.07). Regarding the femoral region, neither alendronate (-0.98 vs -1.07, p=0.23) nor denosumab (-1.39 vs -1.34, p=0.81) were able to produce any statistically relevant effect. However, concerning pain control, BMAs had a significant impact on reducing NRS scoresin the general population (T1 3.94 vs. baseline 4.32, p=0.007), with a likelyspecific contribution from alendronate (T1 3.52 vs. baseline 3.88, p=0.004) compared to denosumab (T1 4.36 vs baseline 4.76, p=0.12), without any differences in analgesic therapy assumption over time (p=0.93).

Discussion

Both alendronate and denosumab significantly contributed to preventing secondary osteoporosis in early BC patients with low BMD undergoing AIs, mostly at the lumbar spine level. Moreover, alendronate seemed to significantly impact pain control in such patients further supporting alendronate as a cost-effective option in this frail setting, although BMAs particularities should be carefully considered on an individual basis according to specific clinical contexts.

Bisphosphonates and osteonecrosis of the jaws: Clinical and forensic aspects

OBJECTIVE

This manuscript aims to provide a comprehensive review of the current knowledge in the pathophysiology, diagnosis, prevention, and other relevant clinical and forensic aspects of a potentially severe complication known as medication-related osteonecrosis of the jaw (MRONJ) while synthesizing state-of-the-art information on bisphosphonates and introducing a possible differential diagnosis.

DESIGN

An extensive search was conducted in PubMed (U.S. National Library of Medicine) without a time or language constraint, focusing on the epidemiology, pathophysiology, risk factors, site specificity, signs and symptoms, differential diagnosis, prevention, and forensic aspects of MRONJ. All types of original articles, reviews, case reports, short communications, opinion articles, guidelines, and letters to editors were considered to produce a complete review on this subject.

RESULTS

MRONJ prevention relies on a multidisciplinary approach and is critical since truly effective treatments are lacking. This therapeutic challenge is partly due to uncertainty regarding this condition's pathophysiology. Differential diagnosis of osteonecrosis of the jaws associated with krokodil abuse, one of the most dangerous and homemade psychoactive illicit substances, should be considered.

CONCLUSIONS

Further research into the etiology and site specificity of MRONJ is encouraged, aiming to develop novel treatment prospects. Indeed, comprehending this would allow for increased efficacy and therapeutic options while emphasizing the importance of prevention. In addition, we advocate for greater consensus among the various societies regarding MRONJ's treatment and management.

Impact of Salvage Surgery on Health-Related Quality of Life in Oral Squamous Cell Carcinoma: A Prospective Multi-Center Study

BACKGROUND

Patients with recurrent oral squamous cell carcinoma (OSCC) have limited treatment options. Salvage surgery offers potential curative therapy. The need for extensive ablative surgery together with microvascular reconstruction implies invasive and painful treatment with questionable functional outcome. To address the impact of salvage surgery on the health-related quality of life (HRQoL) of patients suffering from recurrent OSCC, a multi-center prospective analysis was initiated.

MATERIAL AND METHODS

Patients with recurrent OSCC from 2015 to 2022 at two German cancer centers were included. Interdisciplinary tumor board decisions determined surgery as the only curative treatment modality. HRQoL, was assessed via a EORTC questionnaire (European Organization for Research and Treatment of Cancer-EORTC: QLQ-C30 and QLQ-H&N35) in dependence of the recurrent tumor stage. Patients completed the questionnaires once before surgery (baseline) and then every 3 months during follow-up or up to the end of treatment.

RESULTS

In total, 55 patients were included. The mean follow-up period was 26.7 ± 19.3 months. Global health status showed superior mean scores after 12 months (60.83 ± 22.58) compared to baseline (53.33 ± 26.41) in stage 1 and 2 recurrent tumors. In advanced recurrent tumors' mean scores for global health showed only minor positive differences after 12 months (55.13 ± 22.7) compared to baseline (53.2 ± 25.58). In terms of the mouth pain, mean scores were lower after salvage surgery in small recurrent tumors after 12 months (20.37 ± 17.73) compared to baseline (41.67 ± 33.07; Wilcoxon two-sample signed-rank test p = 0.028). In advanced recurrent tumors, a significant reduction in mean scores was detected 3 months after salvage surgery (29.7 ± 22.94) compared to baseline (47.76 ± 25.77; Wilcoxon two-sample signed-rank test p = 0.003). Up to 12 months, swallowing function was evaluated inferior compared to baseline independent of tumor stage (Mean score recurrent stage I/II: 12-months 48.15 ± 27.57, baseline 28.7 ± 22.87; stage III/IV: 12-months 49.36.42 ± 27.53; baseline 30.13 ± 26.25).

CONCLUSION

Improved HRQoL could be obtained in advanced recurrent OSCC after salvage surgery despite reduced swallowing function. In small recurrent tumors, overall, HRQoL was superior to baseline. Salvage surgery positively affected pain burden. For advanced recurrent tumors, important pain relieve could be observed as soon as 3 months after surgery.

Treating bone metastases with local therapy in a breast cancer patient resulted in decreased pain and prevented fracture

Lytic lesions from bone metastases from breast, lung and prostate carcinomas, are associated with a poor prognosis and significant morbidities that include fracture and debilitating pain. Chemotherapeutics, palliative radiation therapy and surgical intervention are routinely used to treat these lesions. The ZetaMet™ Bone Graft is a novel antitumorigenic and osteoinductive graft that offers a potential alternative treatment option. ZetaMet is composed of calcium phosphate salts, type-I collagen and the small molecule N-allyl noroxymorphone dihydrate. Here, we report the case of a stage IV breast cancer patient with multiple lytic metastatic lesions to the spine that were successfully treated, which led to a significant reduction in pain and increased quality of life. This outcome demonstrates that a locally administered therapeutic intervention may represent an important alternative for patients with bone metastases that warrants further study.

Differences in the Analgesic Effect of Opioids on Pain in Cancer Patients With Spinal Metastases

Background

Spinal metastasis pain includes both inflammatory and neuropathic pain, and opioids, which have only a μ-opioid receptor-stimulating effect, are generally less effective in neuropathic pain. However, no previous study has been conducted for the comparisons of the efficacy of opioids in treating spinal metastasis pain.

Objective

To compare the efficacy of tapentadol and methadone with other opioids for back pain caused by a metastatic spinal tumor.

Design

Retrospective cohort study.

Setting/Subjects

A total of 274 patients were enrolled, who started a tapentadol extended-release tablet, methadone tablet, hydromorphone extended-release tablet, oxycodone extended-release tablet, or transdermal fentanyl patch for cancer pain due to spinal metastasis in Japan from January 1, 2013 to October 31, 2021.

Measurements

The primary endpoint, the difference in the numerical rating scale (NRS) scores before and seven days after each opioid administration, was compared among the five groups.

Results

In patients with numbness, a decrease of the NRS score on day seven compared with before starting each opioid was significantly higher in the tapentadol group than those in the hydromorphone, oxycodone, and fentanyl groups and comparable to that in the methadone group. In patients without numbness, no significant differences were observed in decreases of the NRS scores on day seven among the five groups.

Conclusions

Tapentadol and methadone may be more effective than hydromorphone, oxycodone, and fentanyl for cancer pain due to spinal metastasis with numbness.

Opioid prescriptions at the point of surgery, bone metastasis, or death among patients with breast cancer in Japanese acute care hospitals: a claims-based, retrospective, longitudinal study

PURPOSE

Breast cancer is the most common cancer among Japanese women and often yields a better prognosis than other cancers. However, few studies have been conducted on pain control using opioids in Japan. In this study, we aimed to examine actual opioid use among breast cancer patients.

METHODS

Breast cancer patients were defined as female patients with a first breast cancer diagnosis during the observational period in an acute care hospital database (April 2008 - February 2020). We examined the percentage of patients prescribed opioids, the opioid amount per patient, and the opioid dosage per day around surgery, bone metastasis diagnosis, or death.

RESULTS

Overall, 217,722 breast cancer patients were identified. The percentage of patients prescribed opioids and the average amount of opioids per patient were highest in the month of surgery, 78% and 27 morphine milligram equivalents (MMEs), respectively. The average opioid dosage increased with time after surgery from 19 to 28 MMEs. Around bone metastasis, the percentage of patients prescribed opioids and the average opioid amount per patient peaked one month after the diagnosis, 31% and 371 MMEs, respectively. The average opioid dosage gradually increased from 22 to 35 MMEs in succeeding days after a bone metastasis diagnosis. The percentage of patients prescribed opioids and the average opioid amount per patient increased as the month of death approached.

CONCLUSION

We investigated opioid prescription trends around clinical events in breast cancer patients on a large scale in Japan. These results may be useful to control cancer pain among breast cancer patients.

Cancer-nerve interplay in cancer progression and cancer-induced bone pain

INTRODUCTION

Cancer-induced bone pain (CIBP) is one of the most common and debilitating complications associated with bone metastasis. Although our understanding of the precise mechanism is limited, it has been known that bone is densely innervated, and that CIBP is elicited as a consequence of increased neurogenesis, reprogramming, and axonogenesis in conjunction with sensitization and excitation of sensory nerves (SNs) in response to the noxious stimuli that are derived from the tumor microenvironment developed in bone. Recent studies have shown that the sensitized and excited nerves innervating the tumor establish intimate communications with cancer cells by releasing various tumor-stimulating factors for tumor progression.

APPROACHES

In this review, the role of the interactions of cancer cells and SNs in bone in the pathophysiology of CIBP will be discussed with a special focus on the role of the noxious acidic tumor microenvironment, considering that bone is in nature hypoxic, which facilitates the generation of acidic conditions by cancer. Subsequently, the role of SNs in the regulation of cancer progression in the bone will be discussed together with our recent experimental findings.

CONCLUSION

It is suggested that SNs may be a newly-recognized important component of the bone microenvironment that contribute to not only in the pathophysiology of CIBP but also cancer progression in bone and dissemination from bone. Suppression of the activity of bone-innervating SNs, thus, may provide unique opportunities in the treatment of cancer progression and dissemination, as well as CIBP.

Radiofrequency Ablation Provides Rapid and Durable Pain Relief for the Palliative Treatment of Lytic Bone Metastases Independent of Radiation Therapy: Final Results from the OsteoCool Tumor Ablation Post-Market Study

PURPOSE

The OsteoCool Tumor Ablation Post-Market Study (OPuS One) was a prospective, multi-national, single-arm study to investigate safety and effectiveness of radiofrequency ablation (RFA) for palliation of painful lytic bone metastases with 12 months of follow-up. RFA has demonstrated effective palliation of osseous metastases in small clinical studies with short-term follow-up; however, a long-term assessment with robust subject numbers is lacking.

MATERIALS AND METHODS

Prospective assessments were conducted at Baseline, 3 days, 1 week, and 1, 3, 6, and 12-months. Pain and quality of life were measured prior to RFA and postoperatively using the Brief Pain Inventory, European Quality of Life-5 Dimension, and European Organization for Research and Treatment of Cancer Care Quality of Life Questionnaire for palliative care. Radiation, chemotherapy and opioid usage, and related adverse events were collected.

RESULTS

206 subjects were treated with RFA at 15 institutions in OPuS One. Worst pain, average pain, pain interference and quality of life significantly improved at all visits starting 3 days post-RFA and sustained to 12 months (P < 0.0001). Post hoc analysis found neither systemic chemotherapy nor local radiation therapy at the index site of RFA influenced worst pain, average pain, or pain interference. Six subjects had device/procedure-related adverse events.

CONCLUSION

RFA for lytic metastases provides rapid (within 3 days) and statistically significant pain and quality of life improvements with sustained long-term relief through 12 months and a high degree of safety, independent of radiation.

LEVEL OF EVIDENCE

2B, PROSPECTIVE, NON-RANDOMIZED, POST-MARKET STUDY: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The effects of physical exercise in the palliative care phase for people with advanced cancer: a systematic review with meta-analysis

PURPOSE

The purpose of this systematic review with meta-analysis was to evaluate the safety, feasibility and effectiveness of exercise in the palliative care phase for people with advanced cancer.

METHODS

Electronic databases were searched for exercise randomised controlled trials involving individuals with incurable cancer that were published prior to April 14, 2021. Meta-analyses were performed to evaluate the effects of exercise on health outcomes. Subgroup effects for exercise mode, supervision, intervention duration and cancer diagnosis were assessed.

RESULTS

Twenty-two trials involving interventions ranging between 2 weeks and 6 months were included. Interventions comprised of aerobic (n = 3), resistance (n = 4), mixed-mode (n = 14) and other exercise (n = 1) modalities. Cancer types consisted of lung (n = 6), breast (n = 3), prostate (n = 2), multiple myeloma (n = 1) and mixed cancer types (n = 10). Meta-analysis of 20 RCTs involving 1840 participants showed no difference in the risk of a grade 2-4 adverse event between exercise and usual care (n = 110 adverse events (exercise: n = 66 events; usual care: n = 44 events), RD =  - 0.01 (91% CI =  - 0.01, 0.02); p = 0.24). Overall median recruitment, retention and adherence rates were 56%, 80% and 69%, respectively. Meta-analysis of health outcomes showed effects in favour of exercise for quality of life, fatigue, aerobic fitness and lower-body strength (SMD range = 0.27-0.48, all p < 0.05).

CONCLUSIONS

Participants who engaged in exercise experienced an increase in quality of life, fitness and strength and a decrease in fatigue.

IMPLICATIONS FOR CANCER SURVIVORS

Physical activity programs were found to be safe and feasible for people with advanced cancer in the palliative care phase.

Schwann Cell Insulin-like Growth Factor Receptor Type-1 Mediates Metastatic Bone Cancer Pain in Mice

Insulin growth factor-1 (IGF-1), an osteoclast-dependent osteolysis biomarker, contributes to metastatic bone cancer pain (MBCP), but the underlying mechanism is poorly understood. In mice, the femur metastasis caused by intramammary inoculation of breast cancer cells resulted in IGF-1 increase in femur and sciatic nerve, and IGF-1-dependent stimulus/non-stimulus-evoked pain-like behaviors. Adeno-associated virus-based shRNA selective silencing of IGF-1 receptor (IGF-1R) in Schwann cells, but not in dorsal root ganglion (DRG) neurons, attenuated pain-like behaviors. Intraplantar IGF-1 evoked acute nociception and mechanical/cold allodynia, which were reduced by selective IGF-1R silencing in DRG neurons and Schwann cells, respectively. Schwann cell IGF-1R signaling promoted an endothelial nitric oxide synthase-mediated transient receptor potential ankyrin 1 (TRPA1) activation and release of reactive oxygen species that, via macrophage-colony stimulating factor-dependent endoneurial macrophage expansion, sustained pain-like behaviors. Osteoclast derived IGF-1 initiates a Schwann cell-dependent neuroinflammatory response that sustains a proalgesic pathway that provides new options for MBCP treatment.

Multidisciplinary Approach to Spinal Metastases and Metastatic Spinal Cord Compression—A New Integrative Flowchart for Patient Management

Metastatic spine disease (MSD) and metastatic spinal cord compression (MSCC) are major causes of permanent neurological damage and long-term disability for cancer patients. The development of MSD is pathophysiologically framed by a cooperative interaction between general mechanisms of bone growth and specific mechanisms of spinal metastases (SM) expansion. SM most commonly affects the thoracic spine, even though multiple segments may be affected concomitantly. The great majority of SM are extradural, while intradural-extramedullary and intramedullary metastases are less frequently seen. The management of patients with SM is particularly complex and challenging, with multiple factors—such as the spinal stability status, primary tumor radio and chemosensitivity, cancer biological burden, patient performance status and comorbidities, and patient’s oncological prognosis—influencing the clinical decision-making process. Different frameworks were developed in order to systematize and support this process. A multidisciplinary, personalized approach, enriched by the expertise of each involved specialty, is crucial. We reviewed the most recent evidence and proposed an updated algorithmic approach to patients with MSD according to the clinical scenario of each patient. A flowchart-based approach offers an evidence-based management of MSD, providing a valuable clinical decision tool in a context of high uncertainty and quick-acting need.

Wrist-ankle acupuncture for the treatment of acute orthopedic pain after surgery: a meta-analysis

BACKGROUND

Wrist-ankle acupuncture (WAA) has been reported in the treatment of acute pain in orthopedic surgery. However, the effects of WAA on acute pain were controversial in the current studies. Therefore, the purpose of this meta-analysis was to critically evaluate the effects of WAA on acute pain in orthopedic surgery.

METHODS

Several digital databases were searched from the inception of databases to July 2021, including CNKI, VIP, Wanfang, CBM, Pubmed, Cochrane Central Register of Controlled Trials, Embase, Medline, and Web of Science Core Collection. The risk of bias was evaluated using the Cochrane collaboration criteria. The primary outcome indicators included pain score, pain killer dosage, analgesia satisfaction, and adverse reaction incidence. All analyses were performed with Review Manager 5.4.1.

RESULT

A total of 10 studies with 725 patients with orthopedic surgery (intervention group: 361, control group: 364) were included in this meta-analysis. The results demonstrated that the pain score of the intervention group was lower than the control group, and the difference was statistically significant [MD = - 0.29, 95%CI (- 0.37, - 0.21), P < 0.0001]. Compared with the control group, the patient in the intervention group used smaller amounts of pain killer [MD = - 0.16, 95%CI (- 0.30, - 0.02), P = 0.02]. The satisfaction of patients on pain relief was also higher in the intervention group, and the difference was statistically [OR = 0.25, 95%CI (0.15,0.41), P < 0.0001].

CONCLUSION

WAA has a certain effect on acute pain in orthopedic surgery, and the effect of WAA combined with other therapies is better than that of not using WAA therapy.

IL-1 Generated by Oral Squamous Cell Carcinoma Stimulates Tumor-Induced and RANKL-Induced Osteoclastogenesis: A Possible Mechanism of Bone Resorption Induced by the Infiltration of Oral Squamous Cell Carcinoma

We previously observed a novel osteoclastogenesis system that is induced by oral squamous cell carcinoma (OSCC) cells, which target osteoclast precursor cells (OPC) without upregulation of the master transcriptional factor of osteoclastogenesis, NFATc1. Here, we analyzed inflammatory cytokines that were preferentially expressed in one of the osteoclastogenic OSCC cell lines, namely NEM, compared with the subclone that had lost its osteoclastogenic properties. Based on a gene expression microarray and a protein array analyses, IL-1, IL-6, IL-8, and CXCL1 were chosen as candidates responsible for tumor-induced osteoclastogenesis. From the results of the in vitro osteoclastogenesis assay using OPCs cultured with OSCC cells or their culture supernatants, IL-1 was selected as a stimulator of both OSCC-induced and RANKL-induced osteoclastogenesis. The IL-1 receptor antagonist significantly attenuated osteoclastogenesis induced by NEM cells. The stimulatory effects of IL-1 for OSCC-induced and RANKL-induced osteoclastogenesis were effectively attenuated with cannabidiol and denosumab, respectively. These results suggest that IL-1 secreted from OSCC cells stimulates not only tumor-induced osteoclastogenesis targeting OPCs but also physiological RANKL-induced osteoclastogenesis, and this may be the biological mechanism of bone resorption induced by the infiltration of OSCC. These results also suggest that IL-1 inhibitors are candidates for therapeutic agents against bone resorption induced by OSCC.

Factors associated with adherence to guidelines in cancer pain management among adult patients evaluated at oncology unit, in the University of Gondar Comprehensive Specialized Hospital, Northwest Ethiopia

Introduction

Cancer pain is one of the most important deleterious and distressing symptoms suffered by patients with cancer which disturb their quality of life, especially in the last part of their life. Alleviating pain is a primary goal of prognosis of cancer pain management and pain symptoms must be prevented, treated as a priority, and considered an independent part of cancer management. Despite the presence of guidelines for cancer pain management, many patients with cancer are still undertreated. Therefore, this study aimed to assess factors associated with adherence to guidelines in cancer pain management among adult patients evaluated at the oncology unit, in the University of Gondar Comprehensive Specialized Hospital (UoGCSH), Northwest Ethiopia.

Methods

An institution-based cross-sectional study was conducted from January to March 2021. All patients who were in cancer treatment were our population of interest. A systematic random sampling technique was used to select a total of 384 participants. The dependent variable of the study was adherence to guidelines in cancer pain management. It was determined using the pain management index (PMI) which was calculated by subtracting the pain level from the analgesics level. A negative range was considered an indicator of poor adherence to guidelines in cancer pain management. Bivariable and multivariable binary logistic regression analyses were performed. Adjusted odds ratio (AOR) with a 95% CI was used as a measure of association. Variables having P &lt; 0.05 from the multivariable analysis were considered to have a significant association with the outcome.

Results

The prevalence of poor adherence to guidelines in cancer pain management among 384 adult patients in this study was 21.35% (95%CI: 17.53, 25.76). Patients who were not married [AOR = 2.2; 95%CI: 1.15, 4.19], who know their diagnosis before 4 months ago [AOR = 0.53; 95%CI: 0.26, 0.96], who have metastasis cancer [AOR = 3.76; 95%CI: 1.83, 7.72], and being stage III patients [AOR = 3.21; 95%CI: 1.64, 7.93] and stage IV patients [AOR = 1.63; 95%CI: 1.09, 5.81], respectively, had a significant association with poor adherence to guidelines in cancer pain management.

Conclusion

The prevalence of poor adherence to guidelines in cancer pain management among adult patients with cancer in UoGCSH Northwest Ethiopia is relatively low as compared with other studies. Factors such as patients who were not married and who have metastasis cancer, and being patients with stage III and stage IV cancer had a significant positive association with poor adherence to guidelines in cancer pain management, on the other hand, patients who know their diagnosis 4 months ago had a positive association with having adherence to guidelines in cancer pain management. Patients with high stage and metastasis need care from pain specialists early on in the diagnosis of pain. The hospital should reassure the diagnosis of cancer for the patient before they started the treatment.

A 3D macroporous and magnetic Mg2SiO4-CuFe2O4 scaffold for bone tissue regeneration: Surface modification, in vitro and in vivo studies

Macroporous scaffolds with bioactivity and magnetic properties can be a good candidate for bone regeneration and hyperthermia. In addition, modifying the surface of the scaffolds with biocompatible materials can increase their potential for in vivo applications. Here, we developed a multifunctional nanocomposite Mg₂SiO₄-CuFe₂O₄ scaffold for bone regeneration and hyperthermia. The surface of scaffold was coated with various concentrations of poly-3-hydroxybutyrate (P3HB, 1-5% (w/v)). It was observed that 3% (w/v) of P3HB provided a favorable combination of porosity (79 ± 2.1%) and compressive strength (3.2 ± 0.11 MPa). The hyperthermia potential of samples was assessed in the presence of various magnetic fields in vitro. The coated scaffolds showed a lower degradation rate than the un-coated one up to 35 days of soaking in simulated biological medium. Due to the porous and specific morphology of P3HB, it was found that in vitro bioactivity and cell attachment were increased on the scaffold. Moreover, it was observed that the P3HB coating improved the cell viability, alkaline phosphatase activity, and mineralization of the scaffold. Finally, we studied the bone formation ability of the scaffolds in vivo, and implanted the developed scaffold in the rat's femur for 8 weeks. Micro-computed tomography results including bone volume fraction and trabecular thickness exhibited an improvement in the bone regeneration of the coated scaffold compared to the control. The overall results of this study introduce a highly macroporous scaffold with multifunctional performance, noticeable ability in bone regeneration, and hyperthermia properties for osteosarcoma.

Percutaneous Screw Stabilization of Non-Periacetabular Pelvic Lesions Caused by Metastatic Cancer and Multiple Myeloma

BACKGROUND

The pelvis is one of the most common locations for metastatic bone disease. While many of the publications that describe surgical treatments focus on periacetabular lesions (Enneking zone II), there is a lack of investigation into lesions in the non-periacetabular areas (zones I, III, and IV). We recently described a minimally invasive percutaneous screw application for metastatic zone-II lesions with excellent results. In the present study, we aimed to extend this approach to the other pelvic areas.

METHODS

Twenty-two consecutive patients with painful non-periacetabular pelvic metastatic cancer were included based on retrospective chart review. There were 16 women and 6 men with an average age of 60 years (range, 36 to 81 years). The most common primary cancers were multiple myeloma (7 cases) and breast (5 cases). The most common locations were the sacrum and the ilium. A pathologic fracture was identified in 15 patients. Most of the lesions were treated with multiple large-diameter screws, except for the isolated zone-III lesions. All of the procedures were completed in a standard operating room without the need for special instruments. Radiation therapy was given to 19 patients; the average dose was 15 Gy. The studied outcomes were pain and functionality as assessed by a visual analog scale (VAS) score and the Eastern Cooperative Oncology Group score (ECOG), respectively.

RESULTS

There were no surgical complications and no need for blood transfusion. The average follow-up time was 7 months (range, 0.3 to 34.0 months). Two patients died within 4 weeks of surgery due to COVID-19 infection. There was significant improvement in the postoperative VAS pain score (p < 0.0001) and the ECOG score (p < 0.05) when compared with the preoperative scores. There was no implant failure or revision surgery. Local bone-healing was observed in 12 of 14 patients (86%) who survived for >3 months after surgery.

CONCLUSIONS

Percutaneous screw application is safe and effective in the treatment of metastatic non-periacetabular pelvic lesions. Given the simplicity of the technique and the instrumentation and the tolerance for concomitant treatments, this approach is worthy of broader consideration.

LEVEL OF EVIDENCE

Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

3-T magnetic resonance-guided high-intensity focused ultrasound (3 T-MR-HIFU) for the treatment of pain from bone metastases of solid tumors

INTRODUCTION

Bone metastases (BM) are still the main cause of morbidity and mortality in cancer patients, not only because of their complications, defined as skeletal-related events (SREs), but also because of the negative impact bone pain has on quality of life (QoL) and survival, especially when opioid analgesics and locoregional treatments fail.

MATERIALS AND METHODS

A single-center prospective study was carried out on 12 patients with symptomatic BM treated with MRI-guided focused ultrasound (MR-HIFU). The primary endpoint was the effectiveness of MR-HIFU in reducing current and breakthrough cancer pain (BTCP) scores. The main secondary aims were the evaluation of circulating markers at different time-points and their relation to pain and procedure efficacy. Other secondary objectives included temporal evolution of pain response, evaluation of QoL, and side effects of the treatment. Descriptive statistics were used to evaluate primary and secondary endpoints. Questionnaires on pain and QoL completed at baseline and at 30 days were compared using appropriate statistical tests with exploratory intent.

RESULTS

MR-HIFU was successfully completed in all 12 patients enrolled between September 2015 and December 2018. On day 30, 6 (50.0%) patients showed a complete response of current pain and 6 a partial response, while 5 (41.7%) obtained a complete BTCP response. A partial response of BM evaluated by MD Anderson criteria was obtained in 9 (81.8%) patients. Only one patient progressed in the target lesion after MR-HIFU. No treatment-related adverse events were recorded. Bone turnover markers CTX/RANK-L (P) do not demonstrate any significant change with the pain or BM response.

CONCLUSION

In our patients, targeted therapy of painful BM with MRI-guided focused ultrasound ablation was safe and showed encouraging early-onset and functional results.

Cost-effectiveness of treatment strategies for spinal metastases

PURPOSE

We analyze the cost-effectiveness of standard palliative external beam radiation (EBRT, 8 Gy in 1 fraction), stereotactic body radiation therapy (SBRT, 24 Gy in 2 fractions), and radiofrequency ablation (RFA) for painful spinal metastases. Single-fraction SBRT (delivering 24 Gy) is also assessed.

METHODS AND MATERIALS

A Markov state transition model was constructed. Key model parameters were derived from prospective clinical trial data. Strategies were compared using the incremental cost-effectiveness ratio (ICER), with effectiveness in quality-adjusted life years (QALYs) and a willingness-to-pay (WTP) threshold of $100,000 per QALY gained. Costs included both hospital and professional costs using 2020 Medicare reimbursement.

RESULTS

The base case demonstrated that 2-fraction SBRT was not cost-effective compared to single-fraction EBRT, with an ICER of $194,145/QALY gained. RFA was a dominated treatment strategy (more costly and less effective) in this model. Probabilistic sensitivity analysis demonstrated that EBRT was favored in 66% of model iterations. If median survival were improved after SBRT, two-fraction SBRT became cost-effective, with ICER of $80,394, $57,062, and $47,038 for 3, 6, and 9-month improvements in survival. Because two-fraction SBRT data reported 18% of patients with indeterminant pain response at 3 months, and two-fraction SBRT is infrequently used in clinical practice, single-fraction SBRT data was also assessed. Single-fraction SBRT delivering 24 Gy was cost-effective compared to single-fraction EBRT, with an ICER of $92,833/QALY gained.

CONCLUSIONS

For appropriately chosen patients, single-fraction SBRT is more cost-effective than conventional EBRT or RFA. Conventional EBRT remains a cost-effective treatment for patients with poor expected survival.

Jig-assisted modified Harrington reconstruction for metastatic bone destruction of the acetabulum

INTRODUCTION

We developed a technique using an indigenously designed jig to assist pin placement in producing a stable and long-lasting construct to augment the acetabulum combined with a cemented hip replacement in cases of metastatic destruction of the acetabulum. We describe our novel modified Harrington technique and retrospectively assess our cohort's clinical outcomes and complications.

METHODS

Between 2006 and 2019, 27 patients with a median age of 69 (49-81) years and a median ASA grade of III (II-IV) were managed using our modified 'Harrington' technique. We assessed outcomes on the following criteria: mechanical complications, post-surgery mobility, and functional outcome using Musculoskeletal Tumour Society Score (MSTS).

RESULTS

At the last follow-up, ten patients were alive with disease [median follow-up of 26 months (12-74)], and 17 patients died of their oncological disease [median follow-up of 15 months (9-22)]. There were no perioperative deaths or intra-operative complications in our series. In total, ten complications were noted in nine patients (33%). Mobility-wise, 13 patients (48%) mobilised unaided, ten patients (37%) required a stick or crutch, two patients (7%) required a frame and two patients (7%) were wheel chair-dependent. The median MSTS score of all patients during their latest follow-up was 18 (8-26).

CONCLUSION

Our jig-aided modified Harrington reconstruction technique assists in safe placement of antegrade pins in acetabulum during surgery and offers a long-lasting solution to these high-risk patients. The use of large diameter pins, appropriate patient selection, and cage used during construction in the acetabulum demonstrated relief of pain, improved mobility, and favorable functional outcomes with minimal complication rates.

Managing Advanced Cancer Pain Together (MACPT) conversation tool: an evaluation of use in clinical practice

Aim: To investigate use of the 'Managing Advanced Cancer Pain Together' conversation tool between individuals with advanced cancer and healthcare professionals (HCPs) during routine consultations. Methods: Twenty-one patients and six HCPs completed questionnaires before and after use of the tool (at their routine consultation 1 and consecutive consultation 2, respectively). Results: Patients and HCPs were satisfied with communication during both consultations. When using the tool, patients most frequently selected physical pain descriptors (95.2%), followed by emotional (81.0%), social (28.6%) and spiritual (28.6%) descriptors. Patients found the tool useful, stating that it helped them describe their pain. HCPs considered the tool difficult to incorporate into consultations. Conclusion: The study highlighted the need to consider the various aspects of cancer pain.

Effects of dezocine on morphine tolerance and opioid receptor expression in a rat model of bone cancer pain

BACKGROUND

Clinically, the coadministration of opioids to enhance antinociception and decrease tolerance has attracted increasing research attention. We investigated the effects of dezocine, a mu- and kappa-opioid receptor agonist/antagonist, on morphine tolerance and explored the involvement of opioid receptor expression in a rat model of bone cancer pain.

METHODS

Thermal nociceptive thresholds were measured after the subcutaneous injection of morphine (10 mg/kg) alone or combined with dezocine (10 or 1 mg/kg) for 7 consecutive days. Real-time PCR and western blot analysis were used to examine opioid receptor expression in the periaqueductal gray (PAG) and spinal cord.

RESULTS

The analgesic effect was significantly decreased after 4 days of morphine administration. We observed that low-dose dezocine significantly attenuated morphine tolerance without reducing the analgesic effect of morphine. Low-dose dezocine coadministration significantly reversed the downregulated expression of mu (MOR) and delta (DOR) opioid receptors in the PAG and the upregulated expression of kappa (KOR) and DOR in the spinal cord induced by morphine. Moreover, low-dose dezocine coadministered with morphine significantly inhibited KOR expression in both the PAG and spinal cord.

CONCLUSIONS

The combination of low-dose dezocine with morphine may prevent or delay the development of morphine tolerance in a rat model of bone cancer pain. The regulation of opioid receptor expression in the PAG and spinal cord may be part of the mechanism.

Sensory nerves: A driver of the vicious cycle in bone metastasis?

Bone is one of the preferential target organs of cancer metastasis. Bone metastasis is associated with various complications, of which bone pain is most common and debilitating. The cancer-associated bone pain (CABP) is induced as a consequence of increased neurogenesis, reprogramming and axonogenesis of sensory nerves (SNs) in harmony with sensitization and excitation of SNs in response to the tumor microenvironment created in bone. Importantly, CABP is associated with increased mortality, of which precise cellular and molecular mechanism remains poorly understood. Bone is densely innervated by autonomic nerves (ANs) (sympathetic and parasympathetic nerves) and SNs. Recent studies have shown that the nerves innervating the tumor microenvironment establish intimate communications with tumors, producing various stimuli for tumors to progress and disseminate. In this review, our current understanding of the role of SNs innervating bone in the pathophysiology of CABP will be overviewed. Then the hypothesis that SNs facilitate cancer progression in bone will be discussed in conjunction with our recent findings that SNs play an important role not only in the induction of CABP but also the progression of bone metastasis using a preclinical model of CABP. It is suggested that SNs are a critical component of the bone microenvironment that drives the vicious cycle between bone and cancer to progress bone metastasis. Suppression of the activity of bone-innervating SNs may have potential therapeutic effects on the progression of bone metastasis and induction of CABP.

Efficacy and safety of 177Lu-DOTMP in palliative treatment of symptomatic skeletal metastases: a prospective study

AIMS

Bone-seeking radiopharmaceutical 177Lu-DOTMP with favorable pharmacokinetics in the preclinical studies has been evaluated for its role in reducing bone pain and improving quality of life (QOL) in patients with symptomatic skeletal metastases.

METHOD

Patients with painful widespread skeletal metastases documented on 99mTc-MDP bone scintigraphy were intravenously administered 37 MBq/kg of 177Lu-DOTMP. Visual analogue score (VAS), analgesic score, European Cooperative Group of Oncology (ECOG) and the European Organization of Research and Treatment of Cancer QLQ-C30 of all the patients were assessed at baseline and posttherapy follow-up. Adverse effects were graded according to NCI-CTCAE V 5.0.

RESULTS

Twenty-seven patients with painful widespread skeletal metastases (men 18; median age 61 years; range: 18-81) were studied for their responses as complete response, partial response, minimal response, no response and pain progression based on VAS and analgesic score. Overall response was seen in 77.8% of patients (complete, partial and minimal in 29.6, 33.3 and 14.8%, respectively) with significant improvement in median VAS and mean analgesic score at 2 months posttherapy from baseline (P < 0.001). The best response was seen in patients with breast cancer (100%) followed by prostate cancer (81%) and lung cancer (28%). Improvement in QOL was noted in 40% of patients, with change in ECOG score from 3.07 ± 0.67 at baseline to 2.6 ± 0.9 at 2 months posttherapy. Grade 2/3 anemia, grade 1/2 leukopenia and grade 1/3 thrombocytopenia were seen in 37, 11.1 and 18.5% patients respectively in the follow-up.

CONCLUSION

177Lu-DOTMP appears to be efficacious treatment for bone pain palliation with improvement in QOL though less effective in patients with lung cancer. The patients had transient mild-moderate hematotoxicity.

Spinal Nrf2 translocation may inhibit neuronal NF-κB activation and alleviate allodynia in a rat model of bone cancer pain

Bone cancer pain (BCP) is a clinical pathology that urgently needs to be solved, but research on the mechanism of BCP has so far achieved limited success. Nuclear factor erythroid 2 (NFE2)-related factor 2 (Nrf2) has been shown to be involved in pain, but its involvement in BCP and the specific mechanism have yet to be examined. This study aimed to test the hypothesis that BCP induces the transfer of Nrf2 from the cytoplasm to the nucleus and further promotes nuclear transcription to activate heme oxygenase-1 (HO-1) and inhibit the activation of nuclear factor-kappa B (NF-κB) signalling, ultimately regulating the neuroinflammatory response. Von-Frey was used for behavioural analysis in rats with BCP, whereas western blotting, real-time quantitative PCR (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) were used to detect molecular expression changes, and immunofluorescence was used to detect cellular localization. We demonstrated that BCP induced increased Nrf2 nuclear protein expression with decreased cytoplasmic protein expression in the spinal cord. Further increases in Nrf2 nuclear protein expression can alleviate hyperalgesia and activate HO-1 to inhibit the expression of NF-κB nuclear protein and inflammatory factors. Strikingly, intrathecal administration of the corresponding siRNA reversed the above effects. In addition, the results of double immune labelling revealed that Nrf2 and NF-κB were coexpressed in spinal cord neurons of rats with BCP. In summary, these findings suggest that the entry of Nrf2 into the nucleus promotes the expression of HO-1, inhibiting activation of the NF-κB signalling pathway, reducing neuroinflammation and ultimately exerting an anti-nociceptive effect.

Bone Metastatic Breast Cancer: Advances in Cell Signaling and Autophagy Related Mechanisms

Bone metastasis is a frequent complication of breast cancer with nearly 70% of metastatic breast cancer patients developing bone metastasis during the course of their disease. The bone represents a dynamic microenvironment which provides a fertile soil for disseminated tumor cells, however, the mechanisms which regulate the interactions between a metastatic tumor and the bone microenvironment remain poorly understood. Recent studies indicate that during the metastatic process a bidirectional relationship between metastatic tumor cells and the bone microenvironment begins to develop. Metastatic cells display aberrant expression of genes typically reserved for skeletal development and alter the activity of resident cells within the bone microenvironment to promote tumor development, resulting in the severe bone loss. While transcriptional regulation of the metastatic process has been well established, recent findings from our and other research groups highlight the role of the autophagy and secretory pathways in interactions between resident and tumor cells during bone metastatic tumor growth. These reports show high levels of autophagy-related markers, regulatory factors of the autophagy pathway, and autophagy-mediated secretion of matrix metalloproteinases (MMP's), receptor activator of nuclear factor kappa B ligand (RANKL), parathyroid hormone related protein (PTHrP), as well as WNT5A in bone metastatic breast cancer cells. In this review, we discuss the recently elucidated mechanisms and their crosstalk with signaling pathways, and potential therapeutic targets for bone metastatic disease.

STING suppresses bone cancer pain via immune and neuronal modulation

Patients with advanced stage cancers frequently suffer from severe pain as a result of bone metastasis and bone destruction, for which there is no efficacious treatment. Here, using multiple mouse models of bone cancer, we report that agonists of the immune regulator STING (stimulator of interferon genes) confer remarkable protection against cancer pain, bone destruction, and local tumor burden. Repeated systemic administration of STING agonists robustly attenuates bone cancer-induced pain and improves locomotor function. Interestingly, STING agonists produce acute pain relief through direct neuronal modulation. Additionally, STING agonists protect against local bone destruction and reduce local tumor burden through modulation of osteoclast and immune cell function in the tumor microenvironment, providing long-term cancer pain relief. Finally, these in vivo effects are dependent on host-intrinsic STING and IFN-I signaling. Overall, STING activation provides unique advantages in controlling bone cancer pain through distinct and synergistic actions on nociceptors, immune cells, and osteoclasts.

An automatic framework for evaluating the vascular permeability of bone metastases from prostate cancer

Objectives.Vascular permeability can reflect tumorigenesis and metastasis. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) can assess microvascular permeability by pharmacokinetic parameter estimation. Most estimation methods require manually selected arterial input function (AIF) or reference regions. However, the result will be unstable due to the annotation, which relies on personal experience. In this study, we propose an automatic framework for evaluating vascular permeability of bone metastases from prostate cancer without selecting AIF.Materials and methods.This retrospective study comprised of 15 prostate cancer patients with bone metastases. Based on clinical consensus for three typical DCE-MRI curve patterns, three characteristic curves as regularization constraints were introduced to the extended Tofts model (ETM) using clustering strategy, and the clustering-based blind identification of multichannel (CBM) framework was then proposed for pharmacokinetic parameter estimation. With automatic segmentation of the whole bone area, we obtained the estimation of the pharmacokinetic parameters in the bone area and quantified for bone metastases. Two experienced radiologists compared the CBM estimations with the diagnostic results and we compared the estimations with those of the ETM in bone metastasis regions to evaluate the feasibility of the CBM framework.Results.The higher signal regions ofK^transandK_epindicated the metastasis of prostate cancer, which is consistent with the cancer area marked by the radiologists. In addition, theK^transandK_epin bone metastasis regions were significantly higher than in normal bone regions (P < 0.001,P < 0.001). The consistency of estimation by using the CBM framework and conventional ETM method was confirmed by Bland-Altman analysis.Conclusion.The proposed CBM framework can provide a fully automatic and reliable quantitative estimation of vascular permeability for bone metastases in prostate cancer patients.

Clinical and dosimetric risk factors for vertebral compression fracture after single-fraction stereotactic body radiation therapy for spine metastases

Objectives

This analysis was performed to evaluate the incidence of vertebral compression fracture (VCF) and determine the contributing factors for VCF in patients undergoing single-fraction stereotactic body radiotherapy (SBRT) for spinal bone metastases (SBM).

Methods

A retrospective review of medical records was conducted for patients undergoing SBRT for SBM at our institution between January 2010 and December 2018. Patients who had undergone neither pre-SBRT surgical excision nor post-SBRT prophylactic fixation were included. The effects of clinical and dosimetric parameters were analyzed with respect to VCF risk. The following dosimietric parameters of the planning target volume (PTV) were calculated: mean/minimum/maximum dose, radiation dose to 10-90% volume, and irradiated volume receiving more than 10-25 Gy (PTV_V_{10 - 25 Gy}).

Results

Among 163 patients (179 vertebrae), 21 (12.8%) experienced VCF. The 1-year and 2-year VCF rates were 12.1% and 13.2%, respectively. Among dosimetric parameters, PTV_V15 Gy was the most significant for VCF prediction. In a univariate analysis, breast or prostate primary, no vertebral body collapse, and PTV_V_{15 Gy} ≤42 cm³ were significantly associated with a lower incidence rate of VCF. In a multivariate analysis, PTV_V_{15 Gy} was the only significant factor for VCF risk. The 1-year VCF rate was 3.8% in patients with PTV_V_{15 Gy} ≤42 cm³, while it was 22.1% in those with PTV_V_{15 Gy} > 42 cm³ (p < 0.01).

Conclusions

SBRT-related VCF was found in 12% of patients in our institution. The PTV_V_{15 Gy} is a significant factor for VCF prediction.

The North American Neuroendocrine Tumor Society Consensus Guidelines for Surveillance and Management of Metastatic and/or Unresectable Pheochromocytoma and Paraganglioma

ABSTRACT

This manuscript is the result of the North American Neuroendocrine Tumor Society consensus conference on the medical management and surveillance of metastatic and unresectable pheochromocytoma and paraganglioma held on October 2 and 3, 2019. The panelists consisted of endocrinologists, medical oncologists, surgeons, radiologists/nuclear medicine physicians, nephrologists, pathologists, and radiation oncologists. The panelists performed a literature review on a series of questions regarding the medical management of metastatic and unresectable pheochromocytoma and paraganglioma as well as questions regarding surveillance after resection. The panelists voted on controversial topics, and final recommendations were sent to all panel members for final approval.

Reciprocal interactions between osteoclasts and nociceptive sensory neurons in bone cancer pain

Many common cancers such as breast, prostate, and lung cancer metastasize to bones at advanced stages, producing severe pain and functional impairment. At present, the current pharmacotherapies available for bone cancer pain are insufficient to provide safe and efficacious pain relief. In this narrative review, we discuss the mechanisms used by cancer cells within the bone tumor microenvironment (TME) to drive bone cancer pain. In particular, we highlight the reciprocal interactions between tumor cells, bone-resorbing osteoclasts, and pain-sensing sensory neurons (nociceptors), which drive bone cancer pain. We discuss how tumor cells present within the bone TME accelerate osteoclast differentiation (osteoclastogenesis) and alter osteoclast activity and function. Furthermore, we highlight how this perturbed state of osteoclast overactivation contributes to bone cancer pain through (1) direct mechanisms, through their production of pronociceptive factors that act directly on sensory afferents; and (2) by indirect mechanisms, wherein osteoclasts drive bone resorption that weakens tumor-bearing bones and predisposes them to skeletal-related events, thereby driving bone cancer pain and functional impairment. Finally, we discuss some potential therapeutic agents, such as denosumab, bisphosphonates, and nivolumab, and discuss their respective effects on bone cancer pain, osteoclast overactivation, and tumor growth within the bone TME.

Assessment and management of metastatic bone cancer in emergency departments

A cancer diagnosis in emergency departments (EDs) is often associated with advanced or metastatic cancer. Patients with bone metastases have a complex range of physical and psychological needs. Meeting the needs of patients with cancer is an important part of the role of emergency nurses, but evidence suggests that they often do not feel adequately prepared to provide effective care for this patient group. This article uses a case study of a patient who presented to an ED with metastatic cancer in his right lower limb, to provide an overview of bone metastases, including the relevant anatomy, pain management and psychological support. The article also outlines the signs and symptoms of bone metastases and discusses patient assessment, symptom management and available treatments.

Cryoablation for Palliation of Painful Bone Metastases: The MOTION Multicenter Study

PURPOSE

To assess the clinical effectiveness of cryoablation for palliation of painful bone metastases.

MATERIALS AND METHODS

MOTION (Multicenter Study of Cryoablation for Palliation of Painful Bone Metastases) (ClinicalTrials.gov NCT02511678) was a multicenter, prospective, single-arm study of adults with metastatic bone disease who were not candidates for or had not benefited from standard therapy, that took place from February 2016 to March 2018. At baseline, participants rated their pain using the Brief Pain Inventory-Short Form (reference range from 0 to 10 points); those with moderate to severe pain, who had at least one metastatic candidate tumor for ablation, were included. The primary effectiveness endpoint was change in pain score from baseline to week 8. Participants were followed for 24 weeks after treatment. Statistical analyses included descriptive statistics and logistic regression to evaluate changes in pain score over the postprocedure follow-up period.

RESULTS

A total of 66 participants (mean age, 60.8 years ± 14.3 [standard deviation]; 35 [53.0%] men) were enrolled and received cryoablation; 65 completed follow-up. Mean change in pain score from baseline to week 8 was -2.61 points (95% CI: -3.45, -1.78). Mean pain scores improved by 2 points at week 1 and reached clinically meaningful levels (more than a 2-point decrease) after week 8; scores continued to improve throughout follow-up. Quality of life improved, opioid doses were stabilized, and functional status was maintained over 6 months. Serious adverse events occurred in three participants.

CONCLUSION

Cryoablation of metastatic bone tumors provided rapid and durable pain palliation, improved quality of life, and offered an alternative to opioids for pain control.Keywords: Ablation Techniques, Metastases, Pain Management, Radiation Therapy/OncologySupplemental material is available for this article.© RSNA, 2021.

Quality of life and pain in patients with metastatic bone disease from solid tumors treated with bone-targeted agents- a real-world cross-sectional study from Switzerland (SAKK 95/16)

Background

Bone-targeted agents (BTAs) are widely used in the management of patients with bone metastases from solid tumors. Knowledge of the impact of their routine care use on patient-reported pain and bone pain-related quality of life (QoL) is limited.

Methods

This real world, cross-sectional study enrolled patients over a 3-month period through oncologists across Switzerland. Patients were ≥ 18 years, had solid tumors and at least one bone metastasis, and received routine care for bone metastases. Physicians provided data on BTA-related practices, risk of bone complications and BTA regimen. Patients completed questionnaires about pain (BPI-SF), general and bone pain-related QoL (FACT-G, FACT-BP) and treatment satisfaction (FACIT-TS-G).

Results

Eighteen sites recruited 417 patients. Based on the FACT-BP, 42% of the patients indicated not having bone pain. According to the BPI-SF, 28% reported no, 43% mild, 14% moderate, and 15% severe pain, respectively. Patients not treated with a BTA had better overall QoL (FACT-G: p = 0.031) and bone pain-related QoL (FACT-BP, p = 0.007) than those treated with a BTA. All pain and other QoL scales did not differ between groups. Patients perceived at ‘low risk of bone complications’ by their physician not receiving a BTA reported less pain and better QoL than those considered at ‘low risk’ but receiving BTA treatment or those considered at ‘high risk’ regardless of BTA treatment. Overall satisfaction with the treatment was good; almost 50% of patients reporting that they were completely satisfied.

Conclusions

Overall, pain and QoL did not differ according to BTA treatment or physicians’ risk perception. Patient with low risks not receiving BTA treatment reported least pain and highest QoL scores. These results may suggest that treating physicians assess bone complication risk appropriately and treat patients accordingly, but they need to be confirmed by objective determination of longitudinal skeletal complication risk.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-07903-8.

Conservative Management of Medication-Related Osteonecrosis of the Jaws (MRONJ): A Retrospective Cohort Study

BACKGROUND

Medication-related osteonecrosis of the jaw (MRONJ) is a severe side effect of bisphosphonates and anti-resorptive drugs prescribed for treatment of severe osteoporosis, Paget's disease, and bone malignancies. The aim of this study was to evaluate the clinical outcome of a combined pharmacological and surgical management strategy on patients affected by MRONJ.

MATERIALS AND METHODS

Medical records of patients with MRONJ were retrospectively examined to collect clinical history data. Conservative management included an initial pharmacological phase with antibiotics and antiseptic agents, followed by surgical intervention to remove bone sequestrum. Primary outcomes were healing from MRONJ at short term (1 month after surgery) and at longer term (3 months after surgery). Secondary outcome was assessment of recurrences at longer-term follow-up.

RESULTS

Thirty-five patients were included in the study with mean follow-up of 23.86 ± 18.14 months. Seven cases showed spontaneous exfoliation of necrotic bone during pharmacological therapy, which in one case did not require any further intervention. At 1-month posttreatment, 31 out of 35 (88.5%) patients showed complete healing. The 25 patients who were followed for at least 3 months revealed a healing rate of 92% (23/25). Recurrences occurred in 7 patients out 23 who showed the long-term healing, after a mean period of 7.29 ± 3.45 months. The prognostic score (University of Connecticut Osteonecrosis Numerical Scale-UCONNS) was significantly higher (p = 0.01) in patients with poor healing as compared to complete healing, both at 1 and 3 months posttreatment.

CONCLUSIONS

A MRONJ treatment approach based on a combined pharmacological and surgical treatment strategy showed a high rate of healing and few recurrences.

Recent Advances in Nanomedicine for the Diagnosis and Treatment of Prostate Cancer Bone Metastasis

Patients with advanced prostate cancer can develop painful and debilitating bone metastases. Currently available interventions for prostate cancer bone metastases, including chemotherapy, bisphosphonates, and radiopharmaceuticals, are only palliative. They can relieve pain, reduce complications (e.g., bone fractures), and improve quality of life, but they do not significantly improve survival times. Therefore, additional strategies to enhance the diagnosis and treatment of prostate cancer bone metastases are needed. Nanotechnology is a versatile platform that has been used to increase the specificity and therapeutic efficacy of various treatments for prostate cancer bone metastases. In this review, we summarize preclinical research that utilizes nanotechnology to develop novel diagnostic imaging tools, translational models, and therapies to combat prostate cancer bone metastases.

Wrist-ankle acupuncture has a positive effect on cancer pain: a meta-analysis

Background

Wrist-ankle acupuncture (WAA) as a kind of micro acupuncture therapy has been used to management cancer pain, however, the effects of WAA on cancer pain were controversial in the current studies. Therefore, the purpose of this meta-analysis was to critically evaluate the effect of wrist-ankle acupuncture (WAA) on cancer pain.

Methods

Seven digital databases were searched from the inception of databases to July 2020, including CNKI, Wanfang, VIP, CBM, Cochrane Library, PubMed and Embase. Randomized controlled trials conforming to the inclusion and exclusion criteria were screened and extracted; the risk of bias was evaluated using the Cochrane Collaboration criteria. The primary outcome indicators included pain relief rate and pain score, and the secondary outcome was adverse reaction incidence. All analyses were performed with Review Manager 5.3.

Results

A total of 13 studies with 1005 cancer patients (intervention group: 568, control group: 437) were included in this meta-analysis. The results demonstrated that the pain relief rate of experimental group (WAA / WAA + drug intervention) was better than that of control group (analgesic drug intervention), and the difference was statistically significant [RR = 1.31, 95%CI: 1.15 ~ 1.49, P < 0.01].

Conclusions

WAA has certain effect on cancer pain, and the effect of WAA combined with pharmacological intervention is better than that of drug therapy alone.

Wnt5b/Ryk-mediated membrane trafficking of P2X3 receptors contributes to bone cancer pain

Wnt5b, a member of Wnt family, plays multiple roles in tumor progression and metastasis. However, whether Wnt5b contributes to the sensitization of dorsal root ganglia (DRG) neurons and pathogenesis of bone cancer pain still remains unclear. Here, we found that the protein expression of Wnt5b and its atypical tyrosine protein kinase receptor Ryk was upregulated in ipsilateral DRGs in tumor-bearing mice. Application of Wnt5b evoked an increased discharge frequency in isolated DRG neurons and pain hypersensitivity in naïve mice which were almost completely prevented by anti-Ryk antibody. Moreover, intrathecal injection of anti-Ryk antibody to tumor-bearing mice significantly inhibited bone cancer-induced mechanic allodynia and thermal hyperalgesia. Subsequently, we also demonstrated that application of Wnt5b to cultured DRG neurons could enhance membrane P2X3 receptors and α,β-meATP-induced currents. Intrathecal injection of calmodulin-dependent protein kinase II (CaMKII) inhibitor KN93 or P2X3 receptors antagonist A317491 almost completely abolished Wnt5b-induced mechanical allodynia and thermal hyperalgesia in mice. Meanwhile, pretreatment with anti-Ryk antibody or CaMKII inhibitor KN93 can attenuate bone-cancer induced the upregulation of P2X3 membrane protein as well as pain hypersensitivity. These findings suggested that Wnt5b/Ryk promoted the trafficking of P2X3 receptors to the membrane via the activation of CaMKII in primary sensory neurons, resulting in peripheral sensitization and bone cancer-induced pain. Our results may offer a potential therapeutic strategy for bone cancer pain.

PD-1 blockade inhibits osteoclast formation and murine bone cancer pain

Emerging immune therapy, such as with the anti-programmed cell death-1 (anti-PD-1) monoclonal antibody nivolumab, has shown efficacy in tumor suppression. Patients with terminal cancer suffer from cancer pain as a result of bone metastasis and bone destruction, but how PD-1 blockade affects bone cancer pain remains unknown. Here, we report that mice lacking Pdcd1 (Pd1-/-) demonstrated remarkable protection against bone destruction induced by femoral inoculation of Lewis lung cancer cells. Compared with WT mice, Pd1-/- mice exhibited increased baseline pain sensitivity, but the development of bone cancer pain was compromised in Pd1-/- mice. Consistently, these beneficial effects in Pd1-/- mice were recapitulated by repeated i.v. applications of nivolumab in WT mice, even though nivolumab initially increased mechanical and thermal pain. Notably, PD-1 deficiency or nivolumab treatment inhibited osteoclastogenesis without altering tumor burden. PD-L1 and CCL2 are upregulated within the local tumor microenvironment, and PD-L1 promoted RANKL-induced osteoclastogenesis through JNK activation and CCL2 secretion. Bone cancer upregulated CCR2 in primary sensory neurons, and CCR2 antagonism effectively reduced bone cancer pain. Our findings suggest that, despite a transient increase in pain sensitivity following each treatment, anti-PD-1 immunotherapy could produce long-term benefits in preventing bone destruction and alleviating bone cancer pain by suppressing osteoclastogenesis.

The First Algorithm Calculating Cement Injection Volumes in Patients with Spine Metastases Treated with Percutaneous Vertebroplasty

PURPOSE

This study aims to develop an algorithm to predict cement injection volumes in patients with spine metastases treated with percutaneous vertebroplasty (PVP). Risk factors were also analyzed for intra-spinal canal cement leakages.

PATIENTS AND METHODS

A retrospective analysis of 584 vertebrae in 251 patients. Patients and vertebrae were divided into three groups based on grades of tumor invasion to the spinal cord. Patients with the complete posterior wall of vertebrae were classified into group A, patients without the complete posterior wall of vertebrae but with normal Dural sac were classified into group B, and patients with deformation of the Dural sac but without neurological symptom were classified into group C. We systematically reviewed demographic data, clinical parameters, radiology features, and cement leakages among the three groups. The multiple linear regressions were used to screen potential risk factors and develop the algorithm to predict injected cement volumes in vertebrae. Significant factors were included in the algorithm. Potential risk factors for intra-spinal canal cement leakage were analyzed using the multiple logistic regressions.

RESULTS

In the study, 17.1% (100/584) of vertebrae occurred cement leakages. Vertebrae in group C (28.6%, 8/28) had the highest cement leakage rate than patients in group A (14.4%, 61/424) and B (23.5%, 31/132) (P=0.014). Vertebrae in group C (14.3%, 4/28) were also more prone to intra-spinal canal leakages (P=0.003). The multiple logistic analysis showed that the Bilsky scale was significantly associated with intra-spinal canal cement leakages (P<0.001). The multiple linear regression analysis showed that intercept (P<0.001), treated vertebrae level (P<0.001), cortical osteolytic destruction in posterior wall (P<0.001), and Bilsky scale (P=0.014) were significant and those variables were included in the algorithm. The algorithm was Y=3.1627－0.8677×treated vertebrae level－0.6182×cortical osteolytic destruction in the posterior wall－0.2819×Bilsky scale.

CONCLUSION

An algorithm is proposed and can be used to calculate cement injection volumes in spine metastases treated with PVP. This algorithm can facilitate surgical planning and guide cement injections. Bilsky scale is an independent risk factor for intra-spinal canal cement leakages. We do not recommend PVP treated in patients with a Bilsky scale of 2 and 3 mainly due to a high rate of intra-spinal canal cement leakages.

Targeting of radioactive platinum-bisphosphonate anticancer drugs to bone of high metabolic activity

Platinum-based chemotherapeutics exhibit excellent antitumor properties. However, these drugs cause severe side effects including toxicity, drug resistance, and lack of tumor selectivity. Tumor-targeted drug delivery has demonstrated great potential to overcome these drawbacks. Herein, we aimed to design radioactive bisphosphonate-functionalized platinum (^195mPt-BP) complexes to confirm preferential accumulation of these Pt-based drugs in metabolically active bone. In vitro NMR studies revealed that release of Pt from Pt BP complexes increased with decreasing pH. Upon systemic administration to mice, Pt-BP exhibited a 4.5-fold higher affinity to bone compared to platinum complexes lacking the bone-seeking bisphosphonate moiety. These Pt-BP complexes formed less Pt-DNA adducts compared to bisphosphonate-free platinum complexes, indicating that in vivo release of Pt from Pt-BP complexes proceeded relatively slow. Subsequently, radioactive ^195mPt-BP complexes were synthesized using ^195mPt(NO₃)₂(en) as precursor and injected intravenously into mice. Specific accumulation of ^195mPt-BP was observed at skeletal sites with high metabolic activity using micro-SPECT/CT imaging. Furthermore, laser ablation-ICP-MS imaging of proximal tibia sections confirmed that ^195mPt BP co-localized with calcium in the trabeculae of mice tibia.

Antinociceptive effect of intrathecal injection of miR-9-5p modified mouse bone marrow mesenchymal stem cells on a mouse model of bone cancer pain

Background

A growing body of studies have indicated that bone marrow mesenchymal stem cells (BMSCs) have powerful analgesic effects in animal models of bone cancer pain. Here, we explored the molecular mechanisms underlying how BMSCs alleviate pain sensation in a mouse model of bone cancer pain.

Methods

C3H/HeN adult male mice were used to generate a bone cancer pain model. BMSCs were isolated from mouse bone marrow, modified by transfection with microRNA-9-5p (miR-9-5p), and infused into the spinal cord. Spontaneous flinches, paw withdrawal latency, limb-use score, and weight-bearing score were used to assess pain-related behaviors. ELISA, RT-PCR, western blot, and luciferase assay were used to assess gene expressions.

Results

Our results show that miR-9-5p regulated the expression of both repressor element silencing transcription factor (REST) and μ-opioid receptors (MOR) by targeting REST in primary mouse BMSCs. Overexpression of miR-9-5p reversed the activation of inflammatory pathway in TNF-α- and IL-6-treated BMSCs. In addition, miR-9-5p modified BMSCs alleviated cancer pain in the sarcoma-inoculated mouse model. MiR-9-5p modified BMSCs suppressed cytokine expression in the spinal cord of sarcoma-inoculated mice by suppressing REST gene expression.

Conclusions

Our results indicate that miR-9-5p modified BMSCs can relieve bone cancer pain via modulating neuroinflammation in the central nervous system, suggesting genetically modified BMSCs could be a promising cell therapy in pain management.