Chemotherapy-induced peripheral neuropathy: where are we now?

Effects of acupuncture-related intervention on chemotherapy-induced peripheral neuropathy and quality of life: An umbrella review

BACKGROUND

Numerous studies have explored the role of acupuncture-related treatments in alleviating chemotherapy-induced peripheral neuropathy (CIPN) and improving the quality of life for patients with cancer, resulting in mixed findings. This umbrella review aimed to synthesize existing systematic reviews (SRs) to deliver an updated assessment of the certainty of evidence concerning the effects of acupuncture-related treatments on CIPN and quality of life among a diverse group of patients with cancer.

METHODS

This umbrella review considered eligible SRs published on one of nine electronic databases between inception and August 2024. It included adult patients with cancer of any stage who were undergoing chemotherapy. Interventions encompassed acupuncture, either alone or with electrical stimulation or moxibustion, and transcutaneous electrical acupoint/nerve stimulation (TEAS). The outcomes analyzed were changes in CIPN, nerve conduction velocity (NCV), and quality of life.

RESULTS

The outcomes were evaluated using data obtained from 14 SRs that demonstrated moderate to high methodological and reporting quality. The findings showed that acupuncture (either alone or combined with electrical stimulation) and TEAS effectively alleviated CIPN symptoms, reduced CIPN pain, improved NCV, and enhanced quality of life.

CONCLUSION

The findings of this umbrella review indicate that these benefits were usually noticeable by the second week of treatment, persisted until the sixth week, and then gradually declined. Sensory nerve recovery occurred more rapidly than motor nerve recovery, often within 1.5 weeks. Although acupuncture combined with moxibustion or acupressure also enhanced patient outcomes, there was insufficient information available for further study analysis.

Diosmetin Attenuates Painful Symptoms Caused by Antineoplastics Paclitaxel and Anastrozole in Mice

Cancer patients often experience painful symptoms as an adverse effect resulting from various factors, including antineoplastic therapy. Paclitaxel is a chemotherapeutic agent used to treat solid tumours and, unfortunately, causes acute and chronic peripheral neuropathic pain in patients. Anastrozole is an antineoplastic used to treat hormone receptor-positive breast cancer and causes musculoskeletal pain symptoms. The therapies used to control these pain symptoms have limited efficacy and cause adverse effects, highlighting the importance of finding new treatments. Diosmetin is a flavonoid that has shown efficacy in neuropathic, nociplastic, and inflammatory pain models. Therefore, we verified the antinociceptive effects of diosmetin on nociceptive parameters induced by paclitaxel and anastrozole. We investigated the effects of diosmetin (0.015, 0.15 and 1.5 mg/kg; oral route (p.o.)) on nociceptive parameters (mechanical and cold allodynia and pain affective‑motivational behaviour) induced by a single and repeated paclitaxel (1 mg/kg, intraperitoneal (i.p.)) administrations, as well as on the pain-like symptoms (mechanical allodynia, muscle strength, and pain affective‑motivational behaviour) of a single administration of anastrozole (0.2 mg/kg, p.o.) and the combination of both antineoplastics in mice. Diosmetin reduced the nociceptive parameters induced by paclitaxel and anastrozole. In addition, we observed that anastrozole exacerbated the mechanical allodynia induced by paclitaxel, an effect that was also reversed by diosmetin. These results suggest that diosmetin may be an effective therapeutic alternative for the treatment of painful symptoms caused by antineoplastic drugs, such as paclitaxel and anastrozole.

Influence of statin intervention on peripheral neuropathy in patients treated with anticancer drugs identified from the insurer database

BACKGROUND

Statins, hydroxymethylglutaryl-CoA reductase inhibitors, possess neuroprotective properties. Given the potential neuroprotective properties of statins and their prevalent use in clinical settings, we aimed to investigate their impact on chemotherapy-induced peripheral neuropathy (CIPN) in Japan by assessing both their safety and efficacy in this context.

METHODS

We conducted a retrospective observational study using the Japan Medical Data Centre database, which includes data from 2005 to 2021. We included patients who underwent anticancer therapy and were categorized into non-statin (10,920) and statin (1,537) groups. These groups were matched using a propensity score, resulting in 2,548 non-statin and 1,274 statin users. The primary endpoints were the incidence of CIPN post-first prescription of each anticancer drug and overall survival.

RESULTS

Treatment with statins did not increase the incidence of CIPN (non-statin 27.2% vs. statin 28.4%, P = 0.443). Nevertheless, the incidence of CIPN was significantly high among women (non-statin 28.0% vs. statin 33.2%, P = 0.025). Overall survival was not impacted by statin use (hazard ratio 0.98, 95%CI: 0.83-1.16, P = 0.8846). Among men treated with paclitaxel, we observed an improvement in overall survival (hazard ratio: 0.72; 95% CI: 0.56-0.92; P = 0.0110).

CONCLUSIONS

The use of statins in patients with cancer was not associated with CIPN incidence. However, in men receiving paclitaxel treatment, statins may be linked to improved overall survival. Further studies are necessary to clarify the factors influencing prognosis and CIPN severity.

Contribution of S1pr1 -featured astrocyte subpopulation to cisplatin-induced neuropathic pain

Chemotherapy-induced peripheral neuropathy accompanied by neuropathic pain (CIPN) is a major neurotoxicity of cisplatin, a platinum-based drug widely used for lung, ovarian, and testicular cancer treatment. CIPN causes drug discontinuation and severely impacts life quality with no FDA-approved interventions. We previously reported that platinum-based drugs increase levels of sphingosine 1-phosphate (S1P) in the spinal cord and drive CIPN through activating the S1P receptor subtype 1 (S1PR1). However, the mechanisms engaged downstream of S1PR1 remain poorly understood. Using single cell transcriptomics on male mouse spinal cord, our findings uncovered subpopulation-specific responses to cisplatin associated with CIPN. Particularly, cisplatin increased the proportion of astrocytes with high expression levels of S1pr1 ( S1pr1 high astrocytes), specific to which a Wnt signaling pathway was identified. To this end, several genes involved in Wnt signaling, such as the fibroblast growth factor receptor 3 gene ( Fgfr3 ), were highly expressed in S1pr1 high astrocytes. The functional S1PR1 antagonist, ozanimod, prevented cisplatin-induced neuropathic pain and astrocytic upregulation of the Wnt signaling pathway genes. FGFR3 belongs to the FGF/FGFR family which often signals to activate Wnt signaling. Intrathecal injection of the FGFR3 antagonist, PD173074, prevented the development of CIPN in male mice. These data not only highlight FGFR3 as one of the astrocytic targets of S1PR1 but raise the possibility that S1PR1-induced engagement of Wnt signaling in S1pr1 high astrocytes may contribute to CIPN. Overall, our results provide a comprehensive mapping of cellular and molecular changes engaged in cisplatin-induced neuropathic pain and decipher novel S1PR1-based mechanisms of action.

Sculpting excitable membranes: voltage-gated ion channel delivery and distribution

The polarized and domain-specific distribution of membrane ion channels is essential for neuronal homeostasis, but delivery of these proteins to distal neuronal compartments (such as the axonal ends of peripheral sensory neurons) presents a logistical challenge. Recent developments have enabled the real-time imaging of single protein trafficking and the investigation of the life cycle of ion channels across neuronal compartments. These studies have revealed a highly regulated process involving post-translational modifications, vesicular sorting, motor protein-driven transport and targeted membrane insertion. Emerging evidence suggests that neuronal activity and disease states can dynamically modulate ion channel localization, directly influencing excitability. This Review synthesizes current knowledge on the spatiotemporal regulation of ion channel trafficking in both central and peripheral nervous system neurons. Understanding these processes not only advances our fundamental knowledge of neuronal excitability, but also reveals potential therapeutic targets for disorders involving aberrant ion channel distribution, such as chronic pain and neurodegenerative diseases.

The Effect of Topical Capsaicin 8% on Pain in Chemotherapy-induced Peripheral Neuropathy

BACKGROUND

Chemotherapy-induced peripheral neuropathy (CIPN) can cause chemotherapy dose reductions and impact patients' quality of life. Few proven treatments exist, with generally modest analgesic effects and possible side effects. Small studies show the beneficial effects of topical capsaicin 8% on pain.

AIM

To investigate capsaicin's effects on pain, neurotoxicity, and mood in patients with CIPN.

DESIGN

Prospective data collection in patients treated with capsaicin 8% for painful CIPN.

METHODS

In 17 patients, data was collected before (t0) and directly (t1), 2 weeks (t2), and 8 weeks (t3) after capsaicin 8% treatment. Differences between t0-t2 and t0-3 were assessed for pain (Numeric Rating Scale [NRS]; acceptability), neurotoxicity symptoms (20-item questionnaire [CIPN20]; mechanical detection [MDT] and pain [MPT] thresholds), and mood (Hospital Anxiety and Depression Score [HADS]).

RESULTS

For 9 patients (53%), pain became "acceptable" at t2 and t3, with a significant reduction (pain intensity difference [PID]t0-2: -1.72, PIDt0-3: -2.47, both p < .001), whereas average NRS did not change significantly for patients scoring "unacceptable." HADS anxiety scores remained unchanged, whereas depression scores decreased from baseline (t0-2: -1.47, p = .014; t0-3: -1.36, p = .021). CIPN20 decreased from baseline (t0-2: -1.87, p = .004; t0-3: -3.32 p = .002). MPT was significantly lower post-treatment and MDT did not change.

CONCLUSIONS

Capsaicin 8% can have a beneficial analgesic effect in patients with CIPN-related pain but with a marked "on-off" effect. Mood changes were marginal. Quantitative sensory testing findings do not support earlier findings on nerve degeneration after capsaicin treatment, although the study size was small for definitive conclusions.

Role of Mitochondrial Dysfunction in Neuropathy

Diabetes mellitus is characterized by a state of hyperglycemia, which can lead to severe complications if left untreated or poorly managed. Diabetic peripheral neuropathy (DPN) is one common complication. This condition is characterized by damage to the nerves that supply the legs and feet as well as problems with blood vessels, the heart, or urinary tract. To alleviate pain for patients, clinicians resort to long-term treatment regimens of nerve pain medications, which are usually either anticonvulsants or antidepressants. However, little is understood about the underlying mechanisms of DPN. Many pathogenic pathways have been proposed, one of which is mitochondrial dysfunction. Mitochondrial dysfunction includes a range of possible deficiencies given the number of functions controlled by or located in mitochondria, including their core function of bioenergetics. This review focuses on mitochondrial bioenergetics, including respiration/ATP synthesis and reactive oxygen species (ROS) production, as well as calcium homeostasis and apoptosis, and their potential as targets for the effective treatment of diabetic peripheral neuropathy.

Perineural Electrical Dry Needling and Neural Mobilization for Chemotherapy-Induced Peripheral Neuropathy: Case Report

Background: Chemotherapy-induced peripheral neuropathy (CIPN) affects 20-85% of individuals exposed to neurotoxic chemotherapeutic agents. Perineural electrical dry needling (PEDN) and neural mobilization (NM) interventions may be beneficial in the management of chronic neurogenic pain; however, there is a paucity of research on the efficacy of both interventions for CIPN. Methods: Three patients were referred to an outpatient physical therapy clinic with chronic neuropathic pain associated with CIPN. Each underwent PEDN and NM twice weekly until goals were met or progress stalled. The primary outcome measure was the Numeric Pain Rating Scale (NPRS). Secondary outcomes included the Global Rating of Change (GROC) and the Lower Extremity Functional Scale (LEFS). All outcome measures were assessed at evaluation and discharge. Results: At discharge, patients A and B exceeded the minimum clinically important difference (MCID) for the primary and secondary outcome measures, indicating decreased neuropathic pain and improved lower extremity function. Patient C improved in all outcome measures but only experienced clinically meaningful changes in the NPRS and LEFS, not the GROC. Conclusions: Following 4-8 sessions of PEDN and NM, three patients with CIPN demonstrated clinically meaningful improvements in chronic lower extremity neuropathic pain and function. PEDN and NM may be beneficial in the management of patients presenting with chronic neuropathic pain secondary to CIPN.

Hyperalgesic Priming in the Transition From Acute to Chronic Pain: Focus on Different Models and the Molecular Mechanisms Involved

Poorly treated acute pain can develop into chronic pain, resulting in significant impairment of patients' quality of life. The hyperalgesic priming model is commonly used to study how acute pain transforms into chronic pain. Inflammatory factors, small molecules, opioid receptor agonists, chemotherapy drugs, and stress serve as initiating factors in the hyperalgesic priming model. Various signaling pathways such as PKCε, MOR and ephrin-B2 pathways, and sexual differences also contribute to the transformation process of chronic pain. In this review, we examine various hyperalgesic priming models and their underlying molecular mechanisms. By thoroughly investigating these molecular mechanisms, researchers can more precisely identify the critical nodes involved in pain transformation, thereby developing more targeted treatment strategies.

Neurofilaments as Prognostic Biomarkers in the Assessment of the Risk of Advanced Taxane-Induced Neuropathy in Breast Cancer Patients-A Pilot Study

OBJECTIVES

The aim of the present study was to assess the clinical value of measuring the concentration of neurofilament light chains (NF-Ls) in the diagnosis of taxane-induced neuropathy (CIPN) during neoadjuvant chemotherapy (NAC) in breast cancer patients.

METHODS

This study included a total of 94 patients who qualified for NAC with taxanes. Serum samples were collected before starting NAC, after three and six cycles, and 3-6 months after NAC. The NF-L concentration was determined using the Ella technology. The assessment of CIPN was based on the clinical symptoms included in the EORTC QLQ-CIPN20 scores.

RESULTS

The median NF-L concentrations increased during NAT monitoring. After the end of therapy, a significant decrease in NF-L concentrations was observed (p = 0.001, R = 0.37). We established a cut-off point of 29.5 pg/mL to distinguish between the control group and patients with early symptoms of neuropathy (CIPN G1) (p = 0.001; AUC = 0.982). We showed that NF-L concentrations, regardless of the stage of therapy, increased with the severity of neuropathy symptoms (CIPG1 vs. G2 vs. G3) (p = 0.0189, R = 0.33). According to the established cut-off points, serum NF-L concentrations above 196 pg/mL in patients undergoing therapy likely indicate the presence of low-grade neuropathy (p = 0.0076), while values above 218 pg/mL may indicate advanced CIPN (p = 0.0008).

CONCLUSIONS

In this study, we demonstrated the usefulness of NF-L levels to confirm neuropathy early in the course of treatment, which is important as the questionnaire-based assessment of neuropathy currently used in practice remains subjective. Ultimately, serum NF-L levels are helpful in determining the severity of NAC-induced neuropathy among breast cancer patients.

Increased TRPA1 functionality in the skin of rats and cancer patients following oxaliplatin treatment

Chemotherapy-induced peripheral neuropathy is a debilitating pathology affecting a majority of patients who are being treated with specific cytostatic compounds including oxaliplatin. Various in vitro, ex vivo and in vivo preclinical experiments indicate that transient receptor potential ankyrin 1 (TRPA1) plays a crucial role in the symptomatology of chemotherapy-induced peripheral neuropathy. However, it is unclear whether oxaliplatin also modulates the TRPA1 functionality in the skin of rodents or patients. Here, we quantified the vasodilation after topical application of the TRPA1 agonist cinnamaldehyde in a rodent model of chemotherapy-induced peripheral neuropathy (male Sprague Dawley rats, aged 6 weeks) as well as on fingers of patients suffering from chronic chemotherapy-induced peripheral neuropathy after oxaliplatin treatment. Compared to vehicle-treated rats, a cumulative dose of oxaliplatin 32 mg/kg enhanced the vasodilation after cinnamaldehyde application on rat abdominal skin. Likewise, also in patients with chronic chemotherapy-induced peripheral neuropathy after oxaliplatin, the response to cinnamaldehyde was significantly higher compared to sex- and age-matched healthy controls. Thereby, this study is the first to translate the evidence of increased TRPA1 functionality in vitro or ex vivo in rodents to in vivo conditions in human. The increased TRPA1 functionality in patients with chronic chemotherapy-induced peripheral neuropathy does not only confirm the potential of TRPA1 as target to hit to provide efficacious analgesia, it also paves the way for additional patient stratification on a molecular level and possible treatment response prediction. PERSPECTIVE: The cinnamaldehyde-induced, TRPA1-mediated vasodilation was enhanced in patients with oxaliplatin-induced peripheral neuropathy versus healthy controls, confirming the potential of TRPA1 as target-to-hit for this indication.

Review of the Interactions Between Anesthetic Agents and Chemotherapeutic Agents in Cancer Cell Lines Studied In Vitro

Cancer remains the second leading cause of death worldwide, second to cardiovascular diseases. A significant number of patients with cancer require surgical interventions, highlighting the need to understand the interactions between popular agents used in general anesthesia and in chemotherapy, to provide safe anesthesia and effective anticancer treatment. Given that, for many clinicians, interactions between these 2 broad groups of drugs are not well known; therefore, this topic requires special attention. We have prepared this overview by presenting the actual findings in this field in order to introduce clinicians to this issue. The article considers commonly used drug groups in anesthesiology, such as intravenous and inhaled anesthetics, benzodiazepines, muscle relaxants, and opioids. Their interactions with commonly used antineoplastic drugs, described so far in the literature, are presented. These occurrences highlight the necessity of careful monitoring and control during perioperative care, to not interfere with chemotherapy targets and to prevent the severity of pharmacological adverse effects. To introduce these complex mechanisms, we prepared this article based on the most recent publications possible, considering the many studies carried out in vitro and in vivo, as well as clinical trials. This review was prepared on the basis of 73 articles published from 1989 to 2024, as well as on the authors' knowledge and clinical experience. This article aims to review the interaction between anesthetics and chemotherapeutic agents, based on clinical studies and studies conducted on in vitro cancer cell lines and in vivo animal models.

Pharmacological Treatment of Chemotherapy-Induced Neuropathy: A Systematic Review of Randomized Clinical Trials

PURPOSE

Chemotherapy-induced peripheral neuropathy (CIPN) affects up to 80% of patients undergoing cytotoxic chemotherapy. This painful condition significantly impairs quality of life and often necessitates dose reduction or discontinuation of chemotherapy, negatively impacting overall survival. Currently, duloxetine is the only pharmacological treatment recommended by the American Society of Clinical Oncology (ASCO). This systematic review aims to evaluate the efficacy of various pharmacological interventions in CIPN treatment, providing substantial evidence for clinical practice and future research.

DESIGN

This systematic review was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to assess the effectiveness of pharmacological treatments for CIPN.

METHODS

Only randomized controlled trials (RCTs) were included. Herbal and phytotherapeutic treatments were excluded. Two independent reviewers performed the study selection, with a third reviewer resolving disagreements. Risk of bias assessment was conducted using the COCHRANE's RoB 2 tool.

RESULTS

Out of 860 screened articles, 17 RCTs met the inclusion criteria, encompassing 15 different pharmacological agents. Duloxetine, pregabalin, and amitriptyline were the most studied. Thirteen studies utilized a placebo as a control. Investigated medications exhibited varied outcomes, with some showing significant benefits in reducing neuropathic pain while others did not demonstrate statistically significant efficacy.

CONCLUSION

Duloxetine is an effective and well-tolerated option, while pregabalin shows promising results but requires further investigation. Other agents, such as venlafaxine and tapentadol, lack strong supporting evidence. Treatments like acetyl-l-carnitine, monosialotetrahexo-sylganglioside 1, and tetrodoxine yield inconsistent results, highlighting the need for additional research. Larger RCTs are recommended for comprehensive evaluation. Nurses are essential in CIPN care by monitoring symptoms, educating patients, and collaborating with the team.

A novel model of paclitaxel-induced peripheral neuropathy produces a clinically relevant phenotype in mice

One of the most common adverse side effects of chemotherapeutics is chemotherapy-induced peripheral neuropathy (CIPN). Paclitaxel, a highly effective chemotherapeutic, is associated with a high incidence of paclitaxel-induced peripheral neuropathy (PIPN) that persists for over a year in 64% of patients and worsens with cumulative PTX dose. Patients experiencing PIPN may reduce the dosage of chemotherapy or halt treatment due to this pain. Current preclinical models have improved our understanding of PIPN but have been ineffective in generating translational therapeutic options. These models administer a single cycle of PTX to induce a PIPN phenotype of mechanical and cold hypersensitivity that resolves within 28 days. However, this does not mirror the clinical dosing regimen or the patient experience of CIPN. In this study, we conduct a comprehensive and longitudinal behavioral profile of our novel model of PIPN in mice where three consecutive cycles of PTX (4 mg/kg, 4 doses/cycle) are given to mimic the clinical administration. Repeated cycles of PTX caused long-lasting mechanical and cold hypersensitivity in male and female C57Bl/6J mice that mirrors clinical observations of persistent CIPN without causing detrimental effects to rodent overall health, normal rodent behavior, or motor function. Our findings support the use of this translational model to facilitate a better understanding of PIPN and the development of effective treatment options. Improved pain management will enable the completion of cancer treatment, decrease health care expenditure, decrease mortality, and improve the quality of life for cancer patients and survivors.

Microbiome contributions to pain: a review of the preclinical literature

ABSTRACT

Over the past 2 decades, the microbiome has received increasing attention for the role that it plays in health and disease. Historically, the gut microbiome was of particular interest to pain scientists studying nociplastic visceral pain conditions given the anatomical juxtaposition of these microorganisms and the neuroimmune networks that drive pain in such diseases. More recently, microbiomes both inside and across the surface of the body have been recognized for driving sensory symptoms in a broader set of diseases. Microbiomes have never been a more popular topic in pain research, but to date, there has not been a systematic review of the preclinical microbiome pain literature. In this article, we identified all animal studies in which both the microbiome was manipulated and pain behaviors were measured. Our analysis included 303 unique experiments across 97 articles. Microbiome manipulation methods and behavioral outcomes were recorded for each experiment so that field-wide trends could be quantified and reported. This review specifically details the animal species, injury models, behavior measures, and microbiome manipulations used in preclinical pain research. From this analysis, we were also able to conclude how manipulations of the microbiome alter pain thresholds in naïve animals and persistent pain intensity and duration in cutaneous and visceral pain models. This review summarizes by identifying existing gaps in the literature and providing recommendations for how to best plan, implement, and interpret data collected in preclinical microbiome pain experiments.

Neurotrophins in Peripheral Neuropathy: Exploring Pathophysiological Mechanisms and Emerging Therapeutic Opportunities

Neuropathies, which encompass a wide array of peripheral nervous system disorders, present significant challenges due to their varied causes, such as metabolic diseases, toxic exposures, and genetic mutations. This review article, focused on the critical role of neurotrophins in peripheral neuropathy, highlights the intricate balance of neurotrophins necessary for nerve health and the pathophysiological consequences when this balance is disturbed. Neurotrophins, including Nerve Growth Factor (NGF), Brain-Derived Neurotrophic Factor (BDNF), Neurotrophin-3 (NT- 3), and Neurotrophin-4 (NT-4), are essential for neuronal survival, axonal growth, and synaptic plasticity. Their signaling pathways are crucial for maintaining peripheral nervous system integrity, primarily via the Tropomyosin receptor kinase (Trk) receptors and the p75 neurotrophin receptor p75(NTR). Dysregulation of neurotrophins is implicated in various neuropathies, such as diabetic neuropathy and chemotherapy-induced peripheral neuropathy, leading to impaired nerve function and regeneration. Understanding neurotrophin signaling intricacies and their alterations in neuropathic conditions is crucial for identifying novel therapeutic targets. Recent advancements illuminate neurotrophins' potential as therapeutic agents, promising disease-modifying treatments by promoting neuronal survival, enhancing axonal regeneration, and improving functional recovery post-nerve injury. However, translating these molecular insights into effective clinical applications faces challenges, including delivery methods, target specificity, and the instability of protein- based therapies.

An emerging aspect of cancer neuroscience: A literature review on chemotherapy-induced peripheral neuropathy

The nervous system governs both ontogeny and oncology. Foundational discoveries have clarified the direct communication of neurotransmitters with tumors and indirect interactions through neural effects on the immune system and the tumor microenvironment. Meantime, the nervous system is susceptible to cancer and its treatment. Chemotherapy-induced peripheral neuropathy (CIPN) is the most common side effects that significantly reduce the efficacy of anti-cancer treatment and patients' quality of life by leading to dose reduction or early cessation of chemotherapy. However, there are no effective strategies to reverse or treat CIPN. A better understanding of the mechanisms is expected to enable the development of the next generation of therapies. Here, we summarize the recent important studies on clinical manifestations, risk factors, prediction, pathogenesis, prevention, and treatment of CIPN. We also provide perspectives and insights regarding the rationales of bidirectional interactions between cancer and the nervous system.

Topical menthol for chemotherapy-induced peripheral neuropathy: a randomised controlled trial in breast cancer

OBJECTIVES

Chemotherapy-induced peripheral neuropathy (CIPN) symptom is one of the side effects of paclitaxel in breast cancer patients. This randomised controlled study was conducted to investigate the effect of topical menthol applied on the hands and feet of breast cancer patients receiving chemotherapy on CIPN symptoms.

METHODS

60 breast cancer patients receiving chemotherapy were randomly assigned to an intervention group (n=30), which received topical menthol treatment, or a control group (n=30), which received standard care. Both groups continued their routine pharmacological treatments throughout the study. The intervention group applied 1% menthol topically to their hands and feet two times a day. The effect of the intervention on CIPN symptoms was evaluated 3 weeks and 6 weeks after the intervention.

RESULTS

The intervention group showed a significantly greater improvement in CIPN symptoms over time compared with the control group, with an effect size of η2=0.214 for the group×time interaction. Additionally, the intervention group exhibited a notable positive change in the exposure subscale of the CIPN rating scale, with an effect size of η2=0.114.

CONCLUSIONS

Topical application of menthol significantly mitigates the symptoms of CIPN in breast cancer patients. This study supports the use of menthol as an effective adjunctive treatment for CIPN.

TRIAL REGISTRATION NUMBER

NCT05429814.

α9-Containing Nicotinic Acetylcholine Receptors Are Required for RgIA-5474 Attenuation of Chemotherapy-Induced Neuropathic Pain

Nicotinic acetylcholine receptors containing the α9 subunit have been mechanistically implicated in alleviating chemotherapy-induced neuropathic pain. However, the cell types that underlie these effects are currently unknown. RgIA-5474 is a recently developed, synthetic α-conotoxin analog that is a potent antagonist of human α9α10 nAChRs. We used germline α9 subunit knockout mice, CD3+ T-cell depletion, and conditional knockdown of the α9 subunit in immune cells to examine the role of α9-containing nAChRs that mediate RgIA-5474 alleviation of oxaliplatin-induced neuropathic pain. RgIA-5474 potently and selectively blocked mouse α9α10 nAChRs. A one-time oxaliplatin injection resulted in cold allodynia that was reversed by RgIA-5474 administration in the wild type but not in α9 germline knockout mice. RgIA-5474 also failed to produce analgesia in CD3+ T-cell-depleted male and female animals. Conditional knockdown of the α9 subunit in immune cells of mice by the CreloxP system also eliminated the therapeutic effects of RgIA-5474 in both male and female mice. These results indicate that the α9 nAChR subunit is necessary for the analgesic effects of RgIA-5474 and implicate α9-containing nAChRs in immune cells as a nonopioid target for treating neuropathic pain.

Chemotherapy-induced peripheral neuropathy and its determinants among adult cancer patients on chemotherapy in northwest Ethiopia oncology centers, 2022

Introduction

Peripheral neuropathy is a nerve disorder that causes pain, numbness, and tingling in different parts of the body. It is a major and common clinical problem associated with several chemotherapeutic medications frequently used in cancer treatment, with prevalence rates ranging from 19% to 85%. To the best of the authors' knowledge, there is a lack of data on the magnitude and determinants of chemotherapy-induced peripheral neuropathy in Ethiopia.

Objective

This study aimed to assess the magnitude and associated factors of chemotherapy-induced peripheral neuropathy among adult cancer patients undergoing chemotherapy in northwest Ethiopia oncology centers in 2022.

Method

An institutional-based cross-sectional study was conducted on 406 eligible adult cancer patients undergoing chemotherapy in northwest Ethiopia oncology centers, between May and July 2022.

Results

Out of 406 adult cancer patients included in the study, 54.4% had peripheral neuropathy. The stage of cancer (AOR = 4.36 [95% CI: 1.76; 10.8]), comorbidity (AOR = 2.74 [95% CI: 1.28; 5.83]), drug regimen (AOR = 2.99 [95% CI: 1.36; 6.54]), and cycle of therapy (AOR = 4.00 [CI: 1.67; 9.65]) were significantly associated with the magnitude of chemotherapy-induced peripheral neuropathy.

Conclusion

Chemotherapy-induced peripheral neuropathy is a common adverse event among Ethiopian cancer patients treated with various chemotherapeutic drugs. Therefore, it is necessary to establish more effective diagnostic methods and incorporate validated assessment tools, such as the European Organization for Research and Treatment of Cancer tools, either alone or in combination with other clinical instruments, into the routine evaluation of all patients receiving chemotherapeutic drug.

Factors affecting peripheral neuropathy induced by nanoparticle albumin-bound paclitaxel in patients with pancreatic cancer

AIM

Chemotherapy-induced peripheral neuropathy (CIPN) is a major toxicity limiting the use of nab-paclitaxel (Nab-P) in treating patients with pancreatic cancer. The aim of this study was to identify the factors affecting CIPN using patient-reported outcome measures and the minimally invasive volumetric absorptive microsampling (VAMS) technique.

METHODS

The maximum concentrations of paclitaxel (Cmax) were measured from 81 VAMS samples collected from 44 participants with pancreatic cancer. The association between CIPN development and demographic, clinical and pharmacokinetic factors was determined using univariable and multivariable logistic regression. The association between CIPN severity and the factors was evaluated using Spearman's rank correlation. The impact of Cmax and the number of treatment cycles on the severity was assessed using multivariable linear regression.

RESULTS

The development of CIPN was significantly associated with cumulative dose (odds ratio 1.005, 95% confidence interval [CI] 1.003-1.007), treatment cycles (3.47, 2.25-5.85), alkaline phosphate (0.992, 0.985-0.998) and age (1.092, 1.020-1.179), with an area under the receiver operating characteristic curve of 0.89 (95% CI 0.83-0.95). The severity of CIPN significantly worsened with increasing cumulative dose (coefficient 0.58, 95% CI 0.44-0.69), treatment cycles (0.57, 0.44-0.68) and age (0.18, 0.00-0.35). The severity of CIPN was predictable from treatment cycles (P = .0002) and Cmax (P = .01).

CONCLUSION

The higher the cumulative dose of Nab-P, treatment cycles and age, the more frequently and severely do the patients experience CIPN. In predicting the severity of CIPN using Cmax, minimally invasive VAMS is a feasible alternative to venous blood sampling.

Psychophysical and Functional Outcomes in Chemotherapy-induced Peripheral Neuropathy After Spinal Cord Stimulation: A Narrative Review and Case Series

OBJECTIVES

Chemotherapy-induced peripheral neuropathy (CIPN) is a complication that may occur after treatment with various anticancer drugs. In refractory CIPN cases, spinal cord stimulation (SCS) has garnered increased attention. The use of gait analysis and psychophysical quantitative sensory testing (QST) as an objective measurement of CIPN-related damage has burgeoned; however, these changes have not been reported for patients with CIPN after SCS implantation using either burst or tonic stimulation.

MATERIALS AND METHODS

This manuscript encompasses two parts: 1) a presentation of pain improvement in a series of patients who underwent tonic vs burst SCS for CIPN measured by gait and QST analysis and 2) a narrative review on gait and psychophysical QST outcomes between burst and tonic SCS stimulation pertaining to pain and the extrapolation to CIPN-related sequalae.

RESULTS

In these cases, gait scores improved in both patients. Touch thresholds were higher before SCS whereas skin temperatures were lower at the dorsal foot, subtalus, and posterior calf. Sharpness detection was drastically improved after SCS. In the review, the patients aligned with pain relief, suggesting good response to interventional outcomes with SCS. QST outcomes, particularly touch, sharpness, heat, and cold stimuli, however, were not fully corroborated. Similarly to other non-CIPN SCS gait studies, both tonic and burst studies provided positive outcomes on spatiotemporal gait parameters, gait form, and standardized gait scales.

CONCLUSION

We emphasize the use of different SCS waveforms as a therapy for CIPN management and the use of psychophysical testing as a measure for diagnosis and monitoring CIPN's progress in our case series and review.

Unlocking New Therapeutic Options for Vincristine-Induced Neuropathic Pain: The Impact of Preclinical Research

Vincristine, a vinca alkaloid, is used in chemotherapy protocols for cancers such as acute leukemia, Hodgkin's disease, neuroblastoma, cervical carcinoma, lymphomas, breast cancer, and melanoma. Among the common adverse effects of vincristine is peripheral neuropathy, with most patients receiving a cumulative dose over 4 mg/m2 who develop varying degrees of sensory neuropathy. The onset of vincristine-induced peripheral neuropathy can greatly affect patients' quality of life, often requiring dose adjustments or the discontinuation of treatment. Moreover, managing vincristine-induced peripheral neuropathy is challenging, with few effective therapeutic strategies available. In the past decade, preclinical studies have explored diverse substances aimed at preventing or alleviating VIPN. Our review consolidates these findings, focusing on the analgesic efficacy and potential mechanisms of various agents, including pharmaceutical drugs, natural compounds, and antioxidants, that show promise in reducing neuropathic pain and protecting neural integrity in preclinical models. Key novel therapeutic options, such as metabolic agents (liraglutide), enzyme inhibitors (ulinastatin), antipsychotics (aripiprazole), interleukin-1 receptor antagonists (anakinra), hormones (oxytocin), and antioxidants (thioctic acid), are highlighted for their neuroprotective, anti-inflammatory, and antioxidant effects. Through this synthesis, we aim to enhance the current understanding of VIPN management by identifying pharmacological strategies that target critical molecular pathways, laying the groundwork for future clinical studies. By clarifying these novel pharmacological approaches and elucidating their mechanisms of action, this review provides a foundation for developing more effective VIPN treatment strategies to ultimately improve patient outcomes.

Neuroprotective potential of Alpinia calcarata and HPLC analysis of stigmasterol against cisplatin-induced neuropathy in rat model

Cisplatin is a chemotherapeutic agent known for causing severe peripheral neuropathy as a side effect, impacting patients' quality of life by damaging nerve tissues. This study aims to explore the neuroprotective effects of the ethanolic extract of Alpinia calcarata Roscoe rhizome (EEACR) and stigmasterol identified by high-performance liquid chromatography (HPLC) in a rat model of cisplatin-induced neuropathy. Male Wistar rats were divided into control, cisplatin-induced neuropathic, and two intervention groups receiving different concentrations of EEACR (250 and 500 mg/kg). Neuropathy was induced with cisplatin administered intraperitoneally at a dose of 2 mg/kg per week for five weeks. The intervention groups were treated orally with EEACR daily during the induction period. Treatment with EEACR showed a significant attenuation of neurotoxicity as evidenced by behavioural improvements in mechanical allodynia, thermal hyperalgesia, and cold allodynia. HPLC analysis confirmed the presence of stigmasterol in EEACR, which may contribute to its therapeutic effects. Biochemical assessments revealed a significant decrease in oxidative stress markers and an increase in antioxidant enzyme activities, including superoxide dismutase, catalase, and glutathione peroxidase, in the nervous tissues of EEACR-treated rats. Histopathological examination indicated a reduction in nerve damage and enhanced preservation of myelin and axonal structures in the treatment groups. The findings from this study suggest that EEACR, enriched with stigmasterol, offers promising neuroprotective effects against cisplatin-induced neuropathy in rats.

Molecular mechanisms of neuropathic pain

Peripheral neuropathic pain, which occurs after a lesion or disease affecting the peripheral somatosensory nervous system, is a complex and challenging condition to treat. This chapter will cover molecular mechanisms underlying the pathophysiology of peripheral neuropathic pain, focusing on (1) sensitization of nociceptors, (2) neuro-immune crosstalk, and (3) axonal degeneration and regeneration. The chapter will also emphasize the importance of identifying novel therapeutic targets in non-neuronal cells. A comprehensive understanding of how changes at both neuronal and non-neuronal levels contribute to peripheral neuropathic pain may significantly improve pain management and treatment options, expanding to topical application that bypass the side effects associated with systemic administration.

Modulation of chemotherapy-induced peripheral neuropathy by JZL195 through glia and the endocannabinoid system

Chemotherapy-induced peripheral neuropathy (CIPN) used to treat cancer, is a significant side effect with a complex pathophysiology, and its mechanisms remain unclear. Recent research highlights neuroinflammation, which is modulated by the endocannabinoid system (ECS) and associated with glial activation, and the role of toll-like receptor 4 (TLR4) in CIPN. This study aimed to investigate the effects of JZL195, an inhibitor of fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL), and explore the connection between cannabinoid receptors and TLR4 in glial cells. A CIPN animal model was developed using cisplatin-injected male C57BL/6 mice. Mechanical and cold allodynia were assessed through von Frey and acetone tests. Western blot analysis was used to examine the expression of catabolic enzymes, cannabinoid receptors, glial cells, and neuroinflammatory factors in the dorsal root ganglia (DRGs) and spinal cord. Immunohistochemistry was used to investigate the colocalization of cannabinoid receptors and TLR4 in glial cells. JZL195 alleviated pain by inhibiting FAAH/MAGL, modulating the ECS and neuroinflammatory factors, and suppressing glial cell activity. Additionally, cannabinoid receptors and TLR4 colocalized with astrocytes and microglia in the spinal cord. This study highlights the therapeutic potential of JZL195 in modulating the ECS and suggests a correlation between cannabinoid receptors and TLR4 in spinal glial cells, providing insight into alleviating pain and neuroinflammation in CIPN.

In vitro neurotoxicity testing: lessons from chemotherapy-induced peripheral neurotoxicity

INTRODUCTION

Chemotherapy induced peripheral neurotoxicity (CIPN) is a long-lasting, or even permanent, late toxicity caused by largely used anticancer drugs. CIPN affects a growing population of cancer survivors and diminishes their quality of life since there is no curative/preventive treatment. Among several reasons for this unmet clinical need, there is an incomplete knowledge on mechanisms leading to CIPN. Therefore, bench side research is still greatly needed: in vitro studies are pivotal to both evaluate neurotoxicity mechanisms and potential neuroprotection strategies.

AREAS COVERED

Advantages and disadvantages of in vitro approaches are addressed with respect to their applicability to the CIPN field. Different cell cultures and techniques to assess neurotoxicity/neuroprotection are described. PubMed search-string: (chemotherapy-induced) AND (((neuropathy) OR neurotoxicity) OR neuropathic pain) AND (in vitro) AND (((((model) OR SH-SY5Y) OR PC12) OR iPSC) OR DRG neurons); (chemotherapy-induced) AND (((neuropathy) OR neurotoxicity) OR neuropathic pain) AND (model) AND (((neurite elongation) OR cell viability) OR morphology). No articles published before 1990 were selected.

EXPERT OPINION

CIPN is an ideal experimental setting to test axonal damage and, in general, peripheral nervous system mechanisms of disease and neuroprotection. Therefore, starting from robust preclinical data in this field, potentially, relevant biological rationale can be transferred to other human spontaneous diseases of the peripheral nervous system.

An Immune-Enhancing Injectable Hydrogel Loaded with Esketamine and DDP Promotes Painless Immunochemotherapy to Inhibit Breast Cancer Growth

Chemotherapy is the cornerstone of triple-negative breast cancer. The poor effectiveness and severe neuropathic pain caused by it have a significant impact on the immune system. Studies confirmed that immune cells in the tumor microenvironment (TME), have critical roles in tumor immune regulation and prognosis. In this study, it is revealed that the painless administration of Esketamine, combined with Cisplatin (DDP), can exert an anti-tumor effect, which is further boosted by the hydrogel delivery system. It is also discovered that Esketamine combined with DDP co-loaded in Poloxamer Hydrogel (PDEH) induces local immunity by increasing mature Dendritic Cells (mDCs) and activated T cells in PDEH group while the regulatory T cells (Tregs) known as CD4+CD25+FoxP3+decreased significantly. Finally, , CD8+ and CD4+ T cells in the spleen exhibited a significant increase, suggesting a lasting immune impact of PDEH. This study proposes that Esketamine can serve as a painless immune modulator, enhancing an anti-tumor effect while co-loaded in poloxamer hydrogel with DDP. Along with improving immune cells in the microenvironment, it can potentially alleviate anxiety and depression. With its outstanding bio-safety profile, it offers promising new possibilities for painless clinical therapy.

KLS-13019, a Novel Structural Analogue of Cannabidiol and GPR55 Receptor Antagonist, Prevents and Reverses Chemotherapy-Induced Peripheral Neuropathy in Rats

Neuropathic pain is a form of chronic pain that develops because of damage to the nervous system. Treatment of neuropathic pain is often incompletely effective, and most available therapeutics have only moderate efficacy and present side effects that limit their use. Opioids are commonly prescribed for the management of neuropathic pain despite equivocal results in clinical studies and significant abuse potential. Thus, neuropathic pain represents an area of critical unmet medical need, and novel classes of therapeutics with improved efficacy and safety profiles are urgently needed. The cannabidiol structural analog and novel antagonist of GPR55, KLS-13019, was screened in rat models of neuropathic pain. Tactile sensitivity associated with chemotherapy exposure was induced in rats with once-daily 1-mg/kg paclitaxel injections for 4 days or 5 mg/kg oxaliplatin every third day for 1 week. Rats were then administered KLS-13019 or comparator drugs on day 7 in an acute dosing paradigm or days 7-10 in a chronic dosing paradigm, and mechanical or cold allodynia was assessed. Allodynia was reversed in a dose-dependent manner in the rats treated with KLS-13019, with the highest dose reverting the response to prepaclitaxel injection baseline levels with both intraperitoneal and oral administration after acute dosing. In the chronic dosing paradigm, four consecutive doses of KLS-13019 completely reversed allodynia for the duration of the phenotype in control animals. Additionally, coadministration of KLS-13019 with paclitaxel prevented the allodynic phenotype from developing. Together, these data suggest that KLS-13019 represents a potential new drug for the treatment of neuropathic pain. SIGNIFICANCE STATEMENT: Chemotherapy-induced peripheral neuropathy (CIPN) is a common, debilitating side effect of cancer treatment with no known cure. The GPR55 antagonist KLS-13019 represents a novel class of drug for this condition that is a potent, durable inhibitor of allodynia associated with CIPN in rats in both prevention and reversal-dosing paradigms. This novel therapeutic approach addresses a critical area of unmet medical need.

Challenges and Complications in the Management of Advanced Oropharyngeal Carcinoma: Role of Post-Mortem Diagnosis and Future Perspectives

Oropharyngeal squamous-cell carcinoma (OPSCC) poses significant challenges in diagnosis, treatment, and management and has important medico-legal and forensic implications. In particular, the management of OPSCC and its treatment-related complications can often be challenging. In cases with advanced OPSCC, a loco-regional extension of the tumor can contribute to the destruction of oral cavity tissues, while the radiotherapy treatment can induce profound changes in tissue morphology and structure. These changes, which resemble tumor neoplasms and endovascular effects, are related to a higher risk of fatal bleeding, as reported in the case study illustrated, in which a hemorrhage occurred from a lingual artery, originating from an ulcerative, necrotic, hemorrhagic lesion on the tongue. Bleeding complications in OPSCC and prolonged radiotherapy are associated with high mortality and require comprehensive management strategies to improve survival and quality of life. Autopsy investigations, contributing to the definition of post-mortem diagnosis, can provide valuable insights into the pathogenetic mechanisms underlying bleeding and guide therapeutic decisions and preventive measures. The integration of autopsy and histopathological investigation into clinical practice should be considered as a necessary support to optimize the management of complications in advanced OPSCC patients, emphasizing the importance of a patient-centered approach and continued research.

FTY720/Fingolimod mitigates paclitaxel-induced Sparcl1-driven neuropathic pain and breast cancer progression

Paclitaxel is among the most active chemotherapy drugs for the aggressive triple negative breast cancer (TNBC). Unfortunately, it often induces painful peripheral neuropathy (CIPN), a major debilitating side effect. Here we demonstrate that in naive and breast tumor-bearing immunocompetent mice, a clinically relevant dose of FTY720/Fingolimod that targets sphingosine-1-phosphate receptor 1 (S1PR1), alleviated paclitaxel-induced neuropathic pain. FTY720 also significantly attenuated paclitaxel-stimulated glial fibrillary acidic protein (GFAP), a marker for activated astrocytes, and expression of the astrocyte-secreted synaptogenic protein Sparcl1/Hevin, a key regulator of synapse formation. Notably, the formation of excitatory synapses containing VGluT2 in the spinal cord dorsal horn induced by paclitaxel was also inhibited by FTY720 treatment, supporting the involvement of astrocytes and Sparcl1 in CIPN. Furthermore, in this TNBC mouse model that mimics human breast cancer, FTY720 administration also enhanced the anti-tumor effects of paclitaxel, leading to reduced tumor progression and lung metastasis. Taken together, our findings suggest that targeting the S1P/S1PR1 axis with FTY720 is a multipronged approach that holds promise as a therapeutic strategy for alleviating both CIPN and enhancing the efficacy of chemotherapy in TNBC treatment.

Chemotherapy-Induced Peripheral Neuropathy: A Recent Update on Pathophysiology and Treatment

Chemotherapy-induced peripheral neuropathy (CIPN) is a major long-lasting side effect of some chemotherapy drugs, which threatens cancer survival rate. CIPN mostly affects sensory neurons and occasionally motor neurons, causing numbness, tingling, discomfort, and burning pain in the upper and lower extremities. The pathophysiology of CIPN is not completely understood; however, it is believed that chemotherapies induce peripheral neuropathy via directly damaging mitochondria, impairing the function of ion channels, triggering immunological mechanisms, and disrupting microtubules. The treatment of CIPN is a medical challenge, and there are no approved pharmacological options. Currently, duloxetine and other antidepressants, antioxidant, anti-inflammatory, and ion-channel targeted therapies are commonly used in clinics to relieve the symptoms of CIPN. Several other types of drugs, such as cannabinoids, sigma-1 receptor antagonists, and nicotinamides ribose, are being evaluated in preclinical and clinical studies. This paper summarizes the information related to the physiology of CIPN and medicines that could be used for treating this condition.

The Efficacy of Ketamine for Acute and Chronic Pain in Patients with Cancer: A Systematic Review of Randomized Controlled Trials

Managing cancer-related pain poses significant challenges, prompting research into alternative approaches such as ketamine. This systematic review aims to analyze and summarize the impact of ketamine as an adjuvant to opioid therapy for cancer-related pain. We conducted a literature review in MEDLINE, EMBASE, and Scopus from 1 January 1982 to 20 October 2023. Abstracts were screened against inclusion criteria, and eligible studies underwent a full-text review. Data was extracted from the included studies, and a framework analysis approach summarized the evidence regarding ketamine's use in patients with cancer. A total of 21 randomized clinical trials were included, and the quality of all the included studies was good or fair. Significant improvements in pain scores and reduced morphine consumption were consistently observed with intravenous ketamine administration for postoperative pain control, particularly when combined with other analgesics such as morphine. Ketamine was less effective when used as an analgesic for chronic pain management, with several studies on neuropathic pain or chemotherapy-induced neuropathy finding minimal significant effect on reduction of pain scores or morphine requirements. The efficacy of ketamine in pain management appears to depend on factors such as dosage, route of administration, and patient population.

Impact of exercise on chemotherapy-induced peripheral neuropathy in survivors with post-treatment primary breast cancer

PURPOSE

Chemotherapy-induced peripheral neuropathy (CIPN) is a debilitating side effect of neurotoxic chemotherapy. Exercise activates neuromuscular function and may improve CIPN. We examined the association between exercise and CIPN symptoms in breast cancer survivors.

METHODS

In a retrospective cross-sectional study, we included patients completing a survey assessing exercise exposure and neuropathy symptoms in a tertiary cancer center survivorship clinic. We evaluated exercise duration and intensity using a standardized questionnaire quantified in metabolic equivalent tasks (MET-h/wk). We defined exercisers as patients meeting the National Physical Activity Guidelines' criteria. We used multivariable logistic regressions to examine the relationship between exercise and CIPN and if this differed as a function of chemotherapy regimen adjusting for age, gender, and race.

RESULTS

We identified 5444 breast cancer survivors post-chemotherapy (median age 62 years (interquartile range [IQR]: 55, 71); median 4.7 years post-chemotherapy (IQR: 3.3, 7.6)) from 2017 to 2022. CIPN overall prevalence was 34% (95% confidence interval [CI]: 33%, 36%), 33% for non-taxane, and 37% for taxane-based chemotherapy. CIPN prevalence was 28% (95% CI: 26%, 30%) among exercisers and 38% (95% CI: 37%, 40%) among non-exercisers (difference 11%; 95% CI: 8%, 13%; p < 0.001). Compared to patients with low (<6 MET-h/wk) levels of exercise (42%), 11% fewer patients with moderate (6-20.24 MET-h/wk) to high (>20.25 MET-h/wk) levels of exercise reported CIPN. Exercise was associated with reduced prevalence of all CIPN symptoms regardless of chemotherapy type.

CONCLUSION

CIPN may persist several years following chemotherapy among patients with breast cancer but is significantly reduced by exercise in a dose-dependent manner.

HDAC inhibitors as a potential therapy for chemotherapy-induced neuropathic pain

Cancer, a chronic disease characterized by uncontrolled cell development, kills millions of people globally. The WHO reported over 10 million cancer deaths in 2020. Anticancer medications destroy healthy and malignant cells. Cancer treatment induces neuropathy. Anticancer drugs cause harm to spinal cord, brain, and peripheral nerve somatosensory neurons, causing chemotherapy-induced neuropathic pain. The chemotherapy-induced mechanisms underlying neuropathic pain are not fully understood. However, neuroinflammation has been identified as one of the various pathways associated with the onset of chemotherapy-induced neuropathic pain. The neuroinflammatory processes may exhibit varying characteristics based on the specific type of anticancer treatment delivered. Neuroinflammatory characteristics have been observed in the spinal cord, where microglia and astrocytes have a significant impact on the development of chemotherapy-induced peripheral neuropathy. The patient's quality of life might be affected by sensory deprivation, loss of consciousness, paralysis, and severe disability. High cancer rates and ineffective treatments are associated with this disease. Recently, histone deacetylases have become a novel treatment target for chemotherapy-induced neuropathic pain. Chemotherapy-induced neuropathic pain may be treated with histone deacetylase inhibitors. Histone deacetylase inhibitors may be a promising therapeutic treatment for chemotherapy-induced neuropathic pain. Common chemotherapeutic drugs, mechanisms, therapeutic treatments for neuropathic pain, and histone deacetylase and its inhibitors in chemotherapy-induced neuropathic pain are covered in this paper. We propose that histone deacetylase inhibitors may treat several aspects of chemotherapy-induced neuropathic pain, and identifying these inhibitors as potentially unique treatments is crucial to the development of various chemotherapeutic combination treatments.

Navigating Preclinical Models and Medications for Peripheral Neuropathy: A Review

Peripheral neuropathy (PN) is a multifaceted disorder characterised by peripheral nerve damage, manifesting in symptoms like pain, weakness, and autonomic dysfunction. This review assesses preclinical models in PN research, evaluating their relevance to human disease and their role in therapeutic development. The Streptozotocin (STZ)-induced diabetic rat model is widely used to simulate diabetic neuropathy but has limitations in faithfully replicating disease onset and progression. Cisplatin-induced PN models are suitable for studying chemotherapy-induced peripheral neuropathy (CIPN) and closely resemble human pathology. However, they may not fully replicate the spectrum of sensory and motor deficits. Paclitaxel-induced models also contribute to understanding CIPN mechanisms and testing neuroprotective agents. Surgical or trauma-induced models offer insights into nerve regeneration and repair strategies. Medications such as gabapentin, pregabalin, duloxetine, and fluoxetine have demonstrated promise in these models, enhancing our understanding of their therapeutic efficacy. Despite progress, developing models that accurately mirror human PN remains imperative due to its complex nature. Continuous refinement and innovative approaches are critical for effective drug discovery. This review underscores the strengths and limitations of current models and advocates for an integrated approach to address the complexities of PN better and optimise treatment outcomes.

An investigation on the role of oxytocin in chronic neuropathic pain in a Wistar rat model

Introduction Chemotherapy-induced peripheral neuropathy (CIPN) is a dose-limiting side effect with ineffective preventative and curative treatment. Currently, only Duloxetine has been recommended as effective treatment for CIPN, which has shown individual-dependent, short-term analgesic effects, with limiting adverse effects and poor bioavailability. The neuropeptide, oxytocin, may offer significant analgesic and anxiolytic potential, as it exerts central and peripheral attenuating effects on nociception. However, it is unknown whether the intervention administered in a model of CIPN is an effective therapeutic alternative or adjuvant. Materials and Methods The intervention was divided into two phases. Phase 1 aimed to induce CIPN in adult Wistar rats using the chemotherapeutic agent Paclitaxel. Mechanical (electronic von Frey filament) and thermal (acetone evaporation test and Hargreaves test) hypersensitivity testing were used to evaluate changes due to the neuropathic induction. Phase 2 consisted of a 14-day intervention period with saline (o.g.), duloextine (o.g.), or oxytocin (i.n.) administered as treatment. Following the intervention, anxiety-like behaviour was assessed using the elevated plus maze (EPM) and light-dark box protocols. Analysis of peripheral plasma corticosterone, peripheral plasma oxytocin, and hypothalamic oxytocin concentrations were assessed using ELISA assays. Results The findings showed that we were able to successfully establish a model of chemotherapy-induced peripheral neuropathy during Phase 1, determined by the increase in mechanical and thermal nociceptive responses following Paclitaxel administration. Furthermore, the animals treated with oxytocin displayed a significant improvement in mechanical sensitivity over the intervention phase, indicative of an improvement in nociceptive sensitivity in the presence of neuropathic pain. Animals that received Paclitaxel and treated with oxytocin also displayed significantly greater explorative behaviour during the EPM, indicative of a reduced presence of anxiety-like behaviour. Conclusion Our results support the hypothesis that intranasally administered oxytocin may augment the analgesic and anxiolytic effects of duloxetine in a chemotherapy induced peripheral neuropathy model in a Wistar rat. Future studies should consider administering the treatments in combination to observe the potential synergistic effects.

Efficacy of Mirogabalin for Taxane-associated Chemotherapy-induced Peripheral Neuropathy in Perioperative Chemotherapy for Early Breast Cancer

BACKGROUND/AIM

Treatment with taxanes can result in chemotherapy-induced peripheral neuropathy (CIPN). We investigated the efficacy and safety of mirogabalin for the treatment of CIPN in patients who had been administered perioperative chemotherapy including taxane-based agents for breast cancer.

PATIENTS AND METHODS

We retrospectively analyzed the case of 43 patients with early breast cancer who received a taxane as perioperative chemotherapy and were administered mirogabalin at the diagnosis of CIPN.

RESULTS

Thirty-six patients (83.7%) had grade 1 CIPN and the other seven patients (16.3%) had grade 2 CIPN. The median mirogabalin dose was 10 mg (5-30 mg). CIPN improved from grade 1 to 0 in 12 patients (27.9%) and from grade 2 to 1 in one patient (2.3%); 13 (30.2%) patients thus had an objective therapeutic response. There were no cases in which chemotherapy was reduced or discontinued due to CIPN. Adverse events were evaluated by Common Terminology Criteria for Adverse Events and included five cases of dizziness (11.7%), three of somnolence (7.0%), and two of nausea (4.7%), all of which were grade ≤2. There were no cases of serious (grade ≥3) adverse effects.

CONCLUSION

Mirogabalin may be effective and safe for treating CIPN of patients who receive a taxane in a perioperative breast cancer setting.

Centralizing the Knowledge and Interpretation of Pain in Chemotherapy-Induced Peripheral Neuropathy: A Paradigm Shift towards Brain-Centric Approaches

Chemotherapy-induced peripheral neuropathy (CIPN) is a side effect of cancer treatment, often linked with pain complaints. Patients report mechanical and thermal hypersensitivity that may emerge during chemotherapy treatment and may persist after cancer remission. Whereas the latter situation disturbs the quality of life, life itself may be endangered by the appearance of CIPN during cancer treatment. The causes of CIPN have almost entirely been ascribed to the neurotoxicity of chemotherapeutic drugs in the peripheral nervous system. However, the central consequences of peripheral neuropathy are starting to be unraveled, namely in the supraspinal pain modulatory system. Based on our interests and experience in the field, we undertook a review of the brain-centered alterations that may underpin pain in CIPN. The changes in the descending pain modulation in CIPN models along with the functional and connectivity abnormalities in the brain of CIPN patients are analyzed. A translational analysis of preclinical findings about descending pain regulation during CIPN is reviewed considering the main neurochemical systems (serotoninergic and noradrenergic) targeted in CIPN management in patients, namely by antidepressants. In conclusion, this review highlights the importance of studying supraspinal areas involved in descending pain modulation to understand the pathophysiology of CIPN, which will probably allow a more personalized and effective CIPN treatment in the future.

Roles of Thermosensitive Transient Receptor Channels TRPV1 and TRPM8 in Paclitaxel-Induced Peripheral Neuropathic Pain

Paclitaxel, a microtubule-stabilizing chemotherapy drug, can cause severe paclitaxel-induced peripheral neuropathic pain (PIPNP). The roles of transient receptor potential (TRP) ion channel vanilloid 1 (TRPV1, a nociceptor and heat sensor) and melastatin 8 (TRPM8, a cold sensor) in PIPNP remain controversial. In this study, Western blotting, immunofluorescence staining, and calcium imaging revealed that the expression and functional activity of TRPV1 were upregulated in rat dorsal root ganglion (DRG) neurons in PIPNP. Behavioral assessments using the von Frey and brush tests demonstrated that mechanical hyperalgesia in PIPNP was significantly inhibited by intraperitoneal or intrathecal administration of the TRPV1 antagonist capsazepine, indicating that TRPV1 played a key role in PIPNP. Conversely, the expression of TRPM8 protein decreased and its channel activity was reduced in DRG neurons. Furthermore, activation of TRPM8 via topical application of menthol or intrathecal injection of WS-12 attenuated the mechanical pain. Mechanistically, the TRPV1 activity triggered by capsaicin (a TRPV1 agonist) was reduced after menthol application in cultured DRG neurons, especially in the paclitaxel-treated group. These findings showed that upregulation of TRPV1 and inhibition of TRPM8 are involved in the generation of PIPNP, and they suggested that inhibition of TRPV1 function in DRG neurons via activation of TRPM8 might underlie the analgesic effects of menthol.

Paeoniflorin ameliorates oxaliplatin-induced peripheral neuropathy via inhibiting neuroinflammation through influence on gut microbiota

Oxaliplatin (OXA)-induced peripheral neuropathy (OIPN) is a severe side effect that greatly limits OXA clinical use and threatens patients' life and health. Paeoniflorin exhibits extensive anti-inflammatory and neuroprotective effects, but whether it can protect against OIPN and the underlying mechanisms remain unclear. This study aimed to investigate the effects of paeoniflorin on OIPN and probe into the underlying mechanisms. The OIPN model was established through oxaliplatin injection in rats. The ameliorative effects of paeoniflorin on OIPN was assessed by nociceptive hypersensitivities through pain behavioral methods. Neuroinflammation were examined by measuring the levels of inflammatory cytokines and immune cells infiltration. The signaling pathway of TLR4/MyD88/NF-κB was evaluated by Western blotting. Gut microbial changes were detected by 16S rDNA sequencing technology. In addition, antibiotics-induced microbiota eradication and fecal microbial transplantation (FMT) were applied for exploring the function of gut microbiota in the protective effects of paeoniflorin. The results revealed that paeoniflorin significantly alleviated mechanical and cold hypersensitivity, mitigated neuroinflammation and influenced gut microbial composition in OIPN rats. Fecal microbiota transplantation further verified that gut microbiota was required for paeoniflorin ameliorating OIPN and that the underlying mechanism involved downregulation of TLR4/MyD88/NF-κB signaling. Specifically, Akkermansia, Dubosiella and Corynebacterium might serve as crucial genera regulated by paeoniflorin in the treatment of OIPN. In summary, our investigations delineate paeoniflorin's ameliorative effects on OIPN by alleviating neuroinflammation through regulations of gut microbiota. This suggests that paeoniflorin may serve as a new potential strategy for treatment of OIPN in clinical practice.

Treatment Complications of Head and Neck Cancers and Rehabilitation Measures: A Narrative Review

Head and neck cancers (HNCs) are malignant tumors mainly from squamous cells in the head and neck tissues. Treatment involves a multidisciplinary approach with surgery, radiotherapy, and chemotherapy. However, the long-term prognosis for patients with advanced-stage tumors is guarded, with a median survival time of approximately 24 months. HNC patients have very high rates of depression and anxiety and the highest suicide rate among all cancers due to the intense and challenging nature of the treatment, underscoring the importance of our collective efforts. Rehabilitation success depends on various factors, including tumor, patient, and treatment-related factors. Patients may require post-treatment oral rehabilitation measures, including implants, obturators, and flexible dentures. These measures are crucial, but they often need to be more utilized. Patients may face challenges in maintaining oral hygiene and managing mucositis. Additionally, it is essential to address other intricacies such as trismus, xerostomia, gustatory dysfunctions, neuropathy, speech impairments, and psychological disturbances. Unfortunately, there is little literature on post-treatment rehabilitative measures. Despite its crucial role in improving patients' quality of life, rehabilitation often receives inadequate attention compared to treatment. Our narrative review, which covers various factors that affect rehabilitation, including oral rehabilitation measures and post-treatment complications, is anticipated to deliver practical insights to professionals and inspire positive changes in their regular practice.

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.

Current understanding of the molecular mechanisms of chemotherapy-induced peripheral neuropathy

Chemotherapy-induced peripheral neuropathy (CIPN) is the most common off-target adverse effects caused by various chemotherapeutic agents, such as cisplatin, oxaliplatin, paclitaxel, vincristine and bortezomib. CIPN is characterized by a substantial loss of primary afferent sensory axonal fibers leading to sensory disturbances in patients. An estimated of 19-85% of patients developed CIPN during the course of chemotherapy. The lack of preventive measures and limited treatment options often require a dose reduction or even early termination of life-saving chemotherapy, impacting treatment efficacy and patient survival. In this Review, we summarized the current understanding on the pathogenesis of CIPN. One prominent change induced by chemotherapeutic agents involves the disruption of neuronal cytoskeletal architecture and axonal transport dynamics largely influenced by the interference of microtubule stability in peripheral neurons. Due to an ineffective blood-nerve barrier in our peripheral nervous system, exposure to some chemotherapeutic agents causes mitochondrial swelling in peripheral nerves, which lead to the opening of mitochondrial permeability transition pore and cytochrome c release resulting in degeneration of primary afferent sensory fibers. The exacerbated nociceptive signaling and pain transmission in CIPN patients is often linked the increased neuronal excitability largely due to the elevated expression of various ion channels in the dorsal root ganglion neurons. Another important contributing factor of CIPN is the neuroinflammation caused by an increased infiltration of immune cells and production of inflammatory cytokines. In the central nervous system, chemotherapeutic agents also induce neuronal hyperexcitability in the spinal dorsal horn and anterior cingulate cortex leading to the development of central sensitization that causes CIPN. Emerging evidence suggests that the change in the composition and diversity of gut microbiota (dysbiosis) could have direct impact on the development and progression of CIPN. Collectively, all these aspects contribute to the pathogenesis of CIPN. Recent advances in RNA-sequencing offer solid platform for in silico drug screening which enable the identification of novel therapeutic agents or repurpose existing drugs to alleviate CIPN, holding immense promises for enhancing the quality of life for cancer patients who undergo chemotherapy and improve their overall treatment outcomes.

Effect of Melissa officinalis on Chemotherapy-Induced Peripheral Neuropathy in Cancer Patients: A Randomized Trial

Background: Chemotherapy-induced peripheral neuropathy (CIPN) is a significant cancer treatment side effect that can influence both quality of life and treatment course. Melissa Officinalis (MO), due to its high content of flavonoids, has antioxidant, anti-inflammatory, and neuroprotective properties.  Materials and Methods: The cancer patients diagnosed with CIPN attended a referral center in Sari (Iran). The hydroalcoholic extract of MO leaves was extracted by the maceration method. The control group received a placebo along with gabapentin as the standard treatment, and the intervention group received 500 mg Melissa officinalis 2 times daily for 3 months plus gabapentin. Patients were evaluated at the baseline and 3 months later, according to Common Terminology Criteria for Adverse Effects (CTCAE) and EORTC QLQ-C30 (Integrated System for Quality of Life Assessment).  Results: A total of 40 patients were considered as group D (intervention group), and 35 patients completed the study. Out of 40 subjects in the placebo group (P), 3 patients could not tolerate the drug due to gastrointestinal disturbances. The final values of CTCAE showed a statistically significant difference (p=0.010). Indicators related to the quality of life in both groups showed a significant improvement. In the intervention group, the pain perception and diarrhea experience were significantly reduced. Conclusion: Quality of life indicators were improved by prescribing gabapentin with and without Melissa officinalis. The addition of Melissa officinalis to the chemotherapy regimen may improve diarrhea and pain perception.

Risk factors for taxane-induced peripheral neuropathy in patients with breast cancer

PURPOSE

This study investigated the clinical risk factors for peripheral neuropathy induced by docetaxel and albumin-bound paclitaxel (AP) in patients with breast cancer.

METHODS

This prospective observational study recruited 268 patients between March 2019 and December 2020. Patient information was obtained through the query system for laboratory test results, patient consultations, and scale evaluations. Neuropathic symptoms were followed up throughout and until 3 months after taxane chemotherapy. Univariate and multivariate analyses were used to find the risk factors for overall and moderate-severe taxane-induced peripheral neuropathy (TIPN).

RESULTS

Cumulative dose (odds ratio [OR] = 3.533, 95% confidence interval [CI]: 1.797-6.944, p < 0.001), body mass index (BMI) (OR = 2.926, 95% CI: 1.621-5.281, p < 0.001), body surface area (BSA) (OR = 1.724, 95% CI: 1.011-2.941, p = 0.045), and hypocalcemia (OR = 4.899, 95% CI: 1.518-15.811, p = 0.008) all increased the risk of TIPN. Only cumulative dose (OR = 2.577, 95% CI: 1.161-5.719, p = 0.020) and BSA (OR = 2.040, 95% CI: 1.073-3.877, p = 0.030) were independent risk factors for moderate-severe TIPN.

CONCLUSION

Cumulative dose, BMI, BSA, and hypocalcemia are all risk factors for overall TIPN, whereas cumulative dose and BSA are risk factors for moderate-severe TIPN. Patients with breast cancer who have high BMI, large BSA, hypocalcemia, and large cumulative dose may be at risk of TIPN, and intervention measures must be actively carried out for them.

Transient Receptor Potential Channels: Multiple Modulators of Peripheral Neuropathic Pain in Several Rodent Models

Neuropathic pain, a prevalent chronic condition in clinical settings, has attracted widespread societal attention. This condition is characterized by a persistent pain state accompanied by affective and cognitive disruptions, significantly impacting patients' quality of life. However, current clinical therapies fall short of addressing its complexity. Thus, exploring the underlying molecular mechanism of neuropathic pain and identifying potential targets for intervention is highly warranted. The transient receptor potential (TRP) receptors, a class of widely distributed channel proteins, in the nervous system, play a crucial role in sensory signaling, cellular calcium regulation, and developmental influences. TRP ion channels are also responsible for various sensory responses including heat, cold, pain, and stress. This review highlights recent advances in understanding TRPs in various rodent models of neuropathic pain, aiming to uncover potential therapeutic targets for clinical management.

Molecular and Cellular Involvement in CIPN

Many anti-cancer drugs, such as taxanes, platinum compounds, vinca alkaloids, and proteasome inhibitors, can cause chemotherapy-induced peripheral neuropathy (CIPN). CIPN is a frequent and harmful side effect that affects the sensory, motor, and autonomic nerves, leading to pain, numbness, tingling, weakness, and reduced quality of life. The causes of CIPN are not fully known, but they involve direct nerve damage, oxidative stress, inflammation, DNA damage, microtubule dysfunction, and altered ion channel activity. CIPN is also affected by genetic, epigenetic, and environmental factors that modulate the risk and intensity of nerve damage. Currently, there are no effective treatments or prevention methods for CIPN, and symptom management is mostly symptomatic and palliative. Therefore, there is a high demand for better understanding of the cellular and molecular mechanisms involved in CIPN, as well as the development of new biomarkers and therapeutic targets. This review gives an overview of the current knowledge and challenges in the field of CIPN, focusing on the biological and molecular mechanisms underlying this disorder.

Effect of Silybum Marianum on Reduction of Chemotherapy-Induced Peripheral Neurotoxicity with Cisplatin

Background

Chemotherapy-induced peripheral neurotoxicity (CIPN) is one of the major complications of chemotherapy regimens commonly used in the treatment of solid and hematologic cancers. Given the high incidence of CIPN in antitumor therapies in patients and limited studies on antioxidants, this study was aimed to investigate the effect of Silybum marianum (SM) on cisplatin-induced peripheral neuropathy.

Materials and Methods

This double-blind randomized clinical trial study was performed on 60 cancer patients treated with cisplatin chemotherapy at Seyyed-o-Shohada Hospital of Isfahan during 2019-2020. The patients were divided into two parallel groups as intervention (treated by SM) and placebo, and DN4 (Douleur neuropathique 4 questions) and CIPNAT (chemotherapy-induced peripheral neuropathy assessment tool) were completed for patients in the before and after intervention groups and compared between the two groups.

Results

The mean of DN4 score in the before and after study in the intervention group was in 1.76 ± 1.24 and 2.07 ± 2.03, respectively (P = 0.38), and in the control group was 1.41 ± 1.28 ± 3.11 ± 2.86, respectively (P = 0.012). The mean CIPNAT score in the intervention groups was 5.93 ± 3.65 and 4.20 ± 3.23 (P = 0.01), and in the control group was 4.20 ± 4.22 and 4.16 ± 4.03 (P = 0.39).

Conclusion

Based on our data, SM is an effective agent in reducing peripheral neuropathy. The use of SM was associated with decreased scores of peripheral neuropathy and was helpful in patients undergoing chemotherapy with cisplatin.