Evaluating laser photobiomodulation for chemotherapy-induced peripheral neuropathy: a randomised phase II trial

From molecular mechanisms to clinical applications: A comprehensive review of photobiomodulation in cancer treatment

Photobiomodulation (PBM) is a non-invasive therapeutic technique that regulates biological processes using primarily low-power lasers or light-emitting diodes (LEDs) to achieve therapeutic effects. Its application has expanded significantly, particularly in the field of cancer therapy. This review provides a comprehensive overview of PBM, elucidating its underlying mechanisms of action and its potential applications in cancer therapy. It highlights the benefits of PBM in reducing side effects of cancer treatments such as acute oral mucositis, radiation dermatitis, lymphedema, neuropathic pain, and radiation enteropathy. Furthermore, the ability of PBM to inhibit cancer cell proliferation and induce apoptosis, and discusses safety concerns of PBM in clinical applications, presenting existing research that emphasizes its significant potential in cancer therapy was summarized. PBM therapy may offer promising new clinical options for managing cancer and mitigating the side effects associated with conventional cancer therapies.

Influence of photobiomodulation on sensory symptoms, balance, and gait speed in chemotherapy-induced peripheral neuropathy

INTRODUCTION

Photobiomodulation (PBM) is a non-invasive therapy that uses low-level light in the visible and near-infrared spectrum to stimulate cellular processes, promoting tissue repair and reducing inflammation without causing thermal damage. PBM has shown potential in alleviating neuropathic pain and improving nerve function by enhancing mitochondrial activity, reducing oxidative stress, and modulating inflammatory pathways. Emerging evidence suggests that PBM may be a promising adjunctive treatment for managing chemotherapy-induced peripheral neuropathy (CIPN) and improving patients' quality of life.

OBJECTIVE

To evaluate the influence of photobiomodulation (PBM) on sensory complaints, balance, and gait speed in patients with chemotherapy-induced peripheral neuropathy (CIPN).

METHODS

Prospective clinical study in 47 patients with CIPN in the lower limbs (CAAE: 70504423.9.0000.5382). Patients received PBM (630/850 nm), in the nerve pathway, 2 × /week for 2 weeks. The Neuropathic Pain Questionnaire (DN-4), the Chemotherapy-Induced Peripheral Neuropathy Assessment Tool (FANPIQ) and its interference items, and the Lower Extremity Functional Scale (LEFS) were used. Balance was assessed by measuring the amplitude, speed, and area of displacement with a force platform on rigid and deformable surfaces. Gait speed (GS) was assessed by the 10-m walk test. Measurements were collected at the beginning and end of treatment and analyzed with descriptive statistics and independent t-test.

RESULTS

Sensory symptoms improved, as evidenced by the results of the DN-4 (p < 0.0001) and the FANPIQ (p = 0.0031), but not in the LEFS (p = 0.2379). There was also a significant improvement in the amplitude of the anteroposterior displacement (APD) and in the amplitude of the mediolateral displacement (MLD) (p = 0.0001 and p < 0.0001), in the velocity of the APD and MLD (p = 0.0431 and p = 0.0016), and in the displacement area (p = 0.0001). On the deformable surface, significant reductions were also observed in the APD and MLD (p = 0.0314 and p = 0.0008), as well as in the velocity of the MLD (p = 0.0091) and displacement area (p = 0.0029). GS showed improvement (p = 0.0315).

CONCLUSION

PBM proved to be a promising low-cost resource for the management of sensory symptoms of CIPN, with positive clinical repercussions on balance and gait speed.

Beyond p-values: a cross-sectional umbrella review of chemotherapy-induced peripheral neuropathy treatments

Introduction

Chemotherapy-induced peripheral neuropathy (CIPN) is a common side effect of neurotoxic chemotherapy agents, significantly impacting the daily lives of many cancer survivors. Despite thousands of articles published on CIPN, we remain no closer to a successful treatment regimen for the condition. In recent years, several new clinical trials and systematic reviews have been published, many exploring nonpharmaceutical interventions, prompting the need for a comprehensive synthesis of this emerging evidence.

Methods

We conducted an umbrella review to identify and appraise the 19 systematic reviews (SRs) published in 2023 that examined randomized controlled trials (RCTs) for established CIPN treatment. We focused our analysis on the three most researched treatment options: oral drugs, exercise, and acupuncture. RCTs not previously synthesized together were reviewed, and effect size analyses were performed to allow readers to interpret the existing literature beyond binary p-values.

Results

Our analysis of RCTs revealed the following key findings. For cancer survivors with CIPN after completing chemotherapy, serotonin-norepinephrine reuptake inhibitors (SNRIs) as well as acupuncture provided at least short-term relief for pain and sensory symptoms. For patients with CIPN who were actively undergoing chemotherapy, home-based balance and strength training exercises appeared to alleviate symptoms. Effect size analyses highlighted variability in treatment responses, underscoring the limitations of relying solely on p-values to assess intervention efficacy.

Discussion

Through an umbrella review approach, we demonstrate that SRs are often less systematic than expected. None of the 19 SRs captured all relevant RCTs within their search timeframe. However, by cross-referencing SRs, we identified 41 RCTs across 42 publications, illustrating the feasibility of an umbrella review approach to uncover relevant trials. Furthermore, many SRs exhibited methodological concerns that limit the interpretability of their findings. Finally, we discuss multiple opportunities for refining methods and reporting in future CIPN treatment trials.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/view/CRD42024508283, PROSPERO (42024508283).

Research trends of acupuncture therapy for painful peripheral nervous system diseases from 2004 to 2023: a bibliometric and meta-analysis

Background

Peripheral nervous system diseases (PNSD) have represented a major global health burden, leading to significant economic impacts and diminished productivity. This bibliometric analysis was performed to summarize the current research trends and hotspots over the past two decades, aiming to provide a comprehensive perspective for future research.

Methods

All data were sourced from the Web of Science Core Collection (WoSCC) on March 1, 2024, for publications between January 1, 2004, and December 31, 2023. Data visualization and analyses, including descriptive statistics, co-occurrence mapping, and cluster analysis, were performed using CiteSpace (Version 6.1.R6) and Excel 2021.

Results

Our search yielded 678 references, with the annual publication count demonstrating an increasing trend over the past 20 years. The most productive country and institution were China and Kyung Hee University, respectively. Fang Jianqiao, was the most prolific author with the highest publications. Among journals, "Pain," was the most frequently cited, while the top-cited reference was a randomized controlled pilot trial by Lu Weidong in 2020. "Acupuncture" emerged as the keyword with the highest frequency. The meta-analysis indicated that acupuncture was more effective than standard care for pain associated with Diabetic Peripheral Neuropathy [MD = -2.03, 95% CI (-2.86, -1.21), 2 RCTs, 102 participants, p < 0.0001].

Conclusion

Our bibliometric review revealed key insights into the focal areas of PNSD research, underscoring the urgent need for continued and targeted high-quality investigations.

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.

Decrypting the multifaceted peripheral neuropathy based on molecular pathology and therapeutics: a comprehensive review

CONTEXT

Peripheral neuropathy (PN) is a multifaceted complication characterized by nerve damage due to oxidative stress, inflammatory mediators, and dysregulated metabolic processes. Early PN manifests as sensory changes that develop progressively in a "stocking and glove" pattern.

METHODS AND MECHANISMS

A thorough review of literature has been done to find the molecular pathology, clinical trials that have been conducted to screen the effects of different drugs, current treatments and novel approaches used in PN therapy. Diabetic neuropathy occurs due to altered protein kinase C activity, elevated polyol pathway activity in neurons, and Schwann cells-induced hyperglycemia. Other causes involve chemotherapy exposure, autoimmune ailments, and chronic ethanol intake.

CONCLUSION

Symptomatic treatments for neuropathic pain include use of tricyclic antidepressants, anticonvulsants, and acetyl-L-carnitine. Patients will have new hope if clinicians focus on novel therapies including gene therapy, neuromodulation techniques, and cannabidiol as an alternative to traditional medications, as management is still not ideal.

The Efficacy of Neuromodulation Interventions for Chemotherapy-Induced Peripheral Neuropathy: A Systematic Review and Meta-Analysis

Purpose

To determine the efficacy and safety of a neuromodulation intervention regimen in the treatment of chemotherapy-induced peripheral neuropathy (CIPN).

Patients and Methods

Systematic searches were conducted in seven English databases. Randomized controlled trials of all neuromodulation interventions (both invasive and non-invasive) for the treatment of CIPN were selected. Group comparisons of differences between interventions and controls were also made. We divided the outcomes into immediate-term effect (≤3 weeks), short-term effect (3 weeks to ≤3 months), and long-term effect (>3 months).

Results

Sixteen studies and 946 patients with CIPN were included. Among immediate-term effects, neuromodulation interventions were superior to usual care for improving pain (SMD=-0.77, 95% CI -1.07~ 0.47), FACT-Ntx (MD = 5.35, 95% CI 2.84~ 7.87), and QOL (SMD = 0.44, 95% CI 0.09~ 0.79) (moderate certainty); neuromodulation loaded with usual care was superior to usual care for improving pain (SMD=-0.47, 95% CI -0.71 ~ -0.23), and QOL (SMD = 0.40, 95% CI 0.12 ~ 0.69) (moderate certainty). There were no statistically significant differences between the neuromodulation interventions regimen vs usual care in short- and long-term outcomes and neuromodulation vs sham stimulation from any outcome measure. There were mild adverse events such as pain at the site of stimulation and bruising, and no serious adverse events were reported.

Conclusion

Neuromodulation interventions had significant immediate-term efficacy in CIPN but had not been shown to be superior to sham stimulation; short-term and long-term efficacy could not be determined because there were too few original RCTs. Moreover, there are no serious adverse effects of this therapy.

Non-pharmacological therapy for chemotherapy-induced peripheral neurotoxicity: a network meta-analysis of randomized controlled trials

BACKGROUND

Chemotherapy-induced peripheral neurotoxicity (CIPN) is the most common adverse effect in patients undergoing chemotherapy, and no effective interventions are currently available for its prevention and treatment. Non-pharmacological therapies appear to be beneficial for the prevention and treatment of CIPN, but it remains unclear which therapy is most effective. The aim of this study was to identify the most effective non-pharmacological therapy for CIPN patients.

METHODS

PubMed, Web of Science, Embase, and Cochrane Library were searched for randomized controlled trials on non-pharmacological therapies for CIPN. The primary outcomes included pain and peripheral neuropathological symptoms, and the secondary outcomes included quality of life, sensory and motor symptoms. The pairwise analysis and a network meta-analysis were performed using a random effects model.

RESULTS

A total of 46 articles were included in this study, involving 2,878 participants. Our study showed that massage was more effective in pain-alleviating compared with acupuncture [SMD = 0.81, 95%CI (0.04, 1.57)], vitamin and gabapentin [SMD = 2.56, 95%CI (1.39, 3.74)], and usual care and placebo [SMD = 0.9, 95%CI (0.31, 1.49)]. As for attenuating peripheral neuropathological symptoms, massage was more effective than usual care and placebo [SMD = 0.75, 95%CI (0.33, 1.17)], sensorimotor training [SMD = 1.17, 95%CI (0.24, 2.10)], electrostimulation [SMD=-1.18, 95%CI (-2.14, -0.21)], multimodal exercise [SMD=-0.82, 95%CI (-1.57, -0.08)], and resistance training [SMD = 1.03, 95%CI (0.11, 1.95)]. Massage was also more effective than other non-pharmacological therapies in improving quality of life, sensory and motor symptoms.

CONCLUSIONS

According to our study, massage has advantages in alleviating pain, improving quality of life, and improving peripheral neuropathological symptoms and has better effect than other non-pharmacological interventions, representing certain clinical significance. However, the results of this study should be interpreted with caution due to the limitations of the included studies. In the future, more high-quality multi arm randomized controlled trials can be attempted to provide direct comparisons of the relative effects of non-pharmacological interventions.

Photophysical Mechanisms of Photobiomodulation Therapy as Precision Medicine

Despite a significant focus on the photochemical and photoelectrical mechanisms underlying photobiomodulation (PBM), its complex functions are yet to be fully elucidated. To date, there has been limited attention to the photophysical aspects of PBM. One effect of photobiomodulation relates to the non-visual phototransduction pathway, which involves mechanotransduction and modulation to cytoskeletal structures, biophotonic signaling, and micro-oscillatory cellular interactions. Herein, we propose a number of mechanisms of PBM that do not depend on cytochrome c oxidase. These include the photophysical aspects of PBM and the interactions with biophotons and mechanotransductive processes. These hypotheses are contingent on the effect of light on ion channels and the cytoskeleton, the production of biophotons, and the properties of light and biological molecules. Specifically, the processes we review are supported by the resonant recognition model (RRM). This previous research demonstrated that protein micro-oscillations act as a signature of their function that can be activated by resonant wavelengths of light. We extend this work by exploring the local oscillatory interactions of proteins and light because they may affect global body circuits and could explain the observed effect of PBM on neuro-cortical electroencephalogram (EEG) oscillations. In particular, since dysrhythmic gamma oscillations are associated with neurodegenerative diseases and pain syndromes, including migraine with aura and fibromyalgia, we suggest that transcranial PBM should target diseases where patients are affected by impaired neural oscillations and aberrant brain wave patterns. This review also highlights examples of disorders potentially treatable with precise wavelengths of light by mimicking protein activity in other tissues, such as the liver, with, for example, Crigler-Najjar syndrome and conditions involving the dysregulation of the cytoskeleton. PBM as a novel therapeutic modality may thus behave as "precision medicine" for the treatment of various neurological diseases and other morbidities. The perspectives presented herein offer a new understanding of the photophysical effects of PBM, which is important when considering the relevance of PBM therapy (PBMt) in clinical applications, including the treatment of diseases and the optimization of health outcomes and performance.