Comparison of two chemotherapy-induced peripheral neuropathy measurement approaches in children

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.

Proactive therapeutic drug monitoring of vincristine in pediatric and adult cancer patients: current supporting evidence and future efforts

Vincristine (VCR), an effective antitumor drug, has been utilized in several polytherapy regimens for acute lymphoblastic leukemia, neuroblastoma and rhabdomyosarcoma. However, clinical evidence shows that the metabolism of VCR varies greatly among patients. The traditional based body surface area (BSA) administration method is prone to insufficient exposure to VCR or severe VCR-induced peripheral neurotoxicity (VIPN). Therefore, reliable strategies are urgently needed to improve efficacy and reduce VIPN. Due to the unpredictable pharmacokinetic changes of VCR, therapeutic drug monitoring (TDM) may help to ensure its efficacy and to manage VIPN. At present, there is a lot of supporting evidence for the suitability of applying TDM to VCR therapy. Based on the consensus guidelines drafted by the International Association of Therapeutic Drug Monitoring and Clinical Toxicology (IATDMCT), this review aimed to summarize various available data to evaluate the potential utility of VCR TDM for cancer patients. Of note, valuable evidence has accumulated on pharmacokinetics variability, pharmacodynamics, drug exposure-clinical response relationship, biomarkers for VIPN prediction, and assays for VCR monitoring. However, there are still many relevant clinical pharmacological questions that cannot yet be answered merely based on insufficient evidence. Currently, we cannot recommend a therapeutic exposure range and cannot yet provide a dose-adaptation strategy for clinicians and patients. In areas where the evidence is not yet sufficient, more research is needed in the future. The precision medicine of VCR cannot rely on TDM alone and needs to consider the clinical, environmental, genetic background and patient-specific factors as a whole.

Examination of the psychometric properties of pediatric-modified total neuropathy score in Turkish children with cancer

BACKGROUND

Evaluation of chemotherapy-induced peripheral neuropathy has gained importance in symptom management of pediatric patients with cancer. This study aimed to perform the Turkish validity and reliability study of the Pediatric-Modified Total Neuropathy Score (Ped-mTNS).

METHODS

A methodological, descriptive, and cross-sectional design was used in the study. Forty children aged between 5 and 18 and were treated for cancer and 40 age- and gender-matched healthy children (control group) were included in the study. The mean scores of the items on the Ped-mTNS were compared, and item-total score correlations were evaluated. Cronbach's alpha coefficient of the Ped-mTNS was calculated for internal consistency.

FINDINGS

Cronbach's alpha value of the scale was found as 0.709. The item-total correlations of the scale items ranged from 0.260 to 0.658. The mean score of cancer patients on the Ped-mTNS was found as 4.4 ± 3.8.

DISCUSSION

Ped-mTNS scores of children with cancer indicated more deficits than those of the control group. In the evaluation of children in the patient and control groups, a difference was found in terms of light touch sensation, which is one of the sensory symptoms in the items of the Ped-mTNS, and pin sensibility and strength, which are among the clinical symptoms.

APPLICATION TO PRACTICE

The Ped-mTNS was determined to be a valid and reliable measurement tool for children with cancer aged between 5 and 18 in the Turkish population.

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.

Persistence of Chemotherapy-Induced Peripheral Neuropathy Despite Vincristine Reduction in Childhood B-Acute Lymphoblastic Leukemia

BACKGROUND

Children with B-acute lymphoblastic leukemia (B-ALL) are at risk for chemotherapy-induced peripheral neuropathy (CIPN). Children's Oncology Group AALL0932 randomized reduction in vincristine and dexamethasone (every 4 weeks vs 12 weeks during maintenance in the average-risk subset of National Cancer Institute standard-B-ALL (SR AR B-ALL). We longitudinally measured CIPN, overall and by treatment group.

METHODS

AALL0932 standard-B-ALL patients aged 3 years and older were evaluated at T1-T4 (end consolidation, maintenance month 1, maintenance month 18, 12 months posttherapy). Physical and occupational therapists (PT/OT) measured motor CIPN (hand and ankle strength, dorsiflexion and plantarflexion range of motion), sensory CIPN (finger and toe vibration and touch), function (dexterity [Purdue Pegboard], and walking efficiency [Six-Minute Walk]). Proxy-reported function (Pediatric Outcome Data Collection Instrument) and quality of life (Pediatric Quality of Life Inventory) were assessed. Age- and sex-matched z scores and proportion impaired were measured longitudinally and compared between groups.

RESULTS

Consent and data were obtained from 150 participants (mean age = 5.1 years [SD = 1.7], 48.7% female). Among participants with completed evaluations, 81.8% had CIPN at T1 (74.5% motor, 34.1% sensory). When examining severity of PT/OT outcomes, only handgrip strength (P < .001) and walking efficiency (P = .02) improved from T1-T4, and only dorsiflexion range of motion (46.7% vs 14.7%; P = .008) and handgrip strength (22.2% vs 37.1%; P = .03) differed in vincristine and dexamethasone every 4 weeks vs vincristine and dexamethasone 12 weeks at T4. Proxy-reported outcomes improved from T1 to T4 (P < .001), and most did not differ between groups.

CONCLUSIONS

CIPN is prevalent early in B-ALL therapy and persists at least 12 months posttherapy. Most outcomes did not differ between treatment groups despite reduction in vincristine frequency. Children with B-ALL should be monitored for CIPN, even with reduced vincristine frequency.

Genetic Polymorphisms Associated with Vincristine Pharmacokinetics and Vincristine-Induced Peripheral Neuropathy in Pediatric Oncology Patients

Simple Summary

Vincristine is a type of chemotherapy that is often used in the treatment of children with cancer. The main side effect of vincristine is nerve damage. Patients experience symptoms such as tingling, pain or muscle weakness. Some children are more sensitive to vincristine than others, which may depend on variations in genes and in the breakdown of vincristine by the body. In this study, we investigated the effect of variations in genes on nerve damage due to vincristine and breakdown of vincristine by the body. We found that nine variations in seven genes were associated with nerve damage due to vincristine, whereas three variations in three genes were associated with the breakdown of vincristine by the body. It is important that future studies try to replicate these findings. Our findings help us towards the goal of tailoring vincristine treatment to each child, with optimal therapeutic effect while limiting nerve damage.

Abstract

Vincristine (VCR) is an important component of curative chemotherapy for many childhood cancers. Its main side effect is VCR-induced peripheral neuropathy (VIPN), a dose limiting toxicity. Some children are more susceptible to VIPN, which is at least partially dependent on genetic factors and pharmacokinetics (PK). In this study, we identify and replicate genetic variants associated with VCR PK and VIPN. Patient samples from a randomized clinical trial studying the effect of administration duration of VCR on VIPN in 90 patients were used. PK sampling was conducted on between one and five occasions at multiple time points. A linear two-compartment model with first-order elimination was used, and targeted next-generation DNA sequencing was performed. Genotype–trait associations were analyzed using mixed-effect models or logistic regression analysis for repeated measures, or Poisson regression analysis in which the highest VIPN score per patient was included. Nine single-nucleotide polymorphisms (SNPs) in seven genes (NDRG1, GARS, FIG4, FGD4, SEPTIN9, CEP72, and ETAA1) were associated with VIPN. Furthermore, three SNPs in three genes (MTNR1B, RAB7A and SNU13) were associated with PK of VCR. In conclusion, PK of VCR and VIPN are influenced by SNPs; upfront identification of those that lead to an altered susceptibility to VIPN or VCR exposure could help individualize VCR treatment.

PASTEC - a prospective, single-center, randomized, cross-over trial of pure physical versus physical plus attentional training in children with cancer

Despite recent improvements in survival rates in children with cancer, long-term toxicities remain a major concern. Physical activity could reduce the impact of long-term sequelae, notably in neuropsychological and physical areas. We report of a randomized trial of pure physical versus physical/attentional training in pediatric oncology patients. Twenty-two patients aged 6-18 y.o. were included, irrespective of their clinical diagnosis or treatment status, stratified by age and randomized 1:1 into pure physical vs. physical/attentional activity arms, with a cross-over at study midpoint. Neurological, motor and neuropsychological assessments were performed at inclusion, start, crossover and end of the program. Feasibility, defined as > 80% patients attending > 80% of sessions, was the primary endpoint. Secondary outcomes were improvements in neuropsychological and motor performance tests. While 68% of patients attended more than 80% of sessions during the pre-crossover phase of the study, this dropped to 36% post-crossover. Our study therefore failed to meet our primary endpoint. Nonetheless, significant improvements in anxiety (p<0.001), emotional control (p = 0.04), organization skills (p = 0.03), as well as motor deficit scores (p = 0.04) were observed. We noted no significant difference between the pure physical and the physical/attentional training arms, or when analyzing subgroups by age or sequence of intervention. We conclude that physical activity has a positive impact on anxiety, emotional and organizational aspects as well as motor deficits. Attendance dropped during the course of the study and motivational interventions should be included in future studies or equivalent programs.Supplemental data for this article is available online at https://doi.org/10.1080/08880018.2021.1994677 .

Biomarkers of Chemotherapy-Induced Peripheral Neuropathy: Current Status and Future Directions

Chemotherapy induced peripheral neuropathy (CIPN) is an often severe and debilitating complication of multiple chemotherapeutic agents that can affect patients of all ages, across cancer diagnoses. CIPN can persist post-therapy, and significantly impact the health and quality of life of cancer survivors. Identifying patients at risk for CIPN is challenging due to the lack of standardized objective measures to assess for CIPN. Furthermore, there are no approved preventative treatments for CIPN, and therapeutic options for CIPN remain limited once it develops. Biomarkers of CIPN have been studied but are not widely used in clinical practice. They can serve as an important clinical tool to identify individuals at risk for CIPN and to better understand the pathogenesis and avenues for treatment of CIPN. Here we review promising biomarkers of CIPN in humans and their clinical implications.

Newly identified chemotherapy-induced peripheral neuropathy in a childhood cancer survivorship clinic

Chemotherapy-induced peripheral neuropathy (CIPN), a debilitating side effect of pediatric cancer therapy, can be challenging to diagnose. We estimated the prevalence of newly identified and previously diagnosed CIPN in the regional HEROS Childhood Cancer Survivorship Clinic. From 2016 to 2018, 148 survivors (45.3% female, age 17.1 [SD 7.7] years, 81.8% in ongoing routine oncology follow-up) had their initial survivorship evaluation at an average of 7.4 (SD 6.6) years from diagnosis. Fifty-six survivors (37.8%) had CIPN, of these 46 (82.1%) were newly identified. Our findings demonstrate CIPN may be missed in routine oncology care, and new methods are needed to screen for CIPN.

High-Dose Gabapentin and Amitriptyline in the Treatment of Refractory Chemotherapy-Induced Peripheral Neuropathy in a Toddler

Pharmacologic management of chemotherapy-induced peripheral neuropathy (CIPN) in pediatric patients remains a challenge. Without effective treatment to control pain from CIPN in children, reduction or discontinuation of life-saving chemotherapeutic medications may be required. Various combinations of medications are available, but none have been thoroughly evaluated for their effectiveness in managing CIPN in the pediatric population. We present the clinical management of severe CIPN in a 3-year-old child with pre-B acute lymphoblastic lymphoma that was refractory to a regiment that included high-dose gabapentin and opioids. Therapy was subsequently adjusted to include amitriptyline, eliminating the need for opioids with complete resolution of symptoms. The potential combination pharmacotherapies for pediatric CIPN are discussed and mechanisms accounting for inadequate response with monotherapy are presented.

Impact of cisplatin administration on cerebellar cortical structure and locomotor activity of infantile and juvenile albino rats: the role of oxidative stress

The central neurotoxicity of cisplatin (CisPt) has always raised questions especially during development, but few studies are available. Hence, this work was designed to assess the CisPt's impacts on the postnatal rat cerebellum via evaluation of locomotor activity, histological and immunohistochemical studies, and to focus on cerebellar oxidative stress-related alterations. Eighty newborn pups were divided into 2 equal experimental groups: the control group was kept without any treatment and CisPt-treated group received a single subcutaneous injection of CisPt (5 μg /g b.w.) in their nape at PD10. Ten rats at PD11, PD17, and PD30 ages were weighed, then deeply anesthetized and sacrificed. For locomotor assessment, 20 pups were divided equally into control and CisPt-treated groups and tested at PD11-13, PD15-17, and PD28-30 ages. CisPt-treated rats suffered from decreased motor activity and showed decreased body and cerebellar weights, reduced levels of enzymatic antioxidants (SOD and CAT), and non-enzymatic antioxidant defense (GSH), and increase of lipid peroxidation marker (MDA). Histopathologically, CisPt sowed deleterious changes within cerebellar cortical layers in the form of vacuolations, decreased thickness, and hemorrhage (in PD17), while Purkinje cells exhibited profound degenerative changes in the form of swelling, disrupted arrangement, distortion, and nuclear shrinkage. In CisPt-treated rats, GFAP demonstrated upregulated, hypertrophied, and branched Bergmann glial fibers and reactive astrogliosis. Immuno-localization of Ki-67-positive cells revealed defective migration associated with decreased proliferation in early ages in addition to glial proliferation in PD30. In conclusion, CisPt causes oxidative stress-related deleterious effects on structure of developing cerebellar cortex and affects locomotor activity.

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.

Assessment of Pediatric Chemotherapy-Induced Peripheral Neuropathy Using a New Patient-Reported Outcome Measure: The P-CIN

Background: Chemotherapy-induced peripheral neuropathy (CIPN) is commonly experienced by children receiving neurotoxic chemotherapy. No validated pediatric CIPN patient-reported outcome (PRO) measures exist. Purpose: To test sensitivity, internal consistency reliability, content and convergent validity, and feasibility of the Pediatric Chemotherapy-Induced Neuropathy (P-CIN), an electronic PRO measure for assessing CIPN in children who received neurotoxic chemotherapy. Method: Five experts evaluated content validity of the 14-item P-CIN. Children 5 to 17 years old with CIPN (N = 79) completed the P-CIN via tablet computer; a subset (n = 26) also underwent neurological examinations using the Pediatric-Modified Total Neuropathy Score. Following preliminary analyses, one item was deleted and three others modified. The revised P-CIN was retested with patients (n = 6) who also completed the Bruininks-Oseretsky Test of Motor Proficiency motor function assessment. Means, item response ranges, standard deviations, content validity indexes, Cronbach's alphas, and correlation coefficients were calculated. Results: Mean participant age was 11.25 (SD = 4.0) years. Most had acute leukemia (62.5%) and received vincristine (98.7%). Content validity index coefficients ranged from .80 to 1.0 (p = .05). For 9 of 14 items, responses ranged from 0 to 4 or 5; response ranges for toe numbness, pick up a coin, and three of four pain items were 0 to 3. After deleting one item, Cronbach's alpha coefficient was .83. P-CIN scores were strongly associated with Pediatric-Modified Total Neuropathy Score (r = .52, p < .01) and Bruininks-Oseretsky Test of Motor Proficiency (r = -.83, p = .04) scores. Sixty-eight percent of children 6 to 17 years old completed P-CIN independently. Discussion: Preliminary evidence suggests that the 13-item P-CIN is internally consistent, is valid, and can be completed independently by children ≥ 6 years. However, we recommend additional testing.

Vincristine-Induced Peripheral Neuropathy in Pediatric Oncology: A Randomized Controlled Trial Comparing Push Injections with One-Hour Infusions (The VINCA Trial)

Vincristine (VCR) is a frequently used chemotherapeutic agent. However, it can lead to VCR-induced peripheral neuropathy (VIPN). In this study we investigated if one-hour infusions of VCR instead of push-injections reduces VIPN in pediatric oncology patients. We conducted a multicenter randomized controlled trial in which participants received all VCR administrations through push injections or one-hour infusions. VIPN was measured at baseline and 1-5 times during treatment using Common Terminology Criteria of Adverse Events (CTCAE) and pediatric-modified Total Neuropathy Score. Moreover, data on co-medication, such as azole antifungals, were collected. Overall, results showed no effect of administration duration on total CTCAE score or ped-mTNS score. However, total CTCAE score was significantly lower in patients receiving one-hour infusions concurrently treated with azole antifungal therapy (β = -1.58; p = 0.04). In conclusion, generally VCR administration through one-hour infusions does not lead to less VIPN compared to VCR push injections in pediatric oncology patients. However, one-hour infusions lead to less severe VIPN compared to push-injections when azole therapy is administered concurrently with VCR. These results indicate that in children treated with VCR and requiring concurrent azole therapy, one-hour infusions might be beneficial over push injections, although larger trials are needed to confirm this association.

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.

Association of Exercise Intolerance With Emotional Distress, Attainment of Social Roles, and Health-Related Quality of Life Among Adult Survivors of Childhood Cancer

Importance

Exercise intolerance is associated with increased risk for morbidity and mortality in childhood cancer survivors. However, an association between exercise intolerance and psychosocial outcomes has not been fully explored.

Objective

To examine the associations between exercise intolerance and emotional distress, attainment of social roles, and health-related quality of life in childhood cancer survivors.

Design, Setting, and Participants

A cross-sectional study including 1041 adult survivors of childhood cancer and 286 community controls in the St Jude Lifetime Cohort was conducted at St Jude Children's Research Hospital. The study was performed from April 1, 2012, to March 15, 2020.

Exposures

Exercise intolerance was defined as relative peak oxygen uptake less than 85% of age- and sex-estimated levels from maximal cardiopulmonary exercise testing.

Main Outcomes and Measures

Emotional distress was measured with the 18-item Brief Symptom Inventory-18, which includes overall Global Severity Index and depression, anxiety, and somatization subscales. Participants with T scores greater than or equal to 63 were classified as having elevated levels of distress. Social attainment was evaluated using patient-reported educational, employment, and marital status. Health-related quality of life was examined with the Medical Outcomes Survey Short Form-36. Participants with T scores less than or equal to 40 were classified as reporting poor health-related quality of life.

Results

Of the 1041 participants, 528 were women (50.7%). The prevalence of exercise intolerance among survivors (mean [SD] age, 35.5 [9.2] years) was higher than that among controls (age, 34.5 [10.0] years) (survivors: 634 [60.9%] vs controls: 75 [26.2%], P < .001). After adjusting for age at diagnosis and cardiopulmonary exercise testing, sex, race/ethnicity, smoking, physical activity, and exercise intolerance were associated with an increased risk for anxiety (prevalence rate ratio [PRR], 1.95; 95% CI, 1.20-3.16), somatization (PRR, 1.86; 95% CI, 1.23-2.80), and unemployment (PRR, 1.76; 95% CI, 1.23-2.52); an inverse association was noted with having a college degree (PRR, 0.67; 95% CI, 0.50-0.88). Exercise intolerance was associated with an increased the risk for scoring less than or equal to 40 on the physical component summary of the Medical Outcomes Survey Short Form-36 (PRR, 3.69; 95% CI, 2.34-5.84). These associations persisted when either cancer treatment exposures or chronic health conditions were added to the model.

Conclusions and Relevance

The findings of this study suggest that exercise intolerance is independently associated with emotional distress, attainment of social roles, and health-related quality of life of long-term survivors of childhood cancer. The results also suggest that improving physiologic capacity may benefit general health and wellness, as well as emotional health, ability to participate in social roles, and health-related quality of life.

Population Pharmacokinetics of Vincristine Related to Infusion Duration and Peripheral Neuropathy in Pediatric Oncology Patients

Vincristine (VCR) is frequently used in pediatric oncology and can be administered intravenously through push injections or 1 h infusions. The effects of administration duration on population pharmacokinetics (PK) are unknown. We described PK differences related to administration duration and the relation between PK and VCR-induced peripheral neuropathy (VIPN). PK was assessed in 1-5 occasions (1-8 samples in 24 h per occasion). Samples were analyzed using high-performance liquid chromatography/tandem mass spectrometry. Population PK of VCR and its relationship with administration duration was determined using a non-linear mixed effect. We estimated individual post-hoc parameters: area under the concentration time curve (AUC) and maximum concentration (C_max) in the plasma and peripheral compartment. VIPN was assessed using Common Terminology Criteria for Adverse Events (CTCAE) and the pediatric-modified total neuropathy score (ped-mTNS). Overall, 70 PK assessments in 35 children were evaluated. The population estimated that the intercompartmental clearance (IC-Cl), volume of the peripheral compartment (V₂), and C_max were significantly higher in the push group. Furthermore, higher IC-Cl was significantly correlated with VIPN development. Administration of VCR by push led to increased IC-Cl, V₂, and C_max, but were similar to AUC, compared to 1 h infusions. Administration of VCR by 1 h infusions led to similar or higher exposure of VCR without increasing VIPN.

Approaches to measure paediatric chemotherapy-induced peripheral neurotoxicity: a systematic review

In children who receive neurotoxic chemotherapy, peripheral neurotoxicity occurs frequently, necessitates dose reduction or treatment cessation, and affects function and long-term quality of life. No treatments exist for peripheral neurotoxicity and few assessment measures are specific to children. We did a systematic review to analyse the published literature concerning the evaluation of assessment measures for paediatric chemotherapy-induced peripheral neurotoxicity. We searched PubMed, CINAHL, PsycINFO, and Embase on Nov 7-8, 2018; of 1409 articles, seven met the inclusion criteria. A total of 335 children (excluding ten healthy controls) were enrolled in the seven studies and the sample sizes ranged from 17 to 86 individuals. 276 (82%) of the 335 children were actively undergoing chemotherapy treatment. Most studies did not comprehensively evaluate the psychometric properties of assessment measures for chemotherapy-induced peripheral neurotoxicity. By use of a narrative analysis that combined approaches from the Joanna Briggs Institute (Adelaide, SA, Australia) and the quality of diagnostic accuracy studies assessment method (known as QUADAS), only one study was deemed high quality. We identified two variants of the Total Neuropathy Score, two grading scales, two semi-objective tests, one patient-reported outcome, and several mobility measures. The National Cancer Institute Common Terminology Criteria for Adverse Events and the Balis grading scales showed lower sensitivity and specificity than the items of the Total Neuropathy Score. Although there is insufficient evidence to support the use of most approaches to assess chemotherapy-induced peripheral neurotoxicity in children, two variants of the Total Neuropathy Score, the pediatric-modified Total Neuropathy Score and the Total Neuropathy Score-pediatric vincristine, are promising but require further testing. Other approaches are less sensitive or less feasible. A patient-reported outcome measure for chemotherapy-induced peripheral neurotoxicity in children is needed.

Long-term small-fiber neuropathy and pain sensitization in survivors of pediatric acute lymphoblastic leukemia after stem cell transplantation

PURPOSE

We aimed at describing for the first time peripheral small-fiber neurotoxicity and pain sensitization in survivors of pediatric acute lymphoblastic leukemia after stem cell transplantation (SCT).

METHODS

In a cross-sectional, retrospective, single-center study, we assessed 25 relapse-free long-term survivors (median age at SCT: 11 ± 4.9 years; median time between SCT and testing: 8.25 years, 19 males) using a reduced version of the pediatric-modified total neuropathy score for clinical assessment and Quantitative Sensory Testing (QST).

INCLUSION CRITERIA

[Formula: see text] 6 years old at testing, [Formula: see text] 18 years old at time of SCT, [Formula: see text] 1 year between SCT and testing.

RESULTS

Nine patients (36%) had peripheral neuropathy as defined by the clinical red-pmTNS (≥ 4). The QST parameters mechanical pain sensitivity, mechanical detection threshold, thermal sensory limen, vibration detection threshold and pressure pain threshold were significantly abnormal in the survivor cohort (p < 0.0038). Except for one, all survivors showed at least one abnormal QST parameter. When using QST, signs of small and large fiber dysfunction were present in 22 (88%) and 17 (68%) survivors, respectively. More than half of all survivors were found to experience pathologic sensitization to pain.

CONCLUSIONS AND IMPLICATIONS FOR CANCER SURVIVORS

Survivors of pediatric acute lymphoblastic leukemia after SCT are at high risk for long-term peripheral neuropathy with a dominating small-fiber and pain sensitization pattern.

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.

Polyneuropathy in Acute Lymphoblastic Leukemia Long-Term Survivors: Clinical and Electrophysiological Characteristics With the Impact of Radiotherapy

Introduction: Acute lymphoblastic leukemia (ALL) is the most common childhood cancer with one of the highest survival rates. Long-term complications that occur after intensive oncological treatment often impair normal daily functioning. However, existing data on peripheral nervous system condition in ALL survivors remain conflicting. Materials and Methods: The study group consisted of 215 ALL survivors. Patients were treated with New York (NY, n = 45), previous modified Berlin-Frankfurt-Münster (pBFM, n = 64), and BFM95 (n = 106) protocols. Time elapsed between the end of the treatment and the control examination varied from 0.3 to 20.9 years. The analyzed patients underwent a neurophysiological analysis with electroneurography (ENG) of motor (median and peroneal) and sensory (median and sural) nerves as well as electromyography (EMG) of tibialis anterior, vastus lateralis, and interosseous I muscles. To estimate the influence of radiotherapy on recorded neurophysiological responses, a joint analysis of NY, and pBFM groups was performed. Results: Clinical symptoms of polyneuropathy were noted among 102 (47.4%) children during the ALL therapy and in 111 (51.6%) during follow-up. At the time of treatment, polyneuropathy was diagnosed in 57.8% participants from NY group, 35.9%-pBFM and 50.0%-BFM95 (p = 0.145). A significantly higher incidence of polyneuropathy was observed during a follow-up in the NY group (68.9%; p < 0.001 vs. pBFM, p = 0.002 vs. BFM95). The most frequent abnormality within all the protocols was demyelination (NY: 44.4%, pBFM: 59.4%, BFM95: 41.5%), in contrast to the least frequently registered isolated axonal changes. The negative influence of oncological treatment on neurophysiological parameters in ALL survivors was observed. Complex disorders of motor nerves, sensory nerves, and motor unit potentials were registered. Motor-sensory neuropathy was the most frequently found pathology in all analyzed protocols. The harmful effect of radiotherapy was also observed in EMG results. Conclusions: Detailed neurophysiological analysis in long-term childhood ALL survivors has shown generalized abnormalities in registered parameters. To our knowledge, the current study is the largest and one of the most comprehensive ones among those examining disturbances in ENG and EMG in this group of patients. Moreover, we are the first ones to demonstrate the negative influence of radiotherapy on peripheral nerve conduction parameters.

Measuring vincristine-induced peripheral neuropathy in children with cancer: validation of the Dutch pediatric-modified Total Neuropathy Score

Purpose

The aims were to evaluate the construct validity and reliability of the Dutch version of the pediatric-modified Total Neuropathy Score (ped-mTNS) for assessing vincristine-induced peripheral neuropathy (VIPN) in Dutch pediatric oncology patients aged 5–18 years.

Methods

Construct validity (primary aim) of the ped-mTNS was determined by testing hypotheses about expected correlation between scores of the ped-mTNS (range: 0–32) and the Common Terminology Criteria for Adverse Events (CTCAE) (range: 0–18) for patients and healthy controls and by comparing patients and controls regarding their total ped-mTNS scores and the proportion of children identified with VIPN. Inter-rater and intra-rater reliability and measurement error (secondary aims) were assessed in a subgroup of study participants.

Results

Among the 112 children (56 patients and 56 age- and gender-matched healthy controls) evaluated, correlation between CTCAE and ped-mTNS scores was as expected (moderate (r = 0.60)). Moreover, as expected, patients had significantly higher ped-mTNS scores and more frequent symptoms of VIPN compared with controls (both p < .001). Reliability as measured within the intra-rater group (n = 10) (intra-class correlation coefficient (ICC_agreement) = 0.64, standard error of measurement (SEM_agreement) = 2.92, and smallest detectable change (SDC_agreement) = 8.1) and within the inter-rater subgroup (n = 10) (ICC_agreement = 0.63, SEM_agreement = 3.7, and SDC_agreement = 10.26) indicates insufficient reliability.

Conclusion

The Dutch version of the ped-mTNS appears to have good construct validity for assessing VIPN in a Dutch pediatric oncology population, whereas reliability appears to be insufficient and measurement error high. To improve standardization of VIPN assessment in children, future research aimed at evaluating and further optimizing the psychometric characteristics of the ped-mTNS is needed.

Electronic supplementary material

The online version of this article (10.1007/s00520-019-05106-3) contains supplementary material, which is available to authorized users.

Chemotherapy-induced peripheral neurotoxicity: A multifaceted, still unsolved issue

Chemotherapy-induced peripheral neurotoxicity (CIPN) is a potentially dose-limiting side effect of several commonly used cytotoxic chemotherapy agents. The main pharmacological classes that may cause CIPN include classical anticancer drugs, as well as the recently introduced immune checkpoint inhibitors and antibody drug conjugates. The absence of a complete knowledge of CIPN pathophysiology is only one of the several unsolved issues related to CIPN. Among some of the most relevant aspects of CIPN deserving further attention include the real number of patients exposed to the risk of CIPN, the long-term impact on cancer survivors' quality of life due to incomplete recovery from CIPN, the economic burden related to acute and chronic CIPN, and the different perspective and education of the healthcare specialists in charge of managing patients with CIPN. Overall, CIPN remains a very challenging area of research as there are still several unresolved issues to be addressed in the future. In this special issue, the multifaceted profile of CIPN will be presented, with particular emphasis on bolstering the need to develop more optimized outcome measures than the existing ones to accurately evaluate the extent of CIPN, but also to ascertain the differences in the incidence, risk factors, clinical phenotype, and management of CIPN, according to the most commonly used neurotoxic chemotherapy classes. Perspectives for future research to pursue in order to cover the gaps in knowledge in the CIPN field will also be discussed.

Switching to Bortezomib may Improve Recovery From Severe Vincristine Neuropathy in Pediatric Acute Lymphoblastic Leukemia

PURPOSE

The purpose of this study was to evaluate the impact of switching patients being treated for acute lymphoblastic leukemia (ALL) from vincristine to bortezomib.

PATIENTS AND METHODS

A total of 20 patients with ALL were switched from vincristine to bortezomib (1.3 mg/m/dose) because of worsening neuropathy despite physical therapy interventions (n=18) or at increased risk of neuropathy (n=2). Relapse rates were compared with 56 vincristine-only patients matched by prognostic factors. Maintenance blood counts in bortezomib patients were compared with cooperative group data using vincristine during maintenance. In addition, 6 evaluable patients were assessed for neuropathy using the pediatric-modified total neuropathy score. Neuropathy scores were collected during treatment with vincristine and after switching to bortezomib.

RESULTS

After a median follow-up of 3.5 years the relapse rate in patients switched to bortezomib was nonsignificantly different than those remaining on vincristine. Patients on monthly bortezomib had statistically significantly lower platelet counts that did not require transfusions or dose adjustment. Total neuropathy for all 6 cases decreased significantly when switched to bortezomib from vincristine (P=0.015), with motor neuropathy declines in 5 of 6 subjects.

CONCLUSIONS

Bortezomib substitution for vincristine in ALL treatment is a potential strategy to mitigate severe vincristine neuropathy. These findings should be confirmed in a randomized clinical trial to further assess benefits and risks of this approach.

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.

Cancer Chemotherapy in Early Life Significantly Alters the Maturation of Pain Processing

Advances in pediatric cancer treatment have led to a ten year survival rate greater than 75%. Platinum-based chemotherapies (e.g. cisplatin) induce peripheral sensory neuropathy in adult and pediatric cancer patients. The period from birth through to adulthood represents a period of maturation within nociceptive systems. Here we investigated how cisplatin impacts upon postnatal maturation of nociceptive systems. Neonatal Wistar rats (Postnatal day (P) 7) were injected (i.p.) daily with either vehicle (PBS) or cisplatin (1mg/kg) for five consecutive days. Neither group developed mechanical or thermal hypersensitivity immediately during or after treatment. At P22 the cisplatin group developed mechanical (P < 0.05) and thermal (P < 0.0001) hypersensitivity versus vehicle group. Total DRG or dorsal horn neuronal number did not differ at P45, however there was an increase in intraepidermal nerve fiber density in cisplatin-treated animals at this age. The percentage of IB4+ve, CGRP+ve and NF200+ve DRG neurons was not different between groups at P45. There was an increase in TrkA+ve DRG neurons in the cisplatin group at P45, in addition to increased TrkA, NF200 and vGLUT2 immunoreactivity in the lumbar dorsal horn versus controls. These data highlight the impact pediatric cancer chemotherapy has upon the maturation of pain pathways and later life pain experience.

Vincristine-associated Neuropathy With Antifungal Usage: A Kaiser Northern California Experience

The dose-limiting toxicity for vincristine is peripheral neuropathy which can be potentiated with concurrent usage of azole antifungals. The current retrospective study assessed the incidence of concurrent vincristine and azole antifungal usage to determine if it led to increased neurotoxicity for the Kaiser Northern California pediatric acute lymphoblastic leukemia (ALL) and Hodgkin lymphoma patient population. Data were obtained from the electronic medical record (2007 to 2014). In total, 130 subjects received at least one dose of vincristine for ALL or Hodgkin lymphoma (median age 9, 88% ALL, 58% male, 47% Caucasian). Thirty one percent of patients received concurrent antifungal usage (fluconazole, 78%; voriconazole, 10%; fluconazole/voriconazole, 12%); however, concurrent antifungal usage accounted for <15% of vincristine doses. Grade 2 or greater neuropathy occurred in 51% of patients; grade 3 neuropathy was present in 8% of patients. No difference in the incidence of grade 2 or greater neuropathy was observed with the concurrent use of antifungal therapy (P=0.35), sex (P=0.59), type of cancer (P=0.41), ethnicity (P=0.29), or age (P=0.39), but was higher with increasing amount of vincristine doses (P=0.004). These results suggest that concurrent azole antifungal usage with vincristine for patients with ALL and Hodgkin lymphoma was low in the Kaiser Northern California population and limited usage as needed may be reasonable and safe.

Small-fiber neuropathy and pain sensitization in survivors of pediatric acute lymphoblastic leukemia

BACKGROUND

Chemotherapy-induced Peripheral Neuropathy (CIPN) of large-fibers affects up to 20% of survivors of pediatric acute lymphoblastic leukemia (ALL). We aimed to describe small-fiber toxicity and pain sensitization in this group.

METHODS

In a cross-sectional, bicentric study we assessed 46 survivors of pediatric ALL (Mean age: 5.7 ± 3.5 years at diagnosis, median 2.5 years after therapy; males: 28).

INCLUSION CRITERIA

≥6 years of age, ≥3 months after last administration of Vincristine, and cumulative dose of Vincristine 12 mg/m². We used a reduced version of the Pediatric-modified Total Neuropathy Score (Ped-mTNS) as bedside test and Quantitative Sensory Testing (QST) for assessment of small- and large-fiber neuropathy as well as pain sensitization. We employed Nerve Conduction Studies (NCS) as the most accurate tool for detecting large-fiber neuropathy.

RESULTS

Fifteen survivors (33%) had abnormal rPed-mTNS values (≥4 points) and 5 survivors (11%) reported pain. In QST, the survivor group showed significant (p < 0.001) inferior large-fiber function and pain sensitization when compared to healthy matched peers. We identified deficits of vibration in 33 (72%) and tactile hypoesthesia in 29 (63%), hyperalgesia to blunt pressure in 19 (41%), increased mechanical pain sensitivity in 12 (26%) and allodynia in 16 (35%) of 46 survivors. Only 7 survivors (15%) had pathologic NCS.

CONCLUSION

QST is a sensitive tool that revealed signs of large-fiber neuropathy in two thirds, small-fiber neuropathy and pain sensitization in one third of survivors. Prospective studies using QST in pediatric oncology may help to elucidate the pathophysiology of small-fiber neuropathy and pain sensitization as well as their relevance for quality of survival.

Assessment Tools for Peripheral Neuropathy in Pediatric Oncology: A Systematic Review From the Children's Oncology Group

Peripheral neuropathy is a known side effect of several chemotherapy agents, including vinca alkaloids and platinum-based chemotherapy. Early recognition and monitoring of this side effect is an important role of the pediatric oncology nurse. There are a variety of peripheral neuropathy assessment tools currently in use, but the usefulness of these tools in identifying and grading neuropathy in children varies, and there is currently no standardized tool in place to evaluate peripheral neuropathy in pediatric oncology. A systematic review was performed to identify the peripheral neuropathy assessment tools that best evaluate the early onset and progression of peripheral neuropathy in pediatric patients receiving vincristine. Because of the limited information available in pediatric oncology, this review was extended to any pediatric patient with neuropathy. A total of 8 studies were included in the evidence synthesis. Based on available evidence, the pediatric-modified Total Neuropathy Scale (ped-m TNS) and the Total Neuropathy Score-pediatric version (TNS-PV) are recommended for the assessment of vincristine-induced peripheral neuropathy in children 6 years of age and older. In addition, several studies demonstrated that subjective symptoms alone are not adequate to assess for vincristine-induced peripheral neuropathy. Nursing assessment of peripheral neuropathy should be an integral and regular part of patient care throughout the course of chemotherapy treatment.

Vincristine-induced neuropathy in pediatric patients with acute lymphoblastic leukemia in Oman: Frequent autonomic and more severe cranial nerve involvement

BACKGROUND

Vincristine (VCR) induced peripheral neuropathy is a common complication in children with acute lymphoblastic leukemia (ALL).

PROCEDURES

A retrospective data analysis over an interval of 10 years (2006-2016) of all children with ALL seen at Sultan Qaboos University Hospital was carried out. Electronic medical records of eligible patients were reviewed. Patients with clinical evidence of neuropathy and abnormal nerve conduction studies (NCSs) were included in the study.

RESULTS

Nineteen (nine females and 10 males) out of 103 pediatric patients developed VCR-related neuropathy, and their age ranged between 2.5 and 14 years. Symptoms started after 2-11 doses of VCR. All 19 patients had documented peripheral neuropathy on NCSs. The autonomic nervous system and cranial nerves affection was relatively common in our patients; two presented with bradycardia, two patients with unexplained tachycardia, and five had abdominal pain and constipation, complicated by typhlitis in two patients. One patient developed unilateral hearing loss. Two patients developed severe life-threatening cranial nerve involvement with bilateral ptosis and recurrent laryngeal nerve involvement presented as vocal cord paralysis, hoarseness of voice, frequent chocking, and aspiration episodes.

CONCLUSIONS

Peripheral neuropathy was the commonest form of VCR-related neuropathy. Autonomic neuropathy was relatively common in our patients. Cranial neuropathy is a serious side effect of VCR that can be severe, involving multiple cranial nerves and needs prompt recognition and management. Concomitant administration of pyridoxine and pyridostigmine does not seem to protect against further neurological damage in some patients.

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.

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.

Patient-reported neuropathic pain in adolescent and young adult cancer patients

BACKGROUND

Neuropathic pain, a known complication of cancer and its treatments, negatively impacts quality of life. There are limited data using screening tools to aid in the diagnosis of neuropathic pain in cancer patients. Our primary objective was to determine the proportion of adolescent and young adult cancer patients reporting neuropathic pain on a patient-completed, neuropathic pain screening tool.

PROCEDURES

This prospective, cohort study enrolled patients 14-39 years of age who were receiving therapy for primary cancer diagnosis, cancer relapse, or had recently completed treatment. The painDETECT, a patient-completed, neuropathic pain screening tool used down to age 14, was administered a maximum of three times in on-therapy patients and once in off-therapy patients. Provider documentation of neuropathic pain at the corresponding visit was abstracted from the medical record.

RESULTS

Seventy-eight patients participated. Median (interquartile range) age at study enrollment was 18.1 (16-19.4) years and 47% were female. Cancer diagnoses included 41% leukemia, 26% solid tumor, 23% lymphoma, and 10% central nervous system tumor. The proportion of patients reporting neuropathic pain was 26% (95% confidence interval [CI] 16-40%) in on-therapy patients and 11% (95% CI 3-27%) in off-therapy patients. In patients reporting neuropathic pain, only 26% had a clinical diagnosis of neuropathic pain documented in the medical record at the corresponding visit.

CONCLUSIONS

Neuropathic pain occurs in one in four adolescents and young adults receiving cancer therapy. Use of screening tools may increase the detection of neuropathic pain in adolescents and young adults receiving cancer therapy and could ultimately improve pain treatment.

Short-term recovery of chemotherapy-induced peripheral neuropathy after treatment for pediatric non-CNS cancer

PURPOSE

Chemotherapy-induced peripheral neuropathy (CIPN) is a frequent side effect of pediatric cancer treatment. The presentation of CIPN, trajectory and completeness of recovery over the first 6 months postchemotherapy, and the influence of patient and treatment characteristics on recovery are described.

PATIENTS AND METHODS

Sixty-seven children and adolescents treated for non-CNS cancers were evaluated for CIPN using the pediatric modified total neuropathy score (ped-mTNS) while on treatment and 3 and 6 months postchemotherapy. Differences between diagnostic groups and treatment type were evaluated as well as change in scores over time. Risk factors for on-treatment and persistent CIPN at 6 months were identified.

RESULTS

Overall, ped-mTNSs were in the abnormal range for 86.5% during treatment and scores decreased over time (initial 9.3 ± 0.6, 6 months 4.3 ± 0.4; F = 38.14, P < 0.001). By 6 months posttreatment, mean scores and percentage of children with abnormal scores were reduced to 2.4 ± 0.3 and 11.5%, respectively, in the ALL group, but remained higher at 5.7 ± 0.7 and 57%, respectively, for lymphoma, and 5.2 ± 1.0 and 60%, respectively, for other solid tumors. At 6 months posttreatment, light touch deficits and foot strength deficits remained in 19.4 and 59.7%, respectively, compared with only 4.9 and 9.8% of the control population. Subjects who were older at exposure, female, or who received etoposide in addition to vincristine were at higher risk for on-treatment CIPN. On-treatment sensory abnormalities were associated with increased risk of persistent CIPN.

CONCLUSION

While CIPN improves in most pediatric patients, significant numbers, especially those treated for lymphoma or other solid tumors, have remaining neuropathic signs and symptoms 6 months posttreatment.

Glutamine for the treatment of vincristine-induced neuropathy in children and adolescents with cancer

BACKGROUND

Vincristine is an integral treatment component of many childhood tumors with potentially dose-limiting sensory and/or motor neuropathy. Results from a pilot study on the incidence of vincristine-induced peripheral neuropathy (VIPN) as well as the efficacy and safety of glutamine in reducing signs and symptoms of VIPN in children with cancer are presented.

METHODS

Fifty-six patients between the ages of 5-21 with newly diagnosed leukemia, lymphoma, extracranial solid tumor or medulloblastoma and expected to receive a minimum cumulative dose of 6 mg/m² of vincristine over a 30-week period were eligible. Patients' neurological functioning was monitored every 3 weeks using clinical history, exam, and assessment of motor functioning. Upon identification of neuropathy, patients were randomized to either glutamine (6 g/m² per dose twice daily, maximum 10 g/dose) or placebo for a 3-week period followed by 3-week wash out period (Time 3).

RESULTS

Forty-nine patients were fully evaluable and 100 % developed neuropathy per study definitions. No significant differences in demographics or side effects were noted between the randomized groups. The distribution of sensory neuropathy scores between the two groups was statistically significant after the intervention (p = 0.022). Children receiving glutamine also rated their quality of life (QoL) as 8.42 points higher on the PedsQL total score than those receiving placebo (p = 0.031).

CONCLUSIONS

Glutamine supplementation is well tolerated and associated with improvements in sensory function and self-reported overall quality of life. Future studies are warranted to confirm the efficacy of glutamine for the treatment of vincristine-related sensory neuropathy in pediatric cancer patients.

Challenges Evaluating Chemotherapy-Induced Peripheral Neuropathy in Childhood Cancer Survivors

Children treated for cancer are exposed to a variety of chemotherapeutic agents with known toxicity to the peripheral nervous system. The side effect of peripheral neuropathy can cause changes in sensation, function, and even cause pain. Although peripheral neuropathy is recognized by pediatric oncology nurses as an important and significant side effect, measuring neuropathy can be quite complex for clinical care and research efforts. With more children surviving a cancer diagnosis today, this issue is increasingly important for childhood cancer survivors. This article has reviewed existing literature examining peripheral neuropathy in childhood cancer survivors with particular interest paid to measurement tools available and needs for future research. It is important for nurses to choose appropriate measures for clinical care and research methods in order to have an impact on patients experiencing this condition.

A systematic review of patient-reported outcome measures of neuropathy in children, adolescents and young adults

PURPOSE

Peripheral neuropathy is an important, yet poorly studied, side effect of pediatric cancer treatment. There are many measures of patient-reported peripheral neuropathy in adults but very few in children. We aimed to systematically review and summarize reliable and valid patient-reported peripheral neuropathy scales used in pediatrics.

METHODS

Four major electronic databases (Medline, Embase, EBSCO Host in Cumulative Index to Nursing and Allied Health Literature, and PsycINFO) were reviewed for studies that measured peripheral neuropathy in pediatric patients. Studies eligible for inclusion were those that described use of any patient-reported scale of peripheral neuropathy among children, adolescents, and young adults with any underlying diagnosis (not limited to cancer).

RESULTS

From a total of 765 articles retrieved, 5 met eligibility criteria and were included. One was a neuropathy symptom score used in patients with diabetes, and the remaining four were in oncology patients and all were based on the total neuropathy score. All involved objective assessments conducted by trained professionals; none relied purely on patient report.

CONCLUSIONS

There are no validated instruments that consist solely of a patient-reported outcome measure of neuropathy in pediatrics and adolescents. Because the clinical evaluation of neuropathy requires specialized training, it is not generalizable in large studies conducted in many diverse institutions. Future studies should validate adult patient-reported neuropathy scales in pediatric and adolescent populations, or develop novel instruments designed for this population.

Patterns and severity of vincristine-induced peripheral neuropathy in children with acute lymphoblastic leukemia

Vincristine, a critical component of combination chemotherapy treatment for pediatric acute lymphoblastic leukemia (ALL), can lead to vincristine-induced peripheral neuropathy (VIPN). Longitudinal VIPN assessments were obtained over 12 months from newly diagnosed children with ALL (N = 128) aged 1-18 years who received vincristine at one of four academic children's hospitals. VIPN assessments were obtained using the Total Neuropathy Score-Pediatric Vincristine (TNS©-PV), National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE©), Balis© grading scale, and Pediatric Neuropathic Pain Scale©-Five (PNPS©-5). Of children who provided a full TNS©-PV score, 85/109 (78%) developed VIPN (TNS©-PV ≥4). Mean TNS©-PV, grading scale, and pain scores were low. CTCAE©-derived grades 3 and 4 sensory and motor VIPN occurred in 1.6%/0%, and 1.9%/0% of subjects, respectively. VIPN did not resolve in months 8-12 despite decreasing dose density. VIPN was worse in older children. Partition cluster analysis revealed 2-3 patient clusters; one cluster (n = 14) experienced severe VIPN. In this population, VIPN occurs more commonly than previous research suggests, persists throughout the first year of treatment, and can be severe.

Gait Patterns in Children With Cancer and Vincristine Neuropathy

PURPOSE

Children treated with vincristine often develop chemotherapy-induced peripheral neuropathy (CIPN), but effects of CIPN on gait have not been reported.

METHODS

Gait variables of 52 children/adolescents treated for non-central nervous system cancers with CIPN were compared with an age- and sex-matched control group. Gait data were collected via GaitRite walkway before and after completing a 6-minute walk test (6MWT). Ankle range-of-motion (ROM) measures, balance, and strength tests were also completed.

RESULTS

Participants with CIPN had decreased velocity and step length. Ankle ROM and balance explained variability in step length. Both groups increased self-selected velocity after the 6MWT, but participants with cancer walked with slower velocity, shorter step length, and decreased cadence. Strength, neuropathy, and self-selected velocity measured before the 6MWT explained variability in 6MWT scores.

CONCLUSIONS

Ankle ROM and balance are important factors when treating step length deficits, whereas strength is also an important consideration for walking capacity.

Neurotoxic Effects of Platinum Compounds: Studies in vivo on Intracellular Calcium Homeostasis in the Immature Central Nervous System

Platinum compounds cause significant clinical neurotoxicity. Several studies highlight neurological complications especially in paediatric oncology patients with Central Nervous System (CNS) and non-CNS malignancies. To understand the toxicity mechanisms of platinum drugs at cellular and molecular levels in the immature brain, which appears more vulnerable to injury than in the adult one, we compared the effects in vivo of the most used platinum compounds, i.e., cisdichlorodiammineplatinum (cisplatin, cisPt), and the new [Pt(O,O′-acac)(γ-acac)(DMS)] (PtAcacDMS). As models of developing brain areas, we have chosen the cerebellum and hippocampus dentate gyrus. Both areas show the neurogenesis events, from proliferation to differentiation and synaptogenesis, and therefore allow comparing the action of platinum compounds with DNA and non-DNA targets. Here, we focused on the changes in the intracellular calcium homeostasis within CNS architecture, using two immunohistochemical markers, the calcium buffer protein Calbindin and Plasma Membrane Calcium ATPase. From the comparison of the cisPt and PtAcacDMS effects, it emerges how essential the equilibrium and synergy between CB and PMCA1 is or how important the presence of at least one of them is to warrant the morphology and function of nervous tissue and limit neuroarchitecture damages, depending on the peculiar and intrinsic properties of the developing CNS areas.

Targeting DNA repair pathways for cancer treatment: what's new?

Disruptions in DNA repair pathways predispose cells to accumulating DNA damage. A growing body of evidence indicates that tumors accumulate progressively more mutations in DNA repair proteins as cancers progress. DNA repair mechanisms greatly affect the response to cytotoxic treatments, so understanding those mechanisms and finding ways to turn dysregulated repair processes against themselves to induce tumor death is the goal of all DNA repair inhibition efforts. Inhibition may be direct or indirect. This burgeoning field of research is replete with promise and challenge, as more intricacies of each repair pathway are discovered. In an era of increasing concern about healthcare costs, use of DNA repair inhibitors can prove to be highly effective stewardship of R&D resources and patient expenses.