The effect of n-3 polyunsaturated fatty acids on incidence and severity of oxaliplatin induced peripheral neuropathy: a randomized controlled trial

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.

Delta tocotrienol as a supplement to FOLFOXIRI in first-line treatment of metastatic colorectal cancer. A randomized, double-blind, placebo-controlled phase II study

PURPOSE

Triplet chemotherapy might be more effective than doublet chemotherapy in metastatic colorectal cancer (mCRC), but it may also be marked by increased toxicity. To investigate whether δ-tocotrienol, a vitamin E analogue, with possible neuroprotective and anti-inflammatory effects, reduces the toxicity of triplet chemotherapy, we conducted a randomized, double-blind, placebo-controlled trial in mCRC patients receiving first-line 5-fluorouracil, oxaliplatin and irinotecan (FOLFOXIRI).

MATERIAL AND METHODS

Seventy patients with mCRC were randomly assigned (1:1) to receive FOLFOXIRI plus either δ-tocotrienol or placebo at the Department of Oncology, Vejle Hospital, Denmark. Eligibility criteria were adenocarcinoma in the colon or rectum, age 18-75 years and ECOG performance status 0-1. FOLFOXIRI was given in eight cycles followed by four cycles of 5-fluorouracil. δ-tocotrienol 300 mg or placebo × 3 daily was added during chemotherapy and for a maximum of two years. The primary endpoint was time to hospitalization or death during treatment with chemotherapy.

RESULTS

Median time to first hospitalization or death was 3.7 months in the placebo group (95% CI 1.93-not reached (NR)), and was NR in the δ-tocotrienol group (95% CI 1.87-NR) with a hazard ratio of 0.70 (95% CI 0.36-1.36). Grade 3-4 toxicities were uncommon in both groups, except for neutropenia, which occurred in 19 patients (58%) in the placebo group and 17 patients (50%) in the δ-tocotrienol group. There were no grade 3 or 4 peripheral sensory neuropathy. In the placebo group, 24 patients (71%) had oxaliplatin dose reductions compared to 17 patients (47%) in the δ-tocotrienol group (p = 0.047).

CONCLUSION

The addition of δ-tocotrienol to FOLFOXIRI did not statistically significant prolong the time to first hospitalization or death compared to FOLFOXIRI plus placebo. Toxicity was manageable and not statistically different. There was a statistically significant difference in dose reductions of oxaliplatin pointing to a possible neuroprotective effect of δ-tocotrienol.

Comparative Effects of Different Nutritional Supplements on Inflammation, Nutritional Status, and Clinical Outcomes in Colorectal Cancer Patients: A Systematic Review and Network Meta-Analysis

Nutritional supplements have been widely used in colorectal cancer (CRC) patients. The aim of this network meta-analysis (NMA) was to compare the effects of different nutritional supplements on inflammation, nutritional status, and clinical outcomes in CRC patients. Four electronic databases were searched until December 2022. Randomized controlled trials (RCTs) comparing nutritional supplements of omega-3 fatty acids (omega-3), arginine, vitamin D, glutamine, probiotics, or their combinations with placebo or standard treatment were selected. The outcomes were inflammatory indicators, nutritional indicators, and clinical outcomes. A random-effects Bayesian NMA was performed to rank the effect of each supplement. In total, 34 studies involving 2841 participants were included. Glutamine was superior in decreasing tumor necrosis factor-α (MD -25.2; 95% CrI [-32.62, -17.95]), whereas combined omega-3 and arginine supplementation was more effective in decreasing interleukin-6 (MD -61.41; 95% CrI [-97.85, -24.85]). No nutritional supplements significantly maintained nutritional indicators in CRC patients. Regarding clinical outcomes, glutamine ranked highest in reducing the length of hospital stay (MD -3.71; 95% CrI [-5.89, -1.72]) and the incidence of wound infections (RR 0.12; 95% CrI [0, 0.85]), and probiotics were rated as best in reducing the incidence of pneumonia (RR 0.38; 95% CrI [0.15, 0.81]). Future well-designed RCTs are needed to further confirm these findings.

The association between sociodemographic, clinical, and potentially preventive therapies with oxaliplatin-induced peripheral neuropathy in colorectal cancer patients

PURPOSE

The purpose of this retrospective cohort study was to evaluate whether several potentially preventive therapies reduced the rate of oxaliplatin-induced peripheral neuropathy (OIPN) in colorectal cancer patients and to assess the relationship of sociodemographic/clinical factors with OIPN diagnosis.

METHODS

Data were obtained from the Surveillance, Epidemiology, and End Results database combined with Medicare claims. Eligible patients were diagnosed with colorectal cancer between 2007 and 2015, ≥ 66 years of age, and treated with oxaliplatin. Two definitions were used to denote diagnosis of OIPN based on diagnosis codes: OIPN 1 (specific definition, drug-induced polyneuropathy) and OIPN 2 (broader definition, additional codes for peripheral neuropathy). Cox regression was used to obtain hazard ratios (HR) with 95% confidence intervals (CI) for the relative rate of OIPN within 2 years of oxaliplatin initiation.

RESULTS

There were 4792 subjects available for analysis. At 2 years, the unadjusted cumulative incidence of OIPN 1 was 13.1% and 27.1% for OIPN 2. For both outcomes, no therapies reduced the rate of OIPN diagnosis. The anticonvulsants gabapentin and oxcarbazepine/carbamazepine were associated with an increased rate of OIPN (both definitions) as were increasing cycles of oxaliplatin. Compared to younger patients, those 75-84 years of age experienced a 15% decreased rate of OIPN. For OIPN 2, prior peripheral neuropathy and moderate/severe liver disease were also associated with an increased hazard rate. For OIPN 1, state buy-in health insurance coverage was associated with a decreased hazard rate.

CONCLUSION

Additional studies are needed to identify preventive therapeutics for OIPN in cancer patients treated with oxaliplatin.

Omega-3 polyunsaturated fatty acids: moving towards precision use for prevention and treatment of colorectal cancer

Data from experimental studies have demonstrated that marine omega-3 polyunsaturated fatty acids (O3FAs) have anti-inflammatory and anticancer properties. In the last decade, large-scale randomised controlled trials of pharmacological delivery of O3FAs and prospective cohort studies of dietary O3FA intake have continued to investigate the relationship between O3FA intake and colorectal cancer (CRC) risk and mortality. Clinical data suggest that O3FAs have differential anti-CRC activity depending on several host factors (including pretreatment blood O3FA level, ethnicity and systemic inflammatory response) and tumour characteristics (including location in the colorectum, histological phenotype (eg, conventional adenoma or serrated polyp) and molecular features (eg, microsatellite instability, cyclooxygenase expression)). Recent data also highlight the need for further investigation of the effect of O3FAs on the gut microbiota as a possible anti-CRC mechanism, when used either alone or in combination with other anti-CRC therapies. Overall, these data point towards a precision approach to using O3FAs for optimal prevention and treatment of CRC based on mechanistic understanding of host, tumour and gut microbiota factors that predict anticancer activity of O3FAs.

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

Background

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

Methods

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

Results

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

Conclusion

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

Systematic Review Registration

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

Improving Chemotherapy-Induced Peripheral Neuropathy in Patients with Breast or Colon Cancer after End of (Neo)adjuvant Therapy: Results from the Observational Study STEFANO

INTRODUCTION

Chemotherapy-induced peripheral neuropathy (CIPN) is a common side effect persisting after completion of neurotoxic chemotherapies. This observational study was designed to evaluate the effectiveness of the dietary supplement OnLife® (patented mixture of specific fatty acids and palmitoylethanolamide) in improving symptoms of CIPN in breast and colon cancer patients.

METHODS

Improvement of CIPN was evaluated in adult patients, previously treated with (neo)adjuvant paclitaxel- (breast cancer) or oxaliplatin-based (colon cancer) therapies, receiving OnLife® for 3 months after completion of chemotherapy. The primary endpoint was to compare the severity of peripheral sensory neuropathy (PSN) and peripheral motor neuropathy (PMN) before and at the end of OnLife® treatment. Secondary endpoints included the assessment of patient-reported quality of life and CIPN symptoms as assessed by questionnaires.

RESULTS

146 patients (n = 75 breast cancer patients and n = 71 colon cancer patients) qualified for analysis; 31.1% and 37.5% of breast cancer patients had an improvement of PSN and PMN, respectively. In colon cancer patients, PSN and PMN improved in 16.9% and 20.0% of patients, respectively. According to patient-reported outcomes, 45.9% and 37.5% of patients with paclitaxel-induced PSN and PMN, and 23.9% and 22.0% of patients with oxaliplatin-induced PSN and PMN experienced a reduction of CIPN symptoms, respectively.

CONCLUSION

OnLife® treatment confirmed to be beneficial in reducing CIPN severity and in limiting the progression of neuropathy, more markedly in paclitaxel-treated patients and also in patients with oxaliplatin-induced CIPN.

Systematic review of long-term chemotherapy-induced peripheral neuropathy (CIPN) following adjuvant oxaliplatin for colorectal cancer

PURPOSE

Chemotherapy-induced peripheral neuropathy (CIPN) is the most common dose-limiting side effect of oxaliplatin. It often persists and can adversely affect quality of life of colorectal cancer (CRC) survivors. This systematic review explored the proportions of patients with persistent CIPN and the reporting methods used.

METHODS

MEDLINE, EMBASE, Web of Science and CINAHL were searched up to March 2021 for publications reporting CIPN outcomes following adjuvant oxaliplatin-containing chemotherapy at prespecified timepoints in participants with CRC. Secondary outcomes assessed the tools used to measure CIPN. Two authors reviewed full text publications for eligibility, data extraction and appraisal. Meta-analysis was performed where Common Terminology Criteria for Adverse Events (any grade) was reported at the most frequent timepoints.

RESULTS

From 7895 citations identified, 27 studies met the eligibility criteria: six were randomised control trials, and 21 were non-randomised studies. Pooled prevalence of CIPN at 6, 12, 24 and 36 months after chemotherapy were 58%, 45%, 32% and 24% respectively. The average prevalence of CIPN decreased by 26% per year after chemotherapy (pooled RR = 0.74; 95% CI 0.72-0.75). Across all studies, ten separate tools were used as the primary measure of CIPN. Quality appraisal identified open-label design and inadequate reporting of participants lost to follow-up as the main methodological limitations.

CONCLUSION

Our summary of reported rates of persistent CIPN indicates substantial long-term toxicity affecting CRC survivors, and will help clinicians estimate CIPN risk and its change over time. The heterogeneity of CIPN measures identified in the review highlights the need for a standardised CIPN assessment.

The effect of oral omega-3 polyunsaturated fatty acid supplementation on muscle maintenance and quality of life in patients with cancer: A systematic review and meta-analysis

BACKGROUND & AIMS

Omega-3 polyunsaturated fatty acid (PUFA) supplementation has been proposed as a potential therapy for cancer-related malnutrition, which affects up to 70% of patients with cancer. The aim of this systematic review and meta-analysis was to examine the effects of oral omega-3 PUFA supplementation on muscle maintenance, quality of life, body weight and treatment-related toxicities in patients with cancer.

METHODS

Randomised controlled trials in patients with cancer aged ≥18 years were retrieved from 5 electronic databases: MEDLINE (via PubMed), EMBASE, CENTRAL, CINAHL (via EBSCOhost), and Web of Science, from database inception until 31st of December 2019. The quality of included studies was assessed using the Cochrane risk of bias tool. Trials supplementing ≥600 mg/d omega-3 PUFA (oral capsules, pure fish oil or oral nutritional supplements) compared with a control intervention for ≥3 weeks were included. Meta-analyses were performed in RevMan to determine the mean differences (MD) in muscle mass, quality of life and body weight, and odds ratio (OR) for the incidence of treatment-related toxicities between omega-3 PUFA and control groups with 95% confidence intervals (CI) and I² for heterogeneity.

RESULTS

We included 31 publications in patients with various types of cancers and degrees of malnutrition. The Cochrane risk of bias tool graded most trials as 'unclear' or 'high' risk of bias. Meta-analyses showed no significant difference between omega-3 PUFA supplements and control intervention on muscle mass, quality of life and body weight. Oral omega-3 PUFA supplements reduced the likelihood of developing chemotherapy-induced peripheral neuropathy (OR: 0.20; 95% CI: 0.10-0.40; p < 0.001; I² = 0%).

CONCLUSION

This systematic review and meta-analysis indicates that oral omega-3 PUFA supplementation does not improve muscle maintenance, quality of life or body weight in patients with cancer, but may reduce the incidence of chemotherapy-induced peripheral neuropathy. Well-designed large-scale randomised controlled trials in homogenous patient cohorts are required to confirm these findings.

Potential use of n-3 PUFAs to prevent oxidative stress-derived ototoxicity caused by platinum-based chemotherapy

Platinum-based compounds are widely used for the treatment of different malignancies due to their high effectiveness. Unfortunately, platinum-based treatment may lead to ototoxicity, an often-irreversible side effect without a known effective treatment and prevention plan. Platinum-based compound-related ototoxicity results mainly from the production of toxic levels of reactive oxygen species (ROS) rather than DNA-adduct formation, which has led to test strategies based on direct ROS scavengers to ameliorate hearing loss. However, favorable clinical results have been associated with several complications, including potential interactions with chemotherapy efficacy. To understand the contribution of the different cytotoxic mechanisms of platinum analogues on malignant cells and auditory cells, the particular susceptibility and response of both kinds of cells to molecules that potentially interfere with these mechanisms, is fundamental to develop innovative strategies to prevent ototoxicity without affecting antineoplastic effects. The n-3 long-chain polyunsaturated fatty acids (n-3 PUFAs) have been tried in different clinical settings, including with cancer patients. Nevertheless, their use to decrease cisplatin-induced ototoxicity has not been explored to date. In this hypothesis paper, we address the mechanisms of platinum compounds-derived ototoxicity, focusing on the differences between the effects of these compounds in neoplastic versus auditory cells. We discuss the basis for a strategic use of n-3 PUFAs to potentially protect auditory cells from platinum-derived injury without affecting neoplastic cells and chemotherapy efficacy.

Omega-3 polyunsaturated fatty acid oral supplements for improving peripheral nerve health: a systematic review and meta-analysis

CONTEXT

Peripheral nerve damage can occur in a variety of systemic conditions and can have a profound impact on functional and psychological health. Currently, therapeutic interventions for peripheral nerve damage are limited.

OBJECTIVE

The aim of this systematic review, conducted in accordance with the Cochrane Collaboration's handbook and reported according to the PRISMA checklist, was to evaluate the efficacy and safety of omega-3 oral supplements for improving peripheral nerve structure and function.

DATA SOURCES

PubMed, Embase, and Cochrane databases, along with clinical trial registries, were searched from inception to February 2019. Evidence was identified, critically appraised, and synthesized, and the certainty of evidence was appraised using the Grading of Recommendations Assessment, Development and Evaluation approach.

STUDY SELECTION

Randomized controlled trials assessing the effects of omega-3 oral supplementation on outcomes of peripheral nerve structure, peripheral nerve function, or both were eligible for inclusion. Titles and abstracts of identified articles were independently assessed for potential eligibility by 2 review authors. For studies judged as eligible or potentially eligible, full text articles were retrieved and independently assessed by 2 review authors to determine eligibility; disagreements were resolved by consensus.

DATA EXTRACTION

Fifteen trials were included. Two clinically similar studies that investigated the effect of omega-3 supplementation in individuals receiving chemotherapy were meta-analyzed. Pooled data showed a reduced incidence of peripheral neuropathy (RR = 0.58; 95%CI, 0.43-0.77) and a preservation of sensory nerve action potential amplitudes with omega-3 supplementation compared with placebo (MD = 4.19 µV; 95%CI; 2.19-6.19).

CONCLUSION

This review finds, with low certainty, that omega-3 supplementation attenuates sensory loss and reduces the incidence of neuropathy secondary to oxaliplatin and paclitaxel treatment relative to placebo. There is currently limited evidence to ascertain whether omega-3 supplementation is beneficial in other systemic conditions characterized by peripheral nerve damage.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number CRD 42018086297.

Multifunctional nanomedicines for targeting epidermal growth factor receptor in colorectal cancer

Systemic administration of chemotherapeutics by nanocarriers (NCs) functionalized with targeting agents provides a localized accumulation of drugs in the target tissues and cells. Advanced nanoscaled medicaments can enter into the tumor microenvironment (TME) and overcome the uniquely dysregulated biological settings of TME, including highly pressurized tumor interstitial fluid in an acidic milieu. Such multimodal nanomedicines seem to be one of the most effective treatment modalities against solid tumors such as colorectal cancer (CRC). To progress and invade, cancer cells overexpress various oncogenes and molecular markers such as epidermal growth factor receptors (EGFRs), which can be exploited for targeted delivery of nanoscaled drug delivery systems (DDSs). In fact, to develop effective personalized multimodal nanomedicines, the type of solid tumor and status of the disease in each patient should be taken into consideration. While the development of such multimodal-targeted nanomedicines is largely dependent on the expression level of oncomarkers, the type of NCs and homing/imaging agents play key roles in terms of their efficient applications. In this review, we provide deep insights into the development of EGFR-targeting nanomedicines and discuss various types of nanoscale DDSs (e.g., organic and inorganic nanoparticles) for targeting of the EGFR-positive solid tumors such as CRC.

Docosahexaenoic Acid Enhances Oxaliplatin-Induced Autophagic Cell Death via the ER Stress/Sesn2 Pathway in Colorectal Cancer

Oxaliplatin is an anticancer drug administered to colorectal cancer (CRC) patients in combination with 5-fluorouracil and antibodies (bevacizumab and cetuximab), thereby significantly improving the survival rate of CRC. However, due to various side effects associated with the above treatment strategy, the need for combinatorial therapeutic strategies has emerged. Based on the demand for new combinatorial therapies and the known antitumor effects of the omega-3 polyunsaturated fatty acid, docosahexaenoic acid (DHA), we investigated the Oxaliplatin and DHA combination for its effect. Our results indicated that DHA further enhanced Oxaliplatin-induced cell viability and autophagic cell death, in vitro and in vivo. Oxaliplatin and DHA also increased the expression of Sestrin 2 (SESN2) and endoplasmic reticulum (ER) stress related C/EBP homologous protein (CHOP). Additionally, treatment with Oxaliplatin and DHA enhanced the binding of CHOP to the promotor region of SESN2, increasing SESN2 expression. These results suggested that DHA enhanced Oxaliplatin-induced reduction in cell viability and increase in autophagy via activating SESN2 and increasing ER stress. Thus, SESN2 may be an effective preclinical target for CRC treatment.

Recent advances in targeted therapy of colorectal cancer: impacts of monoclonal antibodies nanoconjugates

Despite rapid advances in diagnostic and treatment approaches, the overall survival rate of cancer has not been improved. Colorectal cancer (CRC) is recognized as the third leading cause of neoplasm-related deaths worldwide, in large part due to its considerable metastasis and drug resistance. For developing new anticancer strategies, rapid progression of multimodal nanomedicines and nanoconjugates has provided promising treatment modalities for effective therapy of cancer. The limitations of cancer chemotherapy might be overcome through the use of such nanosized therapeutics, including nanoconjugates of monoclonal antibodies (mAbs) along with drugs and organic/inorganic nanoparticles. CRC cells express various molecular markers against which mAbs can be designed and used as targeting/therapeutic agents. This editorial highlights the importance of such targeted nanosystems against CRC.

Possible association of CAG repeat polymorphism in KCNN3 encoding the potassium channel SK3 with oxaliplatin-induced neurotoxicity

INTRODUCTION

Data suggest a role of the potassium channel SK3 (KCNN3 gene) in oxaliplatin-induced neurotoxicity (OIN). Length variations in the polymorphic CAG repeat of the KCNN3 gene may be associated with the risk of OIN.

MATERIALS AND METHODS

We performed patch-clamp experiments on HEK293 cell lines, expressing SK3 channel isoforms with short (11) or long (24) CAG repetitions, to measure intracellular calcium concentrations to test the effects of oxaliplatin on current density. A retrospective study was carried out on patients with colorectal cancer who had received oxaliplatin-based chemotherapy. DNA for KCNN3 genotyping was extracted from leukocytes. The region containing the CAG repeats was amplified by PCR and the products separated by capillary electrophoresis for length analysis. The patients were divided into three groups depending on whether they carried two short alleles, one short allele and one long allele, or two long alleles. The primary endpoint was the onset of grade 2 or 3 neuropathy to oxaliplatin.

RESULTS

There was no difference in current density, but oxaliplatin induced a differential effect on apamin-sensitive current density between the two isoforms expressed in the HEK cell lines. There was a significant reduction of store-operated calcium entry into cells expressing the short and more active isoform only after high concentration of oxaliplatin exposition. Eighty-six patients were included in the clinical study. There was no significant association between OIN and KCNN3 polymorphism for the three groups.

CONCLUSION

We observed a slight association between OIN and CAG repeat polymorphisms of the KCNN3 gene in a preclinical model, but not a clinical study.

Ion channels and neuronal hyperexcitability in chemotherapy-induced peripheral neuropathy; cause and effect?

Abstract

Cancer is the second leading cause of death worldwide and is a major global health burden. Significant improvements in survival have been achieved, due in part to advances in adjuvant antineoplastic chemotherapy. The most commonly used antineoplastics belong to the taxane, platinum, and vinca alkaloid families. While beneficial, these agents are frequently accompanied by severe side effects, including chemotherapy-induced peripheral neuropathy (CPIN). While CPIN affects both motor and sensory systems, the majority of symptoms are sensory, with pain, tingling, and numbness being the predominant complaints. CPIN not only decreases the quality of life of cancer survivors but also can lead to discontinuation of treatment, thereby adversely affecting survival. Consequently, minimizing the incidence or severity of CPIN is highly desirable, but strategies to prevent and/or treat CIPN have proven elusive. One difficulty in achieving this goal arises from the fact that the molecular and cellular mechanisms that produce CPIN are not fully known; however, one common mechanism appears to be changes in ion channel expression in primary afferent sensory neurons. The processes that underlie chemotherapy-induced changes in ion channel expression and function are poorly understood. Not all antineoplastic agents directly affect ion channel function, suggesting additional pathways may contribute to the development of CPIN Indeed, there are indications that these drugs may mediate their effects through cellular signaling pathways including second messengers and inflammatory cytokines. Here, we focus on ion channelopathies as causal mechanisms for CPIN and review the data from both pre-clinical animal models and from human studies with the aim of facilitating the development of appropriate strategies to prevent and/or treat CPIN.