Identification of novel neuroprotectants against vincristine-induced neurotoxicity in iPSC-derived neurons

Chemotherapy-induced peripheral neuropathy (CIPN) is a disabling side effect of cancer chemotherapy that can often limit treatment options for cancer patients or have life-long neurodegenerative consequences that reduce the patient's quality of life. CIPN is caused by the detrimental actions of various chemotherapeutic agents on peripheral axons. Currently, there are no approved preventative measures or treatment options for CIPN, highlighting the need for the discovery of novel therapeutics and improving our understanding of disease mechanisms. In this study, we utilized human-induced pluripotent stem cell (hiPSC)-derived motor neurons as a platform to mimic axonal damage after treatment with vincristine, a chemotherapeutic used for the treatment of breast cancers, osteosarcomas, and leukemia. We screened a total of 1902 small molecules for neuroprotective properties in rescuing vincristine-induced axon growth deficits. From our primary screen, we identified 38 hit compounds that were subjected to secondary dose response screens. Six compounds showed favorable pharmacological profiles - AZD7762, A-674563, Blebbistatin, Glesatinib, KW-2449, and Pelitinib, all novel neuroprotectants against vincristine toxicity to neurons. In addition, four of these six compounds also showed efficacy against vincristine-induced growth arrest in human iPSC-derived sensory neurons. In this study, we utilized high-throughput screening of a large library of compounds in a therapeutically relevant assay. We identified several novel compounds that are efficacious in protecting different neuronal subtypes from the toxicity induced by a common chemotherapeutic agent, vincristine which could have therapeutic potential in the clinic.

Parents' perception of treatment-related toxicity in children treated according to the NOPHO ALL2008 protocol for acute lymphoblastic leukemia

This study aimed to assess how parents perceived treatment-related side effects during acute lymphoblastic leukemia (ALL) treatment. Parents of children 1-17.9 years at diagnosis in Sweden, Finland, and Denmark who were alive and in first remission ≥6 months after end of ALL treatment were asked to respond on specific items regarding how their child was affected by side effects related to vincristine (VCR), corticosteroids, peg-asparaginase (ASP), and maintenance therapy, as well as overall impact of these treatments, complications in general, and their perception of impact on their child in comparison with other children with ALL. Parents of 307 children responded. More than a third reported that their child had been affected to a high extent by VCR (39.7%) and corticosteroids (35.8%), with walking difficulties, muscular weakness, pain, changes in appetite, and mood swings as the most common and severe symptoms. Reporting of these toxicities was lacking from the NOPHO ALL2008 database, except for peripheral paralysis (12.1%). For distinct toxicities reported in the NOPHO ALL2008 database, for example, thrombosis and pancreatitis, parent reports were similar to the database. Although a high overall negative impact during treatment was reported, parents generally rated the impact on their child as less, or similar, to other children with ALL. Parents perceived VCR and corticosteroid therapy, in particular, to have a negative impact on their child during ALL treatment, which was not captured in the NOPHO ALL2008 toxicity reporting. Our results highlight the importance of including patient/parent-reported outcomes in toxicity reporting.

Characterising vincristine-induced peripheral neuropathy in adults: symptom development and long-term persistent outcomes

BACKGROUND

Decades following the introduction of vincristine as treatment for haematological malignancies, vincristine-induced peripheral neuropathy (VIPN) remains a pervasive, untreatable side-effect. However there remains a gap in understanding the characteristics of VIPN in adults. This study presents a comprehensive phenotyping of VIPN.

METHODS

Adult patients (n = 57; age = 59.8 ± 14.6) were assessed cross-sectionally following completion of vincristine (months post treatment = 16.3 ± 15.6, cumulative dose = 7.6 ± 4.4), with a subset of 20 patients assessed prospectively during treatment. Patient reported measures (EORTC-QLQ-CIPN20, R-ODS) were used to profile symptoms and disability. Neurological assessment was undertaken using the Total Neuropathy Score and nerve conduction studies. Sensory threshold and fine motor tasks were also undertaken. Comparisons of data between timepoints were calculated using paired-sample t tests or Wilcoxon matched-pairs signed-rank test. Comparisons between outcome measures were calculated with independent sample t tests or Mann-Whitney U tests for non-parametric data.

RESULTS

The majority of patients developed VIPN by mid-treatment (77.8%, 7.0 ± 3.3 weeks post baseline) with the prevalence remaining stable by end-of-treatment (75%, 8.1 ± 1.7 weeks post mid-treatment). By 3 months post-completion, 50% of patients still reported VIPN although there were significant improvements on neurological grading and functional assessment (P < 0.05). VIPN presented with sensorimotor involvement in upper and lower limbs and was associated with decreased sensory and motor nerve amplitudes, reduced fine-motor function and increased disability.

CONCLUSION

VIPN in adults presents as a sensorimotor, upper- and lower-limb neuropathy that significantly impacts disability and function. Neuropathy recovery occurs in a proportion of patients; however, VIPN symptoms may persist and continue to affect long-term quality of life.

Without ENMG, detecting pediatric vincristine neuropathy is a challenge

Objective

Vincristine, a widely used anticancer chemotherapy drug, may cause polyneuropathy (PNP), potentially resulting in permanent functional impairment. We characterized the occurrence and development of vincristine-induced neuropathy (VIPN) in early treatment of childhood leukemia.

Methods

This prospective study of 35 pediatric acute lymphoblastic leukemia (ALL) patients comprised systematic clinical and electrophysiological studies at both the time of diagnosis and at least one time point during the first months of treatment.

Results

After vincristine treatment, all patients had axonal sensorimotor PNP on electroneuromyography (ENMG) In 34/35 patients, the motor and in 24/35 the sensory responses were decreased. Interestingly, in 3 patients PNP was most prominent in the upper limb. However, some children had no PNP symptoms despite moderate ENMG findings, and not all clinical symptoms were correlated with abnormal ENMG.

Conclusions

Pediatric VIPN is a sensorimotor, predominantly motor axonal neuropathy. VIPN can be detected even in its early phase by ENMG, but it is difficult to detect by symptoms and clinical examination only.

Significance

Pediatric ALL patients treated with vincristine are at risk of developing VIPN. Since the clinical signs of PNP in acutely ill children are difficult to identify, VIPN can easily be overlooked if ENMG is not performed.

Prospective assessment of vincristine-induced peripheral neuropathy in paediatric acute lymphoblastic leukemia

OBJECTIVE

Vincristine is a mainstay treatment for paediatric cancers, particularly acute lymphoblastic leukemia (ALL), with common toxicity including vincristine-induced peripheral neuropathy (VIPN). The present study comprehensively assessed VIPN outcomes in patients receiving vincristine treatment for ALL.

METHODS

Children diagnosed with ALL commencing vincristine treatment were prospectively evaluated (baseline, post-induction, pre-reinduction, post-reinduction, follow-up). VIPN was examined clinically using the Balis sensory/motor scale, neurophysiologically using axonal excitability techniques and quality-of-life using Pediatric Quality of Life Inventory.

RESULTS

Thirty-one patients were recruited to this study (age = 6.8 ± 4.4; 61.3% female). Incidence of motor VIPN (motor Balis grade > 0) symptoms were higher than sensory VIPN (sensory Balis grade > 0) at post-induction (92.0% vs 36.0%) and post-reinduction (81.8% vs 22.7%) vincristine treatment. Neurophysiological assessment also demonstrated greater change in motor axonal excitability parameters compared to sensory parameters including changes in depolarising threshold electrotonus (P < 0.0125), superexcitability and subexcitability parameters (all P < 0.0125). Follow-up assessment demonstrated persisting VIPN symptoms with reduced quality-of-life scores compared to baseline.

CONCLUSIONS

Clinical and neurophysiological evaluation of VIPN suggests vincristine produces a motor-prominent sensorimotor neuropathy in children which persisted at follow-up.

SIGNIFICANCE

VIPN signs and symptoms develop early in the treatment course, in line with axonal excitability profiles. Early detection of significant nerve changes may support timely implementation of neuroprotection strategies.

Evaluation of vincristine-induced peripheral neuropathy in children with cancer: Turkish validity and reliability study

BACKGROUND

The evaluation of peripheral neuropathy in children receiving Vincristine treatment is challenging. This study examined the Turkish validity and reliability of the Total Neuropathy Score-Pediatric Vincristine (TNS-PV) measurement tool, which can measure Vincristine-induced peripheral neuropathy symptoms in children with cancer.

METHODS

A total of 53 children aged 5-17 years who received Vincristine treatment in two pediatric hematology-oncology centers participated in the study. Data was collected using the Total Neuropathy Score-Pediatric Vincristine (TNS-PV), the Common Terminology Criteria for Adverse Events (CTCAE), the Wong-Baker FACES Pain Scale, and the Adolescent Pediatric Pain Tool (APPT). The correlation between the TNS-PV total score and other scales and the inter-rater reliability coefficient was evaluated.

FINDINGS

Of the children, 81.1% were diagnosed with ALL and 13.2% with Ewing Sarcoma. Cronbach's alpha values of form A and B of the TNS-PV scale were 0.628 and 0.639, respectively. As the cumulative Vincristine dose increased, the children's scores on TNS-PV were higher. A moderate and significant positive correlation was found between the TNS-PV form A total score and the worst subjective symptoms a, b (A), strength, tendon reflexes, and autonomic / constipation (r = 0.441, r = 0.545, r = 0.472, r = 0.536, p < 0.01).

DISCUSSION

The TNS-PV form B total score was found to have a moderate level, significant correlation with CTCAE sensory neuropathy score and Wong-Baker FACES Pain Scale, and a high level, significant positive correlation with CTCAE motor neuropathy score.

APPLICATION TO PRACTICE

The TNS-PV is valid and reliable for measuring Vincristine-induced peripheral neuropathy in practice in Turkish children 5 years and older.

Electrophysiologic Patterns of Symptomatic Vincristine-Induced Peripheral Neuropathy in Children with Acute Lymphocytic Leukemia

Acute lymphocytic leukemia is one of the most common cancers in children. Multi-drug chemotherapy is used for treatment, and the representative drug is vincristine. Although various side effects may occur due to vincristine, the association with peripheral neuropathy is high compared to that of other drugs. This study focused on children under the age of 18 years of age with ALL who received chemotherapy containing vincristine. We retrospectively analyzed the results of a nerve conduction study and a cumulative dose of vincristine in 30 children diagnosed with peripheral neuropathy. The average cumulative dose until diagnosis of vincristine-induced peripheral neuropathy was 14.99 ± 1.21 mg/m², and motor nerves were predominantly involved. Additionally, a marked decrease in average amplitude was also observed in motor nerves. In addition, when the relationship between the incidence of peripheral neuropathy and the cumulative dose was analyzed through the survival curve, about 50% of children developed peripheral neuropathy at a dose of 15.5 ± 1.77 mg/m². Based on the electrophysiological characteristics of pediatric vincristine-induced peripheral neuropathy, as well as the relationship between the incidence rate and the cumulative dose, it is possible to observe more closely the vincristine-induced peripheral neuropathy occurrence in children with ALL at an appropriate time.

Chemotherapy-induced peripheral neuropathy in children and adolescent cancer patients

Brain cancer and leukemia are the most common cancers diagnosed in the pediatric population and are often treated with lifesaving chemotherapy. However, chemotherapy causes severe adverse effects and chemotherapy-induced peripheral neuropathy (CIPN) is a major dose-limiting and debilitating side effect. CIPN can greatly impair quality of life and increases morbidity of pediatric patients with cancer, with the accompanying symptoms frequently remaining underdiagnosed. Little is known about the incidence of CIPN, its impact on the pediatric population, and the underlying pathophysiological mechanisms, as most existing information stems from studies in animal models or adult cancer patients. Herein, we aim to provide an understanding of CIPN in the pediatric population and focus on the 6 main substance groups that frequently cause CIPN, namely the vinca alkaloids (vincristine), platinum-based antineoplastics (cisplatin, carboplatin and oxaliplatin), taxanes (paclitaxel and docetaxel), epothilones (ixabepilone), proteasome inhibitors (bortezomib) and immunomodulatory drugs (thalidomide). We discuss the clinical manifestations, assessments and diagnostic tools, as well as risk factors, pathophysiological processes and current pharmacological and non-pharmacological approaches for the prevention and treatment of CIPN.

Protective effect of selenium on vincristine-induced peripheral neuropathy in PC12 cell line

Vincristine-induced peripheral neuropathy (VIPN) is the main side effect and major reason for neuropathic pain in cancer survivors treated with vincristine. Vincristine, a chemotherapeutic antimitotic drug, is used frequently in combination chemotherapy. The primary purpose of the current study was to assess the protective effect of sodium selenite (SSe) on VIPN in vitro. Cytotoxicity effects of vincristine were evaluated using PC12 cells as a neuronal model. The cell culture studies were conducted in three groups based on the various treatments, including vincristine, SSe, and co-exposure to both compositions. Cell viability and cell cycle analyses were performed using MTT assay and flow cytometry, respectively. The level of mRNA expression of Bax and Bcl-2 was determined using qRT-PCR. According to the results, vincristine decreased the survival rate of PC12 cells. After 24 and 48 h exposure to different concentrations of vincristine (0.1-20 μΜ), the survival rate of PC12 cells decreased as compared to the control group. The results showed that treatment with 5 μΜ of vincristine resulted in apoptosis of PC12 cells. Interestingly,co-incubation of these cells with SSe significantly reduced the cell damage induced by vincristine. Furthermore, vincristine induced the inhibition of the G2 phase in PC 12 cells, and using SSe in combination with vincristine eliminated the inhibition of the cell cycle in the G2 phase. Briefly, our in vitro preliminary study showed that SSe might protect PC12 cells from vincristine-induced peripheral neuropathy during chemotherapy.

Bridging the Translational Gap in Chemotherapy-Induced Peripheral Neuropathy with iPSC-Based Modeling

Simple Summary

Chemotherapy-induced peripheral neuropathy (CIPN) remains a clinical challenge with a considerable impact on the effective treatment of cancers and quality of life during and after concluding chemotherapy. Given the limited understanding of CIPN, there are no options for the treatment and prevention of CIPN. Decades of research with the unsuccessful translation of preclinical findings to clinical studies argue for the requirement of human model systems. This review focuses on the translational potential of human induced pluripotent stem cells (iPSCs) in CIPN research. We provide an overview of the current studies and discuss important aspects to improve the translation of in vitro findings. We identified distinct effects on the neurite network and cell viability upon exposure to different classes of chemotherapy. Our study revealed considerable variability between donors and between neurons of the central and peripheral nervous system. Translational success may be improved by including multiple iPSC donors with known clinical data and selecting clinically relevant concentrations.

Abstract

Chemotherapy-induced peripheral neuropathy (CIPN) is a common and potentially serious adverse effect of a wide range of chemotherapeutics. The lack of understanding of the molecular mechanisms underlying CIPN limits the efficacy of chemotherapy and development of therapeutics for treatment and prevention of CIPN. Human induced pluripotent stem cells (iPSCs) have become an important tool to generate the cell types associated with CIPN symptoms in cancer patients. We reviewed the literature for iPSC-derived models that assessed neurotoxicity among chemotherapeutics associated with CIPN. Furthermore, we discuss the gaps in our current knowledge and provide guidance for selecting clinically relevant concentrations of chemotherapy for in vitro studies. Studies in iPSC-derived neurons revealed differential sensitivity towards mechanistically diverse chemotherapeutics associated with CIPN. Additionally, the sensitivity to chemotherapy was determined by donor background and whether the neurons had a central or peripheral nervous system identity. We propose to utilize clinically relevant concentrations that reflect the free, unbound fraction of chemotherapeutics in plasma in future studies. In conclusion, iPSC-derived sensory neurons are a valuable model to assess CIPN; however, studies in Schwann cells and motor neurons are warranted. The inclusion of multiple iPSC donors and concentrations of chemotherapy known to be achievable in patients can potentially improve translational success.

Does specificity of electrodiagnostic test referrals predict for test outcome in children?

INTRODUCTION/AIMS

Electrodiagnostic testing (EDX) is important in evaluation of pediatric neuromuscular disease. Non-specific referrals have emerged as a leading reason for EDX in recent years. We examine whether referral-specificity is predictive of test outcomes in children.

METHODS

EDX referrals and outcomes were audited over a 7-year period from 2013 to 2020 at CHI-Crumlin. Pre-test details were coded and compared to EDX outcomes using multinomial logistic regression.

RESULTS

EDX studies were performed in 702 children (median age 10.2 yrs). In 36% of patients, EDX-referrals did not specify any pre-test diagnosis. Mononeuropathy (24%) and polyneuropathy (15%) were the leading pre-specified diagnoses as well as the most common test outcomes. Neurology and orthopedics/plastic surgery contributed the majority of referrals. Metabolic medicine and hematology/oncology were most likely to pre-specify a working diagnosis and were the specialties with both the highest proportion of abnormal outcomes and referral accuracy. EDX abnormality was present in 42% of patients and was predicted by specificity of referral and the absence of pain as a leading symptom. The accuracy of specified pre-test diagnoses was highest for suspected anterior horn cell disorders (67%). Accuracy of referrals, as well as abnormal test outcomes, were negatively predicted by the presence of pain as a leading symptom.

DISCUSSION

EDX is informative in children but the likelihood of abnormal test-outcomes is diminished when a pre-specified working diagnosis is lacking or when the primary reason for referral is pain. This article is protected by copyright. All rights reserved.

Peripheral Nervous System Involvement in Non-Primary Pediatric Cancer: From Neurotoxicity to Possible Etiologies

Peripheral neuropathy is a well described complication in children with cancer. Oncologists are generally well aware of the toxicity of the main agents, but fear the side effects of new drugs. As chemotherapeutic agents have been correlated with the activation of the immune system such as in Chemotherapy Induced Peripheral Neuropathy (CIPN), an abnormal response can lead to Autoimmune Peripheral Neuropathy (APN). Although less frequent but more severe, Radiation Induced Peripheral Neuropathy may be related to irreversible peripheral nervous system (PNS). Pediatric cancer patients also have a higher risk of entering a Pediatric Intensive Care Unit for complications related to therapy and disease. Injury to peripheral nerves is cumulative, and frequently, the additional stress of a malignancy and its therapy can unmask a subclinical neuropathy. Emerging risk factors for CIPN include treatment factors such as dose, duration and concurrent medication along with patient factors, namely age and inherited susceptibilities. The recent identification of individual genetic variations has advanced the understanding of physiopathological mechanisms and may direct future treatment approaches. More research is needed on pharmacological agents for the prevention or treatment of the condition as well as rehabilitation interventions, in order to allow for the simultaneous delivery of optimal cancer therapy and the mitigation of toxicity associated with pain and functional impairment. The aim of this paper is to review literature data regarding PNS complications in non-primary pediatric cancer.

Characteristics and patterns of pediatric chemotherapy-induced peripheral neuropathy: A systematic review

This systematic review provides a high-quality synthesis of the empirical evidence regarding chemotherapy-induced peripheral neuropathy (CIPN) characteristics and patterns described in studies of children who received neurotoxic chemotherapy to treat cancer. PubMed, CINAHL, PsycINFO, and Embase were searched for articles published 2009 - 2019, yielding 861. Forty-two papers met the eligibility criteria, including 31 that described characteristics and patterns of vincristine-induced CIPN. Fifty-seven percent of articles were of low to moderate quality; measurement flaws were the most common limitations. The reported CIPN incidence varies widely (2.8%-100%) depending on risk factors (e.g., race) and the measurement approach. Incidence rates of sensory, motor, autonomic CIPN, and pain were 12-28%, 50-72%, 0.8-83% and 5.7-44%, respectively. The evidence suggests that sensory and motor neuropathy, pain, and functional deficits are common and can persist into adulthood. Caucasian race is a risk factor and, contrary to prior thinking, cumulative chemotherapy dosage alone does not predict CIPN severity. The influence of other risk factors is less clear, and studies to date have not explored potential interactions among race, genetics, age, sex, drug metabolism, and nutritional status, among other factors.

Genetic factors influencing the development of vincristine-induced neurotoxicity

Introduction: One of the most common side effects during vincristine (VCR) use is the establishment of VCR-induced peripheral neuropathy (VIPN). Among several risk factors that can influence the development of VIPN, such as cumulative dose and patient's age, sex, ethnicity, and genetic variants, this review is focused on the genetic variability. Areas covered: A literature research was performed firstly using the following PubMed search string ((((CIPN OR (vincristine AND neurotoxicity OR (vincristine AND neuropathy))) AND (polymorphisms OR (genetic variants OR (genetic factors OR (genetic profile OR (pharmacogenetics OR (genome-wide OR (genetic risk OR (expression genotype))))))))))) but also other relevant papers cited by the selected articles were included. Based on the obtained results, we identified two main categories of genes: genes involved in pharmacokinetics (genes related to metabolism and transport) or pharmacodynamics (genes related to mechanism of action) of VCR. Expert opinion: Despite several clinical retrospective studies investigating the possible correlations between patient genotype and VIPN onset, contrasting and inconsistent results are reported. In conclusion, given the clinical relevance of VIPN, further and more focused research would be fundamental in order to identify genetic variants able to predict its development and to allow a safer management of treated patients.

N-alkylisatin-based microtubule destabilizers bind to the colchicine site on tubulin and retain efficacy in drug resistant acute lymphoblastic leukemia cell lines with less in vitro neurotoxicity

BACKGROUND

Drug resistance and chemotherapy-induced peripheral neuropathy continue to be significant problems in the successful treatment of acute lymphoblastic leukemia (ALL). 5,7-Dibromo-N-alkylisatins, a class of potent microtubule destabilizers, are a promising alternative to traditionally used antimitotics with previous demonstrated efficacy against solid tumours in vivo and ability to overcome P-glycoprotein (P-gp) mediated drug resistance in lymphoma and sarcoma cell lines in vitro. In this study, three di-brominated N-alkylisatins were assessed for their ability to retain potency in vincristine (VCR) and 2-methoxyestradiol (2ME2) resistant ALL cell lines. For the first time, in vitro neurotoxicity was also investigated in order to establish their suitability as candidate drugs for future use in ALL treatment.

METHODS

Vincristine resistant (CEM-VCR R) and 2-methoxyestradiol resistant (CEM/2ME2-28.8R) ALL cell lines were used to investigate the ability of N-alkylisatins to overcome chemoresistance. Interaction of N-alkylisatins with tubulin at the the colchicine-binding site was studied by competitive assay using the fluorescent colchicine analogue MTC. Human neuroblastoma SH-SY5Y cells differentiated into a morphological and functional dopaminergic-like neurotransmitter phenotype were used for neurotoxicity and neurofunctional assays. Two-way ANOVA followed by a Tukey's post hoc test or a two-tailed paired t test was used to determine statistical significance.

RESULTS

CEM-VCR R and CEM/2ME2-28.8R cells displayed resistance indices of > 100 to VCR and 2-ME2, respectively. CEM-VCR R cells additionally displayed a multi-drug resistant phenotype with significant cross resistance to vinblastine, 2ME2, colchicine and paclitaxel consistent with P-gp overexpression. Despite differences in resistance mechanisms observed between the two cell lines, the N-alkylisatins displayed bioequivalent dose-dependent cytotoxicity to that of the parental control cell line. The N-alkylisatins proved to be significantly less neurotoxic towards differentiated SH-SY5Y cells than VCR and vinblastine, evidenced by increased neurite length and number of neurite branch points. Neuronal cells treated with 5,7-dibromo-N-(p-hydroxymethylbenzyl)isatin showed significantly higher voltage-gated sodium channel function than those treated with Vinca alkaloids, strongly supportive of continued action potential firing.

CONCLUSIONS

The N-alkylisatins are able to retain cytotoxicity towards ALL cell lines with functionally distinct drug resistance mechanisms and show potential for reduced neurotoxicity. As such they pose as promising candidates for future implementation into anticancer regimes for ALL. Further in vivo studies are therefore warranted.

Vincristine-induced peripheral neurotoxicity: A prospective cohort

Vincristine-induced peripheral neuropathy (VIPN) is a serious and pervasive problem, affecting 12-78% of pediatric patients, based on retrospective studies. The study objective was to prospectively collect a cohort of well-phenotyped patients receiving vincristine in order to accurately classify and grade their neurotoxicity. All children in British Columbia with leukemia or lymphoma requiring vincristine between 2013 and 2016 were approached for consent. Those recruited were assessed by occupational and physiotherapists at baseline, mid and endpoint of their treatment. Assessments included the Bruininks-Oseretsky Test of Motor Proficiency - 2nd ed. (BOT-2), strength, "Timed up and go" test and vibration sensibility. Seventy-two patients consented (age: 2.0-18.7 years). The majority were below average for age on one or more BOT-2 domains at midpoint (N = 32/45, 71%), which decreased by the endpoint (N = 19/41, 46%, p = .049). Six patients showed severe VIPN throughout treatment (N = 6/53, 11%), defined as a BOT-2 score well below average. Muscle strength for wrist extension/flexion, anterior tibialis and peronei decreased significantly between baseline (Median = 5) and midpoint (Median = 4), with no significant change noted by endpoint. Most patients had normal vibration sensibility in lower (N = 30/60, 50%) and upper limbs (N = 26/38, 68%). In conclusion, with no differences between time points. VIPN is highly prevalent among patients with pediatric cancer, causing significant morbidity and functional deficits. Identification of risk factors would allow for resource appropriation to patients at higher risk, as well as potentially permitting dose escalation in patients with low toxicity to improve survival.

Bifocal Tibial Kaposiform Hemangioendothelioma Responsive to Vincristine Therapy: A Case Report

BACKGROUND Kaposiform hemangioendothelioma is a rare locally aggressive vascular endothelial-derived spindle cells neoplasm. Herein, we report a rare case of bifocal tibial kaposiform hemangioendothelioma. CASE REPORT A 9-year-old female presented with a 2-year history of pain and swelling in the left leg. The patient had a high plasma level of the D-dimer and fibrinogen. Radiography revealed a centric lytic lesion on the left proximal tibial metaphysis and an eccentric lateral distal tibial metaphyseal. Histopathologic examination of the sample taken from the distal tibia revealed a dense spindle cell tumor with lobular architecture composed of compact spindle cells compressing small slit-like vascular spaces, forming glomeruloid nests. No necrosis was identified. Based on these findings and the positive immunohistochemical staining for CD31, CD34, and D2-40, the patient was diagnosed with kaposiform hemangioendothelioma. Treatment was started by using vincristine chemotherapy, after which the patient developed temporary peroneal neuropathy, which improved over the next 3 months. CONCLUSIONS Bifocal tibial kaposiform hemangioendothelioma lesions are unique in pediatric patients and can be successfully treated with vincristine chemotherapy. In these cases, the treating physician should be aware of peroneal neuropathy as a potential complication of vincristine administration.

Chemotherapy-Induced Peripheral Neuropathy in Long-term Survivors of Childhood Cancer: Clinical, Neurophysiological, Functional, and Patient-Reported Outcomes

Importance

In light of the excellent long-term survival of childhood cancer patients, it is imperative to screen for factors affecting health, function, and quality of life in long-term survivors.

Objective

To comprehensively assess chemotherapy-induced peripheral neuropathy in childhood cancer survivors to define disease burden and functional effect and to inform screening recommendations.

Design, Setting, and Participants

In this cross-sectional observational study, cancer survivors who were treated with chemotherapy for extracranial malignancy before age 17 years were recruited consecutively between April 2015 and December 2016 from a single tertiary hospital-based comprehensive cancer survivorship clinic and compared with healthy age-matched controls. Investigators were blinded to the type of chemotherapy. A total of 169 patients met inclusion criteria, of whom 48 (28.4%) were unable to be contacted or declined participation.

Exposures

Chemotherapy agents known to be toxic to peripheral nerves.

Main Outcomes and Measures

The clinical peripheral neurological assessment using the Total Neuropathy Score was compared between recipients of different neurotoxic chemotherapy agents and control participants and was correlated with neurophysiological, functional, and patient-reported outcome measures.

Results

Of the 121 childhood cancer survivors included in this study, 65 (53.7%) were male, and the cohort underwent neurotoxicity assessments at a median (range) age of 16 (7-47) years, a median (range) 8.5 (1.5-29) years after treatment completion. Vinca alkaloids and platinum compounds were the main neurotoxic agents. Clinical abnormalities consistent with peripheral neuropathy were common, seen in 53 of 100 participants (53.0%) treated with neurotoxic chemotherapy (mean Total Neuropathy Score increase, 2.1; 95% CI, 1.4-2.9; P < .001), and were associated with lower limb predominant sensory axonal neuropathy (mean amplitude reduction, 5.8 μV; 95% CI, 2.8-8.8; P < .001). Functional deficits were seen in manual dexterity, distal sensation, and balance. Patient-reported outcomes demonstrating reduction in global quality of life and physical functioning were associated with the Total Neuropathy Score. Cisplatin produced long-term neurotoxicity more frequently than vinca alkaloids.

Conclusions and Relevance

Clinical abnormalities attributable to peripheral neuropathy were common in childhood cancer survivors and persisted long term, with concurrent deficits in patient-reported outcomes. Both the type of neurotoxic agent and a targeted clinical neurological assessment are important considerations when screening survivors for long-term neuropathy. Further development of peripheral neuropathy-specific pediatric assessment tools will aid research into neuroprotective and rehabilitative strategies.

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.

Peripheral neuropathy in children and adolescents treated for cancer

Peripheral neuropathy is a well recognised treatment-related toxicity in children with cancer, associated with exposure to neurotoxic chemotherapy agents. Acute damage can occur in sensory, motor, or autonomic neurons, with symptoms that are rarely life threatening, but often severe enough to interfere with function during therapy and after treatment ends. The type of neuropathy and specific symptoms are associated with multiple factors including age at time of therapy, genetic predisposition, chemotherapy type and cumulative dose, and exposure to other agents during therapy. In this Review, we describe the peripheral neuropathy phenotype in children during cancer therapy and among survivors who have completed therapy, to summarise genetic and treatment-related risk factors for neuropathy, and to outline strategies to monitor and detect neuropathy during and after therapy. Additionally, we outline strategies for medical management of neuropathy during treatment and potential rehabilitation interventions to prevent or remediate functional loss.

Vincristine-induced peripheral neuropathy in survivors of childhood acute lymphoblastic leukaemia

BACKGROUND

Vincristine, an essential component of childhood acute lymphoblastic leukaemia (ALL) therapeutic protocols, is associated with dose-dependent neurotoxicity, but its long-term morbidity in treated children has not been clearly elucidated. The aim of this study is to determine the prevalence of vincristine-induced peripheral neuropathy (VIPN) among Malaysian childhood ALL survivors and its impact on motor function and quality of life.

PROCEDURE

Survivors of childhood ALL aged 4-18 years who had completed chemotherapy for 2 years or more were evaluated for VIPN using both the clinical Total Neuropathy Score (cTNS) and nerve conduction studies. Motor function and quality of life of the survivors were assessed via the Bruininks-Oseretsky Test of Motor Proficiency Brief Form, Second Edition (BOT-2 Brief Form) and the Paediatric Quality of Life version 4.0 Generic Core Scales (PedsQL4.0) questionnaire, respectively.

RESULTS

One hundred and one survivors with a duration of follow-up ranging from 2.0 to 10.3 years were recruited. Twenty-seven (26.7%) had abnormal cTNS scores and 69 (68.3%) had electrophysiological evidence of neuropathy. Of these, 16 (15.8%) had combined clinical and electrophysiological neuropathy (VIPN). Those previously treated on the intermediate- or high-risk treatment stratification arms had a higher risk of developing VIPN (67.3 vs. 32.7%; odds ratio [OR]: 9.06, 95% confidence interval [CI]: 1.14-71.86; P = 0.014). Survivors with VIPN had significantly lower quality of life scores in the physical (P = 0.024) and social domains (P = 0.039) compared with peers without VIPN, but no association with poorer motor function was observed.

CONCLUSIONS

Sixteen percent of ALL survivors had VIPN. VIPN should be increasingly recognised as a late effect of chemotherapy, as it significantly affects physical and social function quality of life.

Electrophysiological Studies to Detect Peripheral Neuropathy in Children Treated With Vincristine

Patients treated with vincristine predictably develop peripheral neuropathy. The aim of our study was to investigate the pattern of vincristine-induced neuropathy in children by nerve conduction studies and somatosensory-evoked potentials (SSEPs). We included data from 39 children who received vincristine for various pediatric malignancies, and we performed initial and follow-up (after a minimum of 4 doses of vincristine 1.5 mg/m) conduction studies in 27 patients and SSEPs studies in 34 patients. On follow-up the most prevalent symptoms were paresthesias (44%) and constipation (22%), and the most common neurological sign was impaired myotatic reflexes (89%). Performing nerve conduction studies we found that significant reductions were measured for distal amplitudes, distal latencies were prolonged, and conduction velocities were relatively preserved. The most pronounced differences in amplitudes and distal latencies were measured in the peroneal nerves. Changes of SSEPs studies were subtle. Vincristine-induced neuropathy presents with primary axonal involvement and is more pronounced on motor neurons. We found a trend between higher age and higher dose and the degree of neuropathy in our group of patients.

Vincristine-induced peripheral neuropathy in children with cancer: A systematic review

Vincristine-induced peripheral neuropathy (VIPN) is a dose-limiting side effect of vincristine (VCR) treatment in children, leading to diminished quality of life. Much remains unknown about the underlying mechanisms of VIPN. This review systematically summarizes the available literature concerning contributing factors of VIPN development in children. Studied factors include patient characteristics, VCR dose, administration method, pharmacokinetics, and genetic factors. Furthermore, this review reports on currently available tools to assess VIPN in children. In total, twenty-eight publications were included. Results indicate that Caucasian race, higher VCR dose, older age and low clearance negatively influence VIPN, although results regarding the latter two factors were rather conflicting. Moreover, genetic pathways influencing VIPN were identified. Furthermore, the studied tools to assess VIPN seriously impairs comparability across study results. Studying the factors and their interactions that seem to influence VIPN in children, should aid in personalized VCR treatment, thereby increasing VCR effectiveness while minimizing toxicity.

Characterization of three human cell line models for high-throughput neuronal cytotoxicity screening

More than 75 000 man-made chemicals contaminate the environment; many of these have not been tested for toxicities. These chemicals demand quantitative high-throughput screening assays to assess them for causative roles in neurotoxicities, including Parkinson's disease and other neurodegenerative disorders. To facilitate high throughput screening for cytotoxicity to neurons, three human neuronal cellular models were compared: SH-SY5Y neuroblastoma cells, LUHMES conditionally-immortalized dopaminergic neurons, and Neural Stem Cells (NSC) derived from human fetal brain. These three cell lines were evaluated for rapidity and degree of differentiation, and sensitivity to 32 known or candidate neurotoxicants. First, expression of neural differentiation genes was assayed during a 7-day differentiation period. Of the three cell lines, LUHMES showed the highest gene expression of neuronal markers after differentiation. Both in the undifferentiated state and after 7 days of neuronal differentiation, LUHMES cells exhibited greater cytotoxic sensitivity to most of 32 suspected or known neurotoxicants than SH-SY5Y or NSCs. LUHMES cells were also unique in being more susceptible to several compounds in the differentiating state than in the undifferentiated state; including known neurotoxicants colchicine, methyl-mercury (II), and vincristine. Gene expression results suggest that differentiating LUHMES cells may be susceptible to apoptosis because they express low levels of anti-apoptotic genes BCL2 and BIRC5/survivin, whereas SH-SY5Y cells may be resistant to apoptosis because they express high levels of BCL2, BIRC5/survivin, and BIRC3 genes. Thus, LUHMES cells exhibited favorable characteristics for neuro-cytotoxicity screening: rapid differentiation into neurons that exhibit high level expression neuronal marker genes, and marked sensitivity of LUHMES cells to known neurotoxicants. Copyright © 2016 John Wiley & Sons, Ltd.