Vitamin E for prevention of oxaliplatin-induced peripheral neuropathy: a pilot randomized clinical trial

Nigella sativa L. and its bioactive and nutraceutical components in the management of diabetic peripheral neuropathy

Diabetes-induced hyperglycemia leads to excessive production of oxygen free radicals, inflammatory cytokines, and oxidative stress, which initiates diabetic peripheral neuropathy (DPN). Currently, this condition affects 20% of adults with diabetes. Despite significant advances in the treatment of diabetes, the incidence of its complications, including DPN, is still high. Thus, there is a growing research interest in developing more effective and treatment approaches with less side effects for diabetes and its complications. Nigella sativa L. (NS) has received much research attention as an antioxidant, anti-yperglycemic factor, and anti-inflammatory agent. This natural compound demonstrates its antidiabetic neuropathy effect through various pathways, including the reduction of lipid peroxidation, the enhancement of catalase and superoxide dismutase enzyme activity, and the decrease in inflammatory cytokine levels. The present review focuses on the bioactive and nutraceutical components of black cumin (Nigella sativa L.) and their effects on DPN. In addition, we have also summarized the findings obtained from several experimental and clinical studies regarding the antidiabetic neuropathy effect of NS in animal models and human subjects.

Natural Health Products for Anti-Cancer Treatment: Evidence and Controversy

Natural Health Products (NHPs) have long been considered a valuable therapeutic approach for the prevention and treatment of various diseases, including cancer. However, research on this topic has led to inconclusive and often controversial results. This review aims to provide a comprehensive update of the effects and mechanisms related to the use of NHPs, to describe the results of randomized clinical trials (RCTs) on their effects in cancer patients, and to critically discuss factors influencing clinical outcomes. RCTs available in the literature, even those studying the same NHP, are very heterogeneous in terms of indications, doses, route and timing of administration, and outcomes evaluated. Silymarin, ginsenoside, and vitamin E appear to be useful in attenuating adverse events related to radiotherapy or chemotherapy, and curcumin and lycopene might provide some benefit in patients with prostate cancer. Most RCTs have not clarified whether NHP supplementation provides any real benefit, while harmful effects have been shown in some cases. Overall, the available data suggest that although there is some evidence to support the benefits of NHPs in the management of cancer patients, further clinical trials with the same design are needed before their introduction into clinical practice can be considered.

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

PURPOSE

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

METHOD

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

RESULTS

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

CONCLUSION

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

Vitamin E in Cancer Treatment: A Review of Clinical Applications in Randomized Control Trials

Vitamin E, along with other vitamins and micronutrients play a range of physiologic roles in the homeostasis of the body. Moreover, they also have postulated therapeutic roles that are often incompletely studied and understood. In this scoping review, we explored the recent randomized control trials (RCTs) of Vitamin E in the context of cancer, to investigate whether Vitamin E has a therapeutic role. We searched major bibliographic electronic databases to identify sixteen RCTs studying the role of Vitamin E in cancer management that have been published in the last ten years. These studies had different methodological qualities, including some that used Vitamin E in combination with other treatments. Furthermore, due to the heterogenous results, it is difficult to make a consensus statement on the effectiveness of Vitamin E in cancer therapeutics. In some cases, there were even suggestion of detriment with Vitamin E supplementation. Therefore, well designed, large, prospective RCTs are needed studying pure isoforms of Vitamin E to establish the safety and efficacy of this dietary supplement.

Antioxidant and Neuroprotective Effect of a Grape Pomace Extract on Oxaliplatin-Induced Peripheral Neuropathy in Rats: Biochemical, Behavioral and Histopathological Evaluation

Oxaliplatin is a widely used chemotherapeutic agent. Despite its many beneficial aspects in fighting many malignancies, it shares an aversive effect of neuropathy. Many substances have been used to limit this oxaliplatin-driven neuropathy in patients. This study evaluates the neuroprotective role of a grape pomace extract (GPE) into an oxaliplatin induced neuropathy in rats. For this reason, following the delivery of the substance into the animals prior to or simultaneously with oxaliplatin, their performance was evaluated by behavioral tests. Blood tests were also performed for the antioxidant activity of the extract, along with a histological and pathological evaluation of dorsal root ganglion (DRG) cells as the major components of the neuropathy. All behavioral tests were corrected following the use of the grape pomace. Oxidative stressors were also limited with the use of the extract. Additionally, the morphometrical analysis of the DRG cells and their immunohistochemical phenotype revealed the fidelity of the animal model and the changes into the parvalbumin and GFAP concentration indicative of the neuroprotective role of the pomace. In conclusion, the grape pomace extract with its antioxidant properties alleviates the harmful effects of the oxaliplatin induced chronic neuropathy in rats.

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.

Dietary Supplements in Chemotherapy-Induced Peripheral Neuropathy: A New Hope?

Chemotherapy-induced peripheral neuropathy (CIPN) is one of the main and most prevalent side effects of chemotherapy, significantly affecting the quality of life of patients and the course of chemotherapeutic treatment. Nevertheless, despite its prevalence, the management of the CIPN is considered particularly challenging, with this condition often being perceived as very difficult or even impossible to prevent with currently available agents. Therefore, it is imperative to find better options for patients diagnosed with this condition. While the search for the new agents must continue, another opportunity should be taken into consideration-repurposing of the already known medications. As proposed, acetyl-L-carnitine, vitamins (group B and E), extracts of medical plants, including goshajinkigan, curcumin and others, unsaturated fatty acids, as well as the diet composed of so-called "sirtuin-activating foods", could change the typical way of treatment of CIPN, improve the quality of life of patients and maintain the continuity of chemotherapy. This review summarizes currently available data regarding mentioned above agents and evaluates the rationale behind future research focused on their efficacy in CIPN.

The Vitamin E Isoform α-Tocopherol is Not Effective as a Complementary Treatment in Cancer Treatment: A Systematic Review

The term vitamin E describes tocopherols and tocotrienols, whose chemical variations result in different biological activities including antioxidants. Neuroprotective effects of alpha-tocopherol against different toxins are assumed, therefore, it is discussed as a possible protective factor for adverse effects in cancer treatment. In July 2020, a systematic search was conducted searching five databases (Embase, Cochrane, PsychInfo, Cinahl, Medline) to find studies concerning the impact of α-tocopherol application and its potential harm on cancer patients. From 7546 search results, 22 publications referring to 20 studies with 1941 patients were included. Included patients were diagnosed with various cancer types and stages. Outcome variables were overall survival of cancer, symptom management of mucositis and chemotherapy-induced peripheral neuropathy (CIPN). The studies had different methodological qualities (mainly acceptable) and reported heterogeneous results: some reported significant improvement of mucositis and CIPN while others did not find changes concerning these endpoints. Due to heterogeneous results and methodical limitations of the included studies, a clear statement regarding the effectiveness of α-tocopherol as complementary treatment for cancer patients is not possible. Despite findings regarding reduction of oral side effects, usage of α-tocopherol during therapy must be discouraged because of potential negative influence on survival rates.

Protective Effects of Vitamin E on Chemotherapy-Induced Peripheral Neuropathy: A Meta-Analysis of Randomized Controlled Trials

INTRODUCTION

Chemotherapy-induced peripheral neuropathy (CIPN) is a common symptom, but prophylactic measures cannot still be carried out effectively. In addition, the efficacy of vitamin E in preventing peripheral neurotoxicity caused by chemotherapy is inconclusive. Therefore, we collected the relevant randomized controlled trials (RCTs) and performed a meta-analysis to examine whether the vitamin E has a positive effect in CIPN.

METHODS

We searched PubMed, EMBASE, Cochrane, and other databases in December 2019 for eligible trials. Two reviewers conducted the analysis independently when studies were homogeneous enough.

RESULTS

Eight RCTs, involving 488 patients, were identified. Upon pooling these RCTs, patients who received vitamin E supplementation of 600 mg/day had a lower incidence of CIPN (risk ratio [RR] 0.31; 95% confidence interval [CI] 0.14-0.65; p = 0.002) than the placebo group. Vitamin E played a key role in decreasing the incidence of peripheral neuropathy in the cisplatin chemotherapy group (RR 0.28; 95% CI 0.14-0.54; p = 0.0001). Moreover, vitamin E supplementation significantly decreased patients' sural amplitude after 3 rounds of chemotherapy (RR -2.66; 95% CI -5.09 to -0.24; p = 0.03) in contrast with that of placebo supplementation, while no significant difference was observed when patients were treated with vitamin E after 6 rounds of chemotherapy. In addition, the vitamin E-supplemented group had better improvement in the neurotoxicity score and lower incidence of reflexes and distal paraesthesias than the control group.

CONCLUSION

Available data in this meta-analysis showed that vitamin E supplementation can confer modest improvement in the prevention of CIPN.

Vitamin E for the Prevention of Chemotherapy-Induced Peripheral Neuropathy: A meta-Analysis

Background: Vitamin E has been increasingly used to prevent chemotherapy-induced peripheral neuropathy (CIPN) in recent years. However, it is still unclear whether vitamin E can effectively prevent CIPN. Methods: We searched all clinical studies in the Embase, Cochrane Library, Clinicaltrials.gov, and PubMed databases from inception to December 2020. We performed a meta-analysis of 9 randomized controlled trials (RCTs) with 486 patients that compared the vitamin E group with the control group. Outcomes of the study were incidence of all-grade CIPN, incidence of severe CIPN, and the total neuropathy scores (TNS). Random effect models were used to make the meta-analysis results more cautious. Results: Notably, vitamin E significantly reduced the incidence of all-grade CIPN (overall risk ratio (RR) = 0.55, 95% CI: 0.36, 0.85, I2 = 77.3%, p = 0.007), and TNS (overall standard mean difference (SMD) = -0.64, 95% CI: -1.03, -0.25, I2 = 42.7%, p = 0.001). However, the results of the subgroup analysis, which included only double-blind RCTs, suggested that vitamin E did not significantly reduce the incidence of all-grade CIPN (overall RR = 0.52, 95% CI: 0.07, 4.06, I2 = 77.5%, p = 0.531). Moreover, there was no significant difference in the incidence of severe CIPN between these two arms (p = 0.440). Conclusion: The results of our meta-analysis suggests that vitamin E has a beneficial effect on the incidence and symptoms of CIPN. However, routine prophylactic use of vitamin E is still not recommended. Moreover, more high-quality double-blind RCTs are needed to further validate the effects of vitamin E in prevention of CIPN.

Research design considerations for chronic pain prevention clinical trials: IMMPACT recommendations

Although certain risk factors can identify individuals who are most likely to develop chronic pain, few interventions to prevent chronic pain have been identified. To facilitate the identification of preventive interventions, an IMMPACT meeting was convened to discuss research design considerations for clinical trials investigating the prevention of chronic pain. We present general design considerations for prevention trials in populations that are at relatively high risk for developing chronic pain. Specific design considerations included subject identification, timing and duration of treatment, outcomes, timing of assessment, and adjusting for risk factors in the analyses. We provide a detailed examination of 4 models of chronic pain prevention (ie, chronic postsurgical pain, postherpetic neuralgia, chronic low back pain, and painful chemotherapy-induced peripheral neuropathy). The issues discussed can, in many instances, be extrapolated to other chronic pain conditions. These examples were selected because they are representative models of primary and secondary prevention, reflect persistent pain resulting from multiple insults (ie, surgery, viral infection, injury, and toxic or noxious element exposure), and are chronically painful conditions that are treated with a range of interventions. Improvements in the design of chronic pain prevention trials could improve assay sensitivity and thus accelerate the identification of efficacious interventions. Such interventions would have the potential to reduce the prevalence of chronic pain in the population. Additionally, standardization of outcomes in prevention clinical trials will facilitate meta-analyses and systematic reviews and improve detection of preventive strategies emerging from clinical trials.

Antioxidant Supplementation in the Treatment of Neurotoxicity Induced by Platinum-Based Chemotherapeutics-A Review

Cancer represents one of the most pernicious public health problems with a high mortality rate among patients worldwide. Chemotherapy is one of the major therapeutic approaches for the treatment of various malignancies. Platinum-based drugs (cisplatin, oxaliplatin, carboplatin, etc.) are highly effective chemotherapeutic drugs used for the treatment of several types of malignancies, but their application and dosage are limited by their toxic effects on various systems, including neurotoxicity. Simultaneously, researchers have tried to improve the survival rate and quality of life of cancer patients and decrease the toxicity of platinum-containing drugs by combining them with non-chemotherapy-based drugs, dietary supplements and/or antioxidants. Additionally, recent studies have shown that the root cause for the many side effects of platinum chemotherapeutics involves the production of reactive oxygen species (ROS) in naive cells. Therefore, suppression of ROS generation and their inactivation with antioxidants represents an appropriate approach for platinum drug-induced toxicities. The aim of this paper is to present an updated review of the protective effects of different antioxidant agents (vitamins, dietary antioxidants and supplements, medicaments, medicinal plants and their bioactive compounds) against the neurotoxicity induced by platinum-based chemotherapeutics. This review highlights the high potential of plant antioxidants as adjuvant strategies in chemotherapy with platinum drugs.

Dietary Patterns and Interventions to Alleviate Chronic Pain

Pain is one of the main problems for modern society and medicine, being the most common symptom described by almost all patients. When pain becomes chronic, the life of the patients is dramatically affected, being associated with significant emotional distress and/or functional disability. A complex biopsychosocial evaluation is necessary to better understand chronic pain, where good results can be obtained through interconnected biological, psychological, and social factors. The aim of this study was to find the most relevant articles existent in the PubMed database, one of the most comprehensive databases for medical literature, comprising dietary patterns to alleviate chronic pain. Through a combined search using the keywords "chronic pain" and "diet" limited to the last 10 years we obtained 272 results containing the types of diets used for chronic pain published in the PubMed database. Besides classical and alternative methods of treatment described in literature, it was observed that different diets are also a valid solution, due to many components with antioxidant and anti-inflammatory qualities capable to influence chronic pain and to improve the quality of life. Thirty-eight clinical studies and randomized controlled trials are analyzed, in an attempt to characterize present-day dietary patterns and interventions to alleviate chronic pain.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Serum micronutrients and prealbumin during development and recovery of chemotherapy-induced peripheral neuropathy

Chemotherapy-induced peripheral neuropathy (CIPN) is a frequent adverse event. Nutritional status can become impaired in cancer patients, potentially contributing to neuropathy's evolution. Our aim was to evaluate serum micronutrients and prealbumin in a cohort of 113 solid-cancer patients receiving platinum and taxane compounds during the development and recovery of neuropathy, up to 1 year after finishing treatment. CIPN was graded according to Total Neuropathy Score(©) and NCI.CTCv3 at T0 (baseline), T1 (1-3 months), and T12 (12 months) after chemotherapy. CIPN was classified as asymptomatic (< grade 2) or symptomatic (≥2). CIPN recovery was defined as ≥1 grade improvement at T12. Symptomatic CIPN developed in 52% of patients. Symptomatic patients presented a higher increase in TNSc (p < 0.001), in TNSr(©) (p < 0.001), and decrease in sural (p < 0.001) and radial nerve conduction (p < 0.001). No significant differences with any of the micronutrients were observed along T0-T1 period between severity or chemotherapy groups. By T12, symptomatic patients without recovery had a decrease in vitamin E levels (p = 0.019) and prealbumin (p = 0.062) compared with those symptomatic that improved. A correlation between the variation of vitamin E and prealbumin at T0-T1 (r = 0.626, p = 0.001) and T1-T12 (r = 0.411, p = 0.06) was observed. After chemotherapy treatment, the improvement of patients displaying symptomatic neuropathy is related to vitamin E and prealbumin serum levels. Our results suggest that nutritional status can play a role in CIPN recovery.

Inhibition of cancer antioxidant defense by natural compounds

All classic, non-surgical anticancer approaches like chemotherapy, radiotherapy or photodynamic therapy kill cancer cells by inducing severe oxidative stress. Even tough chemo- and radiotherapy are still a gold standard in cancer treatment, the identification of non-toxic compounds that enhance their selectivity, would allow for lowering their doses, reduce side effects and risk of second cancers. Many natural products have the ability to sensitize cancer cells to oxidative stress induced by chemo- and radiotherapy by limiting antioxidant capacity of cancer cells. Blocking antioxidant defense in tumors decreases their ability to balance oxidative insult and results in cell death. Though one should bear in mind that the same natural compound often exerts both anti-oxidant and pro-oxidant properties, depending on concentration used, cell type, exposure time and environmental conditions. Here we present a comprehensive overview of natural products that inhibit major antioxidant defense mechanisms in cancer cells and discuss their potential in clinical application.

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

Lessons Learned.

Pregabalin is a medication that can decrease neuronal hyperexcitability, relieve neuropathic pain, and reach stable plasma levels after a titration period of only a few days.

Its use during oxaliplatin infusions was not able to decrease the incidence of chronic, oxalipaltin‐related neuropathic pain, compared with placebo.

Background.

Patients with colorectal cancer (CRC) receiving oxaliplatin (OXA) develop acute and chronic painful oxaliplatin‐induced peripheral neuropathy (OXAIPN). Acute and chronic OXA‐related neuropathies have different pathophysiological bases, but both lead to a common phenomenon: central sensitization (CS) of nociceptive neuronal networks, leading to increased sensitivity (hyperlgesia, allodynia) in the somatosensory system, the common ground of chronic neuropathic pain. Because CS is related to increased risk of painful OXAIPN, we hypothesized that preemptive use of the anti‐hyperalgesic drug pregabaline (known to decrease CS) during OXA infusions would decrease the incidence of chronic OXAIPN.

Methods.

Pain‐free, chemotherapy‐naïve CRC patients receiving at least one cycle of modified‐FLOX [5‐FU(500 mg/m²)+leucovorin(20 mg/m²)/week for] 6 weeks+oxaliplatin(85 mg/m²) at weeks 1‐3‐5 every 8 weeks] were randomized (1:1) into the study. Patients received either pregabalin or placebo for 3 days before and 3 days after each OXA infusion and were followed for up to 6 months. Clinical assessments were performed at baseline, at the end of chemotherapy, and after the follow‐up period. The main outcome was average pain at the last visit assessed by the visual analogic scale (0–10) item of the Brief Pain Inventory (BPI). Secondary endpoints were presence of neuropathic pain according to the Douleur Neuropathique‐4 (DN‐4), pain dimensions (short‐ form McGill Pain Questionnaire [MPQ]), Neuropathic Pain Symptom Inventory (NPSI), and changes in nerve conduction studies (NCS) and side effect profile.

Results.

One hundred ninety‐nine patients (57.0 ± 10.7 years old, 98 female, 101 male) were randomized. Data from 56 patients were not included in the analyses (as they did not receive at least one full cycle of modified FLOX). Data from 78 patients in the pregabalin group and 65 patients in the placebo group were retained for analyses. At the last visit, pain intensity in the pregabalin group was 1.03 (95% confidence interval [CI] = 0.79–1.26), and 0.85 (95% CI = 0.64–1.06) in the placebo group, which did not reach significance. Scores from the BPI, MPQ, DN‐4, NPSI, and NCS and side‐effect profiles and incidence of death did not differ between groups. Quality of life (QoL) score did not differ between groups (placebo = 76.9 ± 23.1, pregabalin group 79.4 ± 20.6). Mood scores were not significantly different between groups (placebo 9.7 [8.1–11.2]; pregabalin 6.8 [5.6–8.0]).

Conclusion.

The preemptive use of pregabalin during OXA infusions was safe, but did not decrease the incidence of chronic pain related to OXAIPN.

Pathophysiology of Chemotherapy-Induced Peripheral Neuropathy

Chemotherapy-induced neuropathy is a common, dose-dependent adverse effect of several antineoplastics. It can lead to detrimental dose reductions and discontinuation of treatment, and severely affects the quality of life of cancer survivors. Clinically, chemotherapy-induced peripheral neuropathy presents as deficits in sensory, motor, and autonomic function which develop in a glove and stocking distribution due to preferential effects on longer axons. The pathophysiological processes are multi-factorial and involve oxidative stress, apoptotic mechanisms, altered calcium homeostasis, axon degeneration and membrane remodeling as well as immune processes and neuroinflammation. This review focusses on the commonly used antineoplastic substances oxaliplatin, cisplatin, vincristine, docetaxel, and paclitaxel which interfere with the cancer cell cycle-leading to cell death and tumor degradation-and cause severe acute and chronic peripheral neuropathies. We discuss drug mechanism of action and pharmacokinetic disposition relevant to the development of peripheral neuropathy, the epidemiology and clinical presentation of chemotherapy-induced neuropathy, emerging insight into genetic susceptibilities as well as current understanding of the pathophysiology and treatment approaches.

Lifestyle-Related Factors in the Self-Management of Chemotherapy-Induced Peripheral Neuropathy in Colorectal Cancer: A Systematic Review

Background. Chemotherapy-induced peripheral neuropathy (CIPN) is a common adverse effect of chemotherapy treatment in colorectal cancer (CRC), negatively affecting the daily functioning and quality of life of CRC patients. Currently, there are no established treatments to prevent or reduce CIPN. The purpose of this systematic review was to identify lifestyle-related factors that can aid in preventing or reducing CIPN, as such factors may promote self-management options for CRC patients suffering from CIPN. Methods. A literature search was conducted through PubMed, Embase, and Google Scholar. Original research articles investigating oxaliplatin-related CIPN in CRC were eligible for inclusion. Results. In total, 22 articles were included, which suggested that dietary supplements, such as antioxidants and herbal extracts, as well as physical exercise and complementary therapies, such as acupuncture, may have beneficial effects on preventing or reducing CIPN symptoms. However, many of the reviewed articles presented various limitations, including small sample sizes and heterogeneity in study design and measurements of CIPN. Conclusions. No strong conclusions can be drawn regarding the role of lifestyle-related factors in the management of CIPN in CRC patients. Certain dietary supplements and physical exercise may be beneficial for the management of CIPN, but further research is warranted.

Chemotherapy-induced neuropathies-a growing problem for patients and health care providers

INTRODUCTION

Chemotherapy-induced neuropathies are one of the most common side effects of cancer treatment, surpassing bone marrow suppression and kidney dysfunction. Chemotherapy effects on the nervous system vary between different classes of drugs and depend on specific chemical and physical properties of the drug used. The three most neurotoxic classes of anti-cancer drugs are: platinum-based drugs, taxanes, and thalidomide and its analogs; other, less neurotoxic but also commonly used drugs are: bortezomib, ixabepilone, and vinca alkaloids.

METHODS

Here, in this paper, based on our experience and current knowledge, we provide a short review of the most common, neuropathy-inducing anti-cancer drugs, describe the most prevalent neuropathy symptoms produced by each of them, and outline preventive measures and treatment guidelines for cancer patients suffering from neuropathy and for their health care providers.

RESULTS

Patients should be encouraged to report any signs of neuropathic pain, alteration in sensory perception, tingling, numbness, burning, increased hot/cold sensitivity and motor dysfunctions as early as possible. If known neurotoxic chemotherapeutics are used, a neurological examination with electrophysiological evaluation should be implemented early in the course of treatment so, both patients and physicians would be better prepared to cope with possible neurotoxic effects.

CONCLUSIONS

The use of neurotoxic chemotherapeutics should be closely monitored and if clinically permitted, that is, if a patient shows signs of cancer regression, drug doses should be reduced or combined with other less neurotoxic anti-cancer medication. If not counteractive, the use of over the counter antineuropathic supplements such as calcium or magnesium might be encouraged. If physically possible, patients should also be encouraged to exercise regularly and avoid factors that might increase nerve damage such as excessive drinking, smoking, or sitting in a cramped position.

[Chemotherapy-induced peripheral neuropathies: an integrative review of the literature]

OBJECTIVE

To identify scientific studies and to deepen the knowledge of peripheral neuropathies induced by chemotherapy antineoplastic, seeking evidence for assistance to cancer patients.

METHOD

Integrative review of the literature conducted in the databases Latin American and Caribbean Health Sciences (LILACS), Scientific Electronic Library Online (SciELO), Medical Literature Analysis (PubMed/MEDLINE), the Cochrane Library and the Spanish Bibliographic Index Health Sciences (IBECS).

RESULTS

The sample consisted of 15 studies published between 2005-2014 that met the inclusion criteria. Studies showed aspects related to advanced age, main symptoms of neuropathy and chemotherapy agents as important adverse effect of neuropathy.

CONCLUSION

We identified a small number of studies that addressed the topic, as well as low production of evidence related to interventions with positive results. It is considered important to develop new studies proposed for the prevention and/or treatment, enabling adjustment of the patient's cancer chemotherapy and consequently better service.

Vitamin E does not decrease the incidence of chemotherapy-induced peripheral neuropathy: a meta-analysis

Aim of this study

Chemotherapy-induced peripheral neuropathy (CIPN) is a major complication of cancer patients with chemotherapy. Although many interventions have been evaluated in previous studies, findings are controversial. The aim of this meta-analysis is to assess the efficacy of vitamin E supplementation in preventing CIPN.

Material and methods

The electronic databases MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were systematically searched from their inception to December 31, 2013 to identify relevant randomised controlled trials. Two reviewers independently scanned and extracted the data of included studies. Review Manager 5.2 was used to analyse data.

Results

Six articles involving 353 patients were included in meta-analysis. The results showed that vitamin E supplementation did not appear to significantly decrease the incidence of CIPN (relative risk (RR), 0.55; 95% confidence interval (CI), 0.29 to 1.05; p = 0.07), with significant heterogeneity (I² = 77%). However, Vitamin E supplementation can significantly prevent cisplatin associated neurotoxicity (RR, 0.31; 95%CI, 0.17 to 0.58; p = 0.0002), with no heterogeneity (I² = 0%).

Conclusions

Vitamin E administration dose not decrease the incidence of CIPN. However, additional randomised controlled trials using large samples are needed to confirm the role of vitamin E supplementation.

Research design considerations for chronic pain prevention clinical trials: IMMPACT recommendations

Although certain risk factors can identify individuals who are most likely to develop chronic pain, few interventions to prevent chronic pain have been identified. To facilitate the identification of preventive interventions, an IMMPACT meeting was convened to discuss research design considerations for clinical trials investigating the prevention of chronic pain. We present general design considerations for prevention trials in populations that are at relatively high risk for developing chronic pain. Specific design considerations included subject identification, timing and duration of treatment, outcomes, timing of assessment, and adjusting for risk factors in the analyses. We provide a detailed examination of 4 models of chronic pain prevention (ie, chronic postsurgical pain, postherpetic neuralgia, chronic low back pain, and painful chemotherapy-induced peripheral neuropathy). The issues discussed can, in many instances, be extrapolated to other chronic pain conditions. These examples were selected because they are representative models of primary and secondary prevention, reflect persistent pain resulting from multiple insults (ie, surgery, viral infection, injury, and toxic or noxious element exposure), and are chronically painful conditions that are treated with a range of interventions. Improvements in the design of chronic pain prevention trials could improve assay sensitivity and thus accelerate the identification of efficacious interventions. Such interventions would have the potential to reduce the prevalence of chronic pain in the population. Additionally, standardization of outcomes in prevention clinical trials will facilitate meta-analyses and systematic reviews and improve detection of preventive strategies emerging from clinical trials.

New Insights into Potential Prevention and Management Options for Chemotherapy-Induced Peripheral Neuropathy

OBJECTIVE

Neurological complications such as chemotherapy-induced peripheral neuropathy (CIPN) and neuropathic pain are frequent side effects of neurotoxic chemotherapy agents. An increasing survival rate and frequent administration of adjuvant chemotherapy treatments involving neurotoxic agents makes it imperative that accurate diagnosis, prevention, and treatment of these neurological complications be implemented.

METHODS

A consideration was undertaken of the current options regarding protective and treatment interventions for patients undergoing chemotherapy with neurotoxic chemotherapy agent or experience with CIPN. Current knowledge on the mechanism of action has also been identified. The following databases PubMed, the Cochrane Library, Science Direct, Scopus, EMBASE, MEDLINE, CINAHL, CNKI, and Google Scholar were searched for relevant article retrieval.

RESULTS

A range of pharmaceutical, nutraceutical, and herbal medicine treatments were identified that either showed efficacy or had some evidence of efficacy. Duloxetine was the most effective pharmaceutical agent for the treatment of CIPN. Vitamin E demonstrated potential for the prevention of cisplatin-IPN. Intravenous glutathione for oxaliplatin, Vitamin B6 for both oxaliplatin and cisplatin, and omega 3 fatty acids for paclitaxel have shown protection for CIPN. Acetyl-L-carnitine may provide some relief as a treatment option. Acupuncture may be of benefit for some patients and Gosha-jinki-gan may be of benefit for protection from adverse effects of oxaliplatin induced peripheral neuropathy.

CONCLUSIONS

Clinicians and researchers acknowledge that there are numerous challenges involved in understanding, preventing, and treating peripheral neuropathy caused by chemotherapeutic agents. New insights into mechanisms of action from chemotherapy agents may facilitate the development of novel preventative and treatment options, thereby enabling medical staff to better support patients by reducing this debilitating side effect.

Natural products and complementary therapies for chemotherapy-induced peripheral neuropathy: A systematic review

Chemotherapy-induced peripheral neuropathy (CIPN) is a serious dose-limiting side-effect without any FDA-approved treatment option. Prior reviews focus mostly on pharmacological interventions, but nonpharmaceutical interventions have also been evaluated. A Web of Science and PubMed database search to identify relevant RCTs from January 2005 to May 2015 included the terms: CIPN, cancer; and supplements, vitamin E, goshajinkigan, kampo, acetyl-L-carnitine, carnitine, alpha-lipoic acid, omega-3, glutamine, or glutamate; or massage, acupuncture, mind-body practice, yoga, meditation, Tai-Chi, physical activity, or exercise. Of 1465 publications screened, 12 RCTs evaluated natural products and one evaluated electroacupuncture. Vitamin E may help prevent CIPN. L-Glutamine, goshajinkigan, and omega-3 are also promising. Acetyl-L-carnitine may worsen CIPN and alpha-lipoic acid activity is unknown. Electroacupuncture was not superior to placebo. No RCTs were published regarding other complementary therapies, although some studies mention positive incidental findings. Natural products and complementary therapies deserve further investigation, given the lack of effective CIPN interventions.

Nutritional supplements and cancer: potential benefits and proven harms

Nutritional supplements are widely used among patients with cancer who perceive them to be anticancer and antitoxicity agents. Large-scale, randomized cancer prevention trials have mainly been negative, with some notable adverse and beneficial effects. For example, these trials showed that beta-carotene increases the risk of lung and stomach cancer, vitamin E increases prostate cancer and colorectal adenoma, and selenium reduces gastric and lung cancer in populations with low selenium levels but increase rates in those with higher levels. Both beta-carotene and vitamin E supplementation increase overall mortality. This article reviews phase II and III trials that examine the effects of multivitamins, antioxidants, vitamin D, and n-3 supplements on outcome and toxicity from cancer treatments. Although vitamin E and beta-carotene reduce toxicity from radiotherapy among patients with head and neck cancer, it has been found to increase recurrence, especially among smokers. Antioxidants have mixed effects on chemotherapy toxicity, but there are no data on outcome. Vitamin D deficiency is relatively common among patients with cancer, and ongoing phase III trials are studying the effect of vitamin D on outcome as well as optimum vitamin D and calcium intakes for bone health. Docosahexanoic and eicosopentanoic acid supplements have mixed effects on cachexia and are currently being tested as potential adjuncts to maximize response to chemotherapy. Nutritional supplementation tailored to an individual's background diet, genetics, tumor histology, and treatments may yield benefits in subsets of patients. Clinicians should have an open dialogue with patients about nutritional supplements. Supplement advice needs to be individualized and come from a credible source, and it is best communicated by the physician.

Effect of Vitamin E on Oxaliplatin-induced Peripheral Neuropathy Prevention: A Randomized Controlled Trial

BACKGROUND

Peripheral neuropathy is one of the most important limitations of oxaliplatin base regimen, which is the standard for the treatment of colorectal cancer. Evidence has shown that Vitamin E may be protective in chemotherapy-induced peripheral neuropathy. The aim of this study is to evaluate the effect of Vitamin E administration on prevention of oxaliplatin-induced peripheral neuropathy in patients with colorectal cancer.

METHODS

This was a prospective randomized, controlled clinical trial. Patients with colorectal cancer and scheduled to receive oxaliplatin-based regimens were enrolled in this study. Enrolled patients were randomized into two groups. The first group received Vitamin E at a dose of 400 mg daily and the second group observed, until after the sixth course of the oxaliplatin regimen. For oxaliplatin-induced peripheral neuropathy assessment, we used the symptom experience diary questionnaire that completed at baseline and after the sixth course of chemotherapy. Only patients with a score of zero at baseline were eligible for this study.

RESULTS

Thirty-two patients were randomized to the Vitamin E group and 33 to the control group. There was no difference in the mean peripheral neuropathy score changes (after - before) between two groups, after sixth course of the oxaliplatin base regimen (mean difference [after - before] of Vitamin E group = 6.37 ± 2.85, control group = 6.57 ± 2.94; P = 0.78). Peripheral neuropathy scores were significantly increased after intervention compared with a base line in each group (P < 0.001).

CONCLUSIONS

The results from this current trial demonstrate a lack of benefit for Vitamin E in preventing oxaliplatin-induced peripheral neuropathy.

Overview of neuropathy associated with taxanes for the treatment of metastatic breast cancer

Taxanes are an established option in the standard treatment paradigm for patients with metastatic breast cancer (MBC). Neuropathy is a common, dose-limiting side effect of taxane therapy that is often managed by dose reductions and delays. The severity, time to onset, and improvement in neuropathy are important considerations for patient management and vary among currently approved taxanes. The rate of grade ≥3 neuropathy with taxanes has been shown to be dose and schedule dependent; however, time to improvement to grade ≤1 is typically shorter for nab-paclitaxel than for other taxanes in patients with MBC. Many tools for assessing patient-reported neuropathy exist. Because MBC is incurable and patient quality of life must be critically considered when making treatment decisions, there is a need for more prospective trials to assess patient-reported neuropathy. Validated predictors of taxane-related neuropathy may play an important role in treatment decisions in the future. This review will focus on the toxicity profile (i.e., neuropathy) of each of the taxanes used in the treatment of MBC, will provide updates on tools used for the assessment of neuropathy, and will highlight newly discovered predictors of taxane-related neuropathy.

Association between the ERCC1 rs11615 polymorphism and clinical outcomes of oxaliplatin-based chemotherapies in gastrointestinal cancer: a meta-analysis

Purpose

The relationship between the excision repair cross-complementing 1 (ERCC1) rs11615 polymorphism (C/T) and responses to oxaliplatin-based chemotherapy for gastric cancer (GC) and colorectal cancer (CRC) patients is controversial. Therefore, we performed a meta-analysis to assess this relationship.

Method

Relevant studies were retrieved by searching the PubMed database. A systematic review and meta-analysis was performed to evaluate the predictive value of the ERCC1 rs11615 polymorphism for the clinical outcomes of GC and CRC patients receiving oxaliplatin-based chemotherapy. Therapeutic response to chemotherapy, progression-free survival (PFS), and overall survival (OS) were analyzed.

Results

A total of 22 studies were included in this meta-analysis, including 1,242 cases of GC and 1,772 cases of CRC. For the ERCC1 rs11615 polymorphism, the T allele was associated with a reduced response to chemotherapy in Asians and GC patients (P<0.05). On the other hand, the T allele was associated with a significant increase in the risk for shorter PFS and OS in all patients (PFS: hazard ratio [HR] =1.22, P<0.001, 95% confidence interval [CI] =0.93–1.51 and OS: HR =1.12, P<0.001, 95% CI =0.85–1.40).

Conclusion

The ERCC1 rs11615 polymorphism was closely associated with the clinical outcomes of GC and CRC patients treated with oxaliplatin-based chemotherapy.

Efficacy and tolerability of controlled-release oxycodone for oxaliplatin-induced peripheral neuropathy and the extension of FOLFOX therapy in advanced colorectal cancer patients

BACKGROUND

The oxaliplatin-based regimen FOLFOX is widely used to treat patients with advanced colorectal cancer (CRC). However, dose-limiting toxicity after continuous oxaliplatin administration can lead to peripheral neuropathy. Several agents, including opioids, that have been employed to treat oxaliplatin-induced peripheral neuropathy (OIPN) have been examined in clinical settings regarding their protective and therapeutic effects. However, the pharmacotherapy of these agents has not yet been established. Therefore, we investigated the efficacy and tolerability of oxycodone for OIPN and subsequently with FOLFOX therapy in CRC patients.

METHODS

This was a single-center retrospective study of 64 CRC patients who underwent FOLFOX therapy at the Toho University Sakura Medical Center (Sakura, Japan). Controlled-release (CR) oxycodone was concomitantly administered to 29 patients (OXY group), whereas the additional 35 patients (non-OXY group) were not given oxycodone during the FOLFOX treatment course. The incidence and severity of OIPN and the number of FOLFOX cycles were measured and compared between the two groups. Neurological toxicities were assessed according to the Common Terminology Criteria for Advanced Events, version 3.0.

RESULTS

All study patients had OIPN. Most patients experienced grade 1 or 2 sensory neuropathy. Grade 3 sensory neuropathy was observed in two patients in the non-OXY group. All patients in the OXY group completed the scheduled FOLFOX therapy, whereas FOLFOX therapy was discontinued in ten patients in the non-OXY group due to severe peripheral neuropathy. The median numbers of FOLFOX cycles in the OXY and non-OXY groups were 13 (range, 6-46) and 7 (range, 2-18), respectively (P < 0.05). The median cumulative oxaliplatin doses were 1072.3 mg/m(2) (range, 408.7-3385.3 mg/m(2)) in the OXY group and 483.0 mg/m(2) (range 76.2-1414.1 mg/m(2)) in the non-OXY group (P < 0.05).

CONCLUSIONS

Our findings indicate that CR oxycodone might attenuate the severity of OIPN and extend the use of FOLFOX therapy.

Neurological Adverse Effects in Patients of Advanced Colorectal Carcinoma Treated with Different Schedules of FOLFOX

The study is designed to assess the frequency and severity of few dose limiting neurological adverse effects of four different schedules of FOLFOX. Patients with histologically confirmed advanced colorectal carcinoma (CRC) were included in the study. Toxicity was graded according to CTC v 2.0. The frequency of grade 3 and 4 adverse effects was comparatively assessed in each treatment arm. The difference in the pattern of toxicity between the treatment schedule was evaluated. The most frequent adverse symptom of neurological adverse effect was grade 1 paresthesia in the patients treated with FOLFOX4 schedule. Grade 4 peripheral neuropathy was reported in few patients of FOLFOX7 treatment arm. Frequency and onset of neurological adverse effects like paresthesia, dizziness, and hypoesthesia were significantly different (P < 0.05), whereas frequency and onset of peripheral neuropathy were highly significant (P < 0.01) in each treatment arm of FOLFOX. Peripheral neuropathy was associated with electrolyte imbalance and diabetes in few patients. Frequency of symptoms, for example, paresthesia, is associated with increased number of recurrent exposure to oxaliplatin (increased number of cycles) even at low doses (85 mg/m²), whereas severity of symptoms, for example, peripheral neuropathy, is associated with higher dose (130 mg/m²) after few treatment cycles.