Risk-reduction and treatment of chemotherapy-induced peripheral neuropathy

Knowledge levels of oncology nurses regarding evidence-based practices in the assessment and management of chemotherapy-induced peripheral neuropathy

Objective

The study aimed to determine the level of oncology nurses' knowledge of evidence-based practice for assessing and managing chemotherapy-induced peripheral neuropathy (CIPN).

Methods

This study employed a descriptive and cross-sectional research design. It was carried out with oncology nurses who were working at a university hospital in the Western Region of Turkey and who were members of the Oncology Nursing Association. The sample of the study consisted of 96 nurses who met the inclusion criteria.

Results

The study sample comprised 94.8% female oncology nurses, 57.3% of whom held an undergraduate degree, and over half (58.5%) of whom were employed as clinical nurses. A majority of nurses (76.0%) indicated that they had not received any training in peripheral neuropathy. 35.4% of the nurses assessed patients receiving neurotoxic chemotherapy for peripheral neuropathy at each visit/each chemotherapy cycle. A total of 43.8% of nurses indicated that they frequently assessed patients for peripheral neuropathy at the conclusion of the treatment protocol. The oncology nurses assessed the patient-reported symptoms of motor neuropathy (58.3%), sensory neuropathy (56.3%), autonomic neuropathy (51.0%), neuropathic pain (55.2%), and co-occurring symptoms (52.1%) on a frequent basis. The nurses reported that they assessed muscle strength (56.3%), gait and balance (58.3%), and quality of life (52.1%) "frequently". In contrast, they assessed deep tendon reflex (41.7%), neurological tests (36.5%), and social activities (46.8%) "rarely".

Conclusions

The study findings indicated that oncology nurses require further education and training in evidence-based practices for the assessment and management of CIPN.

Chemical compounds, anti-tumor and anti-neuropathic pain effect of hemp essential oil in vivo

Hemp (Cannabis sativa L.), an annual dioecious plant, has shown extensive application in the fields of fibers, food, oil, medicine, etc. Currently, most attention has been paid to the therapeutic properties of phytocannabinoids. However, the pharmaceutical research on essential oil from hemp is still lacking. In this study, hemp essential oil (HEO) was extracted from hemp flowers and leaves, and the components were analyzed by GC-MS. Quatitative analysis of three main compounds β-caryophyllene, β-caryophyllene oxide, α -humulene were determined by GC-FID. The anti-tumor and anti-neuropathic pain effects of HEO were evaluated. In the paclitaxel induced neuropathic mice model, HEO reduced the serum level of inflammatory cytokines TNF-α to achieve the analgesic effect, which was tested by evaluating mechanical and thermal hyperalgesia. Further investigation with cannabinoid receptor 2 (CB2 R) antagonist AM630 revealed the mechanism of reversing mechanical hyperalgesia may be related to CB2 R. In Lewis lung cancer grafted mice model, the tumor growth was significantly inhibited, the levels of tumor inflammatory cytokines TNF-α and IL-6 were downregulated, immune organ index was modified and immune-related CD4+, CD8+ T lymphocytes level, CD4+/CD8+ ratio were increased when administered with HEO. These results reveal that HEO plays a role not only in tumor chemotherapy induced peripheral neuropathy treatment, but also in anti-tumor treatment which offers key information for new strategies in cancer treatment and provides reference for the medicinal development of hemp.

The Potential Antinociceptive Effect and Mechanism of Cannabis sativa L. Extract on Paclitaxel-Induced Neuropathic Pain in Rats Uncovered by Multi-Omics Analysis

Cannabis sativa L. (hemp) is a herbaceous plant rich in cannabinoids with a long history of use in pain treatment. The most well-characterized cannabinoids, cannabidiol (CBD) and Δ9-tetrahydrocannabinol (Δ9-THC), garnered much attention in chemotherapy-induced peripheral neuropathy (CIPN) treatment. However, few studies have investigated the biological benefits and mechanism of hemp extract on CIPN. In the present study, hemp extract (JG) rich in cannabinoids was extracted by supercritical fluid carbon dioxide extraction (SFCE). The antinociceptive efficacy was evaluated using a paclitaxel-induced peripheral neuropathy (PIPN) rat model based on behavioral tests. Further omics-based approaches were applied to explore the potential mechanisms. The results showed that JG decreased mechanical allodynia, thermal hyperalgesia, and inflammatory cytokines in PIPN rats significantly. Transcriptome analysis identified seven key genes significantly regulated by JG in PIPN model rats, mainly related to the neuroactive ligand-receptor interaction pathway, PPAR signaling pathway, and cAMP signaling pathway. In metabolomic analysis, a total of 39 significantly altered metabolites were identified, mainly correlated with pentose and glucuronate interconversions and the glycerophospholipid metabolism pathway. Gut microbiota analysis suggested that increased community Lachnoclostridium and Lachnospiraceae_UCG-006 in PIPN rats can be reversed significantly by JG. In conclusion, hemp extract exhibited antinociceptive effects on PIPN. The analgesic mechanism was probably related to the regulation of inflammation, neuroactive ligand-receptor interaction pathway, sphingolipid metabolism, etc. This study provides novel insights into the functional interactions of Cannabis sativa L. extract on PIPN.

Effect of Physical Activity on Static and Dynamic Postural Balance in Women Treated for Breast Cancer: A Systematic Review

BACKGROUND

Therapies against breast cancer (BC) frequently involve complications that impair patients' daily function and quality of life, the most common of which are motor coordination and balance disorders, increasing the risk of falls and injuries. In such cases, physical activity is recommended. Designed following the PRISMA guidelines, this study presents a systematic review of randomised and pilot clinical trials investigating the effect of physical exercises on postural balance in women treated for BC.

METHODS

Scientific databases (PubMed, EBSCO) and the online resources of grey publications were searched for trial reports published between January 2002 and February 2022. The inclusion criteria necessitated full-text, English-language reports from randomised clinical trials (RCTs) or pilot clinical trials (pilot CTs), whose authors used physical exercises to treat women with BC and the experimental and control groups consisted of at least 10 women. The methodological quality of the RCTs and pilot CTs were measured using the Physiotherapy Evidence Database (PEDro) scale and the Methodological Index for Non-Randomized Studies (MINORS), respectively. Data were extracted on the effect of exercise on the women's static and dynamic balance.

RESULTS

Seven reports, five RCTs and two pilot CTs involving a total of 575 women (aged 18-83 years) were included in the systematic review. Their training protocols utilised a variety of aerobic, strength, endurance, sensorimotor, Pilates exercises, and fitness exercises with elements of soccer. The experimental groups usually worked out in fitness or rehabilitation centres under the supervision of physiotherapists or trainers. Training sessions of 30-150 min were held 2 or 3 times a week for 1.5-24 months. Most trials reported that static and dynamic balance in the experimental groups improved significantly more compared with the control groups.

CONCLUSIONS

Physical exercises are able to improve static and dynamic postural balance in women treated for BC. However, as all evidence in support of this conclusion comes from only two pilot CT and five RCTs whose methodologies varied widely, more high quality research is needed to validate their findings and determine which exercise protocols are the most effective in improving postural control in women with BC.

Changes in the expression of endocannabinoid system components in an experimental model of chemotherapy-induced peripheral neuropathic pain: Evaluation of sex-related differences

Chemotherapy-induced neuropathic pain is a serious clinical problem and one of the major side effects in cancer treatment. The endocannabinoid system (ECS) plays a crucial role in regulating pain neurotransmission, and changes in the expression of different components of the ECS have been reported in experimental models of persistent pain. In addition, sex differences have been observed in ECS regulation and function. The aim of our study was to evaluate whether administration of oxaliplatin, a neurotoxic antineoplastic agent, induced changes in the expression of ECS components in peripheral and central stations of the pain pathway, and if those changes exhibited sexual dimorphism. Adult male and female rats were injected with oxaliplatin or saline, and mechanical and cold hypersensitivity and allodynia were evaluated using Von Frey and Choi Tests. The mRNA levels corresponding to cannabinoid receptors (CB1, CB2), cannabinoid-related receptors (GPR55, 5HT1A, TRPV1) and to the main enzymes involved in the synthesis (DAGL, DAGL, NAPE-PLD) and degradation (MGL, FAAH) of endocannabinoids were assessed in lumbar dorsal root ganglia (DRGs) and spinal cord by using real time RT-PCR. In addition, the levels of the main endocannabinoids, 2-arachidonoylglycerol (2-AG) and anandamide (AEA), were evaluated using commercial ELISA kits. Oxaliplatin administration induced the development of mechanical and cold hypersensitivity and allodynia in male and female animals. Oxaliplatin also induced early and robust changes in the expression of several components of the ECS in DRGs. A marked upregulation of CB1, CB2, 5HT1A and TRPV1 was detected in both sexes. Interestingly, while DAGL mRNA levels remained unchanged, DAGL was downregulated in male and upregulated in female rats. Finally, MGL and NAPE-PLD showed increased levels only in male animals, while FAAH resulted upregulated in both sexes. In parallel, reduced 2-AG and AEA levels were detected in DRGs from male or female rats, respectively. In the lumbar spinal cord, only TRPV1 mRNA levels were found to be upregulated in both sexes. Our results reveal previously unreported changes in the expression of cannabinoid receptors, ligands and enzymes occurring mainly in the peripheral nervous system and displaying certain sexual dimorphism. These changes may contribute to the physiopathology of oxaliplatin-induced neuropathic pain in male and female rats. A better understanding of these dynamic changes will facilitate the development of mechanism- and sex-specific approaches to optimize the use of cannabinoid-based medicines for the treatment of chemotherapy-induced pain.

Sex-related differences in oxaliplatin-induced changes in the expression of transient receptor potential channels and their contribution to cold hypersensitivity

Transient receptor potential (TRP) channels are involved in the development of oxaliplatin-induced neuropathic pain, a frequent and debilitating side effect of cancer therapy. Here we explored whether oxaliplatin-induced changes in the expression of TRP channels, as well as the development of pain-related behaviours, differed between male and female animals. Adult rats were injected with oxaliplatin or saline and mechanical and cold allodynia were evaluated using Von Frey and Choi Tests. The mRNA levels of TRPV1, TRPM8 and TRPA1 were assessed in lumbar ganglia and spinal cord by using real time RT-PCR. Oxaliplatin administration induced mechanical and cold hypersensitivity and allodynia in both sexes, with more severe responses to cold stimulation detected in females. Oxaliplatin also induced a significant increase in the expression of TRPV1, TRPM8 and TRPA1 in lumbar dorsal root ganglia. Interestingly, while TRPV1 and TRPA1 upregulation showed no sex difference, the increase in TRPM8 mRNA levels was more pronounced in female ganglia, correlating with the increased sensitivity to innocuous cold stimuli observed in females. TRPV1 and TRPM8 were also found to be upregulated in the spinal cord of animals of both sexes. Our results reveal previously undescribed changes in the expression of TRP channels occurring in peripheral ganglia and spinal cord of both male and female oxaliplatin-treated animals, with some of these changes exhibiting sex-related differences that could underlie the development of sex-specific patterns of pain-related behaviours.

Neutropenic Diet Cannot Reduce the Risk of Infection and Mortality in Oncology Patients With Neutropenia

Background

The purpose of this systematic review and meta-analysis was to evaluate the effect of a neutropenic diet and a control diet on infection and mortality rates in oncology patients with neutropenia.

Methods

We searched the following English electronic databases: PubMed, Embase, Cochrane Central Register of Controlled Trials, and Google Scholar Engine. Published studies involving neutropenic diets (study group) and control diets (control group) in oncology patients with neutropenia were searched. The focus of the meta-analysis was on the outcomes of infection and mortality rates. A subgroup analysis was also performed.

Results

A total of 6 studies were included, with a total sample size of 1114 patients. The patients in the study group had a similar infection rate compared with the patients in the control group (P = 0.11). The patients in the study group had a similar mortality rate compared with the patients in the control group (P = 0.74). Another subgroup analysis showed that the incidence of infection was also similar for pediatric (P = 0.74) and adult (P = 0.11) oncology patients between the study and control groups.

Conclusions

Based on the current evidence, this meta-analysis showed that the application of a neutropenic diet cannot reduce the risk of infection and mortality in oncology patients with neutropenia. However, more rigorous randomized controlled trials are needed to confirm this conclusion in the future.

Role of Intravenous Lidocaine Infusion in the Treatment of Peripheral Neuropathy

PURPOSE OF REVIEW

This is a comprehensive review of the literature regarding intravenous lidocaine infusion to treat peripheral neuropathy. The clinical symptoms of peripheral neuropathy occur on a broad spectrum and stem from many etiologies resulting in complex treatment approaches. This review presents the background, evidence, and indications for the use of intravenous lidocaine infusions as a treatment option for this condition.

RECENT FINDINGS

The clinical range of peripheral neuropathy symptoms includes pain, numbness, muscle weakness, paresthesia, balance difficulty, and autonomic dysfunction. However, severe neuropathic pain remains one of the most debilitating symptoms that significantly affects the quality of life. Current treatment options include antidepressants, anticonvulsants, and, in some cases, opiates, but these are often ineffective, creating the need for other therapeutic approaches.The pathophysiology of neuropathic pain involves sodium channels which create abnormal pain responses. Intravenous lidocaine primarily functions by inhibiting membrane sodium channels which desensitize peripheral nociceptors, thus creating an analgesic effect. The research in using intravenous lidocaine for neuropathic pain is not fully complete and requires further evaluation.

SUMMARY

Peripheral neuropathy is a manifestation commonly resulting from diabetes, alcohol abuse, vitamin deficiencies, and chemotherapy, among other causes. One of the most significant complications is neuropathic pain which is often resistant to multi-modal therapeutic regimens. Intravenous lidocaine infusions are a newer treatment option for neuropathic pain, which have additional anti-inflammatory effects with a minimal side effect profile. Studies have concluded it effectively treats neuropathic pain for weeks after administration, but results are variable depending on specific procedures. Further research, including additional direct comparison studies, should be conducted to fully evaluate this drug's usefulness.

Cell metabolomics analyses revealed a role of altered fatty acid oxidation in neurotoxicity pattern difference between nab-paclitaxel and solvent-based paclitaxel

Peripheral neuropathy (PN) is a dose-limiting, painful adverse reaction associated with the use of paclitaxel. This common side effect was often partially attributed to the solvent used for solubilization of the highly hydrophobic drug substance. Therefore, the development of alternative formulations thrived, which included that of Abraxane® containing nanoparticle albumin-bound paclitaxel (nab-paclitaxel). However, studies demonstrated inconsistent conclusions regarding the mitigation of PN in comparison with the traditional formulation. The mass spectrometry-based cell metabolomics approach was used in the present study to explore the potentially associated mechanisms. Although no significant difference in the effects on cell viability was observed, fold changes in carnitine, several acylcarnitines and long-chain fatty acid(s) were significantly different between treatment groups in differentiated and undifferentiated SH-SY5Y cells. The most prominent difference observed was the significant increase of octanoylcarnitine in cells treated with solvent-based paclitaxel, which was found to be associated with significant decrease of medium-chain acyl-CoA dehydrogenase (MCAD). The findings suggested the potential role of altered fatty acid oxidation in the different neurotoxicity patterns observed, which may be a possible target for therapeutic interventions worth further investigation.

[Rehabilitation methods for cancer patients with peripheral polyneuropathy induced by cytostatics]

An analytical review of the methods of cancer patients' rehabilitation with peripheral polyneuropathy induced by cytostatics (PNPIC) was carried out. Studies from electronic databases were investigated: Scopus, Web of Science, MedLine, World Health Organization, The Cochrane Central Register of Controlled Trials, ScienceDirect, US National Library of Medicine National Institutes of Health, PubMed Cancer, eLIBRARY, CyberLeninka. Despite the improvement of anticancer therapy and an increase in patients' life expectancy, the emerging peripheral polyneuropathy remains an urgent problem, since it significantly affects both the patients' life quality and the selection of adequate therapy. The frequency of detection of PNPIC is 90%, after discontinuation of treatment; symptoms of damaged peripheral nerve fibers remain in 30% of patients. The clinical symptoms of PNPIC are varied and most often include numbness in the extremities and / or increased sensitivity to thermal or mechanical stimuli, neuropathic pain. Currently, to prevent PNPIC, treatment is being modified with a reduction in the duration of courses and doses of cytostatics, and interruption of treatment. Official guidelines do not recommend any prophylaxis other than the possible use of duloxetine or a topical gel containing baclofen, amitriptyline, and ketamine. Over the past few years, there has been no significant progress in the prevention and treatment of PNPIC. The most common drug treatment method in clinical practice is the prescription of vitamins B. Among the non-drug treatment methods of PNPIC, the authors used acupuncture, electro-acupuncture, manual therapy, massage, gymnastics, yoga, sensorimotor training, general vibration therapy, percutaneous electro-neuro-stimulation, electro-analgesia, local cryotherapy, hydrotherapy, low-intensity alternating magnetic radiation. The studies included in the review are heterogeneous in design and protocol, number of patients, and time points for assessing outcomes. In connection with the existing differences, it is not possible to carry out a comparative analysis of the results of these rehabilitation types and to give an unambiguous answer about their effectiveness. As the analysis has shown, peripheral PNPIC is well known all over the world, however, the search for methods of its treatment is far from complete.

Effects of alkaloids on peripheral neuropathic pain: a review

Neuropathic pain is a debilitating pathological pain condition with a great therapeutic challenge in clinical practice. Currently used analgesics produce deleterious side effects. Therefore, it is necessary to investigate alternative medicines for neuropathic pain. Chinese herbal medicines have been widely used in treating intractable pain. Compelling evidence revealed that the bioactive alkaloids of Chinese herbal medicines stand out in developing novel drugs for neuropathic pain due to multiple targets and satisfactory efficacy. In this review, we summarize the recent progress in the research of analgesic effects of 20 alkaloids components for peripheral neuropathic pain and highlight the potential underlying molecular mechanisms. We also point out the opportunities and challenges of the current studies and shed light on further in-depth pharmacological and toxicological studies of these bioactive alkaloids. In conclusion, the alkaloids hold broad prospects and have the potentials to be novel drugs for treating neuropathic pain. This review provides a theoretical basis for further applying some alkaloids in clinical trials and developing new drugs of neuropathic pain.

Effectiveness of Acupuncture Treatment on Chemotherapy-Induced Peripheral Neuropathy: A Pilot, Randomized, Assessor-Blinded, Controlled Trial

Objective

This pilot study aims to evaluate the effectiveness and safety of acupuncture in the treatment of chemotherapy-induced peripheral neuropathy (CIPN).

Methods

This study was a pilot randomized controlled trial, which was conducted with cooperation between Beijing University of Chinese Medicine (BUCM), China, and Tehran University of Medical Science (TUMS), Iran. Forty participants with CIPN were randomly assigned (1 : 1) to receive twelve sessions of acupuncture (20 minutes each session over 4 weeks) or take one 300 mg tablet of vitamin B1 and three 300 mg capsules of gabapentin per day for 4 weeks, after which both groups were followed up for 4 weeks. The primary endpoint was CIPN symptom severity measured by the Numerical Rating Scale (NRS). The secondary endpoints included sensory neuropathy grade evaluated by the National Cancer Institute-Common Toxicity Criteria for Adverse Events (NCI-CTCAE), neurophysiological assessment of CIPN by the nerve conduction study (NCS), and the patient overall satisfaction with treatment. Safety was assessed at each visit.

Results

The NRS and NCI-CTCAE sensory neuropathy grading scales decreased significantly over time in both groups (both P < 0.001), with a significantly higher reduction in the acupuncture group (P < 0.001 and P = 0.03, respectively). In addition, the acupuncture group showed a higher overall satisfaction with the treatment at the end of treatment and after 4 weeks follow-up, in comparison with the vit B1 and gabapentin group (P = 0.01 and P = 0.001, respectively). The NCS (except for the latency of the sural nerve) in the acupuncture group improved significantly (P < 0.05), while improvement in the vit B1 and gabapentin group was not observed (P > 0.05).

Conclusion

Our study revealed that acupuncture, as a kind of traditional Chinese therapeutic method, is significantly effective and safe in the treatment of CIPN. Moreover, acupuncture is more effective than using vitamin B1 and gabapentin as the conventional treatment. Trial registration. This trial is registered with the Iranian Registry of Clinical Trials (IRCT20190615043900N1).

Evaluation of the effect of N-acetylcysteine on the prevention and amelioration of paclitaxel-induced peripheral neuropathy in breast cancer patients: a randomized controlled study

PURPOSE

The aim of the current study was to evaluate the effect of N-acetylcysteine (NAC) on the incidence and severity of paclitaxel-induced peripheral neuropathy (PIPN) in breast cancer patients.

METHOD

A prospective randomized controlled open label study was conducted on 75 breast cancer patients receiving adjuvant paclitaxel 80 mg/m² weekly for 12 weeks. Eligible patients were randomized to either the low dose group; 1200 mg daily NAC, the high dose group; 1200 mg NAC twice daily or the control group; received paclitaxel only. The primary endpoint was the incidence of different grades of PIPN using National Cancer Institute's common toxicity criteria for adverse event (NCI-CTCAE) while secondary endpoints were the severity of PIPN using modified total neuropathy score (mTNS), quality of life (QOL) using Functional Assessment of Cancer Therapy/Gynecologic Oncology Group-Neurotoxicity (FACT-GOG-NTX) subscale, serum nerve growth factor (NGF), and serum malondialdehyde (MDA).

RESULTS

At the end of the 12-week period, the incidence of grade (2, 3) peripheral neuropathy was significantly lower in the high dose group (28.6%) compared to the low dose group (61.9%) and the control group (100%), p value < 0.001. A significant improvement in the mTNS and QOL scores was observed after 6 and 12 weeks in the high dose group and the low dose group compared to the control, p value < 0.001. Significantly higher levels of serum NGF in the high dose group and lower level of serum MDA in the high dose and the low dose group were observed.

CONCLUSION

Oral NAC (1200 mg once and twice daily) might reduce the incidence and severity of PIPN and improve the patients' QOL.

TRIAL REGISTRY

Clinical Trial.gov registration number: NCT03492047.

Chemotherapy-induced peripheral neuropathy: part 1-current state of knowledge and perspectives for pharmacotherapy

Background

Despite the increasing knowledge of the etiology of neuropathic pain, this type of chronic pain is resistant to available analgesics in approximately 50% of patients and therefore is continuously a subject of considerable interest for physiologists, neurologists, medicinal chemists, pharmacologists and others searching for more effective treatment options for this debilitating condition.

Materials and methods

The present review article is the first of the two articles focused on chemotherapy-induced peripheral neuropathy (CIPN).

Results

CIPN is regarded as one of the most common drug-induced neuropathies and is highly pharmacoresistant. The lack of efficacious pharmacological methods for treating CIPN and preventing its development makes CIPN-related neuropathic pain a serious therapeutic gap in current medicine and pharmacotherapy. In this paper, the most recent advances in the field of studies on CIPN caused by platinum compounds (namely oxaliplatin and cisplatin), taxanes, vinca alkaloids and bortezomib are summarized.

Conclusions

The prevalence of CIPN, potential causes, risk factors, symptoms and molecular mechanisms underlying this pharmacoresistant condition are discussed.

Graphic abstract

Chemotherapy-induced peripheral neuropathy among patients with ovarian cancer

OBJECTIVE

To evaluate the course of chemotherapy-induced peripheral neuropathy (CIPN) among patients with ovarian cancer receiving taxanes.

METHODS

In a retrospective case-control study conducted between January 1, 2016, and May 31, 2018, in Xiangya Hospital in Changsha, China, women with ovarian cancer received taxane and platinum-complex combination therapy. The European Organization for Research and Treatment of Cancer Quality of Life, Ovarian cancer module questionnaire, was used to assess the severity of neuropathy by telephone.

RESULTS

Out of the 88 women included in the study, 61 (69.3%) reported CIPN. Twelve months after chemotherapy, the percentage was 19.3%. The percentage of patients suffering from sensory peripheral neuropathy (SPN) was higher than motor peripheral neuropathy at any time during the study. Sensory peripheral neuropathy was associated with the use of docetaxel and paclitaxel (docetaxel vs liposomal paclitaxel: odds ratio [OR] 4.39, 95% confidence interval [CI] 1.69-11.42, P<0.01; paclitaxel vs liposomal paclitaxel: OR 5.91, 95% CI 1.09-31.97, P=0.04). The average weakness score in acute CIPN was lower than chronic CIPN (1.46 vs 2.00, P=0.019). Patients treated with vitamin B₁ and amifostine experienced better relief from CIPN.

CONCLUSION

The present study showed a significant proportion of patients with ovarian cancer receiving taxanes suffered from long-term residual neuropathy, and the use of docetaxel and paclitaxel was associated with SPN. Vitamin B₁ or amifostine may improve the symptoms of CIPN.

A Comparative Review of Chemotherapy-Induced Peripheral Neuropathy in In Vivo and In Vitro Models

Chemotherapy-induced peripheral neuropathy (CIPN) is an adverse effect caused by several classes of widely used anticancer therapeutics. Chemotherapy-induced peripheral neuropathy frequently leads to dose reduction or discontinuation of chemotherapy regimens, and CIPN symptoms can persist long after completion of chemotherapy and severely diminish the quality of life of patients. Differences in the clinical presentation of CIPN by widely diverse classifications of anticancer agents have spawned multiple mechanistic hypotheses that seek to explain the pathogenesis of CIPN. Despite its clinical relevance, common occurrence, and extensive investigation, the pathophysiology of CIPN remains unclear. Furthermore, there is no unequivocal gold standard for the prevention and treatment of CIPN. Herein, we review in vivo and in vitro models of CIPN with a focus on histopathological changes and morphological features aimed at understanding the pathophysiology of CIPN and identify gaps requiring deeper exploration. An elucidation of the underlying mechanisms of CIPN is imperative to identify potential targets and approaches for prevention and treatment.

Optimizing Clinical Screening for Chemotherapy-Induced Peripheral Neuropathy

CONTEXT

Efficient and accurate clinical screening for treatment-related toxicities is a critical component of optimal patient management. A number of alternate screening tools for chemotherapy-induced peripheral neuropathy (CIPN) have been proposed in response to demonstrated limitations with standard clinical screening, although their relative diagnostic value is unclear.

OBJECTIVES

The aim of this study is to evaluate the relative construct validity and discriminant properties of available CIPN screening tools.

METHODS

Patients treated with known potentially neurotoxic therapies underwent CIPN evaluation at one or multiple timepoints (N = 316 patients; age = 56 ± 13 years). At each testing session (N = 644 testing sessions), patients were evaluated using screening tools and comprehensive CIPN assessments. Comprehensive assessments were clinician-rated (Total Neuropathy Score, reduced) or patient-reported outcome (PRO; Functional Assessment of Cancer Therapy-Gynecologic Oncology Group/Neurotoxicity questionnaire). Similarly, screening tools were clinician-rated (National Cancer Institute Common Terminology Criteria for Adverse Events [NCI-CTCAE]) or PRO (Patient Neurotoxicity Questionnaire, PRO-CTCAE).

RESULTS

Analyses revealed moderate-to-high correlations between screening tools and comprehensive assessments (0.55 ≤ rho ≤ 0.75; P < 0.001) and similar discriminant properties across screening tools (P > 0.01). Screening tool grading corresponding to clinically significant (grade 2/3) vs. low-grade (grade 0/1) CIPN would correspond to greater ratings of CIPN severity by more comprehensive assessments in a predicted 77%-91% of cases (c-statistic = 0.77-0.91; P < 0.01).

CONCLUSIONS

PRO screening tools provide adequate CIPN screening while avoiding potential biases demonstrated to limit currently used clinician-rated screening tools. Addition of a brief objective test did not add value to PRO screening. Up to 23% of patients would be misidentified through screening, providing quantitative evidence of the limitations of available screening tools. More extensive CIPN evaluations are critical in patients at risk of serious neurotoxicity.

Randomized controlled trial of cryotherapy to prevent paclitaxel-induced peripheral neuropathy (RU221511I); an ACCRU trial

PURPOSE

This pilot trial aimed to assess if cooling hands and feet with crushed ice during receipt of paclitaxel helps prevent peripheral neuropathy.

METHODS

This prospective, randomized trial compared cryotherapy to standard care in patients initiating paclitaxel weekly x 12. For those on cryotherapy, hands and feet were cooled starting 15 min prior to and ending 15 min after each paclitaxel dose. EORTC QLQ-CIPN20 was completed at baseline, weekly x12, then monthly x6. Area under the curve (AUC) was calculated for subscale scores, adjusting for baseline, and compared between arms (Wilcoxon rank-sum test). Cross-study comparisons used data from 2 prior similarly-conducted neuropathy trials.

RESULTS

Forty-six patients were accrued. Three withdrew and one was ineligible. Of the remaining 42 (21 cryotherapy, 21 control), 39 (19 cryotherapy, 20 control) were analyzable for AUC. Cryotherapy was well tolerated, but the AUC of the CIPN20 sensory scores over 12 weeks of paclitaxel was not found to differ between the study arms (mean difference 3.45, 95% CI -3.13 to 10.02, p = 0.26). However, the control arm of the current trial experienced less neuropathy than did the placebo arms of two previous similar trials. When our cryotherapy arm was compared to the combined control arms from all three trials, the cryotherapy arm had less neuropathy (Wilcoxon Rank-Sum p = 0.01).

CONCLUSION

While there was no difference in CIPN20 scores identified between the 2 study arms in the current phase II trial, further investigation is needed given that the control arm experienced less neuropathy than was expected.

Aspects of vincristine-induced neuropathy in hematologic malignancies: a systematic review

PURPOSE

Vincristine is widely used as anticancer therapy for a variety of hematological malignancies. The treatment is limited by progressive vincristine-induced neuropathy, possibly including both peripheral sensory and motor nerves, autonomic nervous functions, and the central nervous system. This dose-limiting side-effect can diminish quality of life and, furthermore, cause discontinuation of vincristine treatment. The present review elucidates the current knowledge regarding vincristine-induced neuropathy in hematologic malignancies, focusing on neuropathy assessment, clinical and molecular predictive markers, drug-drug interference, prevention, and treatment.

METHODS

This review is conducted by a systematic search strategy for the identification of relevant literature in the PubMed and Embase databases.

RESULTS

No clinical parameters displayed convincing potential as predictors of vincristine-induced neuropathy; however, preexisting neuropathy was consistently reported to be associated with an increased risk of neurotoxicity. In contrast, molecular markers, including polymorphisms in genes involved in the pharmacodynamics and pharmacokinetics of vincristine, displayed great potential as predictive markers of neuropathy incidence and severity. Furthermore, antifungal drugs, such as itraconazole and voriconazole, decrease the metabolism of vincristine and consequently lead to severe neuropathy when co-administered with vincristine, underscoring why fluconazole should be the antifungal drug of choice.

CONCLUSION

Reports from the 71 included studies clearly emphasize the lack of consistency in neuropathy assessment, grading systems, and reporting, making it difficult to interpret results between studies. Thus, truer clinical and molecular markers could emerge if the consistency of neuropathy detection and reporting increases by the use of conventional standardized neuropathy assessment tools and grading scales.

Anti-allodynic and anti-inflammatory effects of 17α-hydroxyprogesterone caproate in oxaliplatin-induced peripheral neuropathy

Chemotherapy-induced peripheral neuropathy is a disabling condition induced by several frequently used chemotherapeutic drugs including the front-line agent oxaliplatin (OXA). Symptoms are predominantly sensory with the development of neuropathic pain. Alternative dosing protocols and treatment discontinuation are the only available therapeutic strategies. The aim of our work was to evaluate the potential of a synthetic derivative of progesterone, 17α-hydroxyprogesterone caproate (HPGC), in the prevention and treatment of OXA-evoked painful neuropathy. We also evaluated glial activation at the dorsal root ganglia (DRG) and spinal cord levels as a possible target mechanism underlying HPGC actions. Male rats were injected with OXA and HPGC following a prophylactic (HPGCp) or therapeutic (HPGCt) scheme (starting either before or after chemotherapy). The development of hypersensitivity and allodynic pain and the expression of neuronal and glial activation markers were evaluated. When compared to control animals, those receiving OXA showed a significant decrease in paw mechanical and thermal thresholds, with the development of allodynia. Animals treated with HPGCp showed patterns of response similar to those detected in control animals, while those treated with HPGCt showed a suppression of both hypersensitivities after HPGC administration. We also observed a significant increase in the mRNA levels of activating transcription factor 3, the transcription factor (c-fos), glial fibrillary acidic protein, ionized calcium binding adaptor protein 1, interleukin 1 beta (IL-1β) and tumor necrosis factor alpha (TNFα) in DRG and spinal cord of OXA-injected animals, and significantly lower levels in rats receiving OXA and HPGC. These results show that HPGC administration reduces neuronal and glial activation markers and is able to both prevent and suppress OXA-induced allodynia, suggesting a promising therapeutic strategy.

Preventive action of benztropine on platinum-induced peripheral neuropathies and tumor growth

The endogenous cholinergic system plays a key role in neuronal cells, by suppressing neurite outgrowth and myelination and, in some cancer cells, favoring tumor growth. Platinum compounds are widely used as part of first line conventional cancer chemotherapy; their efficacy is however limited by peripheral neuropathy as a major side-effect. In a multiple sclerosis mouse model, benztropine, that also acts as an anti-histamine and a dopamine re-uptake inhibitor, induced the differentiation of oligodendrocytes through M1 and M3 muscarinic receptors and enhanced re-myelination. We have evaluated whether benztropine can increase anti-tumoral efficacy of oxaliplatin, while preventing its neurotoxicity.We showed that benztropine improves acute and chronic clinical symptoms of oxaliplatin-induced peripheral neuropathies in mice. Sensory alterations detected by electrophysiology in oxaliplatin-treated mice were consistent with a decreased nerve conduction velocity and membrane hyperexcitability due to alterations in the density and/or functioning of both sodium and potassium channels, confirmed by action potential analysis from ex-vivo cultures of mouse dorsal root ganglion sensory neurons using whole-cell patch-clamp. These alterations were all prevented by benztropine. In oxaliplatin-treated mice, MBP expression, confocal and electronic microscopy of the sciatic nerves revealed a demyelination and confirmed the alteration of the myelinated axons morphology when compared to animals injected with oxaliplatin plus benztropine. Benztropine also prevented the decrease in neuronal density in the paws of mice injected with oxaliplatin. The neuroprotection conferred by benztropine against chemotherapeutic drugs was associated with a lower expression of inflammatory cytokines and extended to diabetic-induced peripheral neuropathy in mice.Mice receiving benztropine alone presented a lower tumor growth when compared to untreated animals and synergized the anti-tumoral effect of oxaliplatin, a phenomenon explained at least in part by benztropine-induced ROS imbalance in tumor cells.This report shows that blocking muscarinic receptors with benztropine prevents peripheral neuropathies and increases the therapeutic index of oxaliplatin. These results can be rapidly transposable to patients as benztropine is currently indicated in Parkinson's disease in the United States.

High concentration of topical amitriptyline for treating chemotherapy-induced neuropathies

PURPOSE

Chemotherapy-induced peripheral neuropathy (CIPN) is a devastating pain condition of cancer therapy that may force chemotherapy dose reduction or discontinuation. Since treatment options for CIPN are quite limited, we investigated the effect of 10% amitriptyline cream on neuropathic pain.

PATIENTS AND METHODS

This pilot study enrolled patients with hematological or solid tumors presenting hands and feet CIPN (for less than 1 month without previous treatment for CIPN [Group 1]; for more than 1 month with previous treatment [Group 2]). Patients applied 10% amitriptyline cream twice a day. Pain intensity was evaluated at 1, 2, and 4 weeks then monthly up to 1 year. The primary endpoint was change from baseline to 4-week treatment in median pain score assessed by visual analogue scale (VAS).

RESULTS

Overall, 44 patients were enrolled. Median (range) age was 67 (46-80) years, 34% were female. The majority (88.6%) had hematological malignancies, and the most commonly used chemotherapeutic agents were bortezomib and oxaliplatin. The median (range) VAS pain score decreased from 7 (4-9) at baseline to 2 (0-4) after 4-week topical treatment. No difference was seen between Group 1 and Group 2. Reduced initial chemotherapy doses in 11 patients as well as chemotherapy discontinued in 5 patients at baseline were resumed after treatment with 10% amitriptyline cream.

CONCLUSION

Considering the limited efficacy of conventional systemic treatments in CIPN and their safety profile, 10% topical amitriptyline appears to be a good candidate for first-line CIPN therapy, allowing continuation of chemotherapy at effective doses. The results are worth to be confirmed in a placebo-controlled clinical trial.

Evaluation of the effects of sensorimotor exercise on physical and psychological parameters in breast cancer patients undergoing neurotoxic chemotherapy

INTRODUCTION

Breast cancer is the most common cancer disease of women in industrialized countries. Neurotoxic chemotherapy drugs are known to harm peripheral nerves and cause a chemotherapy-induced peripheral neuropathy (CIPN). CIPN is one of the most common adverse events associated with Paclitaxel chemotherapy and may remain present long after the termination of chemotherapy. Thus, it reduces the patients' quality of life (QoL) both during chemotherapy and onwards, and can impose a danger on breast cancer survivors due to an increased risk of falling and fall-related injuries.

METHODS

The aim of this randomized-controlled trial (RCT) (n = 36) (IG: intervention group, n = 17) (CG: control group, n = 19) was to determine whether sensorimotor exercises have a positive effect on physical and psychological parameters in breast cancer patients undergoing neurotoxic chemotherapy (Paclitaxel).

RESULTS

As a result, we were able to show significant improvements in postural stability in monopedal stance [left leg 16.17 ± 3.67 vs. 21.55 ± 5.33 (p < 0.001) and right leg 15.14 ± 2.30 vs. 20.85 ± 5.05 (p < 0.001)] and in bipedal stance [T1 vs. T0, - 0.49 (IG) vs. + 1.14 (CG) p = 0.039].

DISCUSSION

These results in posturography correlate with the clinical presentation with intervention group patients scoring significantly better on the Fullerton Advanced Balance Scale [37.71 ± 2.73 vs. 34.47 ± 3.98 (p = 0.004)]. Moderate strength training successfully prevented a strength loss in the IG that was remarkable in the CG (- 1.60 vs. 0.60, p = 0.029). Concerning the psychological parameters assessed via EORTC- and MFI-questionnaires, no significant improvements were found.

CONCLUSION

Future studies should focus on the correlation of clinical and posturometry findings and subjective QOL such as the long-term-development of CIPN.