Vincristine-induced neuropathy in childhood ALL (acute lymphoblastic leukemia) survivors: prevalence and electrophysiological characteristics

Identifying causes of balance impairment and exploring sensory contributions to balance in pediatric oncology: A scoping review

PURPOSE

To identify causes of balance impairment in children undergoing treatment for cancer and childhood cancer survivors.

METHODS

A systematic search was performed according to PRISMA guidelines. Studies were included if participants were 0-19 years of age with a current/past diagnosis of cancer, an objective balance measure was reported, and a cause of balance impairment was either stated or implied.

RESULTS

The 64 full text studies included identified balance impairments as sequelae secondary to CNS tumors, and/or as an effect of medical treatment including chemotherapy, radiation, and/or surgery. Cancer treatment can result in damage to the visual, vestibular and/or somatosensory systems which in turn can contribute to balance dysfunction.

CONCLUSIONS

Balance impairments were caused by the cancer itself or the result of medical treatment. Oncology professionals are integral in recognition and treatment of factors affecting balance impairments in childhood cancer; however, further research is needed to identify interventions targeting specific causes of balance impairment.

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

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

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.

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.

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.

Vincristine-Induced Peripheral Neuropathy in Children With Malignancy and the Effect of Missed Doses on Treatment Success

INTRODUCTION

Recognizing the symptoms of vincristine-induced peripheral neuropathy (VIPN) earlier is crucial to preventing the persistent neurological sequelae. The treatment of neuropathy is to discontinue the drug, and the effect of a missed dose of vincristine on treatment success is unclear. This study aims to evaluate VIPN in children with malignancy and the effect of skipping vincristine doses on the treatment success of patients at a single center, retrospectively.

METHODS

Medical records of the children with cancer who received vincristine in our institution between 2013 and 2020 were analyzed retrospectively.

RESULTS

Vincristine neuropathy was found in 42 (7%) of 598 pediatric patients who received at least one dose of vincristine during the study period. Neuropathy developed at a statistically significantly lower cumulative dose in patients younger than seven years of age (p=0.04). The mean neuropathy duration of the cases was 8.5 months, and the findings of 40 (95.2%) cases improved. The mean cumulative dose was higher in patients with diffuse nerve involvement. The missed dose of vincristine was lower in the cases in complete remission compared to the other cases and higher doses of vincristine were missed in the stable disease group than in the remission group (p=0.03).

CONCLUSION

VIPN can be encountered in less cumulative doses, mainly in the younger age group. Missed doses of vincristine may affect treatment success, and more comprehensive studies are needed to show this effect more clearly.

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.

Vincristine-Induced Neuropathy in Patients Diagnosed with Solid and Hematological Malignancies: The Role of Dose Rounding

BACKGROUND

Vincristine is a vital constituent of chemotherapeutic regimens. Vincristine-induced neuropathy is a challenging adverse effect that impacts quality of life and treatment course. The dose rounding of chemotherapies is a strategy that is commonly used in clinical practice. Nevertheless, the frequency of developed neuropathy in vincristine first-time users and the potential association with dose rounding remains elusive.

METHODS

A retrospective analysis was conducted on patients administered vincristine for the first time between 2016 and 2022 using the King Saud University Medical City (KSUMC) database. Patients were stratified into pediatric and adult groups. Neuropathy frequency, its association with demographic and clinical parameters, and the Impact of dose rounding were assessed using SPSS software version 28.

RESULTS

Approximately 34.6% of patients were diagnosed with neuropathy after vincristine administration. Autonomic neuropathy was common among affected adults and pediatric patients (55.1% and 56.1%, respectively), while cranial neuropathy was more frequent in pediatric patients. Higher BSA (p = 0.038) and Scr (p = 0.044) in the pediatric group, the presence of respiratory comorbidities (p = 0.044), and the use of azole antifungals (p < 0.001) in the adult group were significantly associated with neuropathy episodes. The rounding-up of vincristine doses was significantly associated with increased neuropathy occurrence (p < 0.001), while dose rounding-down was significantly associated with a decrease in neuropathy in both groups of patients (p < 0.001).

CONCLUSIONS

Our findings demonstrate that autonomic neuropathy is the most common vincristine-related neuropathy, regardless of the patient's age. Dose rounding is a significant determinant of vincristine-induced neuropathy in both groups. Further studies are needed to evaluate the variables that exacerbate or prevent neuropathy associated with the first-time use of vincristine.

Curing childhood cancer the "Natural" Way: Nature as the source of chemotherapy agents

For many centuries, products of natural origin from plants, marine, microbes and soil micro-organisms have been studied by numerous researchers across the world to yield many of the chemotherapeutic agents we use in this modern era. There has been a tremendous gain in knowledge from various screening and separating techniques which led to the discovery of biologically active small molecules from natural products. Preclinical studies testing the antitumor activities of these agents against tumor cell lines and xenograft animal models were the gateway to the clinical trials in humans leading to the approval of these agents that are in clinical use today. This review summarizes how various chemotherapeutic agents were discovered from products of natural origin, their preclinical development, and their indications in both pediatric and adult oncology. Many of these natural products have contributed to the very high cure rates of both pediatric leukemias and solid tumors.

Polyneuropathy in Adolescent Childhood Cancer Survivors: The PACCS Study

BACKGROUND

Childhood cancer survivors (CCS) are at risk of polyneuropathy due to chemotherapy, but studies in young survivors are scarce and diagnosis is challenging. We aimed to study the presence of polyneuropathy and the possible effect of cumulative doses of chemotherapeutic agents in a representative group of adolescent survivors.

METHODS

CCS aged nine to 18 years and age- and sex-matched controls were recruited from the cross-sectional Physical Activity and Fitness among Childhood Cancer Survivors (PACCS) study. CCS with various cancer diagnoses who had ended cancer treatment one year or more before study were included. Polyneuropathy was evaluated clinically and with nerve conduction studies (NCSs) in three motor and five sensory nerves. We used mixed-effects linear regression models to compare CCS and controls, and investigate possible associations between cumulative chemotherapy doses and NCS amplitudes.

RESULTS

A total of 127 CCS and 87 controls were included, with 14% CCS having probable or confirmed polyneuropathy. NCS amplitudes were lower in survivors compared with controls in all nerves. The largest mean difference was 3.47 μV (95% confidence interval [CI], 2.18 to 4.75) in the tibial plantar medial sensory and 1.91 mV (95% CI, 0.78 to 3.04) in the tibial motor nerve. The cumulative dose of platinum derivatives was associated with lower tibial motor nerve amplitude (-0.20; 95% CI, -0.35 to -0.04 mV for 100 mg/m² dose increase) but not in other nerves. We found no significant associations between vinca alkaloids cumulative dose and amplitudes.

CONCLUSIONS

CCS without clinical signs or symptoms of polyneuropathy may have subtle nerve affection. The clinical long-term impact of this novel observation should be evaluated in larger, longitudinal studies.

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.

Dapsone improves the vincristine-induced neuropathic nociception by modulating neuroinflammation and oxidative stress

BACKGROUND

Peripheral neuropathy is a dose-limiting adverse effect of vincristine (VCR) in cancer chemotherapies. Dapsone is commonly used for the prevention of opportunistic infections following cancer therapies. Therefore, a high rate of VCR and dapsone co-administration has occurred in leukemias. Recently neuroprotective effects of dapsone have been reported in various diseases.

OBJECTIVES

Regarding the physiopathology of VCR-induced peripheral neuropathy (VIPN) and dapsone neuroprotection, this study evaluated the effect of dapsone on VIPN.

METHODS

VIPN was induced by VCR injection (0.5 mg/kg IP, every other day, 1 week) in male Wistar rats. In the treatment group, dapsone(12.5 mg/kg IP, 1 week) was injected 30 min before VCR. Hot plate, Von Frey, motor neuron conduction velocity (MNCV), and histopathological tests were applied. The levels of TNF-α and NF-kB in the sciatic nerve and caspase-3 activity in dorsal root ganglion were measured by the ELISA method. The levels of malondialdehyde (MDA) and Glutathione (GSH) in the sciatic nerve were measured by spectrophotometry and colorimetric assays.

RESULTS

VIPN was observed as araised thermal and mechanical threshold, reduced MNCV, and sciatic nerve demyelination. However, dapsone reduced the mechanical and thermal threshold and improved the MNCV. Also, dapsone reduced TNF-α, NF-kB, MDA, and Caspase-3 activity, and increased the GSH level in the sciatic nerve. Moreover, dapsone prevented VCR-induced demyelination in the sciatic nerve.

CONCLUSION

This research demonstrated that dapsone could be used as a protective drug against VIPN. It improves the impaired thermal and mechanical sensations by reducing inflammatory, oxidant, and apoptosis factors and preventing demyelination in the sciatic nerve.

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.

Risk factors for renal impairment in patients with hematological cancer receiving antineoplastic treatment

PURPOSE

Antineoplastic treatments, mainly chemotherapy, affect the kidneys, causing toxicity, and can trigger acute and chronic kidney injuries. This study aimed to analyze the prevalence of renal disorders in patients with oncohematological neoplasms receiving antineoplastic treatment.

METHODS

This retrospective cohort study included 75 patients with hematological cancer who underwent chemotherapy between 2012 and 2018 in the Hematology Sector of the Walter Cantídeo University Hospital of the Federal University of Ceará. Sociodemographic and clinical data, blood biochemical assessment findings, and glomerular filtration rate (GFR) were analyzed using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. The data were tabulated; transferred to the Statistical Package for the Social Sciences software, version 20.0; and analyzed using Pearson's chi-square test or Fisher's exact test for categorical variables followed by a multinomial logistic regression model (p < 0.05).

RESULTS

The prevalence of renal disorders was 52.4% according to the CKD-EPI equation for GFR events. There was a significant association between the decrease in GFRs and the following variables: female sex (p = 0.002), diagnosis of multiple myeloma (p = 0.008), start of treatment within 40 days (p = 0.005), and the following antineoplastic treatments: cyclophosphamide, vincristine, and prednisone (p = 0.026); irarubicin (p = 0.032); azacytidine, dexamethasone, and cyclophosphamide (p < 0.001); zoledronic acid (p < 0.001); and pamidronate (p = 0.012). CALGB 8811 (p < 0.001) was inversely associated with a reduction in the GFR.

CONCLUSIONS

The prevalence of renal disorders was high in patients with oncohematological neoplasms receiving antineoplastic treatment. This requires periodic monitoring of the evaluation of renal function since reductions in GFRs were significantly associated with different treatment protocols used.

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.

Neurotoxicity Associated with Treatment of Acute Lymphoblastic Leukemia Chemotherapy and Immunotherapy

Immunotherapy is a milestone in the treatment of poor-prognosis pediatric acute lymphoblastic leukemia (ALL) and is expected to improve treatment outcomes and reduce doses of conventional chemotherapy without compromising the effectiveness of the therapy. However, both chemotherapy and immunotherapy cause side effects, including neurological ones. Acute neurological complications occur in 3.6–11% of children treated for ALL. The most neurotoxical chemotherapeutics are L-asparaginase (L-ASP), methotrexate (MTX), vincristine (VCR), and nelarabine (Ara-G). Neurotoxicity associated with methotrexate (MTX-NT) occurs in 3–7% of children treated for ALL and is characterized by seizures, stroke-like symptoms, speech disturbances, and encephalopathy. Recent studies indicate that specific polymorphisms in genes related to neurogenesis may have a predisposition to MTX toxicity. One of the most common complications associated with CAR T-cell therapy is immune effector cell-associated neurotoxicity syndrome (ICANS). Mechanisms of neurotoxicity in CAR T-cell therapy are still unknown and may be due to disruption of the blood–brain barrier and the effects of elevated cytokine levels on the central nervous system (CNS). In this review, we present an analysis of the current knowledge on the mechanisms of neurotoxicity of standard chemotherapy and the targeted therapy in children with ALL.

Vincristine-Induced Peripheral Neuropathy in Childhood Acute Lymphoblastic Leukemia: Genetic Variation as a Potential Risk Factor

Vincristine (VCR) is the first-line chemotherapeutic medication often co-administered with other drugs to treat childhood acute lymphoblastic leukemia. Dose-dependent neurotoxicity is the main factor restricting VCR’s clinical application. VCR-induced peripheral neuropathy (VIPN) sometimes results in dose reduction or omission, leading to clinical complications or affecting the patient’s quality of life. With regard to the genetic basis of drug responses, preemptive pharmacogenomic testing and simultaneous blood level monitoring could be helpful for the transformation of various findings into individualized therapies. In this review, we discussed the potential associations between genetic variants in genes contributing to the pharmacokinetics/pharmacodynamics of VCR and VIPN incidence and severity in patients with acute lymphoblastic leukemia. Of note, genetic variants in the CEP72 gene have great potential to be translated into clinical practice. Such a genetic biomarker may help clinicians diagnose VIPN earlier. Besides, genetic variants in other genes, such as CYP3A5, ABCB1, ABCC1, ABCC2, TTPA, ACTG1, CAPG, SYNE2, SLC5A7, COCH, and MRPL47, have been reported to be associated with the VIPN, but more evidence is needed to validate the findings in the future. In fact, a variety of complex factors jointly determine the VIPN. In implementing precision medicine, the combination of genetic, environmental, and personal variables, along with therapeutic drug monitoring, will allow for a better understanding of the mechanisms of VIPN, improving the effectiveness of VCR treatment, reducing adverse reactions, and improving patients’ quality of life.

Pharmacogenomics insights into precision pediatric oncology

PURPOSE OF REVIEW

Pharmacogenomic insights provide an opportunity to optimize medication dosing regimens and patient outcomes. However, the potential for interindividual genomic variability to guide medication dosing and toxicity monitoring is not yet standard of care. In this review, we present advances for the thiopurines, anthracyclines and vincristine and provide perspectives on the actionability of pharmacogenomic guidance in the future.

RECENT FINDINGS

The current guideline on thiopurines recommends that those with normal predicted thiopurine methyltransferase and NUDT15 expression receive standard-of-care dosing, while 'poor metabolizer' haplotypes receive a decreased 6-mercaptopurine starting dose to avoid bone marrow toxicity. Emerging evidence established significant polygenic contributions that predispose to anthracycline-induced cardiotoxicity and suggest this knowledge be used to identify those at higher risk of complications. In the case of vincristine, children who express CYP3A5 have a significantly reduced risk of peripheral neuropathy compared with those expressing an inactive form or the CYP3A4 isoform.

SUMMARY

The need for adequately powered pediatric clinical trials, coupled with the study of epigenetic mechanisms and their influence on phenotypic variation and the integration of precision survivorship into precision approaches are featured as important areas for focused investments in the future.

RISK FACTORS OF VINCRISTINE-INDUCED PERIPHERAL NEUROPATHY IN ACUTE LYMPHOBLASTIC LEUKAEMIA CHILDREN

Objective : This study analysed Vincristine-induced peripheral neuropathy (VIPN) risk factors in Acute Lymphoblastic Leukaemia (ALL) children. Method : This cross-sectional study design was performed at Dr. Soetomo Hospital, Surabaya, Indonesia, from August to October 2019. It included ALL children, aged 4-18 years, undergoing the 2013 or 2018 ALL Indonesian Protocol of Chemotherapy, with a cumulative vincristine dose ≥ 12 mg / m2. VIPN diagnosis is based on complaints, the Total Neuropathy Score Pediatric Vincristine (TNS-PV), and nerve conduction studies (NCS). The examined risk factors were sex, age, ALL classification, nutritional status, impaired liver function, and cumulative vincristine dose. Results : There were 52 ALL children : median age 7 years, 59.6% boys, 59.6% ALL standard risk, 44.2% experienced impaired liver function at initial ALL diagnosis. Based on a single parameter for diagnosis, 26.9% had VIPN based on complaints, 76.9% had it based on the TNS-PV, and 100% had it based on NCS. VIPN was diagnosed in 25% of children, with predominantly motor impairment and located in lower extremities. Impaired liver function is a risk factor for VIPN in ALL children (p = 0.046, prevalence ratio (PR) 2.84). Conclusion : Impaired liver function is a significant risk factor for VIPN in ALL children. J. Med. Invest. 68 : 232-237, August, 2021.

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.

Skeletal Muscle and Childhood Cancer: Where are we now and where we go from here

Skeletal muscle (muscle) is essential for physical health and for metabolic integrity, with sarcopenia (progressive muscle mass loss and weakness), a pre-curser of aging and chronic disease. Loss of lean mass and muscle quality (force generation per unit of muscle) in the general population are associated with fatigue, weakness, and slowed walking speed, eventually interfering with the ability to maintain physical independence, and impacting participation in social roles and quality of life. Muscle mass and strength impairments are also documented during childhood cancer treatment, which often persist into adult survivorship, and contribute to an aging phenotype in this vulnerable population. Although several treatment exposures appear to confer increased risk for loss of mass and strength that persists after therapy, the pathophysiology responsible for poor muscle quantity and quality is not well understood in the childhood cancer survivor population. This is partly due to limited access to both pediatric and adult survivor muscle tissue samples, and to difficulties surrounding non-invasive investigative approaches for muscle assessment. Because muscle accounts for just under half of the body's mass, and is essential for movement, metabolism and metabolic health, understanding mechanisms of injury responsible for both initial and persistent dysfunction is important, and will provide a foundation for intervention. The purpose of this review is to provide an overview of the available evidence describing associations between childhood cancer, its treatment, and muscle outcomes, identifying gaps in current knowledge.

Bilateral optic neuropathy following vincristine chemotherapy: A case report with description of multimodal imaging findings

RATIONALE

A few cases of optic neuropathy presumed to be caused by vincristine have been reported. However, none described multimodal imaging findings. Here, we report abnormal magnetic resonance imaging (MRI) and optical coherence tomography (OCT) findings in a putative case of vincristine-induced optic neuropathy.

PATIENT CONCERNS

A 9-year-old boy with Burkett lymphoma who had had no visual problems noticed blurred vision in both eyes 22 days after the first maintenance therapy for lymphoma; the blurred gradually worsened. At that time, the best-corrected visual acuity was 20/200 and 20/100 in the right and left eyes, respectively.

DIAGNOSES

Blood and imaging workup, and cerebrospinal fluid and genetic analyses, were performed; these included fundus photography, OCT, and MRI. We found no plausible cause of the optic neuropathy other than vincristine.

INTERVENTIONS

The scheduled chemotherapy was stopped, and the patient was managed with high-dose corticosteroids. However, as there was no improvement, plasma exchange was then performed.

OUTCOMES

Three days after the initial examination, the visual acuity in both eyes was only light perception and projection. Signal intensity was abnormally high on 3-dimensional T2-weighted turbo spin echo and T2-weighted MRI images. Optic disc atrophy progressed to "total pallor"; thinning of the ganglion cell-inner plexiform and retinal nerve fiber layers also progressed. The patient was followed up for 7 months but showed no improvement in vision. There were no treatment-related complications.

LESSONS

We conclude that vincristine can cause optic neuropathy, and clinicians need to be alert to the possibility of optic neuropathy in any patient prescribed this agent.OCT and MRI may help to diagnose optic neuropathy in pediatric patients. Periodic ophthalmologic examinations, including an OCT scan, may be useful.

Neuropathic pain in children: Steps towards improved recognition and management

Neuropathic pain in children can be severe and persistent, difficult to recognise and manage, and associated with significant pain-related disability. Recognition based on clinical history and sensory descriptors is challenging in young children, and screening tools require further validation at older ages. Confirmatory tests can identify the disease or lesion of the somatosensory nervous system resulting in neuropathic pain, but feasibility and interpretation may be influenced by age- and sex-dependent changes throughout development. Quantitative sensory testing identifies specific mechanism-related sensory profiles; brain imaging is a potential biomarker of alterations in central processing and modulation of both sensory and affective components of pain; and genetic analysis can reveal known and new causes of neuropathic pain. Alongside existing patient- and parent-reported outcome measures, somatosensory system research methodologies and validation of mechanism-based standardised end-points may inform individualised therapy and stratification for clinical trials that will improve evidence-based management of neuropathic pain in children.

Childhood cancer survivorship and late effects: The landscape in India in 2020

Survivorship care is a major area of focus in the holistic management of childhood cancer with current knowledge and information almost exclusively from high-income countries. In this review, we summarize the state of scientific knowledge, service delivery, advocacy initiatives, and research efforts in this field in India. Twenty-one single-center studies published until today (20 in the last decade) confirm some of the well-documented issues in childhood cancer survivors and highlight the high prevalence of hepatitis B and hepatitis C infection in our survivors. Heterogeneity in methodology, outcome metrics, and quality precludes drawing further conclusions, and the ongoing multicenter Indian Pediatric Oncology Group study would address this. Besides the usual model of follow-up clinics in hospital settings, innovative models of service delivery led by not-for-profit organizations are being developed. Advocacy initiatives driven by survivors and support groups are also under way. All of these portend a promising future.

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.

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

Importance

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

Objective

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

Design, Setting, and Participants

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

Exposures

Chemotherapy agents known to be toxic to peripheral nerves.

Main Outcomes and Measures

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

Results

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

Conclusions and Relevance

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

Motor functioning and associated cognitive outcomes in pediatric survivors of acute lymphoblastic leukemia

Pediatric acute lymphoblastic leukemia survivors are at risk for developing neurocognitive late effects following intensive medical treatment. Motor impairments have been highlighted as a common neurocognitive late effect, including fine-, gross-, and visual-motor skills. The severity of these motor deficits is variable in the existing literature, warranting additional investigations with more homogenous samples. In addition, there is an even greater paucity regarding the interrelations between motor deficits and the impact motor challenges may have on other domains of functioning, such as academics. Therefore, the present study aimed to characterize motor functioning in children who were treated for acute lymphoblastic leukemia with chemotherapy (n = 13) in comparison to healthy controls (n = 13). Additionally, this study investigated the relationship between primary (e.g., visual-spatial, fine-motor), secondary (e.g., visual-motor), and tertiary (e.g., academics) skills. The results revealed that oncology survivors had significantly lower fine- and gross-motor skills compared to healthy controls. No significant differences were observed between the groups on visual-perception and visual-motor tasks. Fine-motor functioning was significantly associated with visual-motor functioning in ALL survivors. Motor skills were not related to academic outcomes. The present findings provide evidence for motor impairments in pediatric ALL survivors, along with initial findings highlighting the cascading effect of primary motor impairments on other cognitive domains. This research sheds light on the need for clinical screening and intervention of motor skills in the survivorship population. Future research is warranted to examine the effect of motor deficits on cognitive and psychosocial functioning in pediatric oncology.

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.

The Developmental Pathways of Preschool Children with Acute Lymphoblastic Leukemia: Communicative and Social Sequelae One Year after Treatment

Early childhood is considered to be a period of rapid development, with the acquisition of abilities predicting future positive school competences. Motor, cognitive, and social difficulties related to cancer therapies heavily impact the development of children with cancer. This study focused on two main aims: To assess the developmental pathways of preschool children with acute lymphoblastic leukemia one year post-treatment and to compare these abilities both with those of a control group of healthy peers and with Italian norms. Forty-four children and their families, recruited through the Hematology-Oncologic Clinic of the Department of Child and Woman Health (University of Padua), agreed to participate in this study. The children’s mean age was 4.52 years (SD = 0.94, range = 2.5–6 years), equally distributed by gender, all diagnosed with acute lymphoblastic leukemia. Matched healthy peers were recruited through pediatricians’ ambulatories. Each family was interviewed adopting the Vineland adaptive behavior scales. Paired sample Wilcoxon tests revealed that children were reported to have significantly more developmental difficulties than their healthy peers. When compared with Italian norms, they scored particularly low in verbal competence, social, and coping skills. No significant association was found between treatment variables and developmental abilities. These findings suggest that the creation of specialized interventions, both for parents and children, may fill the possible delays in children’s development probably due to stress, lack of adequate stimulation, or difficult adaptation.

Neonatal vincristine administration modulates intrinsic neuronal excitability in the rat dorsal root ganglion and spinal dorsal horn during adolescence

Our recent work has shown that the early-life administration of vincristine (VNC), commonly used to treat pediatric cancers, evokes mechanical pain hypersensitivity in rats that emerges during adolescence and persists into adulthood. However, the underlying mechanisms remain unclear, as nothing is known about how neonatal VNC treatment influences peripheral and central nociceptive processing at the cellular level. Here, we used in vitro intracellular microelectrode and whole-cell patch-clamp recordings to evaluate the consequences of early-life VNC administration on the intrinsic membrane properties of adolescent dorsal root ganglion and spinal superficial dorsal horn neurons. The results demonstrate that VNC treatment increased the prevalence and rate of repetitive firing in both large- and medium-diameter sensory neurons, while reducing repetitive firing in small-diameter neurons, in comparison with vehicle-treated littermate controls. By contrast, passive membrane properties and peripheral conduction velocities were similar between experimental groups across all classes of primary afferents. Within the adolescent superficial dorsal horn, neonatal VNC exposure significantly enhanced the intrinsic membrane excitability of lamina I spinoparabrachial neurons, as evidenced by a decrease in rheobase and elevation of repetitive firing frequency compared with controls. Meanwhile, putative interneurons within lamina I exhibited a reduction in repetitive action potential discharge after early-life chemotherapy. Collectively, these findings suggest that neonatal VNC treatment evokes cell type-specific changes in intrinsic excitability at multiple levels of the ascending pain pathway. Overall, this work lays an essential foundation for the future exploration of the ionic mechanisms that drive chemotherapy-induced chronic pain in children and adolescents.

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.

The Experience of Chemotherapy-Induced Peripheral Neuropathy Among Childhood Cancer Survivors

As the number of childhood cancer survivors (CCS) is increasing, it is imperative to understand the late effects of childhood cancer therapy to optimize their health and quality of life. Chemotherapy-induced peripheral neuropathy (CIPN) is an unpleasant effect of chemotherapy that affects the peripheral nervous system. This qualitative study uses narrative analysis with a phenomenological influence to understand the lived experience of CIPN among five CCS utilizing photo-elicitation. The lived experience of CIPN is characterized by "a condition of disconnection" with three subthemes: (1) disconnection between mind and body, (2) disconnection between anticipated potential and reality, and (3) disconnection between survivors and support. The condition of disconnection leads to a variety of negative physical and emotional performance outcomes. These findings support the need for refined clinical strategies for identifying this underappreciated condition and further development of interventions to "rebuild the connections" that CCS are lacking.

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.

Motor function in survivors of pediatric acute lymphoblastic leukemia treated with chemotherapy-only

BACKGROUND

Up to 43% of survivors of pediatric acute lymphoblastic leukemia (ALL) may exhibit fine-motor problems. Information on manual dexterity in this cohort is still limited.

OBJECTIVES

We tested survivors of childhood ALL treated with chemotherapy-only for fine-motor function in terms of drawing and handwriting abilities using a Digitizing Tablet (DT) with three tasks for drawing and handwriting of varying complexity, for ataxia using the International Cooperative Ataxia Rating Scale (ICARS), and for tremor and hand-eye coordination using the Nine Hole Steadiness Tester (NHST).

RESULTS

We examined a cohort of non-irradiated survivors (n = 31) after a median time of 3.5 years after end of therapy. In all tasks of the DT the cohort demonstrated significant (p < 0.05) impairment of speed, automation, and variability in at least two tasks and significantly more pressure. Impaired speed (SPV) inversely correlated with lag time since end of therapy. Dexterity performance of six survivors (19%) lay below the 5th percentile. No survivor exhibited ataxia, tremor, or impaired hand-steadiness.

CONCLUSION

Despite the absence of gross ataxia, tremor, and impaired hand-eye coordination, we nevertheless detected significant fine-motor impairment in a relevant number of survivors of childhood ALL. Prospective studies are needed to reveal the pathophysiological underpinnings and genetic risk factors for development of such deficits due to ALL and its treatment.

Influence of fitness on health status among survivors of acute lymphoblastic leukemia

INTRODUCTION

We aimed to determine the prevalence of self-reported adverse health status among childhood acute lymphoblastic leukemia (ALL) survivors and to identify associations between components of physical fitness and health status.

METHODS

Participants included 365 ALL survivors (mean age at evaluation of 28.6 ± 5.9 years) and 365 age-, sex-, and race-matched community controls. Self-report of poor general health, poor mental health, functional impairments, and activity limitations were used to describe adverse health status. Fitness was evaluated by assessing flexibility, muscular strength and endurance, peak oxygen uptake, and balance. Generalized linear models were used to examine associations between fitness metrics and health status.

RESULTS

Survivors were more likely than controls to report poor general health (20.6% vs. 10.4%, risk ratio [RR] = 2.0, 95% confidence intervals [CI] = 1.4-2.9), poor mental health (28.0% vs. 14.5%, RR = 1.9, 95% CI = 1.4-2.6), functional impairments (10.5% vs. 4.1%, RR = 2.5, 95% CI = 1.4-4.6), and activity limitations (29.0% vs. 14.4%, RR = 2.0, 95% CI = 1.5-2.7). Survivors whose balance scores were more than 1.5 standard deviations below the mean of the control population were more likely to report poor general health (RR = 1.7, 95% CI = 1.1-2.8), poor mental health (RR = 1.9, 95% CI = 1.3-2.8), and functional limitations (RR = 2.5, 95% CI = 1.2-56). Survivors with low strength were more likely to report poor general health (RR = 1.8, 95% CI = 1.1-3.1), functional impairments (RR = 4.2, 95% CI = 1.7-10.4), and activity limitations (RR = 1.8, 95% CI = 1.2-2.8).

CONCLUSIONS

ALL survivors, particularly those with poor balance and reduced muscular strength, are at increased risk for adverse health status.

[Chemotherapy-induced peripheral neuropathy: Symptomatology and epidemiology]

Chemotherapy-induced peripheral neuropathy (CIPN) is common with specific semiological characteristics. When CIPN appears, there are many difficulties in guaranteeing sustained treatment, especially with optimal protocol. Moreover, CIPN have bad repercussions on quality of life after cancer disease. In this article, we have achieved a current state of CIPN and try to report details about semiological characteristics and topography. We have also produced some epidemiological data. Nonetheless, we have not voluntarily introduced treatment because it will be the topic of further work.

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.

Peripheral Neuropathy, Sensory Processing, and Balance in Survivors of Acute Lymphoblastic Leukemia

Purpose To compare peripheral nervous system function and balance between adult survivors of childhood acute lymphoblastic leukemia (ALL) and matched controls and to determine associations between peripheral neuropathy (PN) and limitations in static balance, mobility, walking endurance, and quality of life (QoL) among survivors. Patients and Methods Three hundred sixty-five adult survivors of childhood ALL and 365 controls with no cancer history completed assessments of PN (modified Total Neuropathy Score [mTNS]), static balance (Sensory Organization Test [SOT]), mobility (Timed Up and Go), walking endurance (6-minute walk test), QoL (Medical Outcomes Study 36-Item Short Form Survey), and visual-motor processing speed (Wechsler Adult Intelligence Scale). Results PN, but not impairments, in performance on SOT was more common in survivors than controls (41.4% v 9.5%, respectively; P < .001). In multivariable models, higher mTNS scores were associated with longer time to complete the Timed Up and Go (β = 0.15; 95% CI, 0.06 to 0.23; P < .001), shorter distance walked in 6 minutes (β = -4.39; 95% CI, -8.63 to -0.14; P = .04), and reduced QoL (β = -1.33; 95% CI, -1.79 to -0.87; P < .001 for physical functioning; β = -1.16; 95% CI, -1.64 to -0.67; P < .001 for role physical; and β = -0.88; 95% CI, -1.34 to -0.42; P < .001 for general health). Processing speed (β = 1.69; 95% CI, 0.98 to 2.40; P < .001), but not mTNS score, was associated with anterior-posterior sway on the SOT. Conclusion PN in long-term ALL survivors is associated with movement, including mobility and walking endurance, but not with static standing balance. The association between processing speed and sway suggests that static balance impairment in ALL survivors may be influenced by problems with CNS function, including the processing of sensory information.

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.

Short-Term Recovery of Balance Control: Association With Chemotherapy-Induced Peripheral Neuropathy in Pediatric Oncology

PURPOSE

To describe the incidence and short-term recovery of balance control in children and adolescents receiving neurotoxic treatment for noncentral nervous system cancers and to investigate the association of chemotherapy-induced peripheral neuropathy and balance control.

METHODS

Sixty-five children and adolescents diagnosed with leukemia, lymphoma, or other solid tumors were tested 3 to 6 months into treatment and 3 and 6 months following treatment using the Bruininks-Oseretsky Balance Subscale and Pediatric Modified Total Neuropathy Scale scores of chemotherapy-induced peripheral neuropathy (CIPN).

RESULTS

Seventy-eight percent of the participants scored 1 standard deviation or more below population means on the balance subscale while on treatment, and this improved to 53% by 6 months posttreatment, with the leukemia group performing worse at both time points. On-treatment balance scores were moderately associated with motor CIPN, while at 6 months posttreatment they were more closely associated with sensory CIPN.

CONCLUSIONS

Mild to moderate balance impairments improve but can persist, even when CIPN has improved, 6 months after treatment for childhood cancer.