Pregabalin for the Prevention of Oxaliplatin-Induced Painful Neuropathy: A Randomized, Double-Blind Trial

Efficacy of transauricular vagus nerve stimulation for the treatment of chemotherapy-induced painful peripheral neuropathy: a randomized controlled exploratory study

BACKGROUND

Chemotherapy-induced painful peripheral neuropathy (CIPN) is a common adverse event in cancer patients, and there is still a lack of effective treatment. Transauricular vagal nerve stimulation (taVNS) is a minimally invasive treatment, but there are few reports regarding its efficacy for CIPN.

OBJECTIVE

To investigate the efficacy and possible mechanism of taVNS in patients with CIPN.

METHODS

Twenty-seven patients with CIPN were randomly divided into a taVNS group (n = 14) and a sham stimulation (SS) group (n = 13). A numerical rating scale (NRS) for pain, NCICTCAE 4.0 (neurotoxicity classification), quantitative sensory test (QST), Short-Form-Health Survey-12 (SF-12), and Athens Insomnia Scale (AIS) were administered before the intervention (D-10) and on the day after the intervention (D0), and the inflammatory cytokines in plasma were also measured. The NRS, NCI-CTCAE 4.0, SF-12, and AIS were administered again at D30 and D90.

RESULTS

Compared with the SS group, the NRS and AIS in the taVNS group were significantly lower at D0. The impact lasted until D30. There were no statistically significant differences in the NRS and AIS between the 2 groups at D90. On D30, the mental component score of the SF-12 was significantly higher in the taVNS group than in the SS group. No adverse events were found. There was no significant difference in QST and plasma inflammatory cytokines between the 2 groups.

CONCLUSION

taVNS can relieve chemotherapy-induced neuropathic pain in the short term, can improve sleep status and quality of life, and is expected to become a novel clinical treatment method for CIPN.

Topical Oxaliplatin Produces Gain- and Loss-of-Function in Multiple Classes of Sensory Afferents

The platinum chemotherapeutic oxaliplatin produces dose-limiting pain, dysesthesia, and cold hypersensitivity in most patients immediately after infusion. An improved understanding of the mechanisms underlying these symptoms is urgently required to facilitate the development of symptomatic or preventative therapies. In this study, we have used skin-saphenous nerve recordings in vitro and behavioral experiments in mice to characterize the direct effects of oxaliplatin on different types of sensory afferent fibers. Our results confirmed that mice injected with oxaliplatin rapidly develop mechanical and cold hypersensitivities. We further noted profound changes to A fiber activity after the application of oxaliplatin to the receptive fields in the skin. Most oxaliplatin-treated Aδ- and rapidly adapting Aβ-units lost mechanical sensitivity, but units that retained responsiveness additionally displayed a novel, aberrant cold sensitivity. Slowly adapting Aβ-units did not display mechanical tachyphylaxis, and a subset of these fibers was sensitized to mechanical and cold stimulation after oxaliplatin treatment. C fiber afferents were less affected by acute applications of oxaliplatin, but a subset gained cold sensitivity. Taken together, our findings suggest that direct effects on peripheral A fibers play a dominant role in the development of acute oxaliplatin-induced cold hypersensitivity, numbness, and dysesthesia. PERSPECTIVE: The chemotherapeutic drug oxaliplatin rapidly gives rise to dose-limiting cold pain and dysesthesia. Here, we have used behavioral and electrophysiological studies of mice to characterize the responsible neurons. We show that oxaliplatin directly confers aberrant cold responsiveness to subsets of A-fibers while silencing other fibers of the same type.

Chemotherapy-Induced Peripheral Neuropathy: Diagnosis, Agents, General Clinical Presentation, and Treatments

PURPOSE OF REVIEW

This review aims to discuss pathophysiology, diagnosis, clinical presentation, and treatment of chemotherapy-induced peripheral neuropathy. Agent-specific presentation and pathophysiology is also being discussed.

RECENT FINDINGS

As new systemic oncological treatments continue to be developed, the number of cancer survivors continues to grow. Survivors are living longer with the long-term side effects of oncological treatments. We reviewed the pathophysiology of agent-specific chemotherapy-induced peripheral neuropathy and the updates in its treatment and preventative tools. Chemotherapy-induced peripheral neuropathy is a debilitating long-term side effect that often impairs cancer survivors' function and quality of life. The increasing life expectancy of cancer survivors has resulted in increased prevalence of this condition. Understanding its intricacies can provide physicians with better treatment tools and research opportunities to develop or identify new therapeutic agents.

Duloxetine for the Prevention of Oxaliplatin Induced Peripheral Neuropathy: A Randomized, Placebo-Controlled, Double-blind Clinical Trial

PURPOSE

Peripheral neuropathy is a dose-limiting adverse effect of oxaliplatin. The aim of this study was to evaluate the efficacy and safety of duloxetine in the prevention of oxaliplatin-induced peripheral neuropathy (OIPN).

METHOD

Cancer patients receiving oxaliplatin based chemotherapy were randomized into two arms. Duloxetine 60 mg capsule was given in the first 14 days of each chemotherapy cycle to one arm and placebo was similarly given to another. We compared the two arms based on the incidence of neuropathy and the results of the nerve conduction study (NCS). Grade of complained neuropathy was recorded according to Common Terminology Criteria for Adverse Events (CTCAE).

RESULTS

Thirty-two patients mostly rectal cancer (90.6%) were randomized to duloxetine and placebo arms. Highest grade of neuropathy in each cycle was not significantly different between the two groups. Six weeks after treatment incidence of neuropathy of any grade was 52.9 in duloxetine arm compared to 76.9% in placebo arm (P: 0.26). Patients in the duloxetine arm had a lower percentage of chemotherapy cycles (mean) in which they reported distal paresthesia (51% vs. 84%, P = 0.01) and throat discomfort (37% vs. 69%, P = 0.01). Results of NCS were mostly comparable between the two arms except for the velocity in two of the examined nerve which was significantly higher in duloxetine group. Duloxetine was safe and well-tolerated.

CONCLUSION

Although a definite conclusion might be difficult to draw but administering duloxetine for 14 days in each chemotherapy cycle could not decrease the incidence of acute OIPN based on CTCAE grading system.

Duloxetine for prevention and treatment of chemotherapy-induced peripheral neuropathy (CIPN): systematic review and meta-analysis

INTRODUCTION

Duloxetine has previously been reported to be promising in the setting of chemotherapy-induced peripheral neuropathy (CIPN). The aim of this study was to conduct a comprehensive systematic review and meta-analysis, on the use of duloxetine in prevention and treatment of CIPN.

METHODS

PubMed, Embase and Cochrane CENTRAL were searched from database inception up until April 2022. Articles were included in this review if they reported on duloxetine use in the setting of CIPN, in a multiarm comparative human trial. A random effects DerSimonian-Laird model was used to calculate summary risk ratios (RR) and corresponding 95% CIs, comparing duloxetine to placebo. This review was registered on.

RESULTS

Seven randomised controlled trials that included 645 patients were identified. Five reported on duloxetine for treatment of CIPN, and two for prevention of CIPN. Two studies had some concern for bias. Duloxetine was statistically similar to placebo in its efficacy, both in the treatment (RR 0.92, 95% CI 0.84 to 1.01) and prevention (RR 1.02, 95% CI 0.87 to 1.19) of CIPN. Safety profile was similar, in the treatment (RR 1.31, 95% CI 0.90 to 1.89) and prevention (RR 1.52, 95% CI 0.98 to 2.38) setting.

CONCLUSION

There is currently limited evidence supporting duloxetine's use for CIPN. There is a need for more comprehensive and higher-quality trials assessing duloxetine in the setting of CIPN, before further clinical practice recommendations.

TRIAL REGISTRATION NUMBER

PROSPERO (CRD42022327487).

Pregabalin Silences Oxaliplatin-Activated Sensory Neurons to Relieve Cold Allodynia

Oxaliplatin is a platinum-based chemotherapeutic agent that causes cold and mechanical allodynia in up to 90% of patients. Silent Nav1.8-positive nociceptive cold sensors have been shown to be unmasked by oxaliplatin, and this event has been causally linked to the development of cold allodynia. We examined the effects of pregabalin on oxaliplatin-evoked unmasking of cold sensitive neurons using mice expressing GCaMP-3 in all sensory neurons. Intravenous injection of pregabalin significantly ameliorates cold allodynia, while decreasing the number of cold sensitive neurons by altering their excitability and temperature thresholds. The silenced neurons are predominantly medium/large mechano-cold sensitive neurons, corresponding to the "silent" cold sensors activated during neuropathy. Deletion of α2δ1 subunits abolished the effects of pregabalin on both cold allodynia and the silencing of sensory neurons. Thus, these results define a novel, peripheral inhibitory effect of pregabalin on the excitability of "silent" cold-sensing neurons in a model of oxaliplatin-dependent cold allodynia.

Soluble epoxide hydrolase inhibition alleviates chemotherapy induced neuropathic pain

Chemotherapy induced peripheral neuropathy (CIPN) is a particularly pernicious form of neuropathy and the associated pain is the primary dose-limiting factor of life-prolonging chemotherapy treatment. The prevalence of CIPN is high and can last long after treatment has been stopped. Currently, late in the COVID-19 pandemic, there are still increased psychological pressures on cancer patients as well as additional challenges in providing analgesia for them. These include the risks of nonsteroidal anti-inflammatory drug (NSAID) analgesics potentially masking early infection symptoms and the immunosuppression of steroidal and opiate based approaches. Even without these concerns, CIPN is often inadequately treated with few therapies that offer significant pain relief. The experiments we report use soluble epoxide hydrolase inhibitors (sEHI) which relieved this intractable pain in preclinical models. Doses of EC5026, an IND candidate intended to treat neuropathic pain, elicited dose dependent analgesic responses in multiple models including platinum-based, taxane, and vinca alkaloid-based CIPN pain in Sprague Dawley rats. At the same time as a class, the sEHI are known to result in fewer debilitating side effects of other analgesics, likely due to their novel mechanism of action. Overall, the observed dose-dependent analgesia in both male and female rats across multiple models of chemotherapy induced neuropathic pain holds promise as a useful tool when translated to the clinic.

Treatment for chemotherapy-induced peripheral neuropathy: A systematic review of randomized control trials

Purpose: Treatment of chemotherapy-induced peripheral neuropathy (CIPN) is challenging for clinicians, and many clinical trials and meta-analyses on CIPN are controversial. There are also few comparisons of the efficacy among drugs used to treat CIPN. Therefore, this systematic review aimed to study the efficacy of drugs in treating CIPN using existing randomized controlled trials. Methods: Electronic databases were searched for randomized controlled trials (RCTs) involving any pharmaceutical intervention and/or combination therapy of treating CIPN. Results: Seventeen RCTs investigating 16 drug categories, duloxetine, pregabalin, crocin, tetrodotoxin, venlafaxine, monosialotetrahexosyl ganglioside (GM1), lamotrigine, KA (ketamine and amitriptyline) cream, nortriptyline, amitriptyline, topical Citrullus colocynthis (bitter apple) oil, BAK (baclofen, amitriptyline hydrochloride, and ketamine) pluronic lecithin organogel, gabapentin, and acetyl l-carnitine (ALC), in the treatment of CIPN were retrieved. Many of the included RCTs consisted of small sample sizes and short follow-up periods. It was difficult to quantify due to the highly variable nature of outcome indicators. Conclusion: Duloxetine, venlafaxine, pregabalin, crocin, tetrodotoxin, and monosialotetrahexosyl ganglioside exhibited some beneficial effects in treating CIPN. Duloxetine, GM1, and crocin showed moderate benefits based on the evidence review, while lamotrigine, KA cream, nortriptyline, amitriptyline, and topical Citrullus colocynthis (bitter apple) oil were not beneficial. Further studies were necessary to confirm the efficacy of gabapentin in the treatment of CIPN because of the controversy of efficacy of gabapentin. Furthermore, BAK topicalcompound analgesic gel only had a tendency to improve the CIPN symptoms, but the difference was not statistically significant. ALC might result in worsening CIPN. Most studies were not of good quality because of small sample sizes. Therefore, standardized randomized controlled trials with large samples were needed to critically assess the effectiveness of these drugs in treating CIPN in the future.

Pregabalin for chemotherapy-induced neuropathy: background and rationale for further study

Chemotherapy-induced neuropathy is difficult to manage, and the pain associated with neuropathy is poorly responsive to gabapentin in a randomized trial. Duloxetine is the only drug that has been found to be effective in reducing pain from chemotherapy neuropathy. In this qualitative review, the use of pregabalin for chemotherapy-induced neuropathy is discussed including the rationale and pharmacological reasons why pregabalin should be considered in a large, randomized placebo-controlled trial.

Targeting OCT2 with Duloxetine to Prevent Oxaliplatin-Induced Peripheral Neurotoxicity

Oxaliplatin-induced peripheral neurotoxicity (OIPN) is a debilitating side effect that afflicts ~90% of patients that is initiated by OCT2-dependent uptake of oxaliplatin in DRG neurons. The antidepressant drug duloxetine has been used to treat OIPN, although its usefulness in preventing this side effect remains unclear. We hypothesized that duloxetine has OCT2-inhibitory properties and can be used as an adjunct to oxaliplatin-based regimens to prevent OIPN. Transport studies were performed in cells stably transfected with mouse or human OCT2 and in isolated mouse DRG neurons ex vivo. Wild-type and OCT2-deficient mice were used to assess effects of duloxetine on hallmarks of OIPN, endogenous OCT2 biomarkers, and the pharmacokinetics of oxaliplatin, and the translational feasibility of a duloxetine-oxaliplatin combination was evaluated in various models of colorectal cancer. We found that duloxetine potently inhibited the OCT2-mediated transport of several xenobiotic substrates, including oxaliplatin, in a reversible, concentration-dependent manner, and independent of species and cell context. Furthermore, duloxetine restricted access of these substrates to DRG neurons ex vivo and prevented OIPN in wild-type mice to a degree similar to the complete protection observed in OCT2-deficient mice, without affecting the plasma levels of oxaliplatin. Importantly, the uptake and cytotoxicity of oxaliplatin in tumor cell lines in vitro and in vivo were not negatively influenced by duloxetine. The observed OCT2-targeting properties of duloxetine, combined with the potential for clinical translation, provide support for its further exploration as a therapeutic candidate for studies aimed at preventing OIPN in cancer patients requiring treatment with oxaliplatin.

Significance

We found that duloxetine has potent OCT2-inhibitory properties and can diminish excessive accumulation of oxaliplatin into DRG neurons. In addition, pre-treatment of mice with duloxetine prevented OIPN without significantly altering the plasma pharmacokinetics and antitumor properties of oxaliplatin. These results suggest that intentional inhibition of OCT2-mediated transport by duloxetine can be employed as a prevention strategy to ameliorate OIPN without compromising the effectiveness of oxaliplatin-based treatment.

Current and Emerging Pharmacotherapeutic Interventions for the Treatment of Peripheral Nerve Disorders

Peripheral nerve disorders are caused by a range of different aetiologies. The range of causes include metabolic conditions such as diabetes, obesity and chronic kidney disease. Diabetic neuropathy may be associated with severe weakness and the loss of sensation, leading to gangrene and amputation in advanced cases. Recent studies have indicated a high prevalence of neuropathy in patients with chronic kidney disease, also known as uraemic neuropathy. Immune-mediated neuropathies including Guillain-Barré syndrome and chronic inflammatory demyelinating polyradiculoneuropathy may cause significant physical disability. As survival rates continue to improve in cancer, the prevalence of treatment complications, such as chemotherapy-induced peripheral neuropathy, has also increased in treated patients and survivors. Notably, peripheral neuropathy associated with these conditions may be chronic and long-lasting, drastically affecting the quality of life of affected individuals, and leading to a large socioeconomic burden. This review article explores some of the major emerging clinical and experimental therapeutic agents that have been investigated for the treatment of peripheral neuropathy due to metabolic, toxic and immune aetiologies.

Drug treatment for chemotherapy-induced peripheral neuropathy in patients with pancreatic cancer

Pancreatic cancer (PC) is a lethal disease where most tumors are too advanced at diagnosis for resection, leaving chemotherapy as the mainstay of treatment. Although the prognosis of unresectable PC is poor, it has been dramatically improved by new chemotherapy treatments, such as the combination of 5-fluorouracil, oxaliplatin, irinotecan, and leucovorin (FOLFIRINOX) or gemcitabine plus nab-paclitaxel. However, as oxaliplatin and paclitaxel are common neurotoxic drugs, chemotherapy-induced peripheral neuropathy (CIPN) is a common and severe adverse effect of both treatments. As there are no agents recommended in the ASCO guidelines, we review the methods used to treat CIPN caused by PC treatment. The efficacy of duloxetine was observed in a large randomized controlled trial (RCT). In addition, pregabalin was more effective than duloxetine for CIPN in two RCTs. Although duloxetine and pregabalin can be effective for CIPN, they have several side effects. Therefore, the choice between the two drugs should be determined according to effect and tolerability. Mirogabalin is also used in patients with PC and there is hope it will yield positive outcomes when treating CIPN in the future.

Dissecting central post-stroke pain: a controlled symptom-psychophysical characterization

Central post-stroke pain affects up to 12% of stroke survivors and is notoriously refractory to treatment. However, stroke patients often suffer from other types of pain of non- neuropathic nature (musculoskeletal, inflammatory, complex regional) and no head-to-head comparison of their respective clinical and somatosensory profiles has been performed so far.

We compared 39 patients with definite central neuropathic post-stroke pain with two matched- control groups: 32 patients with exclusively non-neuropathic pain developed after stroke and 31 stroke patients not complaining of pain. Patients underwent deep phenotyping via a comprehensive assessment including clinical exam, questionnaires and quantitative sensory testing to dissect central post-stroke pain from chronic pain in general and stroke.

While central post-stroke pain was mostly located in the face and limbs, non-neuropathic pain was predominantly axial and located in neck, shoulders and knees (p<0.05). Neuropathic Pain Symptom Inventory clusters burning (82.1%, n=32, p<0.001), tingling (66.7%, n= 26, p<0.001) and evoked by cold (64.1%, n=25, p<0.001) occurred more frequently in central post-stroke pain. Hyperpathia, thermal and mechanical allodynia also occurred more commonly in this group (p<0.001), which also presented higher levels of deafferentation (p<0.012) with more asymmetric cold and warm detection thresholds compared to controls. In particular, cold hypoesthesia (considered when the threshold of the affected side was less than 41% of the contralateral threshold) odds ratio was 12 (95%CI: 3.8-41.6) for neuropathic pain. Additionally, cold detection threshold/ warm detection threshold ratio correlated with the presence of neuropathic pain (ρ=-0.4, p< 0.001). Correlations were found between specific neuropathic pain symptom clusters and quantitative sensory testing: paroxysmal pain with cold (ρ=-0.4; p=0.008) and heat pain thresholds (ρ=0.5; p=0.003), burning pain with mechanical detection (ρ= -0.4; p=0.015) and mechanical pain thresholds (ρ=-0.4, p<0.013), evoked pain with mechanical pain threshold (ρ= -0.3; p=0.047). Logistic regression showed that the combination of cold hypoesthesia on quantitative sensory testing, the Neuropathic Pain Symptom Inventory, and the allodynia intensity on bedside examination explained 77% of the occurrence of neuropathic pain.

These findings provide insights into the clinical-psychophysics relationships in central post-stroke pain and may assist more precise distinction of neuropathic from non-neuropathic post-stroke pain in clinical practice and in future trials.

Prevention of Oxaliplatin-Induced Peripheral Neuropathy: A Systematic Review and Meta-Analysis

Background

Oxaliplatin-induced peripheral neuropathy (OIPN) has significant clinical impact on the quality of life for cancer patients and is a dose limiting toxicity. Trials studying preventive measures have been inconclusive. A systematic review and meta-analysis were conducted to evaluate the existing pharmacological and non-pharmacological interventions to prevent chronic OIPN.

Methods

Literature databases PubMed-MEDLINE, Embase and Scopus, were searched from 1 Jan 2005 to 08 Aug 2020 and major conferences’ abstracts were reviewed for randomized controlled trials that examined the efficacy of any preventive measure for OIPN. The primary outcome measure was the incidence of chronic OIPN with a preventive intervention as compared to placebo or no intervention. The pooled risk ratio and its 95% confidence interval were calculated using a random effects model. A network meta-analysis was conducted to derive indirect evidence of any preventive effect of an intervention against placebo when original trials compared one intervention against another.

Results

Forty-four trials were analyzed describing 29 chemoprotective interventions, including combinations, and 1 non-pharmacological intervention. Ratings were assessed via a combination of outcomes with quality assessment using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) framework. Of the 30 interventions examined, there were six interventions supporting potential efficacy, 11 interventions with insufficient evidence and 13 interventions not recommended.

Conclusion

Currently, there is insufficient certainty to support any intervention as effective in preventing OIPN. Of note is that most of these studies have focused on pharmacological interventions; non-pharmacological interventions are underexplored. Further research on ways to limit OIPN is needed.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=225095, Prospero Registration Number: CRD42021225095.

Acute inpatient rehabilitation improves function independent of comorbidities in medically complex patients

Objectives

(1) To evaluate the benefits of acute inpatient rehabilitation for a medically complex patient population and (2) to assess the effect of comorbid conditions on rehabilitation outcomes.

Design

Retrospective cohort study.

Setting

Freestanding inpatient rehabilitation facility.

Participants

A total of 270 medically complex adult patients including those with cardiac, pulmonary, and orthopedic conditions, with mean age of 73.6 years; 52.6% were female and 47.4% were male (N=270).

Interventions

Not applicable.

Main Outcome Measures

Functional Independence Measure (FIM) gain, FIM efficiency, rehabilitation length of stay (RLOS), home discharge rate, and readmission to acute care (RTAC).

Results

Among 270 medically complex patients, mean total FIM gain, mean RLOS, and mean FIM efficiency with SD were 26.0±13.6 points, 12.6±5.9 days, and 2.3±1.6, respectively. A total of 71.9% of patients were discharged to home, 12.2% for RTAC, and 15.9% to a skilled nursing facility (SNF). Hypertension (HTN) was the only comorbidity significantly associated with FIM gain (53.7% [total FIM gain ≥27] vs 67.2% [total FIM gain <27]; P=.024) and FIM efficiency (53.3% [FIM efficiency ≥2.12] vs 67.4% [FIM efficiency <2.12]; P=.025), independent of age, body mass index, sex, race, ethnicity, insurance type, and Charlson Comorbidity Index. The 5 most common reasons for RTAC were cardiac, pulmonary, acute blood loss anemia, infection, and neurologic conditions.

Conclusions

Among 270 medically complex patients, 71.9% were discharged to home, 15.9% to an SNF, and 12.2% for RTAC with a mean RLOS 12.6 days, mean total FIM gain of 26 points, and mean FIM efficiency of 2.3, which were all better than those of all admissions at our facility in 2018. Furthermore, RLOS, total FIM gain and FIM efficiency in this study were all better than their corresponding eRehabData weighted national benchmarks (RLOS, 15.82 days; FIM gain, 25.57; FIM efficiency, 2.13) for a total of 202,520 discharges in 2018. These findings support acute inpatient rehabilitation for this patient population. With the exception of HTN, no medical comorbidities or demographic variables were associated with rehabilitation outcomes.

Mirogabalin vs pregabalin for chemotherapy-induced peripheral neuropathy in pancreatic cancer patients

Background

The prognosis of pancreatic cancer (PC) has been improved by new chemotherapy regimens (combination of 5-fluorouracil, oxaliplatin, irinotecan, and leucovorin (FOLFIRINOX) or gemcitabine plus nab-paclitaxel (GnP)). Unfortunately, chemotherapy-induced peripheral neuropathy (CIPN) is a common adverse event of these two regimens. The efficacy of pregabalin for CIPN has been reported in previous studies. However, the efficacy of mirogabalin for CIPN remains unknown. Thus, in this study, we aimed to clarify which drug (mirogabalin or pregabalin) was more valuable for improving CIPN.

Methods

A total of 163 PC patients who underwent FOLFIRINOX or GnP between May 2014 and January 2021 were enrolled. Among them, 34 patients were diagnosed with CIPN. Thirteen patients were treated with mirogabalin (mirogabalin group), and twenty-one patients were treated with pregabalin (pregabalin group). Treatment efficacy was compared between the two groups.

Results

In both the mirogabalin group and the pregabalin group, the grade of patients with CIPN at 2, 4, and 6 weeks after the initiation of treatment showed significant improvement compared to the pretreatment grade. Notably, the rate of CIPN improvement was higher in the mirogabalin group than in the pregabalin group (2 weeks: 84.6% (11/13) vs 33.3% (7/21), P value = 0.005; 4 weeks, 6 weeks: 92.3% (12/13) vs 33.3% (7/21), P value = 0.001).

Conclusions

Although both mirogabalin and pregabalin were effective at improving CIPN, mirogabalin might be a suitable first choice for CIPN in PC patients.

Trial registration

Not applicable

Chemotherapy-Induced Peripheral Neuropathy: Epidemiology, Pathomechanisms and Treatment

PURPOSE

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

FINDINGS

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

IMPLICATIONS

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

Renin-angiotensin-aldosterone system inhibitors prevent the onset of oxaliplatin-induced peripheral neuropathy: A retrospective multicenter study and in vitro evaluation

Oxaliplatin (OXA) is used in chemotherapy for various cancer types and is associated with acute and chronic neurotoxicity. However, a preventive strategy for OXA-induced peripheral neuropathy (OIPN) and its underlying mechanism remain unclear. We examined the effects of renin-angiotensin-aldosterone system inhibitors (RAASIs) on OIPN by performing a retrospective multicenter study and an in vitro assay. We retrospectively evaluated electronic medical records of 976 patients who underwent one or more courses of OXA-containing regimens at Ehime, Okayama, and Tokushima University Hospitals. The primary endpoint was the incidence of OIPN during or after OXA administration. The effects of RAASIs and OXA on the neurite length in PC12 cells were determined. The combined administration of an OXA-containing regimen and RAASI significantly inhibited the cumulative incidence grade-2 or higher OIPN (log-rank test; P=0.0001). RAASIs markedly suppressed the development of both acute and chronic OIPN (multivariate analysis; P=0.017 and P=0.011). In an in vitro assay, 10 µM OXA suppressed the neurite length; treatment with 1 μM aliskiren, spironolactone, 10 μM candesartan, and enalapril significantly restored neurite length to the control level. Moreover, 1 μM SCH772984 (a selective inhibitor of extracellular signal-regulated kinase, ERK1/2) and 500 μM SQ22536 (a cell-permeable adenylate cyclase [AC] inhibitor) markedly abolished neuroprotective effects of candesartan and enalapril. These results indicate that RAASIs possess preventive or therapeutic effects in acute and chronic OIPN, candesartan and enalapril may directly increase in the activity of ERK1/2 and AC in PC12 cells.

Targeting strategies for oxaliplatin-induced peripheral neuropathy: clinical syndrome, molecular basis, and drug development

Oxaliplatin (OHP)-induced peripheral neurotoxicity (OIPN) is a severe clinical problem and potentially permanent side effect of cancer treatment. For the management of OIPN, accurate diagnosis and understanding of significant risk factors including genetic vulnerability are essential to improve knowledge regarding the prevalence and incidence of OIPN as well as enhance strategies for the prevention and treatment of OIPN. The molecular mechanisms underlying OIPN are complex, with multi-targets and various cells causing neuropathy. Furthermore, mechanisms of OIPN can reinforce each other, and combination therapies may be required for effective management. However, despite intense investigation in preclinical and clinical studies, no preventive therapies have shown significant clinical efficacy, and the established treatment for painful OIPN is limited. Duloxetine is the only agent currently recommended by the American Society of Clinical Oncology. The present article summarizes the most recent advances in the field of studies on OIPN, the overview of the clinical syndrome, molecular basis, therapy development, and outlook of future drug candidates. Importantly, closer links between clinical pain management teams and oncology will advance the effectiveness of OIPN treatment, and the continued close collaboration between preclinical and clinical research will facilitate the development of novel prevention and treatments for OIPN.

Chemotherapy-induced peripheral neuropathy and rehabilitation: A review

Chemotherapy-induced peripheral neuropathy (CIPN) is a common complication after chemotherapy that can damage the sensory, motor, autonomic, or cranial nerves in approximately 30%-60% of patients with cancer. CIPN can lead to detrimental dose modifications and/or premature chemotherapy discontinuation due to patient intolerance. The long-term impact of CIPN is particularly challenging and can have a profound impact on the quality of life (QoL) and survivorship. However, this condition is often underdiagnosed. No agents have been established to prevent CIPN. Pre-chemotherapy testing is recommended for high-risk patients. Duloxetine is considered a first-line treatment, whereas gabapentin, pregabalin, tricyclic antidepressants, and topical compounding creams may be used for neuropathic pain control. Home-based, low-to-moderate walking, and resistance exercise during chemotherapy can reduce the severity and prevalence of CIPN symptoms, especially in older patients. Pre-habilitation and rehabilitation should be recommended for all patients receiving cytotoxic chemotherapies. The purpose of this article is to review common chemotherapeutic drugs causing CIPN, risk factors, diagnosis and treatment of CIPN, and evidence of the benefits of rehabilitation.

Treatment strategy of oxaliplatin-induced peripheral neuropathy: a retrospective, nationwide study

PURPOSE

Chemotherapy-induced peripheral neuropathy (CIPN) is a common adverse event of cancer treatment; however, no drug is recommended for the prevention of CIPN. In Japan, several drugs such as Gosha-Jinki-Gan and duloxetine are frequently administered as a treatment for CIPN. The aim of this study was to elucidate prescription patterns of drugs administered for CIPN caused by oxaliplatin and the association between these drugs and the duration of oxaliplatin treatment.

METHODS

We conducted a retrospective nationwide study using the JMDC administrative claims database (January 2005-June 2020; JMDC Inc., Japan). Patients newly treated with oxaliplatin were identified, and prescription patterns of CIPN medication including Gosha-Jinki-Gan, pregabalin, duloxetine, mecobalamin, and mirogabalin were investigated. The primary outcome was the duration of oxaliplatin treatment. Multivariable logistic regression analysis was performed to examine the association between CIPN medication and duration of oxaliplatin treatment.

RESULTS

A total of 4,739 patients who newly received oxaliplatin were identified. Of these, 759 (16.0%) had received CIPN medication. Duloxetine was administered in 99 (2.1%) patients. Multivariable logistic regression analysis revealed that CIPN medication was significantly associated with the prolonged duration of oxaliplatin treatment (odds ratio: 2.35, [95% confidence interval: 1.99-2.77]).

CONCLUSION

Real-world data demonstrated that the administration rate of CIPN medication was higher in patients who received oxaliplatin treatment for over 6 months.

Preventive Efficacy and Safety of Yiqi-Wenjing-Fang Granules on Oxaliplatin-Induced Peripheral Neuropathy: A Protocol for a Randomized, Double-Blind, Placebo-Controlled, Multicenter Trial

Background. Oxaliplatin-induced peripheral neuropathy (OIPN) is one of the most common side effects of oxaliplatin, which can cause reduction and cessation of oxaliplatin-based chemotherapy and significantly affect patients' quality of life. However, no drug has got recognition to prevent or treat OIPN. Yiqi-Wenjing-Fang (YWF) is a joint name of Chinese medicine prescriptions with similar effects of tonifying qi and warming meridians, represented by Huangqi Guizhi Wuwu decoction (HGWD) and Danggui Sini decoction (DSD), both from "Treatise on Cold Pathogenic and Miscellaneous Diseases." YWF granules, including HGWD granules and DSD granules, have been, respectively, demonstrated to be effective in preventing OIPN in previous small-sample observations. The purpose of this study is to enlarge the sample size for further evaluation of the preventive efficacy and safety of YWF granules on OIPN. Methods and Analysis. This study is a randomized, double-blind, placebo-controlled, and multicenter clinical trial. 360 postoperative patients with stage IIa-IIIc colorectal cancer will be randomly assigned into placebo-control group, intervention group I, and intervention group II, taking the mimetic granules of YWF as placebo, HGWD granules and DSD granules, respectively. All subjects will receive oxaliplatin-based chemotherapy regimen at the same time. EORTC QLQ-CIPN20 will be used to assess the degree of OIPN as the primary outcome measure. The grades of OIPN, quality of life, chemotherapeutic efficacy, and the number of completed chemotherapy cycles are selected as the secondary outcome measures. Discussion. Based on the condition of no recognized effective drugs in preventing OIPN, evidence-based medical study will be conducted for seeking a breakthrough in the field of Chinese herb medicine. This protocol could provide reliable and systemic research basis about the efficacy of YWF granules and the differentiation of two classical prescriptions of YWF on preventing OIPN objectively. Trial Registration. This study was registered at ClinicalTrials.gov on 26 December 2020 (ID: https://clinicaltrials.gov/ct2/show/NCT04690283).

Review of the Role of the Brain in Chemotherapy-Induced Peripheral Neuropathy

Chemotherapy-induced peripheral neuropathy (CIPN) is a common, debilitating, and dose-limiting side effect of many chemotherapy regimens yet has limited treatments due to incomplete knowledge of its pathophysiology. Research on the pathophysiology of CIPN has focused on peripheral nerves because CIPN symptoms are felt in the hands and feet. However, better understanding the role of the brain in CIPN may accelerate understanding, diagnosing, and treating CIPN. The goals of this review are to (1) investigate the role of the brain in CIPN, and (2) use this knowledge to inform future research and treatment of CIPN. We identified 16 papers using brain interventions in animal models of CIPN and five papers using brain imaging in humans or monkeys with CIPN. These studies suggest that CIPN is partly caused by (1) brain hyperactivity, (2) reduced GABAergic inhibition, (3) neuroinflammation, and (4) overactivation of GPCR/MAPK pathways. These four features were observed in several brain regions including the thalamus, periaqueductal gray, anterior cingulate cortex, somatosensory cortex, and insula. We discuss how to leverage this knowledge for future preclinical research, clinical research, and brain-based treatments for CIPN.

The Role of Nucleotide Excision Repair in Cisplatin-Induced Peripheral Neuropathy: Mechanism, Prevention, and Treatment

Platinum-based chemotherapy-induced peripheral neuropathy (CIPN) is one of the most common dose-limiting effects of cancer treatment and results in dose reduction and discontinuation of life-saving chemotherapy. Its debilitating effects are often permanent and lead to lifelong impairment of quality of life in cancer patients. While the mechanisms underlying the toxicity are not yet fully defined, dorsal root ganglia sensory neurons play an integral role in symptom development. DNA-platinum adducts accumulate in these cells and inhibit normal cellular function. Nucleotide excision repair (NER) is integral to the repair of platinum adducts, and proteins involved in its mechanism serve as potential targets for future therapeutics. This review aims to highlight NER’s role in cisplatin-induced peripheral neuropathy, summarize current clinical approaches to the toxicity, and discuss future perspectives for the prevention and treatment of CIPN.

Emerging Pharmacological and Non-Pharmacological Therapeutics for Prevention and Treatment of Chemotherapy-Induced Peripheral Neuropathy

Simple Summary

Chemotherapy-induced peripheral neuropathy (CIPN) is a common and persistent complication of commonly used chemotherapy drugs. This article provides an overview of emerging therapeutics for the prevention and treatment of CIPN and focuses on pharmacological strategies that are derived from novel mechanistic insights and have the potential to be translated into clinically beneficial approaches. It is our contention to call for fostering collaboration between basic and clinical researchers to improve the development of effective strategies.

Abstract

Chemotherapy-induced peripheral neuropathy (CIPN) is a common adverse event of several first-line chemotherapeutic agents, including platinum compounds, taxanes, vinca alkaloids, thalidomide, and bortezomib, which negatively affects the quality of life and clinical outcome. Given the dearth of effective established agents for preventing or treating CIPN, and the increasing number of cancer survivors, there is an urgent need for the identification and development of new, effective intervention strategies that can prevent or mitigate this debilitating side effect. Prior failures in the development of effective interventions have been due, at least in part, to a lack of mechanistic understanding of CIPN and problems in translating this mechanistic understanding into testable hypotheses in rationally-designed clinical trials. Recent progress has been made, however, in the pathogenesis of CIPN and has provided new targets and pathways for the development of emerging therapeutics that can be explored clinically to improve the management of this debilitating toxicity. This review focuses on the emerging therapeutics for the prevention and treatment of CIPN, including pharmacological and non-pharmacological strategies, and calls for fostering collaboration between basic and clinical researchers to improve the development of effective strategies.

Therapeutic Agents for Oxaliplatin-Induced Peripheral Neuropathy; Experimental and Clinical Evidence

Oxaliplatin is an essential drug in the chemotherapy of colorectal, gastric, and pancreatic cancers, but it frequently causes peripheral neuropathy as a dose-limiting factor. So far, animal models of oxaliplatin-induced peripheral neuropathy have been established. The mechanisms of development of neuropathy induced by oxaliplatin have been elucidated, and many drugs and agents have been proven to have neuroprotective effects in basic studies. In addition, some of these drugs have been validated in clinical studies for their inhibitory effects on neuropathy. In this review, we summarize the basic and clinical evidence for the therapeutic effects of oxaliplatin. In basic research, there are many reports of neuropathy inhibitors that target oxidative stress, inflammatory response, sodium channel, transient receptor potential (TRP) channel, glutamate nervous system, and monoamine nervous system. Alternatively, very few drugs have clearly demonstrated the efficacy for oxaliplatin-induced peripheral neuropathy in clinical trials. It is important to activate translational research in order to translate basic research into clinical research.

Therapeutic Agents for Oxaliplatin-Induced Peripheral Neuropathy; Experimental and Clinical Evidence

Oxaliplatin is an essential drug in the chemotherapy of colorectal, gastric, and pancreatic cancers, but it frequently causes peripheral neuropathy as a dose-limiting factor. So far, animal models of oxaliplatin-induced peripheral neuropathy have been established. The mechanisms of development of neuropathy induced by oxaliplatin have been elucidated, and many drugs and agents have been proven to have neuroprotective effects in basic studies. In addition, some of these drugs have been validated in clinical studies for their inhibitory effects on neuropathy. In this review, we summarize the basic and clinical evidence for the therapeutic effects of oxaliplatin. In basic research, there are many reports of neuropathy inhibitors that target oxidative stress, inflammatory response, sodium channel, transient receptor potential (TRP) channel, glutamate nervous system, and monoamine nervous system. Alternatively, very few drugs have clearly demonstrated the efficacy for oxaliplatin-induced peripheral neuropathy in clinical trials. It is important to activate translational research in order to translate basic research into clinical research.

Therapeutic Agents for Oxaliplatin-Induced Peripheral Neuropathy; Experimental and Clinical Evidence

Oxaliplatin is an essential drug in the chemotherapy of colorectal, gastric, and pancreatic cancers, but it frequently causes peripheral neuropathy as a dose-limiting factor. So far, animal models of oxaliplatin-induced peripheral neuropathy have been established. The mechanisms of development of neuropathy induced by oxaliplatin have been elucidated, and many drugs and agents have been proven to have neuroprotective effects in basic studies. In addition, some of these drugs have been validated in clinical studies for their inhibitory effects on neuropathy. In this review, we summarize the basic and clinical evidence for the therapeutic effects of oxaliplatin. In basic research, there are many reports of neuropathy inhibitors that target oxidative stress, inflammatory response, sodium channel, transient receptor potential (TRP) channel, glutamate nervous system, and monoamine nervous system. Alternatively, very few drugs have clearly demonstrated the efficacy for oxaliplatin-induced peripheral neuropathy in clinical trials. It is important to activate translational research in order to translate basic research into clinical research.

Prevention, diagnosis and management of chemotherapy-induced peripheral neuropathy: a cross-sectional study of French oncologists' professional practices

PURPOSE

Chemotherapy-induced peripheral neuropathy (CIPN) is challenging for oncologists. Many publications mention the high incidence of CIPN and the lack of effective preventive/management strategies and robust diagnostic tools. This cross-sectional study was aimed at assessing the practice of French oncologists for CIPN prevention, diagnosis and management.

METHODS

This web-based survey was sent to French oncologists by the regional cancer networks. Incidence and impact of CIPN were assessed using visual analogue scales (VAS) and diagnostic strategies were recorded. Also recorded were the drugs used to prevent or manage CIPN and their perceived efficacy and safety (VAS).

RESULTS

Among the 210 oncologists included, the perceived incidence of CIPN was about 36.2 ± 22.1% of patients. About 99.5% of oncologists declared that they assess CIPN during medical follow-up. The use of drugs to prevent CIPN was reported by 9.6% of oncologists (group B vitamins (35.0%) and calcium and magnesium infusion (25.0%)). In the case of CIPN, the therapeutic adjustment of neurotoxic anticancer drugs is performed by 99.0% of oncologists (chemotherapy change (49.8%), dose reduction (30.9%) or interruption (19.3%)). The pharmacological management of CIPN was declared by 72.9% of oncologists. The main drugs used are pregabalin (75.8%), amitriptyline (32.7%) and gabapentin (25.5%). Duloxetine (ASCO recommendation) is used by only 11.8% of oncologists.

CONCLUSION

Oncologists were clearly aware of CIPN risks, but its incidence tended to be underestimated and the ASCO recommendations for the management of CIPN were not followed. The prevention, diagnosis and management of CIPN remain problematic in clinical practice in France.

TRIAL REGISTRATION

ClinicalTrials.gov : NCT03854864.

Prevention and Management of Chemotherapy-Induced Peripheral Neuropathy in Survivors of Adult Cancers: ASCO Guideline Update

PURPOSE

To update the ASCO guideline on the recommended prevention and treatment approaches in the management of chemotherapy-induced peripheral neuropathy (CIPN) in adult cancer survivors.

METHODS

An Expert Panel conducted targeted systematic literature reviews to identify new studies.

RESULTS

The search strategy identified 257 new references, which led to a full-text review of 87 manuscripts. A total of 3 systematic reviews, 2 with meta-analyses, and 28 primary trials for prevention of CIPN in addition to 14 primary trials related to treatment of established CIPN, are included in this update.

RECOMMENDATIONS

The identified data reconfirmed that no agents are recommended for the prevention of CIPN. The use of acetyl-l-carnitine for the prevention of CIPN in patients with cancer should be discouraged. Furthermore, clinicians should assess the appropriateness of dose delaying, dose reduction, substitutions, or stopping chemotherapy in patients who develop intolerable neuropathy and/or functional impairment. Duloxetine is the only agent that has appropriate evidence to support its use for patients with established painful CIPN. Nonetheless, the amount of benefit from duloxetine is limited.Additional information is available at www.asco.org/survivorship-guidelines.

Oxaliplatin-Induced Lhermitte's Sign in Gastric Cancer

A 64-year-old Japanese man with no significant medical history presented with epigastric discomfort of 2-weeks' duration. He was diagnosed with metastatic HER2-positive gastric cancer. Chemotherapy with capecitabine, oxaliplatin, and trastuzumab was initiated. During the eighth cycle, he suddenly complained of electric shock-like pain in both legs upon neck flexion, consistent with Lhermitte's sign. Oxaliplatin was discontinued, and Lhermitte's sign resolved after 3 months. Neurotoxicity is commonly observed in platinum-based chemotherapy, but Lhermitte's sign is rare. This is the first report of oxaliplatin-induced Lhermitte's sign in a gastric cancer patient.

Spinal Cord Stimulation as a Treatment Option for Refractory Chemotherapy-Induced Peripheral Neuropathy: Case Report

Colorectal cancer is one of the most common oncological diseases. Chemotherapy is usually recommended as an adjuvant treatment for stage-II, -III, and -IV tumors. Approximately 10% of the patients develop neuropathic pain after chemotherapy, and they may remain refractory despite the administration of drugs that are commonly used to treat neuropathic pain. Spinal cord stimulation is a good treatment option for neuropathic pain of the lower limbs, and it should be trialed in patients with chemotherapy-induced peripheral neuropathy. We report the case of a patient with oxaliplatin-induced neuropathy and neuropathic pain refractory to oral medication who was successfully treated by spinal cord stimulation.

Management of Oxaliplatin-Induced Peripheral Sensory Neuropathy

Oxaliplatin-induced peripheral neurotoxicity (OIPN) is a severe and potentially permanent side effect of cancer treatment affecting the majority of oxaliplatin-treated patients, mostly with the onset of acute symptoms, but also with the establishment of a chronic sensory loss that is supposed to be due to dorsal root ganglia neuron damage. The pathogenesis of acute as well as chronic OIPN is still not completely known, and this is a limitation in the identification of effective strategies to prevent or limit their occurrence. Despite intense investigation at the preclinical and clinical levels, no treatment can be suggested for the prevention of OIPN, and only limited evidence for the efficacy of duloxetine in the treatment setting has been provided. In this review, ongoing neuroprotection clinical trials in oxaliplatin-treated patients will be analyzed with particular attention paid to the hypothesis leading to the study, to the trial strengths and weaknesses, and to the outcome measures proposed to test the efficacy of the therapeutic approach. It can be concluded that (1) prevention and treatment of OIPN still remains an important and unmet clinical need, (2) further, high-quality research is mandatory in order to achieve reliable and effective results, and (3) dose and schedule modification of OHP-based chemotherapy is currently the most effective approach to limit the severity of OIPN.

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

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

Recent advances in understanding chemotherapy-induced peripheral neuropathy

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

Inhibitory Effects of Columbianadin on Nociceptive Behaviors in a Neuropathic Pain Model, and on Voltage-Gated Calcium Currents in Dorsal Root Ganglion Neurons in Mice

Radix angelicae pubescentis (RAP) has been used in Chinese traditional medicine to treat painful diseases such as rheumatism and headache. A previous study has reported that columbianadin (CBN), a major coumarin in RAP inhibits acute and inflammatory pain behaviors. However, the effects of CBN on neuropathic pain behaviors, and the potential underlying mechanism have not been reported. In the present study, the effects of CBN, compared to another major coumarin of RAP osthole (OST), on oxaliplatin-induced neuropathic pain behaviors and on the voltage-gated calcium currents in small dorsal root ganglion (DRG) neurons were studied in mice. It was found that CBN and OST inhibited both mechanical and cold hypersensitivity induced by oxaliplatin. Moreover, CBN and OST might preferentially inhibit T- and L-type calcium currents (Ica). The inhibitory effects of CBN and OST on the oxaliplatin-induced mechanical allodynia were prevented by gabapentin. These results suggest that CBN, as well as OST might inhibit neuropathic pain behaviors through an inhibition of T- and L-type calcium currents in nociceptive DRG neurons.

Prevention of chemotherapy-induced peripheral neuropathy: A review of recent findings

Chemotherapy-induced peripheral neuropathy (CIPN) is an adverse effect of chemotherapy that is frequently experienced by patients receiving treatment for cancer. CIPN is caused by many of the most commonly used chemotherapeutic agents, including taxanes, vinca alkaloids, and bortezomib. Pain and sensory abnormalities may persist for months, or even years after the cessation of chemotherapy. The management of CIPN is a significant challenge, as it is not possible to predict which patients will develop symptoms, the timing for the appearance of symptoms can develop anytime during the chemotherapy course, there are no early indications that warrant a reduction in the dosage to halt CIPN progression, and there are no drugs approved to prevent or alleviate CIPN. This review focuses on the etiology of CIPN and will highlight the various approaches developed for prevention and treatment. The goal is to guide studies to identify, test, and standardize approaches for managing CIPN.

Chemotherapy-induced peripheral neuropathy-part 2: focus on the prevention of oxaliplatin-induced neurotoxicity

BACKGROUND

Chemotherapy-induced peripheral neuropathy (CIPN) is regarded as one of the most common dose-limiting adverse effects of several chemotherapeutic agents, such as platinum derivatives (oxaliplatin and cisplatin), taxanes, vinca alkaloids and bortezomib. CIPN affects more than 60% of patients receiving anticancer therapy and although it is a nonfatal condition, it significantly worsens patients' quality of life. The number of analgesic drugs used to relieve pain symptoms in CIPN is very limited and their efficacy in CIPN is significantly lower than that observed in other neuropathic pain types. Importantly, there are currently no recommended options for effective prevention of CIPN, and strong evidence for the utility and clinical efficacy of some previously tested preventive therapies is still limited.

METHODS

The present article is the second one in the two-part series of review articles focused on CIPN. It summarizes the most recent advances in the field of studies on CIPN caused by oxaliplatin, the third-generation platinum-based antitumor drug used to treat colorectal cancer. Pharmacological properties of oxaliplatin, genetic, molecular and clinical features of oxaliplatin-induced neuropathy are discussed.

RESULTS

Available therapies, as well as results from clinical trials assessing drug candidates for the prevention of oxaliplatin-induced neuropathy are summarized.

CONCLUSION

Emerging novel chemical structures-potential future preventative pharmacotherapies for CIPN caused by oxaliplatin are reported.

Skin platinum deposition in colorectal cancer patients following oxaliplatin-based therapy

BACKGROUND

Oxaliplatin is widely used in the treatment of gastrointestinal malignancies. One of the most common and dose-limiting side effects of oxaliplatin is the chronic peripheral sensory neuropathy. The mechanism of this neurotoxicity is poorly understood and there are no effective preventive or treatment strategies, other than oxaliplatin dose interruption or reduction.

METHODS

Colorectal cancer patients who completed FOLFOX at least 6 months prior to enrollment were eligible. EORTC QLQ-CIPN20 questionnaire was used for assessing self-reported neuropathic symptom. Blood samples and skin biopsies were obtained and analyzed for platinum.

RESULTS

Twelve patients were enrolled. The mean cumulative dose of oxaliplatin was 818 ± 54 mg/m², and the median time from last dose of oxaliplatin was 38.7 months (range: 7.2-65.6 months). The QLQ-CIPN20 sensory score was 18 or less in 10 patients and 19 and 25, respectively, in 2 patients. Platinum was detectable in plasma from 4/12 patients up to 63.3 months after the completion of FOLFOX. In all six patients with skin biopsies, platinum was present in the skin with imaging mass cytometry.

CONCLUSIONS

QLQ-CIPN20 scores and plasma platinum concentrations were not related to cumulative doses of oxaliplatin or interval from the last dose of oxaliplatin. Platinum was readily detectable in skin biopsies more than 60 months post-completion of FOLFOX. This is the first demonstration of platinum deposition in skin post-oxaliplatin treatment and it provides a possible mechanism for oxaliplatin-induced peripheral sensory neuropathy and its persistence.

A critical appraisal of gabapentinoids for pain in cancer patients

PURPOSE OF REVIEW

Gabapentinoids are frequently used in the management of cancer pain. In recent Cochrane systematic reviews, although there was an abundance of evidence relating to non-cancer pain, only a few studies related to cancer pain. This review summarizes recent randomised controlled trials (RCTs) evaluating the use of gabapentinoids for tumour-related (as monotherapy or part of combination therapy) and treatment-related pain.

RECENT FINDINGS

For tumour-related pain, ten out of thirteen studies showed statistically significant benefits in favour of gabapentinoids. When used, as part of monotherapy or combination therapy, benefits were observed in five out of six studies evaluating gabapentin, and in six out of eight studies evaluating pregabalin. For treatment-related pain, none of the four studies (two gabapentin, two pregabalin) showed statistically significant benefits in favour of gabapentinoids. Unfortunately, many of the studies included were limited by small sample size, lack of blinding, and inadequate follow-up.

SUMMARY

More and better quality studies are required, although it may be challenging to accomplish in this patient population. Gabapentinoids may offer benefits to cancer patients with pain, but careful titration and monitoring of adverse effects is necessary.

Prevention and Treatment for Chemotherapy-Induced Peripheral Neuropathy: Therapies Based on CIPN Mechanisms

BACKGROUND

Chemotherapy-induced peripheral neuropathy (CIPN) is a progressive, enduring, and often irreversible adverse effect of many antineoplastic agents, among which sensory abnormities are common and the most suffering issues. The pathogenesis of CIPN has not been completely understood, and strategies for CIPN prevention and treatment are still open problems for medicine.

OBJECTIVES

The objective of this paper is to review the mechanism-based therapies against sensory abnormities in CIPN.

METHODS

This is a literature review to describe the uncovered mechanisms underlying CIPN and to provide a summary of mechanism-based therapies for CIPN based on the evidence from both animal and clinical studies.

RESULTS

An abundance of compounds has been developed to prevent or treat CIPN by blocking ion channels, targeting inflammatory cytokines and combating oxidative stress. Agents such as glutathione, mangafodipir and duloxetine are expected to be effective for CIPN intervention, while Ca/Mg infusion and venlafaxine, tricyclic antidepressants, and gabapentin display limited efficacy for preventing and alleviating CIPN. And the utilization of erythropoietin, menthol and amifostine needs to be cautious regarding to their side effects.

CONCLUSIONS

Multiple drugs have been used and studied for decades, their effect against CIPN are still controversial according to different antineoplastic agents due to the diverse manifestations among different antineoplastic agents and complex drug-drug interactions. In addition, novel therapies or drugs that have proven to be effective in animals require further investigation, and it will take time to confirm their efficacy and safety.

Distinguishing analgesic drugs from non-analgesic drugs based on brain activation in macaques with oxaliplatin-induced neuropathic pain

The antineoplastic agent oxaliplatin is a first-line treatment for colorectal cancer. However, neuropathic pain, characterized by hypersensitivity to cold, emerges soon after treatment. In severe instances, dose reduction or curtailing treatment may be necessary. While a number of potential treatments for oxaliplatin-induced neuropathic pain have been proposed based on preclinical findings, few have demonstrated efficacy in randomized, placebo-controlled clinical studies. This failure could be related, in part, to the use of rodents as the primary preclinical species, as there are a number of distinctions in pain-related mechanisms between rodents and humans. Also, an indicator of preclinical pharmacological efficacy less subjective than behavioral endpoints that is translatable to clinical usage is lacking. Three days after oxaliplatin treatment in Macaca fascicularis, a significantly reduced response latency to cold (10 °C) water was observed, indicating cold hypersensitivity. Cold-evoked bilateral activation of the secondary somatosensory (SII) and insular (Ins) cortex was observed with functional magnetic resonance imaging. Duloxetine alleviated cold hypersensitivity and significantly attenuated activation in both SII and Ins. By contrast, neither clinically used analgesics pregabalin nor tramadol affected cold hypersensitivity and cold-evoked activation of SII and Ins. The current findings suggest that suppressing SII and Ins activation leads to antinociception, and, therefore, could be used as a non-behavioral indicator of analgesic efficacy in patients with oxaliplatin-induced neuropathic pain.

Care After Chemotherapy: Peripheral Neuropathy, Cannabis for Symptom Control, and Mindfulness

As cancer therapies improve, patients are living longer. With these improvements in therapy comes a responsibility to optimize patients' quality of life during cancer therapy and beyond. This report reviews three timely and important topics. The first section reviews the mechanism underlying chemotherapy-induced peripheral neuropathy and evaluates the evidence for interventions to prevent and treat peripheral neuropathy. It also provides a framework for approaching the diagnosis and management of this common and bothersome side effect. The second section addresses the controversial but effective use of cannabinoids for cancer and chemotherapy symptoms. Although clinical trials are difficult to conduct because of the political and social stigma of this class of drugs, this review provides evidence of the efficacy of cannabinoids for treatment of pain and nausea. The last section addresses the mind-body connection, with a focus on the negative emotions patients with cancer often experience. This section assesses the literature regarding mindfulness-based programs to improve cancer-related stress. These three topics may appear unrelated, but all address one common goal: treating the body and the mind to optimize quality of life during and after cancer therapy.

Neuropathic cancer pain: prevalence, pathophysiology, and management

Neuropathic cancer pain (NCP) is caused by nerve damage attributable to the cancer per se, and/or treatments including chemotherapy, radiotherapy, and surgery; the prevalence is reported to be as high as 40%. The etiologies of NCP include direct nerve invasion or nerve compression by the cancer, neural toxicity, chemotherapy, and radiotherapy. NCP is subdivided into plexopathy, radiculopathy, and peripheral neuropathies, among several other categories. The clinical characteristics of NCP differ from those of nociceptive pain in terms of both the hypersensitivity symptoms (burning, tingling, and an electrical sensation) and the hyposensitivity symptoms (numbness and muscle weakness). Recovery requires several months to years, even after recovery from injury. Management is complex; NCP does not usually respond to opioids, although treatments may feature both opioids and adjuvant drugs including antidepressants, anticonvulsants, and anti-arrhythmic agents, all of which improve the quality-of-life. This review addresses the pathophysiology, clinical characteristics and management of NCP, and factors rendering pain control difficult.

Preventive Effects of Renin-angiotensin System Inhibitors on Oxaliplatin-induced Peripheral Neuropathy: A Retrospective Observational Study

PURPOSE

Oxaliplatin-induced peripheral neuropathy has remained an unresolved issue in clinical practice. Our previous study hypothesized that inhibition of the renin-angiotensin system (RAS) may produce a preventive effect on oxaliplatin-induced neuropathy. The aim of this study was to clarify whether RAS inhibitors prevent oxaliplatin-induced peripheral neuropathy.

METHODS

This study retrospectively analyzed data from cancer patients who had received chemotherapy including oxaliplatin and were treated with or without RAS inhibitors. This retrospective observational study was conducted at Ehime University Hospital using electronic medical records from May 2009 to December 2016. The primary end point was the incidence of severe peripheral neuropathy during or after oxaliplatin treatment, according to the Common Terminology Criteria for Adverse Events, version 4.0. A multivariate Cox proportional hazards model analysis was used to identify risk factors.

FINDINGS

A total of 150 patients were included in the study. The estimated incidence of peripheral neuropathy was 36.9% and 91.7% in the RAS inhibitor group and the non-RAS inhibitor group, respectively. The multivariate analysis using a Cox proportional hazards model showed that the RAS inhibitor group was slightly associated with a decreased risk of neurotoxicity (adjusted hazard ratio, 0.42 [95% CI, 0.18-0.99]; P = 0.048).

IMPLICATIONS

The present findings suggest that RAS inhibitors have the ability to prevent oxaliplatin-induced peripheral neuropathy.

Gaps in Understanding Mechanism and Lack of Treatments: Potential Use of a Nonhuman Primate Model of Oxaliplatin-Induced Neuropathic Pain

The antineoplastic agent oxaliplatin induces an acute hypersensitivity evoked by cold that has been suggested to be due to sensitized central and peripheral neurons. Rodent-based preclinical studies have suggested numerous treatments for the alleviation of oxaliplatin-induced neuropathic pain, but few have demonstrated robust clinical efficacy. One issue is that current understanding of the pathophysiology of oxaliplatin-induced neuropathic pain is primarily based on rodent models, which might not entirely recapitulate the clinical pathophysiology. In addition, there is currently no objective physiological marker for pain that could be utilized to objectively indicate treatment efficacy. Nonhuman primates are phylogenetically and neuroanatomically similar to humans; thus, disease mechanism in nonhuman primates could reflect that of clinical oxaliplatin-induced neuropathy. Cold-activated pain-related brain areas in oxaliplatin-treated macaques were attenuated with duloxetine, the only drug that has demonstrated clinical efficacy for chemotherapy-induced neuropathic pain. By contrast, drugs that have not demonstrated clinical efficacy in oxaliplatin-induced neuropathic pain did not reduce brain activation. Thus, a nonhuman primate model could greatly enhance understanding of clinical pathophysiology beyond what has been obtained with rodent models and, furthermore, brain activation could serve as an objective marker of pain and therapeutic efficacy.