Chemotherapy-induced Peripheral Neurotoxicity Research Articles

Impact of Pain on Symptom Burden in Chemotherapy-Induced Peripheral Neurotoxicity.

Chemotherapy-induced peripheral neurotoxicity (CIPN) affects the quality of life of cancer survivors. However, the impact of pain on symptom burden remains undefined. This study aimed to define differences in the clinical symptom profile of patients with painful and nonpainful CIPN. A total of 579 participants (median age, 59 years [IQR, 19 years]; F=66%) were assessed cross-sectionally 6 months posttreatment. CIPN severity was graded using multiple methods, including patient-reported outcome measures, a clinically graded scale (NCI-CTCAE), and a neurologic examination score. Participants were classified into subgroups based on patient symptom report, with painful CIPN characterized by the presence of shooting/burning pain, and nonpainful CIPN characterized by the presence of numbness or tingling without shooting/burning pain. Behavioral changes were assessed via structured patient interview regarding symptom impact on sleep, exercise, and treatment-seeking. Among 579 participants, 24% (n=140) reported painful CIPN, 48% (n=280) reported nonpainful CIPN, and 28% (n=159) had no CIPN. Participants with painful CIPN demonstrated higher CIPN severity than those with nonpainful CIPN across multiple measures, including NCI-CTCAE, neurologic grading, and patient report (all P<.05). Participants with painful CIPN were more likely to report that their symptoms affected their ability to exercise (P=.007), produced sleep impairment, and increased treatment-seeking behavior due to their symptoms (both P<.001) compared with participants with nonpainful CIPN. Overall, participants with painful CIPN reported higher scores across all CIPN severity measures, including behavioral changes. This study underlines the need for accurate identification of different CIPN subgroups in hopes of informing better treatment and rehabilitation options for cancer survivors with painful CIPN.

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

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. 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. 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). 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.

Effect of age on metabolomic changes in a model of paclitaxel-induced peripheral neurotoxicity.

Chemotherapy-induced peripheral neurotoxicity (CIPN) is one of the most common dose-limiting side effects of paclitaxel (PTX) treatment. Many age-related changes have been hypothesized to underlie susceptibility to damage or impaired regeneration/repair after nerve injury. The results of these studies, however, are inconclusive and other potential biomarkers of nerve impairment need to be investigated. Twenty-four young (2 months) and 24 adult (9 months) Wistar male rats were randomized to either PTX treatment (10 mg/kg i.v. once/week for 4 weeks) or vehicle administration. Neurophysiological and behavioral tests were performed at baseline, after 4 weeks of treatment and 2-week follow-up. Skin biopsies and nerve specimens collected from sacrificed animals were examined for intraepidermal nerve fiber (IENF) density assessment and nerve morphology/morphometry. Blood and liver samples were collected for targeted metabolomics analysis. At the end of treatment, the neurophysiological studies revealed a reduction in sensory nerve action potential amplitude (p < .05) in the caudal nerve of young PTX-animals, and in both the digital and caudal nerve of adult PTX-animals (p < .05). A significant decrease in the mechanical threshold was observed only in young PTX-animals (p < .001), but not in adult PTX-ones. Nevertheless, both young and adult PTX-rats had reduced IENF density (p < .0001), which persisted at the end of follow-up period. Targeted metabolomics analysis showed significant differences in the plasma metabolite profiles between PTX-animals developing peripheral neuropathy and age-matched controls, with triglycerides, diglycerides, acylcarnitines, carnosine, long chain ceramides, sphingolipids, and bile acids playing a major role in the response to PTX administration. Our study identifies for the first time multiple related metabolic axes involved in PTX-induced peripheral neurotoxicity, and suggests age-related differences in CIPN manifestations and in the metabolic profile.

Upper-limb dysfunction in cancer survivors with chemotherapy-induced peripheral neurotoxicity

IntroductionUpper-limb symptoms are often reported in the context of chemotherapy-induced peripheral neurotoxicity (CIPN), but objective quantification of functional deficits is often lacking. We examined and compared a range of neurophysiological and functional assessments of the upper-limb in the assessment of CIPN severity. MethodsCross-sectional assessment of neurotoxic chemotherapy-treated patients was undertaken using patient-reported and clinically-graded CIPN measures. Upper-limb functional assessments comprised of assessing fine motor skills, sensory perception, and neurophysiological measures of the median nerve. Group comparisons between participants who reported absence or presence of upper-limb functional deficits were investigated. Results60 participants who were 11.5 (IQR = 4.0–26.0) months post-neurotoxic chemotherapy treatment reported CIPN. 65% (n = 39) reported upper-limb CIPN symptoms. Reduction in fine motor skills, sensory perception and median nerve SNAP amplitudes were associated with higher CIPN severity. Participants who self-reported presence of upper-limb functional deficits had worse CIPN severity across all measures, compared to participants who reported no upper-limb functional deficits. ConclusionsParticipants who reported upper-limb symptoms and functional deficits had worse CIPN severity and quality-of-life. There is a high burden of upper-limb dysfunction long after neurotoxic chemotherapy treatment cessation. Focus on research into supportive care and rehabilitation options to improve upper-limb function is warranted to improve patient quality-of-life.

Sleep dysfunction associated with worse chemotherapy-induced peripheral neurotoxicity functional outcomes

PurposeSleep problems are commonly reported by cancer survivors; however, knowledge of the impact of chemotherapy-induced peripheral neurotoxicity (CIPN) on sleep quality remains limited. In this study, we explored the impact of CIPN on sleep quality, as well as identified clinical characteristics associated with poor sleep quality.MethodsParticipants were assessed cross-sectionally post-neurotoxic chemotherapy. CIPN severity was graded using a range of questionnaires that assessed CIPN severity and quality of life, as well as neurological grading scales. Sleep quality was assessed using a self-rated questionnaire (Pittsburgh Sleep Quality Index, PSQI). Participants with poor sleep quality were further grouped according to whether sleep impairment was due to CIPN or other factors.ResultsAmong 77 participants who reported CIPN, 75% (n = 58) reported poor sleep quality. Of those, 41% (n = 24) reported CIPN as contributing to sleep impairment, while 59% (n = 34) reported other causes. Participants with CIPN-induced sleep impairments had higher CIPN severity across all outcome measures, as well as greater neuropathic pain (all p < 0.05). Furthermore, participants with CIPN-induced sleep impairments reported worse impact of neuropathy on physical and social functioning, as well as emotional well-being (all p < 0.05).ConclusionsParticipants with CIPN-induced poor sleep quality reported worse scores across all CIPN severity measures. This emphasises the negative impacts of CIPN symptoms on quality of life of chemotherapy-treated patients and highlights the importance of sleep quality assessment in cancer survivors.

An In Vitro Assessment Method for Chemotherapy-Induced Peripheral Neurotoxicity Caused by Anti-Cancer Drugs Based on Electrical Measurement of Impedance Value and Spontaneous Activity.

Chemotherapy-induced peripheral neurotoxicity (CIPN) is a major adverse event of anti-cancer drugs, which still lack standardized measurement and treatment methods. In the present study, we attempted to evaluate neuronal dysfunctions in cultured rodent primary peripheral neurons using a microelectrode array system. After exposure to typical anti-cancer drugs (i.e., paclitaxel, vincristine, oxaliplatin, and bortezomib), we successfully detected neurotoxicity in dorsal root ganglia neurons by measuring electrical activities, including impedance value and spontaneous activity. The impedance value decreased significantly for all compounds, even at low concentrations, which indicated cell loss and/or neurite degeneration. The spontaneous activity was also suppressed after exposure, which suggested neurotoxicity again. However, an acute response was observed for paclitaxel and bortezomib before toxicity, which showed different mechanisms based on compounds. Therefore, MEA measurement of impedance value could provide a simple assessment method for CIPN, combined with neuronal morphological changes.

Morphofunctional characterisation of axonal damage in different rat models of chemotherapy-induced peripheral neurotoxicity: The role of nerve excitability testing.

Chemotherapy-induced peripheral neurotoxicity (CIPN) is a common and long-lasting adverse event of several anticancer compounds, for which treatment has not yet been developed. To fill this gap, preclinical studies are warranted, exploiting highly translational outcome measure(s) to transfer data from bench to bedside. Nerve excitability testing (NET) enables to test in vivo axonal properties and can be used to monitor early changes leading to axonal damage. We tested NET use in two different CIPN rat models: oxaliplatin (OHP) and paclitaxel (PTX). Animals (female) were chronically treated with either PTX or OHP and compared to respective control animals. NET was performed as soon as the first injection was administered. At the end of the treatment, CIPN onset was verified via a multimodal and robust approach: nerve conduction studies, nerve morphometry, behavioural tests and intraepidermal nerve fibre density. NET showed the typical pattern of axonal hyperexcitability in the 72 h following the first OHP administration, whereas it showed precocious signs of axonal damage in PTX animals. At the end of the month of treatment, OHP animals showed a pattern compatible with a mild axonal sensory polyneuropathy. Instead, PTX cohort was characterised by a rather severe sensory axonal polyneuropathy with minor signs of motor involvement. NET after the first administration demonstrated the ongoing OHP-related channelopathy, whereas in PTX cohort it showed precocious signs of axonal damage. Therefore, NET could be suggested as an early surrogate marker in clinical trials, to detect precocious changes leading to axonal damage.

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

BackgroundChemotherapy-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.MethodsPubMed, 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.ResultsA 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.ConclusionsAccording 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.

Preliminary evaluation of novel Bodily Attention Task to assess the role of the brain in chemotherapy-induced peripheral neurotoxicity (CIPN)

Chemotherapy-induced peripheral neurotoxicity (CIPN) is a common, sometimes dose-limiting side effect of neurotoxic chemotherapy. Treatment is limited because its pathophysiology is poorly understood. Compared to research on peripheral mechanisms, the role of the brain in CIPN is understudied and it may be important to develop better treatments. We propose a novel task that assesses brain activation associated with attention to bodily sensations (interoception), without the use of painful stimulation, to understand how CIPN symptoms may be processed in the brain. The goals of this preliminary study were to assess, 1) feasibility of the task, 2) sensitivity to changes in brain activity, and 3) suitability for assessing relationships between brain activation and CIPN severity. Eleven participants with varying types of cancer completed a brain fMRI scan and rated CIPN severity (CIPN-20) before and/or 12 weeks after starting neurotoxic chemotherapy. The Bodily Attention Task is a 7.5-min long fMRI task involving attentional focus on the left fingertips, the heart, or a flashing word “target” for visual attention (reference condition). Feasibility was confirmed, as 73% of all data collected were usable and participants reported feeling or focus during 75% of the trials. Regarding brain activity, finger attention increased activation in somatosensory regions (primary sensory cortex, insula) and sensory integration regions (precuneus, dorsolateral prefrontal cortex). Exploratory analyses suggested that brain activation may be associated with CIPN severity. A larger sample size and accounting of confounding factors is needed to test for replication and to identify brain and interoceptive biomarkers to help improve the prediction, prevention, and treatment of CIPN.

Blood neurofilaments as biomarkers of chemotherapy-induced peripheral neurotoxicity

Blood neurofilaments as biomarkers of chemotherapy-induced peripheral neurotoxicity

P14.02.B LONGITUDINAL COMPARATIVE ANALYSIS OF BLOOD NEUROFILAMENTS AS BIOMARKERS OF CHEMOTHERAPY-INDUCED PERIPHERAL NEUROTOXICITY

Abstract BACKGROUND The identification of a biomarker of chemotherapy-induced peripheral neurotoxicity (CIPN) remains an unmet need. Increasing evidence supports that light-chain Neurofilament (NfL) could be useful to quantify the extend of peripheral nerve damage due to chemotherapy. The aim of the study is to ascertain differences in plasma NfL (pNfL) among agents to evaluate the clinical usefulness of pNfL. MATERIAL AND METHODS Prospective longitudinal comparative study including patients treated with paclitaxel (N=24) for breast cancer, brentuximab vedotin (BV) (n=20) for lymphoma and oxaliplatin (n=16) for gastrointestinal cancer. All patients were assessed using the Total Neuropathy Score-clinical, Common Toxicity Criteria for Adverse Events before (T1), at finishing (T2) and at next follow-up (T3). Serial pNfL were collected at the same timepoints and quantified using the SIMOA technique. The changes in pNfL were compared between group of agents (platinum (oxaliplatin) or microtubule disruptors (MT) (BV or paclitaxel) and correlated with clinical data, depending on the degree of CIPN. Clinically relevant (CR) was defined as &amp;gt; grade 2-CIPN. RESULTS 60 patients are included, mostly women (66,7%) with median age of 52 [22-88] years. pNfL at T1 was 16,51 ± 1,65 pg/mL, and correlated with age (r= 0.284, p &amp;lt; 0.036). pNfL increased at T2 (141,39 ± 18,89 pg/mL) and decreased at last follow-up (T3) (28,08 ± 2,52 pg/mL) in the whole series, at a median of 3 (1-5) months after finishing chemotherapy. Patients with CR-CIPN had higher pNfL at T2 (209,90 ± 40,09 vs 103.02 ± 96.74 pg/mL, p=0.005). One third of patients receiving MT disruptors (31,6%) or platinum agents (35,7%) developed CR-CIPN. Higher pNfL level at T2 were identified in patients receiving anti MT agents than oxaliplatin (160, 27 ± 22,75 vs 70,04 ± 11,24 pg/mL), p&amp;lt;0,001). Among the group of MT, pNfL at T2 were higher in those receiving paclitaxel compared to BV (233,90 ± 31.84 vs 62,09 ± 9.60 pg/mL, p&amp;lt;0.001), despite no differences in rate of CR-CIPN (26,6% BV and 34.7% Paclitaxel, p=0.7). At T3, no differences in pNfL were identified between BV (33,53 ± 4,67 pg/mL) and paclitaxel (29,20 ± 4,24 pg/mL) treated patients. A significant correlation between pNfL and TNSc was identified (r = 0.663, p &amp;lt; 0.001). CONCLUSION Variable change of pNfL according to the type of agent and mechanism of neurotoxicity can be observed regardless of the comparable degree of clinical CIPN severity. Further studies to better dissect cut-off values for each agent are needed before implementing pNfL as CIPN biomarker.

Exploring Outcome Priorities and Real-Life Management of Chemotherapy-Induced Peripheral Neurotoxicity: A Survey of the Italian Association for the Study of Pain members.

Chemotherapy-induced peripheral neurotoxicity (CIPN) affects nearly 70% of cancer patients after chemotherapy, causing sensory, motor, autonomic dysfunction, and neuropathic pain. The Desirability of Outcome Ranking (DOOR) framework is proposed as a better way to assess preventive or therapeutic interventions for CIPN. A survey was conducted among Italian healthcare professionals and researchers affiliated to the Italian Chapter of the International Association for the Study of Pain (AISD) to identify the most important outcomes in clinical management and research. Among the 73 respondents, 61 qualified for the survey, with an overall response rate of 1.2%. The vast majority were physicians (77%), most of whom were anesthesiologists (47.5%). The results showed that pain, survival, sensory impairment, motor impairment, and quality of life were consistently ranked as the most important outcomes, but there was significant disagreement in the outcomes relative ranking, making it difficult to develop a DOOR algorithm. The study also revealed that clinicians commonly use structured interviews to evaluate patients with CIPN, and the most prescribed drugs or supplements were palmitoylethanolamide, pregabalin, gabapentin and alpha lipoic acid as preventive agents and pregabalin, palmitoylethanolamide, duloxetine, gabapentin, and amitriptyline as therapeutic agents. However, many of these drugs have not been clinically proven to be effective for CIPN. This study suggests that the implementation of a DOOR framework for CIPN using healthcare professionals is more difficult than expected, given the significant disagreement in our respondents' ranking of outcomes. Our work provides interesting topics for future research in CIPN, but its limitations include a small sample size, a low response rate, and a possible selection bias.

Framework to leverage physical therapists for the assessment and treatment of chemotherapy-induced peripheral neurotoxicity (CIPN)

Chemotherapy-induced peripheral neurotoxicity (CIPN) is a highly prevalent, dose-limiting, costly, and tough-to-treat adverse effect of several chemotherapy agents, presenting as sensory and motor dysfunction in the distal extremities. Due to limited effective treatments, CIPN can permanently reduce patient function, independence, and quality of life. One of the most promising interventions for CIPN is physical therapy which includes exercise, stretching, balance, and manual therapy interventions. Currently, there are no physical therapy guidelines for CIPN, thus limiting its uptake and potential effectiveness. Utilizing the authors' collective expertise spanning physical therapy, symptom management research, oncology, neurology, and treating patients with CIPN, we propose a comprehensive clinical workflow for physical therapists to assess and treat CIPN. This workflow is based on (1) physical therapy guidelines for treating neurologic symptoms like those of CIPN, (2) results of clinical research on physical therapy and exercise, and (3) physical therapy clinical judgement. We present detailed tables of pertinent physical therapy assessment and treatment methods that can be used in clinical settings. CIPN assessment should include detailed sensory assessment, objective strength assessments of involved extremities, and validated physical performance measures incorporating static and dynamic balance, gait, and functional mobility components. CIPN treatment should involve sensorimotor, strength, balance, and endurance-focused interventions, alongside a home-based exercise prescription that includes aerobic training. We conclude with action items for oncology teams, physical therapists, patients, and researchers to best apply this framework to address CIPN. Physical therapists are in a unique position to help assess, prevent, and treat CIPN given their training and prevalence, yet there are no physical therapy clinical practice guidelines for CIPN. Our preliminary suggestions for CIPN assessments and treatments can catalyze the development of guidelines to assess and treat CIPN. We urge oncology teams, physical therapists, patients, and researchers to develop, adapt, and disseminate this framework to help alleviate the burden of chemotherapy on patients with cancer.

Patient-Reported Outcome Measures in Chemotherapy-Induced Peripheral Neurotoxicity: Defining Minimal and Clinically Important Changes.

Chemotherapy-induced peripheral neurotoxicity (CIPN) is a common complication of cancer treatment that produces functional disability. Increasingly, patient-reported outcome measures (PROMs) are used to assess CIPN, providing a broader symptom perspective than clinician-graded scales. Understanding when a reported change in CIPN symptoms meets the threshold for clinical significance is challenging. This study aimed to provide interpretation guidelines for validated CIPN PROMs, and thereby enable estimation of thresholds to identify clinically relevant symptoms. Patients commencing neurotoxic cancer treatments were assessed at 3 timepoints: baseline, midtreatment, and end-of-treatment. Trajectory of CIPN development was assessed by means of CIPN PROMs, EORTC Quality of Life - Chemotherapy-Induced Peripheral Neuropathy questionnaire (QLQ-CIPN20), and Functional Assessment of Cancer Therapy/Gynecologic Oncology Group - Neurotoxicity questionnaire (FACT/GOG-NTX). Thresholds were estimated for CIPN PROMs using the NCI CTCAE sensory neuropathy scale as the clinical anchor by midtreatment and end-of-treatment. Patients were assigned to a clinical change group according to CIPN development: either no development; grade 1 neuropathy (minimally important difference [MID]); or grade 2 neuropathy (clinically important difference). Distribution-based estimates (SD, 0.5) were also evaluated as supportive evidence. In total, 406 patients were recruited to the study, of whom 62% (n=199/320) developed CIPN by midtreatment and 80% (n=274/343) by end-of-treatment. Anchor-based MID estimates by midtreatment were 5.06 (95% CI, 4.26-5.86) for the QLQ-CIPN20 and 3.54 (95% CI, 2.87-4.20) for the FACT/GOG-NTX. End-of-treatment MIDs were estimated to be 7.32 (95% CI, 6.23-8.40) for the QLQ-CIPN20 and 4.84 (95% CI, 3.98-5.70) for the FACT/GOG-NTX. Distribution-based MID estimations yielded lower values than anchor-based methods, at 3.73 for the QLQ-CIPN20 and 2.64 for the FACT/GOG-NTX at midtreatment and 5.52 for the QLQ-CIPN20 and 3.64 for the FACT/GOG-NTX at end-of-treatment. Findings from the present series aid meaningful interpretation for commonly used validated CIPN PROMs and provide thresholds that serve as guidance on how to interpret score changes, which will be useful for design and evaluation of clinical trials and clinical practice.

Paclitaxel, but Not Cisplatin, Affects Satellite Glial Cells in Dorsal Root Ganglia of Rats with Chemotherapy-Induced Peripheral Neurotoxicity

Chemotherapy-induced peripheral neurotoxicity is one of the most common dose-limiting toxicities of several widely used anticancer drugs such as platinum derivatives (cisplatin) and taxanes (paclitaxel). Several molecular mechanisms related to the onset of neurotoxicity have already been proposed, most of them having the sensory neurons of the dorsal root ganglia (DRG) and the peripheral nerve fibers as principal targets. In this study we explore chemotherapy-induced peripheral neurotoxicity beyond the neuronocentric view, investigating the changes induced by paclitaxel (PTX) and cisplatin (CDDP) on satellite glial cells (SGC) in the DRG and their crosstalk. Rats were chronically treated with PTX (10 mg/Kg, 1qwx4) or CDDP (2 mg/Kg 2qwx4) or respective vehicles. Morpho-functional analyses were performed to verify the features of drug-induced peripheral neurotoxicity. Qualitative and quantitative immunohistochemistry, 3D immunofluorescence, immunoblotting, and transmission electron microscopy analyses were also performed to detect alterations in SGCs and their interconnections. We demonstrated that PTX, but not CDDP, produces a strong activation of SGCs in the DRG, by altering their interconnections and their physical contact with sensory neurons. SGCs may act as principal actors in PTX-induced peripheral neurotoxicity, paving the way for the identification of new druggable targets for the treatment and prevention of chemotherapy-induced peripheral neurotoxicity.

A mechanistic understanding of the relationship between skin innervation and chemotherapy-induced neuropathic pain.

Neuropathic pain is a frequent complication of chemotherapy-induced peripheral neurotoxicity (CIPN). Chemotherapy-induced peripheral neuropathies may serve as a model to study mechanisms of neuropathic pain, since several other common causes of peripheral neuropathy like painful diabetic neuropathy may be due to both neuropathic and non-neuropathic pain mechanisms like ischemia and inflammation. Experimental studies are ideally suited to study changes in morphology, phenotype and electrophysiologic characteristics of primary afferent neurons that are affected by chemotherapy and to correlate these changes to behaviors reflective of evoked pain, mainly hyperalgesia and allodynia. However, hyperalgesia and allodynia may only represent one aspect of human pain, i.e., the sensory-discriminative component, while patients with CIPN often describe their pain using words like annoying, tiring and dreadful, which are affective-emotional descriptors that cannot be tested in experimental animals. To understand why some patients with CIPN develop neuropathic pain and others not, and which are the components of neuropathic pain that they are experiencing, experimental and clinical pain research should be combined. Emerging evidence suggests that changes in subsets of primary afferent nerve fibers may contribute to specific aspects of neuropathic pain in both preclinical models and in patients with CIPN. In addition, the role of cutaneous neuroimmune interactions is considered. Since obtaining dorsal root ganglia and peripheral nerves in patients is problematic, analyses performed on skin biopsies from preclinical models as well as patients provide an opportunity to study changes in primary afferent nerve fibers and to associate these changes to human pain. In addition, other biomarkers of small fiber damage in CIPN, like corneal confocal microscope and quantitative sensory testing, may be considered.

Development and consensus process for a clinical pathway for the assessment and management of chemotherapy-induced peripheral neuropathy

BackgroundCancer patients treated with neurotoxic chemotherapy are at risk of developing neurological symptoms that can impact functional capacity and quality of life. However, there are no standardised pathways to assess and manage chemotherapy-induced peripheral neurotoxicity (CIPN). This study aimed to determine consensus on statements regarding a CIPN assessment and management clinical pathway.MethodsA CIPN clinical pathway (CIPN-path) was developed and reviewed by an expert multi-disciplinary panel and consumers. Agreement with 18 statements regarding four content themes (pretreatment review, screening and assessment, management and referral, and CIPN-path feasibility) were assessed by 70 Australian respondents (68 health professionals, 2 consumers), using a 2-stage Delphi survey process to reach consensus. Respondents rated statements using a 5-point Likert scale to determine the level of agreement, with consensus defined as ≥ 80% of respondents agreeing with each statement.ResultsThe consensus was reached for 14 of 18 items after stage 1 and all items after stage 2. Feedback was obtained for all items to refine the CIPN-path. There was an agreement on important characteristics of the CIPN-path, including pretreatment screening, regular patient-reported assessment, and a stepped-care approach to investigating and managing symptom burden. There was a lack of agreement on who should oversee CIPN assessment, which may differ according to the structure and resources of each site.ConclusionsThere was an overall agreement concerning the CIPN-path to assess and manage CIPN, which may be adapted accordingly to the resources of each clinic. The CIPN-path may assist teams across different health services in identifying CIPN symptoms, aiding decision-making, and reducing morbidity from CIPN.

Rehabilitation, exercise, and related non-pharmacological interventions for chemotherapy-induced peripheral neurotoxicity: Systematic review and evidence-based recommendations.

Pharmacological strategies for chemotherapy-induced peripheral neurotoxicity (CIPN) are very limited. We systematically reviewed data on rehabilitation, exercise, physical therapy, and other physical non-pharmacological interventions and offered evidence-based recommendations for the prevention and treatment of CIPN. A literature search using PubMed, Web of Science and CINAHL was conducted from database inception until May 31st, 2021. 2791 records were title-abstract screened, 71 papers were full-text screened, 41 studies were included, 21 on prevention and 20 on treatment of CIPN. Treatment type, cancer type, chemotherapy compounds were heterogeneous, sample size was small (median: N = 34) and intention-to-treat analysis was lacking in 26/41 reports. Because of the methodological issues of included studies, the reviewed evidence should be considered as preliminary. Exercise, endurance, strength, balance, and sensorimotor training have been studied in low-to-moderate quality studies, while the evidence for other treatments is preliminary/inconclusive. We offer recommendation for the design of future trials on CIPN.

Intravenous Immunoglobulin Suppresses Chemotherapy-Induced Peripheral Neurotoxicity Via Macrophage Modulation in Rats and Mice

Chemotherapy-induced peripheral neurotoxicity (CIPN) is a serious adverse effect that leads to treatment discontinuation by patients receiving anticancer therapy. Treatment discontinuation is a serious and life-threatening problem for patients with cancer; hence, there is a need for drugs that suppress the induction of CIPN by anticancer drugs. Here, using rat and mouse models, we showed that intravenous immunoglobulin (IVIg) can suppress CIPN induced by not only paclitaxel but also by doxorubicin. Furthermore, the suppressive effect of IVIg is eliminated when macrophages are depleted. Here, we proposed two novel independent mechanisms underlying the alleviation of CIPN by IVIg. First, IVIg suppresses CIPN in a macrophage-dependent manner. Second, IVIg combined with anticancer drugs can avoid restrictions on the use of anticancer drugs owing to CIPN induction. However, further research is necessary for the bench-to-bedside translation of these novel applications of IVIg. Our findings lay a strong foundation for research on IVIg therapeutics.

Management of Side Effects in the Personalized Medicine Era: Chemotherapy-Induced Peripheral Neurotoxicity.

Pharmacogenomics is a powerful tool to predict individual response to treatment, in order to personalize therapy, and it has been explored extensively in oncology practice. Not only efficacy on the malignant disease has been investigated but also the possibility to predict adverse effects due to drug administration. Chemotherapy-induced peripheral neurotoxicity (CIPN) is one of those. This potentially severe and long-lasting/permanent side effect of commonly administered anticancer drugs can severely impair quality of life (QoL) in a large cohort of long survival patients. So far, a pharmacogenomics-based approach in CIPN regard has been quite delusive, making a methodological improvement warranted in this field of interest: even the most refined genetic analysis cannot be effective if not applied correctly. Here we try to devise why it is so, suggesting how THE "bench-side" (pharmacogenomics) might benefit from and should cooperate with THE "bed-side" (clinimetrics), in order to make genetic profiling effective if applied to CIPN.