Measuring vincristine-induced peripheral neuropathy in children with acute lymphoblastic leukemia

Severe Vincristine-Induced Peripheral Neuropathic Weakness in Both Lower Limbs in an Asian Adolescent with CYP3A4 rs2740574 TT Genotype

Background

Vincristine (VCR)-induced peripheral neuropathy (VIPN) is a common adverse reaction during cancer treatment, typically characterized by numbness and paresthesias. This study aimed to report a rare case of VIPN with an atypical genotype, manifesting as grade 3 weakness of the lower limbs.

Case Presentation

A 19-year-old man, diagnosed with alveolar rhabdomyosarcoma for 8 months, was transferred to our hospital for further treatment after the failure of first-line treatment. He developed severe long-standing weakness in both lower limbs and could not walk after four sessions of second-line chemotherapy. The diagnosis of VIPN was confirmed based on the patient's physical examination, imaging studies, electromyogram results, and treatment history. Furthermore, the pharmacogenetic analysis indicated that the patient harbored CYP3A4 rs2740574 TT genotypes.

Conclusion

We have reported for the first time a VIPN patient whose main clinical manifestation is severe weakness in both lower limbs, accompanied by the CYP3A4 rs2740574 TT phenotype. This case may provide new information on the phenotypic features of VIPN, and may help to better understand the disease pathogenesis and contributing factors.

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.

Vincristine Disposition and Neurotoxicity Are Unchanged in Humanized CYP3A5 Mice

Previous studies have suggested that the incidence of vincristine-induced peripheral neuropathy (VIPN) is potentially linked with cytochrome P450 (CYP)3A5, a polymorphic enzyme that metabolizes vincristine in vitro, and with concurrent use of azole antifungals such as ketoconazole. The assumed mechanism for these interactions is through modulation of CYP3A-mediated metabolism, leading to decreased vincristine clearance and increased susceptibility to VIPN. Given the controversy surrounding the contribution of these mechanisms, we directly tested these hypotheses in genetically engineered mouse models with a deficiency of the entire murine Cyp3a locus [Cyp3a(-/-) mice] and in humanized transgenic animals with hepatic expression of functional and nonfunctional human CYP3A5 variants. Compared with wild-type mice, the systemic exposure to vincristine was increased by only 1.15-fold (95% confidence interval, 0.84-1.58) in Cyp3a(-/-) mice, suggesting that the clearance of vincristine in mice is largely independent of hepatic Cyp3a function. In line with these observations, we found that Cyp3a deficiency or pretreatment with the CYP3A inhibitors ketoconazole or nilotinib did not influence the severity and time course of VIPN and that exposure to vincristine was not substantially altered in humanized CYP3A5*3 mice or humanized CYP3A5*1 mice compared with Cyp3a(-/-) mice. Our study suggests that the contribution of CYP3A5-mediated metabolism to vincristine elimination and the associated drug-drug interaction potential is limited and that plasma levels of vincristine are unlikely to be strongly predictive of VIPN. SIGNIFICANCE STATEMENT: The current study suggests that CYP3A5 genotype status does not substantially influence vincristine disposition and neurotoxicity in translationally relevant murine models. These findings raise concerns about the causality of previously reported relationships between variant CYP3A5 genotypes or concomitant azole use with the incidence of vincristine neurotoxicity.

Performance of the FACT-GOG-Ntx to assess chemotherapy-induced peripheral neuropathy (CIPN) in pediatric high risk Hodgkin lymphoma: report from the Children's Oncology Group AHOD 1331 study

BACKGROUND

Chemotherapy-induced peripheral neuropathy (CIPN) is an under-recognized complication of several chemotherapy agents used as part of curative-intent therapy for Hodgkin Lymphoma (HL). In the absence of validated self- or proxy-report measures for children and adolescents, CIPN reporting has relied on clinician rating, with grading scales often restricted to severe manifestations. In a proof-of-concept study, we assessed the feasibility and psychometric performance of the Functional Assessment of Cancer Therapy-Gynecologic Oncology Group-Neurotoxicity (FACT-GOG-Ntx), a unidimensional CIPN symptom scale widely used adults with CIPN, in pediatric HL at risk for CIPN.

METHODS

Youth (11+ years) and parents of all children (5-17.9 years) with newly diagnosed high-risk HL enrolled on Children's Oncology Group AHOD1331 (NCT02166463) were invited to complete the FACT-GOG-Ntx and a health-related quality of life (HRQL) measure at pre-treatment (Time 1), and during cycles 2 (Time 2) and 5 (Time 3) of chemotherapy during the first half of study accrual. Clinical grading of CIPN by providers was also assessed using the Balis Pediatric Neuropathy Scale. We evaluated Cronbach's alpha, construct validity, and agreement between raters. Change in FACT-GOG-Ntx scores over time was assessed using a repeated measures model.

RESULTS

306 patients had at least one completed FACT-GOG-Ntx with time-specific completion rates of > 90% for both raters. Cronbach's alpha was > 0.7 for youth and parent-proxy report at all time points. Correlations between FACT-GOG-Ntx and HRQL scores were moderate (0.41-0.48) for youth and parent-proxy raters across all times. Youth and parent-proxy raters both reported worse FACT-GOG-Ntx scores at Time 3 for those who had clinically-reported CIPN compared to those who did not. Agreement between raters was moderate to high. Compared to baseline scores, those at Time 3 were significantly lower for youth (β = - 2.83, p < 0.001) and parent-proxy raters (β = - 1.99, p < 0.001).

CONCLUSIONS

High completion rates at all time points indicated feasibility of eliciting youth and parent report. Psychometric performance of the FACT-GOG-Ntx revealed acceptable reliability, evidence of validity, and strong inter-rater agreement, supporting the use of this self- or proxy-reported measure of CIPN in youth with high-risk HL exposed to tubulin inhibitors, as part of a Phase 3 clinical trial.

CLINICAL TRIAL INFORMATION

Clinical Trials Registry, NCT02166463. Registered 18 June 2014, https://clinicaltrials.gov/ct2/show/study/NCT02166463.

Assessment of proxy-reported responses as predictors of motor and sensory peripheral neuropathy in children with B-lymphoblastic leukemia

Chemotherapy-induced peripheral neuropathy (CIPN), a common condition in children with acute lymphoblastic leukemia, can be challenging to diagnose. Using data from Children's Oncology Group AALL0932 physical function study, we sought to determine if parent/guardian proxy-reported responses from the Pediatric Outcomes Data Collection Instrument could identify children with motor or sensory CIPN diagnosed by physical/occupational therapists (PT/OT). Four variables moderately discriminated between children with and without motor CIPN (c-index 0.76, 95% confidence interval [CI]: 0.64-0.84), but sensory and optimism-corrected models had weak discrimination (c-index sensory models 0.65, 95% CI: 0.54-0.74). New proxy-report measures are needed to identify children with PT/OT diagnosed CIPN.

Vincristine Side Effects With Concomitant Fluconazole Use During Induction Chemotherapy in Pediatric Acute Lymphoblastic Leukemia

As a mainstay of treatment for acute lymphoblastic leukemia (ALL), vincristine's side effect profile is well known. Parallel administration of the antifungal fluconazole has been shown to interfere with the metabolism of vincristine, potentially resulting in increased side effects. We conducted a retrospective chart review to determine whether concomitant administration of vincristine and fluconazole during pediatric ALL induction therapy impacted the frequency of vincristine side effects, namely, hyponatremia and peripheral neuropathy. We also evaluated whether the incidence of opportunistic fungal infections was impacted by fluconazole prophylaxis. Medical charts of all pediatric ALL patients treated with induction chemotherapy at Children's Hospital and Medical Center in Omaha, NE, from 2013 to 2021 were retrospectively reviewed. Fluconazole prophylaxis did not significantly impact the rate of fungal infections. We found no correlation between fluconazole use and increased incidence of hyponatremia or peripheral neuropathy, which supports the safety of fungal prophylaxis with fluconazole during pediatric ALL induction therapy.

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.

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.

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.

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.

The Development of New Methodology for Determination of Vincristine (VCR) in Human Serum Using LC-MS/MS-Based Method for Medical Diagnostics

In this article, we have presented the development and validation of a rapid and sensitive reversed-phase liquid chromatography with tandem mass spectrometry (LC-MS/MS) method for the determination of vincristine (VCR) in patient serum samples. Chromatographic separation was achieved on a Kinetex® (Singapore) column using a mobile phase consisting of 25 mM acetic acid and 0.3% formic acid (A) and methanol (B) in a gradient elution mode at a flow rate of 0.3 mL/min. The VCR and internal standard (vinblastine) were monitored using the multiple reaction monitoring mode under positive electrospray ionization. The lower limit of quantification (LLOQ) was 0.67 ng/mL, and the upper limit of quantification (ULOQ) was 250 ng/mL for VCR. The calculated values of LOD and LOQ for VCR were 0.075 and 0.228 ng/mL, respectively. The calibration curve was linear over the VCR concentration range of 1.0−250 ng/mL in serum. The intra- and inter-day precision and precision were within the generally accepted criteria for the bioanalytical method (<15%). The method was successfully applied to the analysis of serum samples in clinical practice.

Brentuximab Vedotin with Chemotherapy in Pediatric High-Risk Hodgkin's Lymphoma

BACKGROUND

In adults with advanced-stage Hodgkin's lymphoma, the CD30-directed antibody-drug conjugate brentuximab vedotin combined with multiagent chemotherapy has been shown to have greater efficacy, but also more toxic effects, than chemotherapy alone. The efficacy of this targeted therapy approach in children and adolescents with Hodgkin's lymphoma is unclear.

METHODS

We conducted an open-label, multicenter, randomized, phase 3 trial involving patients 2 to 21 years of age with previously untreated Hodgkin's lymphoma of stage IIB with bulk tumor or stage IIIB, IVA, or IVB. Patients were assigned to receive five 21-day cycles of brentuximab vedotin with doxorubicin, vincristine, etoposide, prednisone, and cyclophosphamide (brentuximab vedotin group) or the standard pediatric regimen of doxorubicin, bleomycin, vincristine, etoposide, prednisone, and cyclophosphamide (standard-care group). Slow-responding lesions, defined by a score of 4 or 5 (on a 5-point scale, with scores of 1 to 3 indicating rapid-responding lesions), were identified on centrally reviewed positron-emission tomography-computed tomography after two cycles. Involved-site radiation therapy was administered after the fifth cycle of therapy to slow-responding lesions and to large mediastinal adenopathy that was present at diagnosis. The primary end point was event-free survival, defined as the time until disease progression occurred, relapse occurred, a second malignant neoplasm developed, or the patient died. Safety and overall survival were assessed.

RESULTS

Of 600 patients who were enrolled across 153 institutions, 587 were eligible. At a median follow-up of 42.1 months (range, 0.1 to 80.9), the 3-year event-free survival was 92.1% (95% confidence interval [CI], 88.4 to 94.7) in the brentuximab vedotin group, as compared with 82.5% (95% CI, 77.4 to 86.5) in the standard-care group (hazard ratio for event or death, 0.41; 95% CI, 0.25 to 0.67; P<0.001). The percentage of patients who received involved-site radiation therapy did not differ substantially between the brentuximab vedotin group and the standard-care group (53.4% and 56.8%, respectively). Toxic effects were similar in the two groups. Overall survival at 3 years was 99.3% (95% CI, 97.3 to 99.8) in the brentuximab vedotin group and 98.5% (95% CI, 96.0 to 99.4) in the standard-care group.

CONCLUSIONS

The addition of brentuximab vedotin to standard chemotherapy resulted in superior efficacy, with a 59% lower risk of an event or death, and no increase in the incidence of toxic effects at 3 years. (Funded by the National Institutes of Health and others; AHOD1331 ClinicalTrials.gov number, NCT02166463.).

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.

Gross motor disorders in pediatric patients with acute lymphoblastic leukemia and survivors: A systematic review

Acute Lymphoblastic Leukemia (ALL) is the most common cancer in children and toxicities related to treatment are common. One of these adverse effects is related to the musculoskeletal system and especially to gross motor skills that allow body movements: walking, running, jumping, and balance. This systematic review aims to describe gross motor impairments in pediatric patients with ALL during and after chemotherapeutic treatment and to identify the most commonly used tools for their assessment. Multiple electronic databases were searched for observational studies describing gross motor skills in children with ALL and the assessment tool used. The STROBE checklist was used to assess the reporting quality of each study. Ten studies were included in this review with assessments of gross motor skills in children with ALL undergoing treatment and survivors. Evidence suggests impairments in the performance of daily life activities during intensification and maintenance and persists up to 5 to 6 years after treatment´s cessation. Balance problems are noted at the start of treatment when the cumulative dose of vincristine is low and, in the survivors, it was the most reported alteration. These skills are essential for an adequate performance of children in daily life activities, recreation and leisure. We emphasize the need to assess gross motor skills and implement interventions that include physiotherapy and occupational rehabilitation in children with ALL.

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.

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.

Pharmacogenomics of Vincristine-Induced Peripheral Neuropathy in Children with Cancer: A Systematic Review and Meta-Analysis

Simple Summary

Vincristine is a drug that is part of the treatment for many children with cancer. Its main side-effect is vincristine-induced peripheral neuropathy (VIPN), which often presents as tingling, pain, and lack of strength in the hands and feet. It is not yet possible to predict which children will suffer from VIPN. In this review, we report on all genetic variations that are associated with VIPN. We found that variations in genes related to vincristine transport, cell structure, hereditary nerve disease, and genes without a previously known connection to vincristine or VIPN are related to VIPN. Variations in genes involved in vincristine breakdown are not significantly associated with VIPN. In conclusion, genetic variations affect a child’s tendency to develop VIPN. In the future, this information might be used to predict the risk of VIPN and adapt treatment on this.

Abstract

Vincristine-induced peripheral neuropathy (VIPN) is a debilitating side-effect of vincristine. It remains a challenge to predict which patients will suffer from VIPN. Pharmacogenomics may explain an individuals’ susceptibility to side-effects. In this systematic review and meta-analysis, we describe the influence of pharmacogenomic parameters on the development of VIPN in children with cancer. PubMed, Embase and Web of Science were searched. In total, 1597 records were identified and 21 studies were included. A random-effects meta-analysis was performed for the influence of CYP3A5 expression on the development of VIPN. Single-nucleotide polymorphisms (SNPs) in transporter-, metabolism-, cytoskeleton-, and hereditary neuropathy-associated genes and SNPs in genes previously unrelated to vincristine or neuropathy were associated with VIPN. CYP3A5 expression status was not significantly associated with VIPN. The comparison and interpretation of the results of the included studies was limited due to heterogeneity in the study population, treatment protocol and assessment methods and definitions of VIPN. Independent replication is essential to validate the clinical significance of the reported associations. Future research should aim for prospective VIPN assessment in both a discovery and a replication cohort. Ultimately, the goal would be to screen patients upfront to determine optimal vincristine dosage with regards to efficacy and risk of VIPN.

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.

Longitudinal Evaluation of Neuromuscular Dysfunction in Long-term Survivors of Childhood Cancer: A Report from the Childhood Cancer Survivor Study

BACKGROUND

Children treated for cancer are at risk for neuromuscular dysfunction, but data are limited regarding prevalence, longitudinal patterns, and long-term impact.

METHODS

Longitudinal surveys from 25,583 childhood cancer survivors ≥5 years from diagnosis and 5,044 siblings from the Childhood Cancer Survivor Study were used to estimate the prevalence and cumulative incidence of neuromuscular dysfunction. Multivariable models adjusted for age, sex, race, and ethnicity estimated prevalence ratios (PR) of neuromuscular dysfunction in survivors compared with siblings, and associations with treatments and late health/socioeconomic outcomes.

RESULTS

Prevalence of neuromuscular dysfunction was 14.7% in survivors 5 years postdiagnosis versus 1.5% in siblings [PR, 9.9; 95% confidence interval (CI), 7.9-12.4], and highest in survivors of central nervous system (CNS) tumors (PR, 27.6; 95% CI, 22.1-34.6) and sarcomas (PR, 11.5; 95% CI, 9.1-14.5). Cumulative incidence rose to 24.3% in survivors 20 years postdiagnosis (95% CI, 23.8-24.8). Spinal radiotherapy and increasing cranial radiotherapy dose were associated with increased prevalence of neuromuscular dysfunction. Platinum exposure (vs. none) was associated with neuromuscular dysfunction (PR, 1.8; 95% CI, 1.5-2.1), even after excluding survivors with CNS tumors, cranial/spinal radiotherapy, or amputation. Neuromuscular dysfunction was associated with concurrent or later obesity (PR, 1.1; 95% CI, 1.1-1.2), anxiety (PR, 2.5; 95% CI, 2.2-2.9), depression (PR, 2.1; 95% CI, 1.9-2.3), and lower likelihood of graduating college (PR, 0.92; 95% CI, 0.90-0.94) and employment (PR, 0.8; 95% CI, 0.8-0.9).

CONCLUSIONS

Neuromuscular dysfunction is prevalent in childhood cancer survivors, continues to increase posttherapy, and is associated with adverse health and socioeconomic outcomes.

IMPACT

Interventions are needed to prevent and treat neuromuscular dysfunction, especially in survivors with platinum and radiation exposure.

Vincristine-Induced Peripheral Neuropathy (VIPN) in Pediatric Tumors: Mechanisms, Risk Factors, Strategies of Prevention and Treatment

Vincristine-induced peripheral neurotoxicity (VIPN) is a very common side effect of vincristine chemotherapy among pediatric patients with cancer. Neuropathy may be sensory, motor and/or autonomic, with consequent reduction, delay or discontinuation of vincristine-chemotherapy, but also pain, disability, reduced quality of life of patients and an increase in medical costs. Vincristine acts out its antineoplastic function by altering the normal assembly and disassembly of microtubules, with their consequent mitosis block and death. Vincristine leads to VIPN through a complex mechanism of damage, which occurs not only on the microtubules, but also on the endothelium and the mitochondria of nerve cells. Furthermore, both patient-related risk factors (age, race, ethnicity and genetic polymorphisms) and treatment-related risk factors (dose, time of infusion and drug–drug interactions) are involved in the pathogenesis of VIPN. There is a lack of consensus about the prophylaxis and treatment of VIPN among pediatric oncologic patients, despite several molecules (such as gabapentin, pyridoxine and pyridostigmine, glutamic acid and glutamine) having been already investigated in clinical trials. This review describes the molecular mechanisms of VIPN and analyzes the risk factors and the principal drugs adopted for the prophylaxis and treatment of VIPN in pediatric patients with cancer.

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.

Obesity as a Potential Risk Factor for Vincristine-induced Peripheral Neuropathy

Acute lymphoblastic leukemia (ALL) is the most common pediatric cancer. Vincristine is a core chemotherapeutic agent for patients with ALL; unfortunately, ∼78% will develop vincristine-induced peripheral neuropathy (VIPN). VIPN can result in vincristine dose reductions that decrease therapeutic efficacy: making it important to understand which children are at highest risk for VIPN. We hypothesized that pediatric ALL patients who were obese at diagnosis would develop worse VIPN than healthy weight children with ALL within the first year. Our results confirmed that obese pediatric patients have significantly (P=0.03) worse VIPN than patients of healthy weight.

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.

A Metabolomics Approach for Early Prediction of Vincristine-Induced Peripheral Neuropathy

Vincristine is a core chemotherapeutic drug administered to pediatric acute lymphoblastic leukemia patients. Despite its efficacy in treating leukemia, it can lead to severe peripheral neuropathy in a subgroup of the patients. Peripheral neuropathy is a debilitating and painful side-effect that can severely impact an individual’s quality of life. Currently, there are no established predictors of peripheral neuropathy incidence during the early stage of chemotherapeutic treatment. As a result, patients who are not susceptible to peripheral neuropathy may receive sub-therapeutic treatment due to an empirical upper cap on the dose, while others may experience severe neuropathy at the same dose. Contrary to previous genomics based approaches, we employed a metabolomics approach to identify small sets of metabolites that can be used to predict a patient’s susceptibility to peripheral neuropathy at different time points during the treatment. Using those identified metabolites, we developed a novel strategy to predict peripheral neuropathy and subsequently adjust the vincristine dose accordingly. In accordance with this novel strategy, we created a free user-friendly tool, VIPNp, for physicians to easily implement our prediction strategy. Our results showed that focusing on metabolites, which encompasses both genotypic and phenotypic variations, can enable early prediction of peripheral neuropathy in pediatric leukemia patients.

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.

Recent advances in understanding chemotherapy-induced peripheral neuropathy

Chemotherapy-induced peripheral neuropathy (CIPN) is a common cause of pain and poor quality of life for those undergoing treatment for cancer and those surviving cancer. Many advances have been made in the pre-clinical science; despite this, these findings have not been translated into novel preventative measures and treatments for CIPN. This review aims to give an update on the pre-clinical science, preventative measures, assessment and treatment of CIPN.

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.

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.

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.

Reducing pain in children with cancer: Methodology for the development of a clinical practice guideline

Although pain is one of the most prevalent and bothersome symptoms children with cancer experience, evidence-based guidance regarding assessment and management is lacking. With 44 international, multidisciplinary healthcare professionals and nine patient representatives, we aimed to develop a clinical practice guideline (following GRADE methodology), addressing assessment and pharmacological, psychological, and physical management of tumor-, treatment-, and procedure-related pain in children with cancer. In this paper, we present our thorough methodology for this development, including the challenges we faced and how we approached these. This lays the foundation for our clinical practice guideline, for which there is a high clinical demand.

Mechanisms, Predictors, and Challenges in Assessing and Managing Painful Chemotherapy-Induced Peripheral Neuropathy

OBJECTIVE

To describe the known predictors and pathophysiological mechanisms of chronic painful chemotherapy-induced peripheral neuropathy (CIPN) in cancer survivors and the challenges in assessing and managing it.

DATA SOURCES

PubMed/Medline, CINAHL, Scopus, and PsycINFO.

CONCLUSION

The research on chronic painful CIPN is limited. Additional research is needed to identify the predictors and pathophysiological mechanisms of chronic painful CIPN to inform the development of assessment tools and management options for this painful and possibly debilitating condition.

IMPLICATIONS FOR NURSING PRACTICE

Recognition of the predictors of chronic painful CIPN and proactive CIPN assessment and palliative management are important steps in reducing its impact on physical function and quality of life.

Neuropathic Pain in Pediatric Oncology: A Clinical Decision Algorithm

Neuropathic pain in pediatric oncology can be caused by distinct lesions or disease processes affecting the somatosensory system, including chemotherapy-related neuronal injury, solid tumor-related involvement of neural structures, post-surgical neuropathic pain-including phantom limb pain and pain after limb-sparing surgery-and the complex circumstances of neuropathic pain at the end of life. Treatment algorithms reflect the general treatment principles applied for adult neuropathic pain, but the dose regimens applied in children are modest and rarely escalated to the maximum doses to optimize analgesic efficacy. Pharmacological management of neuropathic pain should be based on a stepwise intervention strategy, as combinations of medications are the most effective approach. Gabapentinoids and tricyclic antidepressants are recommended as first-line therapy. Methadone, ketamine, and lidocaine may be useful adjuvants in selected patients. Prospective studies extended over a substantial length of time are recommended because of the nature of neuropathic pain as persistent, chronic pain and based on the need for sufficient time to escalate medication dose regimens to full analgesic efficacy.

Genetic Variants Associated With Vincristine-Induced Peripheral Neuropathy in Two Populations of Children With Acute Lymphoblastic Leukemia

Vincristine is one of the core chemotherapy agents used in the treatment of pediatric acute lymphoblastic leukemia (ALL). However, one of the major toxicities resulting from vincristine exposure is vincristine-induced peripheral neuropathy (VIPN). When VIPN results in significant morbidity, the vincristine dose may need to be reduced, thus potentially decreasing the effectiveness of treatment. To date, there are no robust biomarkers used clinically to determine which patients will be at risk for worse neuropathy. The current study included genomewide association study (GWAS) in two independent cohorts: Pediatric Oncology Group (POG) ALL trials and a multicenter study based at Indiana University in children with ALL. A meta-analysis of the cohorts identified two single-nucleotide polymorphisms (SNPs), rs1045644 and rs7963521, as being significantly (P value threshold 0.05/4749 = 1.05E-05) associated with neuropathy. Subsequently these SNPs may be effective biomarkers of VIPN in children with ALL.

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.

In Search of a Gold Standard Patient-Reported Outcome Measure for Use in Chemotherapy- Induced Peripheral Neuropathy Clinical Trials

Purpose:

To test a reduced version—CIPN15—of the European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Chemotherapy-Induced Peripheral Neuropathy scale (QLQ-CIPN20) to establish a possible gold-standard patient-reported outcome measure for chemotherapy-induced peripheral neuropathy (CIPN).

Methods:

Using a prospective, longitudinal, case–control design, patients (n = 121) receiving neurotoxic chemotherapy completed the CIPN15 at baseline and 12 weeks and underwent objective neurological assessment using the 5-item Total Neuropathy Score-Clinical (TNSc). Healthy controls (n = 30) completed the CIPN15 once. Structural validity was evaluated using factor analysis. Because a stable factor structure was not found, a sum score was used to evaluate measures of the CIPN15’s psychometric properties—reliability, validity, sensitivity, and responsiveness—as follows: internal consistency via Cronbach’s α and item–item correlations; test–retest reliability via correlation between 2 CIPN15 scores from each patient; concurrent validity via correlation between CIPN15 and 5-item TNSc scores; contrasting group validity via comparison of CIPN15 scores from patients and healthy controls; sensitivity via descriptive statistics (means, standard deviation, ranges); and responsiveness via Cohen’s d effect size.

Results:

Most patients received single agent oxaliplatin (33.7%), paclitaxel (21.2%), or more than 1 neurotoxic drug concurrently (29.8%). Factor analysis revealed no stable factor structure. Cronbach’s α for the CIPN15 sum score was 0.91 (confidence interval [CI] = 0.89-0.93). Test–retest reliability was demonstrated based on strong correlations between the 2 scores obtained at the 12-week time point (r = 0.86; CI = 0.80-0.90). The CIPN15 and 5-item TNSc items reflecting symptoms (not signs) were moderately correlated (r range 0.57-0.72): concurrent validity. Statistically significant differences were found between patient and healthy control CIPN15 mean scores (P < .0001): contrasting group validity. All items encompassed the full score range but the CIPN15 linearly converted sum score did not: sensitivity. The CIPN15 was responsive based on a Cohen’s d of 0.52 (CI = 0.25-0.79).

Conclusion:

The sum-scored CIPN15 is reliable, valid, sensitive, and responsive when used to assess taxane- and platinum-induced CIPN.

A phase 1 study of eribulin mesylate (E7389), a novel microtubule-targeting chemotherapeutic agent, in children with refractory or recurrent solid tumors: A Children's Oncology Group Phase 1 Consortium study (ADVL1314)

BACKGROUND

Eribulin mesylate is a novel anticancer agent that inhibits microtubule growth, without effects on shortening, and promotes nonproductive tubulin aggregate formation. We performed a phase 1 trial to determine the dose-limiting toxicities (DLTs), maximum tolerated or recommended phase 2 dose (MTD/RP2D), and pharmacokinetics (PK) of eribulin in children with refractory or recurrent solid (excluding central nervous system) tumors.

METHODS

Eribulin was administered intravenously on days 1 and 8 in 21-day cycles. Three dose levels (1.1, 1.4, and 1.8 mg/m2 /dose) were evaluated using the rolling six design with additional patients enrolled into a PK expansion cohort at the MTD. PK samples were obtained following the day 1, cycle 1 dose.

RESULTS

Twenty-three patients, ages 3-17 (median 14) years were enrolled; 20 were evaluable for toxicity. DLTs occurred in 0/6 and 1/6 subjects at the 1.1 and 1.4 mg/m2 /dose, respectively. One subject at the 1.4 mg/m2 /dose had grade 4 neutropenia and grade 3 fatigue. At the 1.8 mg/m2 /dose, 2/5 subjects experienced dose-limiting (grade 4) neutropenia. Grade 3/4 non-DLTs included lymphopenia and hypokalemia, while low-grade toxicities included anorexia and nausea. No episodes of grade > 2 corrected QT interval prolongation or peripheral neuropathy were reported. Eribulin pharmacokinetic parameters were highly variable; the median elimination half-life was 39.6 (range 24.2-96.4) hr. A partial response was observed in one patient (Ewing sarcoma).

CONCLUSIONS

Eribulin was well tolerated in children with refractory or recurrent solid tumors with neutropenia identified as the primary DLT. The RP2D of eribulin is 1.4 mg/m2 /dose on days 1 and 8 of a 21-day cycle.

Early life vincristine exposure evokes mechanical pain hypersensitivity in the developing rat

Vincristine (VNC) is commonly used to treat pediatric cancers, including the most prevalent childhood malignancy, acute lymphoblastic leukemia. Although clinical evidence suggests that VNC causes peripheral neuropathy in children, the degree to which pediatric chemotherapeutic regimens influence pain sensitivity throughout life remains unclear, in part because of the lack of an established animal model of chemotherapy-induced neuropathic pain during early life. Therefore, this study investigated the effects of VNC exposure between postnatal days (P) 11 and 21 on mechanical and thermal pain sensitivity in the developing rat. Low doses of VNC (15 or 30 μg/kg) failed to alter nociceptive withdrawal reflexes at any age examined compared with vehicle-injected littermate controls. Meanwhile, high dose VNC (60 μg/kg) evoked mechanical hypersensitivity in both sexes beginning at P26 that persisted until adulthood and included both static and dynamic mechanical allodynia. Hind paw withdrawal latencies to noxious heat and cold were unaffected by high doses of VNC, suggesting a selective effect of neonatal VNC on mechanical pain sensitivity. Gross and fine motor function appeared normal after VNC treatment, although a small decrease in weight gain was observed. The VNC regimen also produced a significant decrease in intraepidermal nerve fiber density in the hind paw skin by P33. Overall, the present results demonstrate that high-dose administration of VNC during the early postnatal period selectively evokes a mechanical hypersensitivity that is slow to emerge during adolescence, providing further evidence that aberrant sensory input during early life can have prolonged consequences for pain processing.

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.

CYP3A5 genotype and its impact on vincristine pharmacokinetics and development of neuropathy in Kenyan children with cancer

BACKGROUND

Vincristine (VCR) is a critical part of treatment in pediatric malignancies and is associated with dose-dependent peripheral neuropathy (vincristine-induced peripheral neuropathy [VIPN]). Our previous findings show VCR metabolism is regulated by the CYP3A5 gene. Individuals who are low CYP3A5 expressers metabolize VCR slower and experience more severe VIPN as compared to high expressers. Preliminary observations suggest that Caucasians experience more severe VIPN as compared to nonCaucasians.

PROCEDURE

Kenyan children with cancer who were undergoing treatment including VCR were recruited for a prospective cohort study. Patients received IV VCR 2 mg/m² /dose with a maximum dose of 2.5 mg as part of standard treatment protocols. VCR pharmacokinetics (PK) sampling was collected via dried blood spot cards and genotyping was conducted for common functional variants in CYP3A5, multi-drug resistance 1 (MDR1), and microtubule-associated protein tau (MAPT). VIPN was assessed using five neuropathy tools.

RESULTS

The majority of subjects (91%) were CYP3A5 high-expresser genotype. CYP3A5 low-expresser genotype subjects had a significantly higher dose and body surface area normalized area under the curve than CYP3A5 high-expresser genotype subjects (0.28 ± 0.15 hr·m² /l vs. 0.15 ± 0.011 hr·m² /l, P = 0.027). Regardless of which assessment tool was utilized, minimal neuropathy was detected in this cohort. There was no difference in the presence or severity of neuropathy assessed between CYP3A5 high- and low-expresser genotype groups.

CONCLUSION

Genetic factors are associated with VCR PK. Due to the minimal neuropathy observed in this cohort, there was no demonstrable association between genetic factors or VCR PK with development of VIPN. Further studies are needed to determine the role of genetic factors in optimizing dosing of VCR for maximal benefit.

Consensus definitions of 14 severe acute toxic effects for childhood lymphoblastic leukaemia treatment: a Delphi consensus

Although there are high survival rates for children with acute lymphoblastic leukaemia, their outcome is often counterbalanced by the burden of toxic effects. This is because reported frequencies vary widely across studies, partly because of diverse definitions of toxic effects. Using the Delphi method, 15 international childhood acute lymphoblastic leukaemia study groups assessed acute lymphoblastic leukaemia protocols to address toxic effects that were to be considered by the Ponte di Legno working group. 14 acute toxic effects (hypersensitivity to asparaginase, hyperlipidaemia, osteonecrosis, asparaginase-associated pancreatitis, arterial hypertension, posterior reversible encephalopathy syndrome, seizures, depressed level of consciousness, methotrexate-related stroke-like syndrome, peripheral neuropathy, high-dose methotrexate-related nephrotoxicity, sinusoidal obstructive syndrome, thromboembolism, and Pneumocystis jirovecii pneumonia) that are serious but too rare to be addressed comprehensively within any single group, or are deemed to need consensus definitions for reliable incidence comparisons, were selected for assessment. Our results showed that none of the protocols addressed all 14 toxic effects, that no two protocols shared identical definitions of all toxic effects, and that no toxic effect definition was shared by all protocols. Using the Delphi method over three face-to-face plenary meetings, consensus definitions were obtained for all 14 toxic effects. In the overall assessment of outcome of acute lymphoblastic leukaemia treatment, these expert opinion-based definitions will allow reliable comparisons of frequencies and severities of acute toxic effects across treatment protocols, and facilitate international research on cause, guidelines for treatment adaptation, preventive strategies, and development of consensus algorithms for reporting on acute lymphoblastic leukaemia treatment.

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.

The Stoplight Program: A Proactive Physical Therapy Intervention for Children With Acute Lymphoblastic Leukemia

Chemotherapy may cause neuromuscular impairments that can have life-long effects. The Stoplight Program (SLP) was developed as a proactive physical therapy (PT) intervention directed at impairments in children with acute lymphoblastic leukemia (ALL). In this program evaluation, we assessed the feasibility of the SLP delivered as part of standard care and identified body function and activity patterns in patients who received the intervention. Children ages 1 to 22 years, diagnosed with ALL, received an assessment by a physical therapist as part of usual care. The SLP intervention used 3 levels to categorize the impairment levels and intensity of PT. Of the children (n = 135) screened, 46% completed 5 intervention visits and 32% completed the program and met discharge criteria. At initial assessment, 46% of children ages 1 to 5 years and 67% of children ages 6 to 22 years had abnormal motor function. Those completing the program tested within the healthy norms. Research is needed on variables that influence adherence to a PT program and the range of functional impairment and activity limitations in this population.

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.