Prevention of Bortezomib-Related Peripheral Neuropathy With Docosahexaenoic Acid and α-Lipoic Acid in Patients With Multiple Myeloma: Preliminary Data

Dyslipidemia, lipid-lowering agents and neuroendocrine neoplasms: new horizons

PURPOSE

Neuroendocrine neoplasms (NENs) are a heterogeneous group of malignancies originating from cells with a neuroendocrine phenotype. The complex relationship between lipid metabolism and cancer is gaining interest and a potential anti-cancer effect of lipid lowering agents is being considered. This review aims to discuss the current understanding and treatment of dyslipidaemia in NENs, focusing on the role of lipid lowering agents, including new therapeutic approaches, and future perspectives as possible tool in cancer prevention and tumor-growth control.

METHODS

We performed an electronic-based search using PubMed updated until December 2023, summarizing the available evidence both in basic and clinical research about lipid lowering agents in NENs.

RESULTS

Dyslipidemia is an important aspect to be considered in NENs management, although randomized studies specifically addressing this topic are lacking, unlike other cancer types. Available data mainly regard statins, and in vitro studies have demonstrated direct antitumor effects, including antiproliferative effects in some cancers, supporting possible pleiotropic effects also in NENs, but data remain conflicting. Ezetimibe, omega 3-fatty acids, fibrates and inhibitors of proprotein convertase subtilisin/kexin type 9 (PCSK9) may enhance the regulation of lipid homeostasis, as demonstrated in other cancers.

CONCLUSIONS

Targeting dyslipidemia in NENs should be part of the multidisciplinary management and an integrated approach may be the best option for both metabolic and tumor control. Whether lipid lowering agents may directly contribute to tumor control remains to be confirmed with specific studies, focusing on association with other metabolic risk, disease stage and primary site.

Bortezomib-induced peripheral neuropathy: Clinical features, molecular basis, and therapeutic approach

Bortezomib is the first-line standard and most effective chemotherapeutic for multiple myeloma; however, bortezomib-induced peripheral neuropathy (BIPN) severely affects the chemotherapy regimen and has long-term impact on patients under maintenance therapy. The pathogenesis of BIPN is poorly understood, and basic research and development of BIPN management drugs are in early stages. Besides chemotherapy dose reduction and regimen modification, no recommended prevention and treatment approaches are available for BIPN apart from the International Myeloma Working Group guidelines for peripheral neuropathy in myeloma. An in-depth exploration of the pathogenesis of BIPN, development of additional therapeutic approaches, and identification of risk factors are needed. Optimizing effective and standardized BIPN treatment plans and providing more decision-making evidence for clinical diagnosis and treatment of BIPN are necessary. This article reviews the recent advances in BIPN research; provides an overview of clinical features, underlying molecular mechanisms, and therapeutic approaches; and highlights areas for future studies.

Recent advances in the treatment and prevention of peripheral neuropathy after multiple myeloma treatment

The incidence of multiple myeloma (MM) is increasing year by year, requiring chemotherapy drugs to control the condition. With the advent of new proteasome inhibitors, immunomodulators, and monoclonal antibodies, the prognosis of patients has improved significantly. However, peripheral neuropathy caused by drugs limits the dose and duration of treatment, which seriously affects patients' quality of life and treatment outcome. Although the neuropathies induced by chemotherapy drugs have attracted much attention, their mechanism and effective prevention and treatment measures are not clear. Therefore, how to alleviate peripheral neuropathy caused by drugs for treatment of MM is a key issue in improving patients' quality of life and prolonging their survival time, which have some clinical value. In this paper, we review the current research on the pathogenesis, pharmacological and nonpharmacological treatment, and prevention, which expects to present instruction for peripheral neuropathy after treatment of MM.

CaMKII and CaV3.2 T-type calcium channel mediate Connexin-43-dependent inflammation by activating astrocytes in vincristine-induced neuropathic pain

Vincristine (VCR), an alkaloid isolated from vinca, is a commonly used chemotherapeutic drug. However, VCR therapy can lead to dose-dependent peripheral neurotoxicity, mainly manifesting as neuropathic pain, which is one of the dominant reasons for limiting its utility. Experimentally, we discovered that VCR-induced neuropathic pain (VINP) was accompanied by astrocyte activation; the upregulation of phospho-CaMKII (p-CaMKII), CaV3.2, and Connexin-43 (Cx43) expression; and the production and release of inflammatory cytokines and chemokines in the spinal cord. Similar situations were also observed in astrocyte cultures. Interestingly, these alterations were all reversed by intrathecal injection of KN-93 (a CaMKII inhibitor) or L-Ascorbic acid (a CaV3.2 inhibitor). In addition, KN-93 and L-Ascorbic acid inhibited the increase in [Ca2+]i associated with astrocyte activation. We also verified that knocking down or inhibiting Cx43 level via intrathecal injection of Cx43 siRNA or Gap27 (a Cx43 mimetic peptide) relieved pain hypersensitivity and reduced the release of inflammatory factors; however, they did not affect astrocyte activation or p-CaMKII and CaV3.2 expression. Besides, the overexpression of Cx43 through the transfection of the Cx43 plasmid did not affect p-CaMKII and CaV3.2 expressions in vitro. Therefore, CaMKII and CaV3.2 may activate astrocytes by increasing [Ca2+]i, thereby mediating Cx43-dependent inflammation in VINP. Moreover, we demonstrated that the CaMKII signalling pathway was involved in VCR-induced inflammation, apoptosis, and mitochondrial damage. Collectively, our findings show a novel mechanism by which CaMKII and CaV3.2 mediate Cx43-dependent inflammation by activating astrocytes in neuropathic pain induced by VCR.

Emerging Approaches for the Management of Chemotherapy-Induced Peripheral Neuropathy (CIPN): Therapeutic Potential of the C5a/C5aR Axis

Chemotherapy-induced peripheral neuropathy (CIPN) is the most common neurologic complication of chemotherapy, resulting in symptoms like pain, sensory loss, and numbness in the hands and feet that cause lots of uneasiness in patients with cancer. They often suffer from pain so severe that it interrupts the treatment, thus invalidating the entire chemotherapy-based healing process, and significantly reducing their quality of life. In this paper, we underline the role of the complement system in CIPN, highlighting the relevance of the C5a fragment and its receptor C5aR1, whose activation is thought to be involved in triggering a cascade of events that can lead to CIPN onset. Recent experimental data showed the ability of docetaxel and paclitaxel to specifically bind and activate C5aR1, thus shining light on one of the molecular mechanisms by which taxanes may activate a cascade of events leading to neuropathy. According to these new evidence, it was possible to suggest new mechanisms underlying the pathophysiology of CIPN. Hence, the C5a/C5aR1 axis may represent a new target for CIPN treatment, and the use of C5aR1 inhibitors can be proposed as a potential new therapeutic option to manage this high unmet medical need.

Mechanistic involvement of inflammation in bortezomib induced peripheral neuropathy

AIM

To establish the role of inflammation in bortezomib induced peripheral neuropathy (BIPN).

BACKGROUND

Peripheral neuropathy is the dose-limiting toxicity of bortezomib which can lead to discontinuation of the treatment. There are multiple mechanisms involved in the disposition of BIPN. However, the role of inflammatory mediators is still under investigation. The complete understanding of inflammatory markers in relation to BIPN can lead to the development of effective therapy for prophylaxis and treatment of peripheral neuropathy.

OBJECTIVE

Based on the available data, postulate the role of inflammatory mediators in the development of peripheral neuropathy due to bortezomib.

METHOD

The "Pubmed" and "Google Scholar" were used as the search engines with terms like "peripheral neuropathy", "bortezomib induced peripheral neuropathy" and "inflammation". Original research, case reports and review articles were considered.

RESULTS

Bortezomib use is associated with the development of peripheral neuropathy. This effect is due to the damage to Schwann cells and dorsal root ganglion neurons; mitochondrial damage; increased ion channel susceptibility; and higher infiltration of macrophages in the spinal cord. All these factors collectively increase the secretion of inflammatory mediators and lead to the development of neuropathic pain.

CONCLUSION

Targeting inflammatory mediators may be helpful in the treatment of bortezomib-induced peripheral neuropathy.

Chemotherapy-Induced Peripheral Neuropathy: Epidemiology, Pathomechanisms and Treatment

PURPOSE

This review provides an update on the current clinical, epidemiological and pathophysiological evidence alongside the diagnostic, prevention and treatment approach to chemotherapy-induced peripheral neuropathy (CIPN).

FINDINGS

The incidence of cancer and long-term survival after treatment is increasing. CIPN affects sensory, motor and autonomic nerves and is one of the most common adverse events caused by chemotherapeutic agents, which in severe cases leads to dose reduction or treatment cessation, with increased mortality. The primary classes of chemotherapeutic agents associated with CIPN are platinum-based drugs, taxanes, vinca alkaloids, bortezomib and thalidomide. Platinum agents are the most neurotoxic, with oxaliplatin causing the highest prevalence of CIPN. CIPN can progress from acute to chronic, may deteriorate even after treatment cessation (a phenomenon known as coasting) or only partially attenuate. Different chemotherapeutic agents share both similarities and key differences in pathophysiology and clinical presentation. The diagnosis of CIPN relies heavily on identifying symptoms, with limited objective diagnostic approaches targeting the class of affected nerve fibres. Studies have consistently failed to identify at-risk cohorts, and there are no proven strategies or interventions to prevent or limit the development of CIPN. Furthermore, multiple treatments developed to relieve symptoms and to modify the underlying disease in CIPN have failed.

IMPLICATIONS

The increasing prevalence of CIPN demands an objective approach to identify at-risk patients in order to prevent or limit progression and effectively alleviate the symptoms associated with CIPN. An evidence base for novel targets and both pharmacological and non-pharmacological treatments is beginning to emerge and has been recognised recently in publications by the American Society of Clinical Oncology and analgesic trial design expert groups such as ACTTION.

Clinical significance of SIRT3 and inflammatory factors in multiple myeloma patients with bortezomib-induced peripheral neuropathy: a cohort study

The present study aimed to investigate the role of SIRT3 and inflammatory factors in bortezomib-induced peripheral neuropathy (PN). This prospective observational cohort study included a total of 159 patients of multiple myeloma patients during June 2016 to June 2019. All patients received the strategy of bortezomib and dexamethasone and were further divided into the PN group and the non-PN group. Serum SIRT3, CRP, IL-6 and TNF-α levels were measured by enzyme-linked immunosorbent assay (ELISA). During the study period, 76 (47.8%) patients developed PN. The inflammatory factors all gradually decreased and SIRT3 levels were gradually increased after treatment by bortezomib combined with dexamethasone compared with the baseline. The levels of all inflammatory factors were markedly higher, while SIRT3 levels were lower in PN patients compared with the non-PN patients at the same time point after treatment. In PN grade III patients, the serum levels of CRP, IL-6 and TNF-α were significantly higher, while serum levels of SIRT3 were markedly lower than the grade I-II patients. SIRT3 was negatively correlated with CRP, IL-6 and TNF-α. After nursing treatment and reduction of bortezomib dose, the levels of SIRT3 significantly increased, while levels of inflammatory decreased in PN patients with grade III. SIRT3 and inflammatory factors showed the potential for diagnosis of bortezomib-induced PN. Besides, SIRT3, IL-6 and TNF-α were the independent risk factors for MM patients developing PN after treatment of bortezomib. Higher inflammatory factors and lower SIRT3 might be associated with the development of bortezomib-induced PN in multiple myeloma patients, which might be reversed by decreased bortezomib dose and proper nursing treatment.

Effects of Fatty Acids on Hematological Neoplasms: A Mini Review

Hematological neoplasias are the fourth cause of death in the world. All of them are responsible of bad quality of life, due to heavy therapies administration and a lot of side effects correlated to. It arises a new concept of "multitherapy", in which fatty acids availment is used to contrast and reduce toxic effects and ameliorate chemotherapeutic agents asset. In Vitro studies have confirmed that fatty acids, in particular ω-3 eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are able to help canonical therapies to contrast cancer cell expansion and proliferation. In clinical trials it is also almost clear that fatty acids are useful to build new personalized therapies for a better condition of life. In this review we have summarized most recent studies on cancer cell lines and clinical trials on patients with fatty acids supplementation in diet therapies. We have found that fatty acids could be useful to contrast side effects during chemotherapeutic drugs therapies; they are also able to block cancer cell metabolic pathways for proliferation and contrast adverse effects, even when they are used in combination with traditional therapies or innovative, like monoclonal antibodies or CAR-T therapy. These aspects are crucial for better health condition of patients.

N-3 Long-Chain Polyunsaturated Fatty Acids, Eicosapentaenoic and Docosahexaenoic Acid, and the Role of Supplementation during Cancer Treatment: A Scoping Review of Current Clinical Evidence

Simple Summary

There has been extensive research into the beneficial anticancer effects of n-3 long-chain polyunsaturated fatty acids (LCPUFA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in preclinical models of cancer. However, clinical evidence is limited. The aim of this scoping review was to summarize the current clinical evidence of n-3 LCPUFA supplementation in cancer treatment and highlight areas where more clinical evidence is needed. We summarized the results of 57 clinical trials with an EPA/DHA intervention and determined that supplementation could improve a variety of outcomes important to the patient and the disease process, including immune system modulation, improved weight maintenance and increased disease-free or progression-free survival. There is, however, a need for larger, well-controlled, statistically powered randomized controlled trials to move n-3 supplementation to clinical practice.

Abstract

This scoping review examines the evidence for n-3 long-chain polyunsaturated fatty acid [LCPUFA, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)] supplementation in clinical cancer therapy. A comprehensive literature search was performed to identify relevant clinical intervention studies conducted through August 2020. Fifty-seven unique cancer trials, assessing EPA and/or DHA supplementation pre- or post-treatment, concomitant with neoadjuvant chemotherapy, radiation or surgery, or in palliative therapy were included. Breast, head and neck, gastrointestinal, gastric, colorectal/rectal, esophageal, leukemia/lymphoma, lung, multiple myeloma and pancreatic cancers were investigated. Across the spectrum of cancers, the evidence suggests that supplementation increased or maintained body weight, increased progression-free and overall survival, improved overall quality of life, resulted in beneficial change in immune parameters and decreased serious adverse events. Taken together, the data support that EPA and/or DHA could be used to improve outcomes important to the patient and disease process. However, before incorporation into treatment can occur, there is a need for randomized clinical trials to determine the dose and type of n-3 LCPUFA intervention required, and expansion of outcomes assessed and improved reporting of outcomes.

Prevention of oxaliplatin-related neurotoxicity by ω-3 PUFAs: A double-blind randomized study of patients receiving oxaliplatin combined with capecitabine for colon cancer

BACKGROUND

Peripheral neurotoxicity (PN) is a frequent side effect of oxaliplatin treatment, and also is its dose-limiting toxicity. Studies have confirmed that ω-3 polyunsaturated fatty acids (ω-3 PUFAs) had a neuroprotective effect. However, the efficacy of ω-3 PUFAs on the prevention of oxaliplatin-related neurotoxicity remains unclear. We assessed the effect of ω-3 PUFAs on the neurotoxicity in colon cancer patients treated by oxaliplatin combined with capecitabine.

METHODS

In a randomized, double-blind, placebo-controlled study, 179 patients with colon cancer receiving oxaliplatin combined with capecitabine were recruited, and randomly assigned to take ω-3 PUFAs, 640 mg t.i.d during chemotherapy and 1 month after the end of the treatment or placebo. All patients were treated with chemotherapy for 6 treatment cycles. The incidence and severity of PN were evaluated, and the nerve conduction was measured before the onset of chemotherapy and 1 month after treatment. In addition, the quality of life was also accessed using Chinese version of European organization for research and treatment of cancer quality of life questionnaire.

RESULTS

The incidence of PN in the ω-3 PUFAs group and placebo group was 52.22% and 69.66%, respectively (P = .017). In addition, there was a significant difference in the severity of PN between the 2 groups (P = .017). In terms of motor and sensory nerve conduction, the sensory action potentials amplitude of sural nerve in the ω-3 PUFAs group and placebo group after chemotherapy treatment were (15.01 ± 3.14) and (13.00 ± 3.63) μ V respectively, suggesting there was a significant difference in the 2 groups (P = .000). In addition, the mean score of the global health-status/quality of life was obviously higher in the ω-3 PUFAs group than that in the placebo group.

CONCLUSION

ω-3 PUFAs seem to reduce the incidence and severity of oxaliplatin-related neurotoxicity, and improve the quality of patients' life, indicating it is expected to be a potential drug for the treatment of oxaliplatin-related neurotoxicity.

Exosomal circRNA as a novel potential therapeutic target for multiple myeloma-related peripheral neuropathy

Peripheral neuropathy (PN) is an incurable complication of multiple myeloma (MM) which adversely affects patients' quality of life. The important roles that Circular RNAs (circRNAs) play in tumor progression, and exosome-mediated intracellular communication has been recognized as a crucial factor in the pathogenesis of MM. However, the role of exosome-derived circRNAs (exo-circRNAs) in MM and MM-induced PN remains elusive. In this study, we aimed to investigate the correlation between serum exo-circRNAs and MM to preliminarily explore the role of exo-circRNAs in MM-related PN. A cohort of 25 MM patients and 5 healthy control (HC) individuals were enrolled in the study. High-throughput sequencing and qRT PCR validation of serum exo-circRNAs were used to generate the aberrantly expressed exo-circRNAs profiles. Bioinformatics analysis was done using GO, KEGG, miRanda, Targetscan and Metascape. Correlation analysis was conducted between chr2:2744228-2,744,407+ and clinical characteristics of PN. ROC curve, univariate and multivariate COX regression models were conducted to identify the prognostic potential of chr2:2744228-2,744,407+ in the MM-related PN. 265 upregulated circRNAs and 787 downregulated circRNAs, with at least a two-fold difference in expression level in MM patients vs HC, were screened. Bioinformatics analysis indicated that upregulated circRNAs had the potential to facilitate MM-related PN. Furthermore, PCR validated the abundant expression of chr2:2744228-2,744,407+ in the serum exosomes of 25 MM patients. Bioinformatics analysis indicated that chr2:2744228-2,744,407+ might induce MM related PN via the downstream miRNA and GRIN2B axis. Overexpressed chr2:2744228-2,744,407+ in the serum exosomes of MM patients might lead to the downregulation of hsa-miR-6829-3p, elevation of GRIN2B in the serum and PC12 cells, and inhibited cell viability. The correlation analysis indicated that the expression of chr 2:2744228-2,744,407+ was positively correlated with the clinical characteristics of PN. ROC curve, univariate and multivariate COX regression analysis identified that chr2:2744228-2,744,407+ is an independent prognostic factor in the MM related PN. We identified that the abnormal expression of the serum exo-circRNA was correlated with MM-related PN, implying that exo-circRNA has potential as a novel therapeutic target for MM related PN.

The effect of rat nerve growth factor combined with vitamin B on peripheral neuropathy in multiple myeloma patients

Background: Peripheral neuropathy can induce marked disability and negative effects on quality of life and is the most common therapy-related complication in multiple myeloma patients treated with bortezomib. Currently, there is no useful method to prevent or treat it. So, it is necessary to study the clinical efficacy of rat nerve growth factor combined with vitamin B for the treatment of peripheral neuropathy in multiple myeloma patients. Methods: Sixty multiple myeloma patients who developed peripheral neuropathy after bortezomib-based chemotherapy in Jiaxing First Hospital from October 2015 to May 2018 were randomly divided into treatment and control groups. Changes in serum NGF level and electromyograms before and after treatment were analyzed, and the effects were evaluated via a FACT/GOG-Ntx questionnaire score. Results: After treatment, the NGF level in the treatment group (13.2 ± 3.73 pg/ml) was higher than that in the control group (9.22 ± 2.93 pg/ml, P < 0.05). Improvements in the electromyograms were more pronounced in treatment group than those in the control group, with statistical significance. The FACT/GOG-Ntx questionnaire scores, both in the treatment group and the control group, were decreased (4.00 ± 1.58 vs. 5.20 ± 2.33; P < 0.05), and the alleviation of the symptoms in the treatment group were more obvious. Conclusion: Rat nerve growth factor combined with vitamin B is a safe and effective method for treating peripheral neuropathy in multiple myeloma patients.

Non-Hematologic Toxicity of Bortezomib in Multiple Myeloma: The Neuromuscular and Cardiovascular Adverse Effects

Simple Summary

Multiple myeloma (MM) is a still uncurable tumor of mainly elderly patients originating from the terminally differentiated B cells. Introduction to the treatment of MM patients of a new class of drugs called proteasome inhibitors (bortezomib followed by carfilzomib and ixazomib) significantly improved disease control. Proteasome inhibitors interfere with the major mechanism of protein degradation in a cell leading to the severe imbalance in the protein turnover that is deadly to MM cells. Currently, these drugs are the mainstream of MM therapy but are also associated with an increased rate of the injuries to multiple organs and tissues. In this review, we summarize the current knowledge on the molecular mechanisms of the first-in-class proteasome inhibitor bortezomib-induced disturbances in the function of peripheral nerves and cardiac and skeletal muscle.

Abstract

The overall approach to the treatment of multiple myeloma (MM) has undergone several changes during the past decade. and proteasome inhibitors (PIs) including bortezomib, carfilzomib, and ixazomib have considerably improved the outcomes in affected patients. The first-in-class selective PI bortezomib has been initially approved for the refractory forms of the disease but has now become, in combination with other drugs, the backbone of the frontline therapy for newly diagnosed MM patients, as well as in the maintenance therapy and relapsed/refractory setting. Despite being among the most widely used and highly effective agents for MM, bortezomib can induce adverse events that potentially lead to early discontinuation of the therapy with negative effects on the quality of life and outcome of the patients. Although peripheral neuropathy and myelosuppression have been recognized as the most relevant bortezomib-related adverse effects, cardiac and skeletal muscle toxicities are relatively common in MM treated patients, but they have received much less attention. Here we review the neuromuscular and cardiovascular side effects of bortezomib. focusing on the molecular mechanisms underlying its toxicity. We also discuss our preliminary data on the effects of bortezomib on skeletal muscle tissue in mice receiving the drug.

Alpha-lipoic acid alters the antitumor effect of bortezomib in melanoma cells in vitro

Bortezomib (BOZ) is a proteasome inhibitor chemotherapeutic agent utilized to treat multiple myeloma and recently offered to cure melanoma. Bortezomib-induced neuropathy is one of the dose-limiting side-effects, which can be treated with antioxidants (e.g. alpha-lipoic acid-ALA and Vitamin B1-vit B1). We hypothesized that these antioxidants may counteract the antitumor activity by disrupting the BOZ-induced pathways (e.g. proteasome inhibition or reactive oxygen species generation). The objectives were: (i) to verify the anti-proliferative effect of BOZ; (ii) to compare the influence of the antioxidants on the antitumor effect of BOZ in melanoma (A2058) and myeloma (U266) cells. At first, the reduction in the anti-proliferative effect of BOZ by ALA was proved in melanoma cells. Analysis of p53 phosphorylation and the cell cycle progression revealed that ALA failed to counteract these effects of BOZ. Nevertheless, a good correlation was found between the inhibition of the anti-proliferative effect, the anti-proteasome activity and the oxidative stress level after the co-treatment with 20 ng/mL BOZ + 100 μg/mL ALA. Downregulation of apoptotic proteins such as HO-1 and Claspin along with the inhibition of the cleavage of Caspase-3 indicated the proteomic background of the altered responsiveness of the melanoma cells exposed to BOZ + ALA. This phenomenon draws attention to the proper application of cancer supportive care to avoid possible interactions.

The Actions and Mechanisms of P2X7R and p38 MAPK Activation in Mediating Bortezomib-Induced Neuropathic Pain

The proteasome inhibitor bortezomib (BTZ) is a potent first-line anticancer drug for multiple myeloma; nonetheless, it induced peripheral neuropathy. It has been suggested that many cytokines may play a role in mediating neuropathic pain, but the underlying molecular mechanism is not fully understood. Recent studies have shown that neuropathic pain is closely related to the purinergic ligand-gated ion channel 7 receptor (P2X7R), one of the P2X receptors, which is richly expressed in glial cells. P2X7-p38 pathway is correlated with microglia- and satellite glial cell- (SGC-) mediated neuropathic pain. However, the association of P2X7R and p38MAPK in mediating BTZ-induced neuropathic pain remains unclear. In this study, the relationship between P2X7R activation and p38 phosphorylation in the dorsal root ganglion (DRG) and spinal dorsal horn (SDH) in the development and maintenance of BTZ-induced neuropathic pain was elucidated. The results showed that BTZ increased mechanical thresholds in rats, accompanied with upregulation of P2X7R expression and p38MAPK phosphorylation, indicating that P2X7R and p38MAPK are key molecules in the development and maintenance of BTZ-induced neuropathic pain. Inhibiting p38MAPK phosphorylation with SB203580 resulted in downregulation of P2X7R expression levels. Inhibition of P2X7R with Brilliant Blue G (BBG) reversed neuropathic pain might decrease through the expression of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and IL-6 via inhibiting p38MAPK phosphorylation. The P2X7R/p38MAPK signaling pathway in SGCs of DRG and microglia of SDH might be a potential pharmacological target behind this mechanism as an opportunity to relieve BTZ-induced neuropathic pain.

Bortezomib and other proteosome inhibitors-induced peripheral neurotoxicity: From pathogenesis to treatment

Proteasome inhibitors (PIs), especially bortezomib (BTZ), have come to the forefront over the last years because of their unprecedented efficacy mainly against multiple myeloma (MM). Unfortunately, peripheral neuropathy (PN) secondary to treatment of MM with PIs has emerged as a clinically relevant complication, which negatively impacts the quality of life of MM survivors. Bortezomib-induced peripheral neuropathy (BIPN) is a dose-limiting toxicity, which develops in 30% to 60% of patients during treatment. Typically, BIPN is a length-dependent sensory axonopathy characterized by numbness, tingling, and severe neuropathic pain in stocking and glove distribution. BIPN mechanisms have not yet been fully elucidated. Experimental studies suggest that aggresome formation, endoplasmic reticulum stress, myotoxicity, microtubule stabilization, inflammatory response, and DNA damage could contribute to this neurotoxicity. A new generation of structurally distinct PIs has been developed, being increasingly used in clinical settings. Carfilzomib exhibits a much lower neurotoxicity profile, with a significantly lower incidence of PN compared to BTZ. Pre-existing PN increases the risk of developing BIPN. Besides, BIPN is related to dose, schedule and mode of administration and modifications of these factors have lowered the incidence of PN. However, to date there is no cure for PIs-induced PN (PIIPN), and a careful neurological monitoring and dose adjustment is a key strategy for preserving quality of life. This review critically looks at the pathogenesis, incidence, risk factors, both clinical and pharmacogenetics, clinical phenotype and management of PIIPN. We also make recommendations for further elucidating the whole clinical spectrum of PIIPN.

Role of Pregabalin in Treatment of Polyneuropathy in Multiple Myeloma Patients: A Retrospective Study

OBJECTIVES

Polyneuropathy (PN) is a frequent and significant clinical manifestation of multiple myeloma that may be observed at onset of disease or induced during treatment as a therapy-related complication. Polyneuropathy may be a relevant issue in myeloma patients owing to its significant impact on the quality of life, considering that it may lead to dose reduction or treatment discontinuation. The present retrospective study intended to evaluate efficacy of pregabalin (PGB) in treatment of PN in multiple myeloma patients.

MATERIALS AND METHODS

Medical charts of 108 consecutive PN myeloma patients were reviewed. Data regarding the tumor history and therapy as well as the clinical and neurophysiological examinations 6 months before and after initiation of PGB therapy were collected.

RESULTS

Thirty-eight medical charts had all the requested information. All patients (n = 38) underwent bortezomib-based treatment; 19 were previously treated and 19 were treatment naive. At first neurologic visit, all patients had PN symptoms (grade 2 of National Cancer Institute-Common Toxicity Criteria) without relevant pain. Neurophysiological evaluation showed a significant decrease in sensory nerve action potential amplitude (P = 0.006), conduction velocity (P = 0.006), and distal latency (P = 0.03) of sensory nerves between the first and the last neurological examination, in all patient population. Similar results were observed in treatment-naive patients, when the study cohort was stratified according to previous treatment. On the contrary, no significant differences were found between the first and the last neurophysiological follow-up evaluation in previously treated patients. Six months after PGB treatment, all patients reported disappearance of neurological symptoms (grade 0 National Cancer Institute-Common Toxicity Criteria).

CONCLUSIONS

In this retrospective study, improvement in neurological symptoms during PGB therapy was observed in the total population, despite the presence of a distal, sensory axonal neuropathy, as evidenced by neurophysiological examination.

Recent advances in understanding chemotherapy-induced peripheral neuropathy

Chemotherapy-induced peripheral neuropathy (CIPN) is a common cause of pain and poor quality of life for those undergoing treatment for cancer and those surviving cancer. Many advances have been made in the pre-clinical science; despite this, these findings have not been translated into novel preventative measures and treatments for CIPN. This review aims to give an update on the pre-clinical science, preventative measures, assessment and treatment of CIPN.

The Effect of Docosahexaenoic Acid and α-Lipoic Acid as Prevention of Bortezomib-Related Neurotoxicity in Patients With Multiple Myeloma

Background and Aims: In cancer patients, a common complication during chemotherapy is chemotherapy-induced peripheral neuropathy (CIPN). For this reason, we decided to conduct a phase II prospective study on 33 patients with multiple myeloma at first diagnosis, to evaluate whether a nutraceutical compound given for 6 months during bortezomib (BTZ) treatment succeeded in preventing the onset of neurotoxicity. Methods: Neurological evaluation, electroneurography, and functional and quality of life (QoL) scales were performed at baseline and after 6 months. We administered a tablet containing docosahexaenoic acid 400 mg, α-lipoic acid 600 mg, vitamin C 60 mg, and vitamin E 10 mg bid for 6 months. Results: Concerning the 25 patients who completed the study, at 6-month follow-up, 10 patients had no neurotoxicity (NCI-CTCAE [National Cancer Institute-Common Terminology Criteria for Adverse Events] = 0), while 13 progressed to NCI-CTCAE grade 1, 1 had NCI-CTCAE grade 1 with pain, and 1 experienced a NCI-CTCAE grade 2. Painful symptoms were reported only in 2 patients, and we observed stability on functional and QoL scales in all patients. None of the 25 patients stopped chemotherapy due to neurotoxicity. Conclusions: Our data seem to indicate that the co-administration of a neuroprotective agent during BTZ treatment can prevent the appearance/worsening of symptoms related to CIPN, avoiding the interruption of BTZ and maintaining valuable functional autonomy to allow normal daily activities. We believe that prevention remains the mainstay to preserve QoL in this particular patient population, and that future studies with a larger patient population are needed.

Protective Effects of Omega-3 Fatty Acids in Cancer-Related Complications

Omega-3 polyunsaturated fatty acids (PUFAs) are considered immunonutrients and are commonly used in the nutritional therapy of cancer patients due to their ample biological effects. Omega-3 PUFAs play essential roles in cell signaling and in the cell structure and fluidity of membranes. They participate in the resolution of inflammation and have anti-inflammatory and antinociceptive effects. Additionally, they can act as agonists of G protein-coupled receptors, namely, GPR40/FFA1 and GPR120/FFA4. Cancer patients undergo complications, such as anorexia-cachexia syndrome, pain, depression, and paraneoplastic syndromes. Interestingly, the 2017 European Society for Clinical Nutrition and Metabolism (ESPEN) guidelines for cancer patients only discuss the use of omega-3 PUFAs for cancer-cachexia treatment, leaving aside other cancer-related complications that could potentially be managed by omega-3 PUFA supplementation. This critical review aimed to discuss the effects and the possible underlying mechanisms of omega-3 PUFA supplementation in cancer-related complications. Data compilation in this critical review indicates that further investigation is still required to assess the factual benefits of omega-3 PUFA supplementation in cancer-associated illnesses. Nevertheless, preclinical evidence reveals that omega-3 PUFAs and their metabolites might modulate pivotal pathways underlying complications secondary to cancer, indicating that this is a promising field of knowledge to be explored.