Role of pattern recognition receptors in chemotherapy-induced neuropathic pain.

Progress in the development of effective chemotherapy is producing a growing population of patients with acute and chronic painful chemotherapy-induced peripheral neuropathy (CIPN), a serious treatment-limiting side effect for which there is currently no US Food and Drug Administration-approved treatment. CIPNs induced by diverse classes of chemotherapy drugs have remarkably similar clinical presentations, leading to the suggestion they share underlying mechanisms. Sensory neurons share with immune cells the ability to detect damage associated molecular patterns (DAMPs), molecules produced by diverse cell types in response to cellular stress and injury, including by chemotherapy drugs. DAMPs, in turn, are ligands for pattern recognition receptors (PRRs), several of which are found on sensory neurons, as well as satellite cells, and cells of the immune system. In the present experiments, we evaluated the role of two PRRs, TLR4 and RAGE, present in dorsal root ganglion (DRG), in CIPN. Antisense (AS)-oligodeoxynucleotides (ODN) against TLR4 and RAGE mRNA were administered intrathecally before ('prevention protocol') or 3 days after ('reversal protocol') the last administration of each of three chemotherapy drugs that treat cancer by different mechanisms (oxaliplatin, paclitaxel and bortezomib). TLR4 and RAGE AS-ODN prevented the development of CIPN induced by all three chemotherapy drugs. In the reversal protocol, however, while TLR4 AS-ODN completely reversed oxaliplatin- and paclitaxel-induced CIPN, in rats with bortezomib-induced CIPN it only produced a temporary attenuation. RAGE AS-ODN, in contrast, reversed CIPN induced by all three chemotherapy drugs. When a TLR4 antagonist was administered intradermally to the peripheral nociceptor terminal, it did not affect CIPN induced by any of the chemotherapy drugs. However, when administered intrathecally, to the central terminal, it attenuated hyperalgesia induced by all three chemotherapy drugs, compatible with a role of TLR4 in neurotransmission at the central terminal but not sensory transduction at the peripheral terminal. Finally, since it has been established that cultured DRG neurons can be used to study direct effects of chemotherapy on nociceptors, we also evaluated the role of TLR4 in CIPN at the cellular level, using patch-clamp electrophysiology in DRG neurons cultured from control and chemotherapy-treated rats. We found that increased excitability of small-diameter DRG neurons induced by in vivo and in vitro exposure to oxaliplatin is TLR4-dependent. Our findings suggest that in addition to the established contribution of PRR-dependent neuroimmune mechanisms, PRRs in DRG cells also have an important role in CIPN.

The associations of oxaliplatin-induced peripheral neuropathy, sociodemographic characteristics, and clinical characteristics with time to fall in older adults with colorectal cancer.

Our purpose was to investigate the associations between falls and oxaliplatin-induced peripheral neuropathy (OIPN), sociodemographic characteristics, and clinical characteristics of older patients with colorectal cancer. The study population consisted of older adults diagnosed with colorectal cancer whose data were obtained from the Surveillance, Epidemiology, and End Results database combined with Medicare claims. We defined OIPN using specific (OIPN 1) and broader (OIPN 2) definitions of OIPN, based on diagnosis codes. Extensions of the Cox regression model to accommodate repeated events were used to obtain overall hazard ratios (HRs) with 95% CIs and the cumulative hazard of fall. The unadjusted risk of fall for colorectal cancer survivors with versus without OIPN 1 at 36 months of follow-up was 19.6% versus 14.3%, respectively. The association of OIPN with time to fall was moderate (for OIPN 1, HR = 1.37; 95% CI, 1.04-1.79) to small (for OIPN 2, HR = 1.24; 95% CI, 1.01-1.53). Memantine, opioids, cannabinoids, prior history of fall, female sex, advanced age and disease stage, chronic liver disease, diabetes, and chronic obstructive pulmonary disease all increased the hazard rate of falling. Incorporating fall prevention in cancer care is essential to minimize morbidity and mortality of this serious event in older survivors of colorectal cancer.

Randomized adaptive selection trial of cryotherapy, compression therapy, and placebo to prevent taxane-induced peripheral neuropathy in patients with breast cancer.

BACKGROUND: Chemotherapy-induced peripheral neuropathy (CIPN) is a common and debilitating adverse effect of taxane therapy. Small non-randomized studies in patients with early-stage breast cancer (ESBC) suggest both cryotherapy and compression therapy may prevent CIPN. It is unknown which is more effective. METHODS: We conducted a randomized phase IIB adaptive sequential selection trial of cryotherapy vs. compression therapy vs. placebo ("loose" gloves/socks) during taxane chemotherapy. Participants were randomized in triplets. Garments were worn for 90-120 min, beginning 15 min prior and continuing for 15 min following the infusion. The primary goal was to select the best intervention based on a Levin-Robbins-Leu sequential selection procedure. The primary endpoint was a < 5-point decrease in the Functional Assessment of Cancer Therapy Neurotoxicity (FACT-NTX) at 12 weeks. An arm was eliminated if it had four or more fewer successes than the currently leading arm. Secondary endpoints included intervention adherence and patient-reported comfort/satisfaction. RESULTS: Between April 2019 and April 2021, 63 patients were randomized (cryotherapy (20); compression (22); placebo (21)). Most patients (60.3%) were treated with docetaxel. The stopping criterion was met after the 17th triplet (n = 51) was evaluated; success at 12 weeks occurred in 11 (64.7%) on compression therapy, 7 (41.1%) on cryotherapy, and 7 (41.1%) on placebo. Adherence to the intervention was lowest with cryotherapy (35.0%) compared to compression (72.7%) and placebo (76.2%). CONCLUSION: Compression therapy was the most effective intervention in this phase IIB selection trial to prevent CIPN and was well tolerated. Compression therapy for the prevention of CIPN should be evaluated in a phase III study. CLINICAL TRIAL REGISTRATION: ClinicaTrials.gov Identifier: NCT03873272.

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

PURPOSE: Chemotherapy-induced peripheral neuropathy (CIPN) is a debilitating side effect of neurotoxic chemotherapy. Exercise activates neuromuscular function and may improve CIPN. We examined the association between exercise and CIPN symptoms in breast cancer survivors. METHODS: In a retrospective cross-sectional study, we included patients completing a survey assessing exercise exposure and neuropathy symptoms in a tertiary cancer center survivorship clinic. We evaluated exercise duration and intensity using a standardized questionnaire quantified in metabolic equivalent tasks (MET-h/wk). We defined exercisers as patients meeting the National Physical Activity Guidelines' criteria. We used multivariable logistic regressions to examine the relationship between exercise and CIPN and if this differed as a function of chemotherapy regimen adjusting for age, gender, and race. RESULTS: We identified 5444 breast cancer survivors post-chemotherapy (median age 62 years (interquartile range [IQR]: 55, 71); median 4.7 years post-chemotherapy (IQR: 3.3, 7.6)) from 2017 to 2022. CIPN overall prevalence was 34% (95% confidence interval [CI]: 33%, 36%), 33% for non-taxane, and 37% for taxane-based chemotherapy. CIPN prevalence was 28% (95% CI: 26%, 30%) among exercisers and 38% (95% CI: 37%, 40%) among non-exercisers (difference 11%; 95% CI: 8%, 13%; p < 0.001). Compared to patients with low (<6 MET-h/wk) levels of exercise (42%), 11% fewer patients with moderate (6-20.24 MET-h/wk) to high (>20.25 MET-h/wk) levels of exercise reported CIPN. Exercise was associated with reduced prevalence of all CIPN symptoms regardless of chemotherapy type. CONCLUSION: CIPN may persist several years following chemotherapy among patients with breast cancer but is significantly reduced by exercise in a dose-dependent manner.

Nicotinamide riboside activates SIRT3 to prevent paclitaxel-induced peripheral neuropathy.

Paclitaxel (PTX) is a microtubule stabilizer that disrupts the normal cycle of microtubule depolymerization and repolymerization, leading to cell cycle arrest and cancer cell death. It is commonly used as a first-line chemotherapeutics for various malignancies, such as breast cancer, non-small cell lung cancer, and ovarian cancer. However, PTX chemotherapy is associated with common and serious side effects, including chemotherapy-induced peripheral neuropathy (CIPN). As cancer treatment advances and survival rates increase, the impact of CIPN on patients' quality of life has become more significant. To date, there is no effective treatment strategy for CIPN. Surtuin3 (SIRT3) is a nicotinamide adenine dinucleotide (NAD+) dependent protein deacetylase located on mitochondria. It transfers the acetyl group of the lysine side chain of acetylated substrate proteins to NAD+, producing deacetylated proteins to regulate mitochondrial energy metabolic processes. SIRT3 has been found to play an important role in various diseases, including aging, neurodegenerative diseases, cancer, heart disease, metabolic diseases, etc. However, the role of SIRT3 in CIPN is still unknown. This study found for the first time that activating SIRT3 helps to improve paclitaxel-induced CIPN. Nicotinamide riboside (NR) can protect dorsal root ganglion (DRG) mitochondria against oxidative damage caused by paclitaxel through activating SIRT3-MnSOD2 and SIRT3-Nrf2 pathway. Moreover, NR can enhance the anticancer activity of paclitaxel. Together, our research provides new strategy and candidate drug for the treatment of CIPN.

Ursolic acid alleviates paclitaxel-induced peripheral neuropathy through PPARγ activation.

BACKGROUND: Chemotherapy-induced peripheral neuropathy (CIPN) reduces the overall quality of life and leads to interruption of chemotherapy. Ursolic acid, a triterpenoid naturally which presents in fruit peels and in many herbs and spices, can function as a peroxisome proliferator-activated receptor γ (PPARγ) agonist, and has been widely used as an herbal medicine with a wide spectrum of pharmacological activities, including anti-cancer, anti-inflammatory and neuroprotective effect. METHODS: We used a phenotypic drug screening approach to identify ursolic acid as a potential neuroprotective drug in vitro and in vivo and carried out additional biochemical experiments to identify its mechanism of action. RESULTS: Our study demonstrated that ursolic acid reduced neurotoxicity and cell apoptosis induced by pacilitaxel, resulting in an improvement of CIPN. Moreover, we explored the potential mechanisms of ursolic acid on CIPN. As a result, ursolic acid inhibited CHOP (C/EBP Homologous Protein) expression, indicating the endoplasmic reticulum (ER) stress suppression, and regulating CHOP related apoptosis regulator (the Bcl2 family) to reverse pacilitaxel induced apoptosis. Moreover, we showed that the therapeutic effect of ursolic acid on the pacilitaxel-induced peripheral neuropathy is PPARγ dependent. CONCLUSIONS: Taken together, the present study suggests ursolic acid has potential as a new PPARγ agonist targeting ER stress-related apoptotic pathways to ameliorate pacilitaxel-induced peripheral neuropathic pain and nerve injury, providing new clinical therapeutic method for CIPN.

Study protocol: fish oil supplement in prevention of oxaliplatin-induced peripheral neuropathy in adjuvant colorectal cancer patients - a randomized controlled trial. (OxaNeuro).

BACKGROUND: Oxaliplatin-induced peripheral neuropathy (OIPN) in general and painful OIPN in particular is a debilitating late effect that severely affects cancer survivors' quality of life and causes premature cessation of potentially lifesaving treatment. No preventive treatments and no effective treatment for chronic OIPN exist despite many attempts. One of several suggested mechanisms includes neuroinflammation as a contributing factor to OIPN. Fish oil containing long-chain n-3 polyunsaturated fatty acids (n-3 LCPUFAs) are precursors to specialized proresolving mediators that mediate the resolution of inflammation. Our primary hypothesis is that a high supplementation of n-3 LCPUFAs will lower the prevalence and severity of OIPN. METHODS: The OxaNeuro project is an investigator-initiated, multicenter, double-blinded, randomized, placebo-controlled clinical study. We will include 120 patients eligible to receive adjuvant oxaliplatin after colorectal cancer surgery. Patients will receive fish oil capsules containing n-3 LCPUFAs or corn oil daily for 8 months. The primary endpoint is the prevalence of OIPN at 8 months defined as relevant symptoms, including one of the following: abnormal nerve conduction screening, abnormal vibration threshold test, abnormal skin biopsy, or abnormal pinprick test. Additional endpoints include the intensity and severity of OIPN-related neuropathic pain, patient-reported OIPN symptoms, quality of life, mental health symptoms, body composition, and cognitive evaluation. Furthermore, we will evaluate inflammatory biomarkers in blood samples and skin biopsies, including the potential OIPN biomarker neurofilament light protein (NfL) which will be measured before each cycle of chemotherapy. DISCUSSION: If readily available fish oil supplementation alleviates OIPN prevalence and severity, it will significantly improve the lives of both cancer survivors and palliative cancer patients receiving oxaliplatin; it will improve their quality of life, optimize chemotherapeutic treatment plans by lowering the need for dose reduction or premature cessation, and potentially increase survival. TRIAL REGISTRATION: ClinicalTrial.gov identifier: NCT05404230 Protocol version: 1.2, April 25th. 2023.

LPA3 agonist-producing Bacillus velezensis ADS024 is efficacious in multiple neuroinflammatory disease models.

Neuroinflammation is a common component of neurological disorders. In the gut-brain-immune axis, bacteria and their metabolites are now thought to play a role in the modulation of the nervous and immune systems which may impact neuroinflammation. In this respect, commensal bacteria of humans have recently been shown to produce metabolites that mimic endogenous G-protein coupled receptor (GPCR) ligands. To date, it has not been established whether plant commensal bacteria, which may be ingested by animals including humans, can impact the gut-brain-immune axis via GPCR agonism. We screened an isopropanol (IPA) extract of the plant commensal Bacillus velezensis ADS024, a non-engrafting live biotherapeutic product (LBP) with anti-inflammatory properties isolated from human feces, against a panel of 168 GPCRs and identified strong agonism of the lysophosphatidic acid (LPA) receptor LPA3. The ADS024 IPA extracted material (ADS024-IPA) did not agonize LPA2, and only very weakly agonized LPA1. The agonism of LPA3 was inhibited by the reversible LPA1/3 antagonist Ki16425. ADS024-IPA signaled downstream of LPA3 through G-protein-induced calcium release, recruitment of ß-arrestin, and recruitment of the neurodegeneration-associated proteins 14-3-3γ, ε and ζ but did not recruit the ß isoform. Since LPA3 agonism was previously indirectly implicated in the reduction of pathology in models of Parkinson's disease (PD) and multiple sclerosis (MS) by use of the nonselective antagonist Ki16425, and since we identified an LPA3-specific agonist within ADS024, we sought to examine whether LPA3 might indeed be part of a broad underlying mechanism to control neuroinflammation. We tested oral treatment of ADS024 in multiple models of neuroinflammatory diseases using three models of PD, two models of MS, and a model each of amyotrophic lateral sclerosis (ALS), Huntington's disease (HD), and chemo-induced peripheral neuropathy (CIPN). ADS024 treatment improved model-specific functional effects including improvements in motor movement, breathing and swallowing, and allodynia suggesting that ADS024 treatment impacted a universal underlying neuroinflammatory mechanism regardless of the initiating cause of disease. We used the MOG-EAE mouse model to examine early events after disease initiation and found that ADS024 attenuated the increase in circulating lymphocytes and changes in neutrophil subtypes, and ADS024 attenuated the early loss of cell-surface LPA3 receptor expression on circulating white blood cells. ADS024 efficacy was partially inhibited by Ki16425 in vivo suggesting LPA3 may be part of its mechanism. Altogether, these data suggest that ADS024 and its LPA3 agonism activity should be investigated further as a possible treatment for diseases with a neuroinflammatory component.

Pharmacogenomic predictor of long-term residual chemotherapy-induced peripheral neuropathy in ovarian cancer survivors: A substudy of the GINECO Vivrovaire study.

BACKGROUND: Chemotherapy (CT) remains a backbone treatment of epithelial ovarian cancer (EOC) inducing persistent peripheral neuropathy (CIPN). Using a dedicated patient-reported outcome tool, this study investigated persistent CIPN and its pharmacogenetic predictors in a cohort of long-term EOC survivors. METHODS: Vivrovaire was a French multicenter cohort of patients with EOC free of disease 3 years after CT completion. Persistent CIPN was assessed using the FACT/GOG-Ntx4 self-questionnaire. The association of homozygous (hom) or heterozygous (het) single nucleotide polymorphisms (SNPs) in selected genes was evaluated. RESULTS: 130 patients were included with a median time from CT completion of 63 [35-180] months. The median CIPN score was 37 [18-44], with 35 (26.9%) patients reporting severe CIPN (<33). SNPs were identified as follows: CYP2C8 [hom, n = 32 (24.6%)/het, n = 99, (76.2%)]; CYP3A4 [hom, n = 0 (0%)/het, n = 8 (6.2%)], ERCC1 [hom, n = 21 (16.2%)/het, n = 57 (43.8%)], and XPC [hom, n = 45 (34.6%)/het, n = 66 (50.8%)]. In univariate analysis, the identification of ≥1 hom SNP was associated with a lower CIPN score (continuous variable; p = 0.045). Patients harboring hom or het CYP2C8_rs1934951 SNP reported more likely severe CIPN (threshold <33) score (OR 2.482; 95% CI [1.126-5.47], p = 0.024). In the multivariate analyses, age, interval from CT completion, type and number of CT courses were not significantly associated with CIPN score (OR 5.165, 95% CI [0.478-55.83], p = 0.176). CONCLUSIONS: Persistent CIPN is common among ovarian cancer long-term survivors. CYP2C8_rs1934951 SNP may be associated with severe residual CIPN in EOC survivors. More studies are warranted to identify predictive factors of CIPN.

Repurposing chemotherapy-induced peripheral neuropathy grading.

BACKGROUND AND PURPOSE: Chemotherapy-induced peripheral neuropathy (CIPN) is perceived differently by patients and physicians, complicating its assessment. Current recommendations advocate combining clinical and patient-reported outcomes measures, but this approach can be challenging in patient care. This multicenter European study aims to bridge the gap between patients' perceptions and neurological impairments by aligning both perspectives to improve treatment decision-making. METHODS: Data were pooled from two prospective studies of subjects (n = 372) with established CIPN. Patient and physician views regarding CIPN were assessed using the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE), Total Neuropathy Scale-clinical version (TNSc) items, and the disease-specific quality of life - Chemotherapy-Induced Peripheral Neuropathy questionnaire (QLQ-CIPN20) from the European Organization for Research and Treatment of Cancer (EORTC). To identify inherent neurotoxic severity patterns, we employed hierarchical cluster analysis optimized with k-means clustering and internally validated by discriminant functional analysis. RESULTS: Both NCI-CTCAE and TNSc demonstrated a significant difference in the distribution of severity grades in relation to QLQ-CIPN20 scores. However, a proportion of subjects with different neurotoxic severity grades exhibited overlapping QLQ-CIPN20 scores. We identified three distinct clusters classifying subjects as having severely impaired, intermediately impaired, and mildly impaired CIPN based on TNSc and QLQ-CIPN20 scores. No differences in demographics, cancer type distribution, or class of drug received were observed. CONCLUSIONS: Our results confirm the heterogeneity in CIPN perception between patients and physicians and identify three well-differentiated subgroups of patients delineated by degree of CIPN impairment based on scores derived from TNSc and QLQ-CIPN20. A more refined assessment of CIPN could potentially be achieved using the calculator tool derived from the cluster equations in this study. This tool, which facilitates individual patient classification, requires prospective validation.

Rate and characteristics of inflammatory neuropathies associated with brentuximab vedotin therapy.

BACKGROUND AND PURPOSE: Peripheral neuropathy is a frequent complication of brentuximab vedotin (BV), used in CD30+ lymphoma treatment. Classic BV-induced neuropathy (BV-CN) is a mild distal sensory axonal polyneuropathy. Severe BV-induced inflammatory neuropathies (BV-IN) have been described. BV-IN contribute to lymphoma-associated morbidity but might be immunotherapy-responsive. Our primary objective was to evaluate the rate of BV-IN. Our secondary objectives were to determine risk factors and warning signs. METHODS: We conducted a retrospective cohort study on all patients treated with BV at our center between April 2014 and September 2021. Clinical, biological, and electrophysiological data were collected. BV-induced neuropathy was defined as the occurrence of neuropathy up to 3 months after BV discontinuation. BV-IN was defined with criteria adapted from European Academy of Neurology/Peripheral Nerve Society 2021 electrodiagnostic criteria for chronic inflammatory demyelinating polyradiculoneuropathy. Other neuropathies were classified as BV-CN. RESULTS: Among 83 patients, 41 (49%) developed neuropathy: 35 BV-CN and 6 BV-IN. Thus, the rate of BV-IN was 7.2%. Compared to patients with BV-CN, no predisposing factor was identified. However, patients with BV-IN more frequently presented muscle weakness (67% vs. 5.7%, p < 0.05), gait disorders (83% vs. 20%, p < 0.05), or acute or subacute onset (67% vs. 14%, p < 0.05). BV-IN was frequently more severe (Common Terminology Criteria for Adverse Events grade ≥3; 50% vs. 0%, p < 0.05). Four patients were treated with immunotherapy. CONCLUSIONS: Brentuximab vedotin-induced neuropathy is an overlooked complication. Based on four easily identifiable "red flags", we provide an algorithm to help non-neurologist physicians that care for BV-treated patients to detect BV-IN. The aim of the algorithm is to decrease the diagnostic and management delay of this disabling neuropathy.

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

AIM: Chemotherapy-induced peripheral neuropathy (CIPN) is a major toxicity limiting the use of nab-paclitaxel (Nab-P) in treating patients with pancreatic cancer. The aim of this study was to identify the factors affecting CIPN using patient-reported outcome measures and the minimally invasive volumetric absorptive microsampling (VAMS) technique. METHODS: The maximum concentrations of paclitaxel (Cmax) were measured from 81 VAMS samples collected from 44 participants with pancreatic cancer. The association between CIPN development and demographic, clinical and pharmacokinetic factors was determined using univariable and multivariable logistic regression. The association between CIPN severity and the factors was evaluated using Spearman's rank correlation. The impact of Cmax and the number of treatment cycles on the severity was assessed using multivariable linear regression. RESULTS: The development of CIPN was significantly associated with cumulative dose (odds ratio 1.005, 95% confidence interval [CI] 1.003-1.007), treatment cycles (3.47, 2.25-5.85), alkaline phosphate (0.992, 0.985-0.998) and age (1.092, 1.020-1.179), with an area under the receiver operating characteristic curve of 0.89 (95% CI 0.83-0.95). The severity of CIPN significantly worsened with increasing cumulative dose (coefficient 0.58, 95% CI 0.44-0.69), treatment cycles (0.57, 0.44-0.68) and age (0.18, 0.00-0.35). The severity of CIPN was predictable from treatment cycles (P = .0002) and Cmax (P = .01). CONCLUSION: The higher the cumulative dose of Nab-P, treatment cycles and age, the more frequently and severely do the patients experience CIPN. In predicting the severity of CIPN using Cmax, minimally invasive VAMS is a feasible alternative to venous blood sampling.

Exploring clinical markers of Axon degeneration processes in Chemotherapy-induced peripheral neuropathy among young adults receiving vincristine or paclitaxel.

BACKGROUND: Approximately 70% of patients receiving neurotoxic chemotherapy (e.g., paclitaxel or vincristine) will develop chemotherapy-induced peripheral neuropathy. Despite the known negative effects of CIPN on physical functioning and chemotherapy dosing, little is known about how to prevent CIPN. The development of efficacious CIPN prevention interventions is hindered by the lack of knowledge surrounding CIPN mechanisms. Nicotinamide adenine dinucleotide (NAD+) and cyclic-adenosine diphosphate ribose (cADPR) are potential markers of axon degeneration following neurotoxic chemotherapy, however, such markers have been exclusively measured in preclinical models of chemotherapy-induced peripheral neuropathy (CIPN). The overall objective of this longitudinal, observational study was to determine the association between plasma NAD+, cADPR, and ADPR with CIPN severity in young adults receiving vincristine or paclitaxel. METHODS: Young adults (18-39 years old) beginning vincristine or paclitaxel were recruited from Dana-Farber Cancer Institute. Young adults completed the QLQ-CIPN20 sensory and motor subscales and provided a blood sample prior to starting chemotherapy (T1) and at increasing cumulative vincristine (T2: 3-5 mg, T3: 7-9 mg) and paclitaxel (T2: 300-500 mg/m2, T3: 700-900 mg/m2) dosages. NAD+, cADPR, and ADPR were quantified from plasma using mass spectrometry. Metabolite levels and QLQ-CIPN20 scores over time were compared using mixed-effects linear regression models and/or paired two-sample tests. RESULTS: Participants (N = 50) were mainly female (88%), white (80%), and receiving paclitaxel (78%). Sensory and motor CIPN severity increased from T1-T3 (p < 0.001). NAD+ (p = 0.28), cADPR (p = 0.62), and ADPR (p = 0.005) values decreased, while cADPR/NAD+ ratio increased from T1-T3 (p = 0.50). There were no statistically significant associations between NAD + and QLQ-CIPN20 scores over time. CONCLUSIONS: To our knowledge, this is the first study to measure plasma NAD+, cADPR, and ADPR among patients receiving neurotoxic chemotherapy. Although, no meaningful changes in NAD+, cADPR, or cADPR/NAD+ were observed among young adults receiving paclitaxel or vincristine. Future research in an adequately powered sample is needed to explore the clinical utility of biomarkers of axon degeneration among patients receiving neurotoxic chemotherapy to guide mechanistic research and novel CIPN treatments.

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

BACKGROUND AND AIMS: 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. METHODS: 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. RESULTS: 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. INTERPRETATION: 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.

Exploring the reliability and validity of clinically-relevant outcome measures for chemotherapy-induced peripheral neuropathy.

PURPOSE: To explore the reliability and validity of clinically-relevant outcome measures for balance (i.e., The Short Physical Performance Battery [SPPB] - Balance Subscale) and sensation (i.e., monofilament threshold testing) for use in clinical trials of chemotherapy-induced peripheral neuropathy (CIPN). METHODS: Adult, post-treatment cancer survivors (N = 142) who had reported ≥ 4/10 CIPN symptom severity following neurotoxic chemotherapy were recruited from six National Cancer Institute Community Oncology Research Program (NCORP) sites associated with the University of Rochester Cancer Center NCORP Research Base. Participants completed the monofilament threshold test at the screening and baseline time points (i.e., one week apart), while the Quality of Life Questionnaire-CIPN20, Treatment-Induced Neuropathy Assessment Scale, and SPPB - Balance Subscale were completed at baseline. Test-retest reliability of the monofilament threshold testing scores was assessed using the Intraclass Correlation Coefficient (ICC). The convergent validity among monofilament threshold testing, SPPB - Balance Subscale, and CIPN patient-reported outcome (PRO) scores at baseline was assessed using Spearman's correlation. RESULTS: Ceiling effects were observed for SPPB-Balance Subscale scores as 113 (79.6%) respondents reported the highest score. Agreement between the screening and baseline monofilament threshold testing scores was moderate (ICC = 0.65). Monofilament threshold testing (rs Range: 0.14 - 0.21) and SPPB Balance Subscale scores (rs Range: -0.36 - -0.22) showed largely low correlations with all PRO measures. CONCLUSIONS: Monofilament threshold testing demonstrated moderate test-retest reliability, but low convergent validity with CIPN PROs, while the SPPB - Balance Subscale demonstrated low convergent validity with CIPN PROs and ceiling effects (i.e., highest possible score) among post-treatment cancer survivors with CIPN. Future research is needed to identify promising measures of balance and sensation loss for use in clinical trials that complement CIPN PROs to aid in the identification of clinically relevant treatments for CIPN. TRIAL REGISTRATION: NCT04367490 [April 29, 2020].

Efficacy of cryotherapy in the prevention of chemotherapy-induced peripheral neuropathy: A systematic review and meta-analysis.

PURPOSE: The study investigates cryotherapy's efficacy in mitigating Chemotherapy-induced peripheral neuropathy (CIPN), an adverse effect of chemotherapy that often leads to dosage reduction or treatment discontinuation. METHOD: The study was registered with PROSPERO (CRD42023428936). A literature search was conducted using the PubMed, Embase, and Cochrane Library databases. Randomized and nonrandomized controlled trials that investigated the effects of cryotherapy on CIPN were included for systematic review and meta-analysis. The primary outcome for prevention was the incidence of CIPN. RESULTS: We identified 17 trials involving 2,851 patients. In total, 11 trials compared the incidence of CIPN between cryotherapy and control groups. Significant differences in the incidence of CIPN at the midpoint and end of chemotherapy were observed, with risk ratios (RRs) of 0.23 (95% confidence interval [CI] = 0.13 to 0.43) and 0.54 (95% CI = 0.33 to 0.88), respectively. Cryotherapy also significantly reduced the incidence of sensory CIPN, with an RR of 0.67 (95% CI = 0.49 to 0.92). Additionally, cryotherapy demonstrated a significant reduction in the incidence of CIPN in patients with gynecological cancers (RR = 0.24, 95% CI = 0.14 to 0.41). Significantly favorable global quality of life scores following chemotherapy (standardized mean difference = 1.43; 95% CI = 0.50 to 2.36) and relieved neuropathic symptoms were found with cryotherapy. CONCLUSIONS: Cryotherapy demonstrates a pronounced preventive effect against the development of CIPN, providing substantial symptomatic relief and quality of life improvements for patients undergoing chemotherapy. The administration of cryotherapy through the use of frozen gloves and socks, or continuous-flow cooling systems, optimally initiated 15 min prior to and concluded 15 min following chemotherapy, is recommended for achieving maximum therapeutic efficacy.

Home-based high tone therapy may alleviate chemotherapy-induced neuropathic symptoms in patients with colorectal cancer: A randomized double-blind placebo-controlled pilot evaluation.

BACKGROUND: Most oncologic patients receiving chemotherapy suffer from neuropathy, which not only severely affects quality of life but also may lead to chemotherapy dose reductions or even discontinuation of cancer therapy. Still, it is difficult to sufficiently control these symptoms with the currently available pharmacological treatments. High tone therapy was reported to be an effective option for neuropathies due to different etiologies. However, to date, there are no studies on high tone therapy in patients with chemotherapy-induced peripheral neuropathy. METHODS: This randomized, double-blind, and placebo-controlled two-center study was conducted at the Departments of Physical and Rehabilitation Medicine at the Clinics Donaustadt and Ottakring, Vienna, Austria. Patients with histologically verified colorectal carcinoma treated with a platin derivate and neuropathic symptoms were invited to participate. High tone therapy took place in a home-based setting using the HiToP 191 PNP ® or placebo device for three weeks. Neuropathic symptoms and quality of life were assessed via questionnaires. After the follow-up examination, an opt-in was offered to the patients in the placebo group in terms of an open-label treatment with a verum HiToP PNP ® device. In addition, patients with chemotherapy-induced peripheral neuropathy due to various malignant diseases were treated in an open-label setting reflecting a clinical application observation. These patients are reported as a separate group. RESULTS: In the verum group, there was a significant reduction of paresthesias and mental stress due to paresthesias from baseline until end of therapy, compared to placebo. These findings were observed in the opt-in subgroup, as well. In the open-label clinical application observation group, intensity and mental stress due to paresthesia, pain, cramps, and intensity of tightness/pressure were significantly lower at the end of therapy, compared to baseline. CONCLUSIONS: Home-based high tone therapy brought about a significant alleviation in paresthesias and mental stress due to paresthesias in the verum but not the placebo group. In the clinical application observation, a significant alleviation in several further neuropathic symptoms was seen. TRIAL REGISTRATION: This study was registered at clinicaltrials.gov (NCT06048471, 03/02/2020).

Motor disorders related to oxaliplatin-induced peripheral neuropathy: long-term severity and impact on quality of life.

PURPOSE: Sensory chemotherapy-induced peripheral neuropathy (CIPN) is well-recognized, but motor CIPN remains understudied. This secondary analysis focused on the long-term severity and impact of motor disorders, their relation to sensory CIPN, neuropathic pain, psychological distress, and health-related quality of life (HRQoL) after oxaliplatin-based chemotherapy in colorectal cancer (CRC) survivors. METHODS: Data from a multicenter, cross-sectional study were re-analyzed to explore motor CIPN among CRC survivors up to 5 years post-chemotherapy, with no longitudinal follow-up. Questionnaires assessed sensory and motor CIPN (QLQ-CIPN20), neuropathic pain (DN4), anxiety and depression (HADS), and HRQoL (QLQ-C30). RESULTS: Among 405 CRC survivors, 31.1% had sensory CIPN as previously described. When categorizing the 405 CRC survivors based on the years since their last oxaliplatin-based chemotherapy, the motor scores derived from the QLQ-CIPN20 showed no significant difference between years (p = 0.08). Motor CIPN scores correlated with female gender, higher oxaliplatin dose intensity, sensory CIPN, and neuropathic pain. Motor CIPN also linked to decreased HRQoL and increased psychological distress. CONCLUSION: The study underscores the detrimental impact of motor disorders on CRC survivors post-oxaliplatin-based chemotherapy. Oncologists should prioritize assessing and managing motor manifestations alongside sensory symptoms to enhance post-cancer quality of life. TRIAL REGISTRATION: NCT02970526 (2016-11-22). https://classic. CLINICALTRIALS: gov/ct2/show/NCT02970526?term=NCT02970526&draw=2&rank=1 .

Summary of evidence on comprehensive healthcare for chemotherapy-induced peripheral neuropathy in cancer patients.

OBJECTIVE: This paper aims to provide an evidence-based summary of the most effective strategies for comprehensive healthcare of chemotherapy-induced peripheral neuropathy (CIPN) in cancer patients. METHOD: Following the "6S" model, relevant evidence on CIPN management was collected from reputable evidence-based resource websites and databases nationally and internationally. The included articles were evaluated for methodological quality, and evidence was extracted using the Australian JBI Evidence-based Health Care Center's literature evaluation standard (2016 edition). RESULTS: A total of 60 articles were included in this study, comprising 2 guidelines, 5 expert consensus statements, and 53 systematic reviews. The findings of these articles were summarized across 7 dimensions, including risk factor screening, assessment, diagnosis, prevention, treatment, management, and health education, resulting in the identification of 42 relevant pieces of evidence. CONCLUSIONS: This study provides a comprehensive synthesis of evidence-based recommendations for managing CIPN in cancer patients, offering guidance for healthcare professionals engaged in clinical practice. However, when implementing these recommendations, it is crucial to consider the individual patient's clinical circumstances, preferences, and expert judgment, ensuring feasibility and applicability in real-world clinical settings.

Personalized Outcomes in Neuropathic Pain: A Clinical Relevance and Assay Sensitivity Analysis from a Randomized Controlled Trial.

OBJECTIVE: To explore the clinical relevance and assay sensitivity of using personalized outcomes using data from a randomized clinical trial (RCT) in people with chemotherapy induced peripheral neuropathy (CIPN). DESIGN: This study is a secondary analysis that leveraged data from a RCT of transcutaneous electrical stimulation for CIPN to test whether personalized outcomes could minimize potential floor effects and increase the assay sensitivity of pain clinical trials (ie, ability to detect a true treatment effect). SETTING: Participants were recruited for a RCT from community oncology clinics in the U.S. PARTICIPANTS: Adults with CIPN (N = 72) who reported on average ≥4 intensity (measured via a 7-day baseline diary) for at least one of the following pain qualities hot/burning pain, sharp/shooting pain and/or cramping. METHODS: Personalized outcomes were defined based on participants' unique presentation of pain qualities at baseline, measured via 0-10 numeric rating scales (NRS), or ranking of the distress caused by the pain qualities. Analysis of covariance models estimated the treatment effect as measured by personalized and non-personalized outcomes. RESULTS: The adjusted mean difference between groups was higher using personalized outcomes (ie, 1.21-1.25 NRS points) compared to a non-personalized outcome (ie, 0.97 NRS points), although the standardized effect sizes were similar between outcomes (0.49-0.54). CONCLUSIONS: These results suggest that personalized pain quality outcomes could minimize floor effects, while providing similar assay sensitivity to non-personalized pain quality outcomes. Personalized outcomes better reflect an individual's unique experience, inherently providing more clinically relevant estimates of treatment effects. Personalized outcomes may be advantageous particularly for clinical trials in populations with high inter-individual variability in pain qualities.