Methotrexate-induced neurotoxicity and leukoencephalopathy in childhood acute lymphoblastic leukemia

Prevalence and management of methotrexate-induced neurotoxicity in pediatric patients with osteosarcoma: a single-center experience

AIMS

To determine the incidence, clinical presentation, and outcome of methotrexate (MTX) associated neurotoxicity in pediatric patients treated for osteosarcoma, with the aim of identifying possible risk factors and suggesting recommended treatment for these sequelae.

MATERIALS AND METHODS

All medical files of patients treated for osteosarcoma in a single pediatric haemato-oncology center between November 2011 and August 2021 were retrospectively reviewed. All patients were treated according to the EURAMOS AOST0331 protocol, using cisplatin, doxorubicin, and high-dose MTX at a dose of 12 g/m² over 4 h.

RESULTS

Seventy-eight patients with osteosarcoma were identified (age range 5 to 23 years, 42 males). Seven patients (9%) sustained neurotoxicity following treatment with high-dose MTX. Manifestations of neurotoxicity included among others, generalized seizures, confusion, encephalopathy, dysarthria, and choreiform movements. All but one episode occurred following two sequential cycles of high-dose MTX. All 7 had subacute toxicity, 5-10 days following MTX administration, and 1 had both acute and subacute toxicity. Brain MRI was performed for all patients and demonstrated typical MRI changes attributed to MTX neurotoxicity in 4 of them. Two patients received aminophylline; one patient received dextromethorphan. Patients with normal MRI imaging resumed MTX therapy without any sequels. No risk factors were found for high-dose MTX-related toxicity occurrence.

CONCLUSIONS

The time of risk of neurotoxicity due to high-dose MTX treatment for osteosarcoma is days 5-10 following two sequential treatment cycles. These findings together with treatment options for these adverse effects should be detailed in the therapeutic protocol of MTX use among pediatric patients with osteosarcoma.

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.

Evolving management of HER2+ breast cancer brain metastases and leptomeningeal disease

Patients with human epidermal growth factor receptor 2 (HER2)-positive breast cancer are at a particularly high risk of breast cancer brain metastasis (BCBM) and leptomeningeal disease (LMD). Improvements in systemic therapy have translated to improved survival for patients with HER2-positive BCBM and LMD. However, the optimal management of these cases is rapidly evolving and requires a multidisciplinary approach. Herein, a team of radiation oncologists, medical oncologists, neuro-oncologists, and breast surgeon created a review of the evolving management of HER2-positive BCBM and LMD. We assess the epidemiology, diagnosis, and evolving treatment options for patients with HER2-positive BCBM and LMD, as well as the ongoing prospective clinical trials enrolling these patients. The management of HER2-positive BCBM and LMD represents an increasingly common challenge that involves the coordination of local and systemic therapy. Advances in systemic therapy have resulted in an improved prognosis, and promising targeted therapies currently under prospective investigation have the potential to further benefit these patients.

Clinical Characteristics and Outcomes of Acute Childhood Encephalopathy in a Tertiary Pediatric Intensive Care Unit

AIM

Childhood encephalopathy comprises a wide range of etiologies with distinctive distribution in different age groups. We reviewed the pattern of encephalopathy admitted to the pediatric intensive care unit (PICU) of a tertiary children's hospital.

METHODS

We reviewed the medical records and reported the etiologies, clinical features, and outcomes of children with encephalopathy.

RESULTS

Twenty-four admissions to the PICU between April 2019 and May 2020 were reviewed. The median (interquartile range) age was 10.0 (14.7) years and 62.5% were boys. Confusion (66.7%) was the most common presentation. Adverse effects related to medications (33.3%) and metabolic disease (20.8%) were predominant causes of encephalopathies in our study cohort. Methotrexate was responsible for most of the medication-associated encephalopathy (37.5%), whereas Leigh syndrome, pyruvate dehydrogenase deficiency and Wernicke's encephalopathy accounted for those with metabolic disease. The median Glasgow Coma Scale (GCS) on admission was 12.5 (9.0). Antimicrobials (95.8%) and antiepileptic drugs (60.9%) were the most frequently given treatment. Children aged 2 years or younger were all boys (P = 0.022) and had a higher proportion of primary metabolic disease (P = 0.04). Intoxication or drug reaction only occurred in older children. The mortality was 8.3%, and over half of the survivors had residual neurological disability upon PICU discharge. Primary metabolic disease (P = 0.002), mechanical ventilation (P = 0.019), failure to regain GCS back to baseline level (P = 0.009), and abnormal cognitive function on admission (P = 0.03) were associated with cerebral function impairment on PICU discharge.

CONCLUSIONS

Primary metabolic encephalopathy was prevalent in younger children, whereas drug-induced toxic encephalopathy was common among older oncology patients. Survivors have significant neurologic morbidity. Failure to regain baseline GCS was a poor prognostic factor for neurological outcomes.

Clinically reversible ustekinumab-induced encephalopathy: case report and review of the literature

Ustekinumab, a monoclonal antibody against interleukin (IL)-12 and IL-23 approved for the treatment of Crohn’s disease, has shown to be an effective therapy with a favourable safety profile. Clinical trials and real-world studies have reported very few neurological adverse events, including posterior reversible encephalopathy syndrome, idiopathic intracranial hypertension and headache. We describe the case of a 48-year-old man with Crohn’s disease who initiated treatment with ustekinumab on top of ongoing treatment with methotrexate 25 mg/week who presented with an acute-onset encephalopathy that rapidly evolved to severe tetraparesis and akinetic mutism, associated with extensive leukoencephalopathy and restricted diffusion on brain magnetic resonance imaging (MRI), 1 month after the second dose of ustekinumab. Comprehensive in-patient diagnostic testing ruled out vascular, demyelinating, metabolic, tumoral and infectious etiologies. Brain biopsy showed patchy infiltrates of foamy histiocytes with perivascular distribution, associated with edema, diffuse astrocytic gliosis and focal perivascular axonal destruction without demyelination, and ustekinumab-induced neurotoxicity was suspected. After drug discontinuation, the patient presented a complete clinical recovery despite the persistence of leukoencephalopathy. In conclusion, in an era in which biological therapies are continually evolving and expanding, knowledge about the potential neurotoxicity of these new therapies and their management becomes crucial. Although ustekinumab-induced encephalopathy is uncommon, the recognition of this potentially serious side effect is important because prompt withdrawal is associated with a favourable outcome. Whether methotrexate played an additional contributing role is currently unknown, but it is a factor that should be considered.

Central Nervous System Involvement in Adults with Acute Leukemia: Diagnosis, Prevention, and Management

PURPOSE OF REVIEW

Recent treatment advances in both acute myeloid leukemia and acute lymphoblastic leukemia have drastically improved outcomes for these diseases, but central nervous system (CNS) relapses still occur. Treatment of CNS disease can be challenging due to the impermeability of the blood-brain barrier to many systemic therapies.

RECENT FINDINGS

The diagnosis of CNS leukemia relies on assessment of clinical symptoms, cerebrospinal fluid sampling for conventional cytology and/or flow cytometry, and neuroimaging. While treatment of CNS leukemia with systemic or intrathecal chemotherapy and/or radiation can be curative in some patients, these modalities can also lead to serious toxicities. In the modern era, prophylaxis with intrathecal chemotherapy is the most important strategy to prevent CNS relapses in high risk patients. Accurate risk stratification tools and the use of risk-adapted prophylactic therapy are imperative to improving the outcomes of patients with acute leukemias and preventing the development of CNS leukemia.

Effect of Polymorphisms of ABCB1 and MTHFR on Methotrexate-Related Toxicities in Adults With Hematological Malignancies

Study of the association between single nucleotide polymorphisms (SNPs) of methotrexate (MTX) pathway genes and MTX-related toxicity in the treatment of hematological malignancies is popular. Here, we studied the association between SNPs of MTHFR and ABCB1 and MTX-related toxicity in 157 adult Chinese patients diagnosed with hematological malignancies. Patients were genotyped for MTHFR rs1801131, MTHFR rs1801133, and ABCB1 rs1045642 by fluorescence in situ hybridization. Patients with MTHFR rs1801133T allele had a significantly higher risk of hematopoietic toxicity compared with those with CC genotype (p=0.003). With respect to MTHFR rs1801131, patients with CC and AC genotypes had significantly lower frequency of hematopoietic toxicity than patients with AA genotype (p=0.044). In conclusion, we identified an important influence of the SNPs of ABCB1 and MTHFR on MTX-related hematopoietic toxicity in adults with hematological malignancies. To optimize high-dose (HD)-MTX therapy and reduce related hematopoietic toxicity, it is necessary to detect the SNPs of MTHFR and ABCB1 before initiating HD-MTX and deciding the optimal dose of MTX and duration of leucovorin rescue, according to genetic tests and disease type in adults with hematological malignancies.

Central Nervous System Prophylaxis and Treatment in Acute Leukemias

OPINION STATEMENT

Improvements in systemic therapy in the treatment of acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) have improved patient outcomes and reduced the incidence of CNS relapse. However, management of patients with CNS disease remains challenging, and relapses in the CNS can be difficult to salvage. In addition to treatment with CNS-penetrant systemic therapy (high-dose methotrexate and cytarabine), intrathecal prophylaxis is indicated in all patients with ALL, however is not uniformly administered in patients with AML without high-risk features. There is a limited role for radiation treatment in CNS prophylaxis; however, radiation should be considered for consolidative treatment in patients with CNS disease, or as an option for palliation of symptoms. Re-examining the role of established treatment paradigms and investigating the role of radiation as bridging therapy in the era of cellular therapy, particularly in chemotherapy refractory patients, is warranted.

Treatment Options in Refractory Autoimmune Encephalitis

Autoimmune encephalitis represents a potentially treatable immune-mediated condition that is being more frequently recognized. Prompt immunotherapy is a key factor for the management of autoimmune encephalitis. First-line treatments include intravenous steroids, plasma exchange, and intravenous immunoglobulins, which can be combined in most severe cases. Rituximab and cyclophosphamide are administered as second-line agents in unresponsive cases. A minority of patients may still remain refractory, thus representing a major clinical challenge. In these cases, treatment strategies are controversial, and no guidelines exist. Treatments proposed for refractory autoimmune encephalitis include (1) cytokine-based drugs (such as tocilizumab, interleukin-2/basiliximab, anakinra, and tofacitinib); (2) plasma cell-depleting agents (such as bortezomib and daratumumab); and (3) treatments targeting intrathecal immune cells or their trafficking through the blood-brain barrier (such as intrathecal methotrexate and natalizumab). The efficacy evidence of these drugs is mostly based on case reports or small case series, with few reported controlled studies or systematic reviews. The aim of the present review is to summarize the current evidence and related methodological issues in the use of these drugs for the treatment of refractory autoimmune encephalitis.

Intrathecal methotrexate-induced aseptic meningitis in a patient with acute lymphoblastic leukemia

The central nervous system is often a site of spread for patients with acute lymphoblastic leukemia (ALL). ALL is often treated with ongoing intrathecal chemotherapy with the most common regimens including methotrexate and/or cytarabine. Uncommonly, intrathecal methotrexate has been associated with stroke-like symptoms. To the author’s knowledge, we present the first reported case of a patient who developed symptoms more akin to bacterial meningitis than stroke-like symptoms as a consequence of intrathecal methotrexate chemotherapy.

Prognostic significance of CNSL at diagnosis of childhood B-cell acute lymphoblastic leukemia: A report from the South China Children's Leukemia Group

OBJECTIVES

The prognostic significance of acute lymphoblastic leukemia (ALL) patients with central nervous system leukemia (CNSL) at diagnosis is controversial. We aimed to determine the impact of CNSL at diagnosis on the clinical outcomes of childhood B-cell ALL in the South China Children's Leukemia Group (SCCLG).

METHODS

A total of 1,872 childhood patients were recruited for the study between October 2016 and July 2021. The diagnosis of CNSL depends on primary cytological examination of cerebrospinal fluid, clinical manifestations, and imaging manifestations. Patients with CNSL at diagnosis received two additional courses of intrathecal triple injections during induction.

RESULTS

The frequency of CNLS at the diagnosis of B-cell ALL was 3.6%. Patients with CNSL at diagnosis had a significantly higher mean presenting leukocyte count (P = 0.002) and poorer treatment response (P <0.05) compared with non-CNSL patients. Moreover, CNSL status was associated with worse 3-year event-free survival (P = 0.030) and a higher risk of 3-year cumulative incidence of relapse (P = 0.008), while no impact was observed on 3-year overall survival (P = 0.837). Multivariate analysis revealed that CNSL status at diagnosis was an independent predictor with a higher cumulative incidence of relapse (hazard ratio = 2.809, P = 0.016).

CONCLUSION

CNSL status remains an adverse prognostic factor in childhood B-cell ALL, indicating that additional augmentation of CNS-directed therapy is warranted for patients with CNSL at diagnosis.

Long-Term Cognitive Dysfunction in Cancer Survivors

Cancer-related cognitive impairment (CRCI) is a frequent side effect experienced by an increasing number of cancer survivors with a significant impact on their quality of life. Different definitions and means of evaluation have been used in available literature; hence the exact incidence of CRCI remains unknown. CRCI can be described as cognitive symptoms reported by cancer patients in self-reported questionnaires or as cognitive changes evaluated by formal neuropsychological tests. Nevertheless, association between cognitive symptoms and objectively assessed cognitive changes is relatively weak or absent. Studies have focused especially on breast cancer patients, but CRCI has been reported in multiple types of cancer, including colorectal, lung, ovarian, prostate, testicular cancer and hematological malignancies. While CRCI has been associated with various treatment modalities, including radiotherapy, chemotherapy, hormone therapy and novel systemic therapies, it has been also detected prior to cancer treatment. Therefore, the effects of cancer itself with or without the psychological distress may be involved in the pathogenesis of CRCI as a result of altered coping mechanisms after cancer diagnosis. The development of CRCI is probably multifactorial and the exact mechanisms are currently not completely understood. Possible risk factors include administered treatment, genetic predisposition, age and psychological factors such as anxiety, depression or fatigue. Multiple mechanisms are suggested to be responsible for CRCI, including direct neurotoxic injury of systemic treatment and radiation while other indirect contributing mechanisms are hypothesized. Chronic neuroinflammation mediated by active innate immune system, DNA-damage or endothelial dysfunction is hypothesized to be a central mechanism of CRCI pathogenesis. There is increasing evidence of potential plasma (e.g., damage associated molecular patterns, inflammatory components, circulating microRNAs, exosomes, short-chain fatty acids, and others), cerebrospinal fluid and radiological biomarkers of cognitive dysfunction in cancer patients. Discovery of biomarkers of cognitive impairment is crucial for early identification of cancer patients at increased risk for the development of CRCI or development of treatment strategies to lower the burden of CRCI on long-term quality of life. This review summarizes current literature on CRCI with a focus on long-term effects of different cancer treatments, possible risk factors, mechanisms and promising biomarkers.

Intensive chemotherapy perturbs heart rate variability in children with cancer

OBJECTIVES

In children, cancer chemotherapy may impair the functioning of the cardiac autonomic nervous system. Moreover, it is not known whether there are any differences between intensive and maintenance phases of chemotherapy. Therefore, the aim of the current study was to assess autonomic nervous system activity using heart rate variability, in children receiving intensive or maintenance cancer chemotherapy.

METHODS

For that purpose, children who were healthy (healthy control, n = 30), receiving intensive chemotherapy (chemotherapy, n = 30), and receiving maintenance chemotherapy (maintenance, n = 25) were included in the study. Autonomic nervous system activity was measured by means of heart rate variability. Electrocardiogram recordings were used to calculate time- and frequency-domain heart rate variability parameters.

RESULTS

Time-domain parameters such as standard deviation of NN intervals and frequency-domain parameters such as total power were lower during the intensive chemotherapy but not during maintenance phase (standard deviation of NN intervals: 50±5, 33±3, and 48±3 ms, and total power: 2613±504, 1379±296 and 2295±264 ms², respectively for healthy control, chemotherapy and maintenance groups, P<0.001 for both standard deviation of NN intervals and total power).

DISCUSSION

The present results indicate that intensive chemotherapy perturbs the function of heart rate variability in children, with recovery during the maintenance phase. This suggests that intensive chemotherapy is likely to affect the autonomic nervous system but this effect does not appear to be permanent.

Intrathecal methotrexate - Another tool for the treatment of refractory autoimmune encephalitis - Single institution cohort and literature review

BACKGROUND

Autoimmune encephalitis (AIE) encompasses a range of inflammatory disorders manifesting with some combination of encephalopathy, seizures, behavioral changes, movement disorders, dysautonomia or other neurologic symptoms. Anti-N-methyl-d-aspartate receptor encephalitis (NMDARE) is the most common AIE and is an autoantibody mediated disorder, often paraneoplastic. Untreated or undertreated AIE has a high degree of morbidity and mortality. Immunosuppressive treatment regimens including glucocorticoids, plasma exchange (PLEX), intravenous immunoglobulin (IVIG) and rituximab used alone or in combination for such patients. Patients' refractory to such treatments requires more aggressive and potentially toxic therapies. We report favorable outcomes in patients with refractory AIE who received intrathecal methotrexate (IT-MTX) as part of treatment.

METHODS

Cases at our institution seen between 2010 and 2020 were reviewed. We identified 5 patients in our clinical practice whose clinical presentation was compatible with NMDARE. Three patients met criteria for definite NMDARE. An additional two patients met criteria for probable NMDARE in the acute setting but were ultimately seronegative autoimmune encephalitis. All patients received at least one dose of IT-MTX after failing conventional therapies. At the time of IT-MTX administration patients were catatonic, comatose, or severely encephalopathic despite initial treatments.

RESULTS

All patients were treated with methylprednisolone; 3 received a course of IVIG, 4 underwent PLEX, and 4 received rituximab. At the time IT-MTX was given, three patients required mechanical ventilation and 1 had a pacemaker placed for autonomic failure. Two patients were under consideration for transition to palliative care. All patients improved and were at or near their premorbid baseline at last follow-up. All patients tolerated IT-MTX well.

CONCLUSIONS

This retrospective review demonstrates the efficacy of intrathecal methotrexate in the treatment of severe AIE who had failed other immunosuppressive regimens.

Managing therapy-associated neurotoxicity in children with ALL

Several chemotherapeutic agents and novel immunotherapies provide excellent control of systemic and central nervous system (CNS) leukemia but can be highly neurotoxic. The manifestations of subacute methotrexate neurotoxicity are diverse and require vigilant management; nonetheless, symptoms are transient in almost all patients. As methotrexate is a crucial drug to prevent CNS relapse, it is important to aim to resume it after full neurologic recovery. Most children tolerate methotrexate rechallenge without significant delays or prophylactic medications. Neurotoxicity is more frequent with newer immunotherapies such as CD19- chimeric antigen receptor T (CAR T) cells and blinatumomab. A uniform grading system for immune effector cell-associated neurotoxicity syndrome (ICANS) and algorithms for management based on severity have been developed. Low-grade ICANS usually resolves within a few days with supportive measures, but severe ICANS requires multispecialty care in the intensive care unit for life-threatening seizures and cerebral edema. Pharmacologic interventions include anticonvulsants for seizure control and glucocorticoids to reduce neuroinflammation. Anticytokine therapies targeted to the pathophysiology of ICANS are in development. By using illustrative patient cases, we discuss the management of neurotoxicity from methotrexate, CAR T cells, and blinatumomab in this review.

Association between body composition and chemotherapy-related toxicity in children with lymphoma and rhabdomyosarcoma

BACKGROUND

Body composition is associated with chemotherapy toxicity (chemotoxicity) in adults with cancer; this association remains unexplored in children with cancer.

METHODS

Using baseline computed tomography scans of 107 children with Hodgkin lymphoma (n = 45), non-Hodgkin lymphoma (n = 42), or rhabdomyosarcoma (n = 20), this study examined body composition (skeletal muscle index [SMI], skeletal muscle density [SMD], and height-adjusted total adipose tissue [hTAT]) to determine its association with chemotoxicity. Clinical characteristics and chemotoxicities were abstracted from medical records. Primary outcomes included grade 4 or higher hematologic toxicities and grade 3 or higher nonhematologic toxicities within 6 months of the diagnosis. Logistic regression models accounting for repeated measures were constructed to examine the association between body composition indices and chemotoxicities; adjustments were made for age at diagnosis, sex, race/ethnicity, cancer type, risk group, body mass index (measured as a percentile), or body surface area.

RESULTS

The median SMI was 41.0 cm² /m² (range, 25.8-68.6 cm² /m² ), the median SMD was 54.1 HU (range, 35-69.4 HU), and the median hTAT was 19.5 cm² /m² (range, 0-226.7 cm² /m² ). Grade 4 or higher hematologic toxicities and grade 3 or higher nonhematologic toxicities were observed in 74.7% and 66.3% of the chemotherapy cycles, respectively. A higher SMD at diagnosis was associated with lower odds of grade 4 or higher hematologic toxicity (odds ratio [OR], 0.90; 95% confidence interval [CI], 0.85-0.97; P = .004). SMI (OR, 0.99; 95% CI, 0.95-1.04; P = .7) and hTAT (OR, 1.00; 95% CI, 0.99-1.01; P = .9) were not associated with hematologic toxicities. Nonhematologic toxicities did not show any association with body composition.

CONCLUSIONS

The association between low SMD and hematologic toxicities in children with lymphoma or rhabdomyosarcoma could be due to body composition-based biodistribution of chemotherapeutic agents and needs further investigation.

LAY SUMMARY

Body composition at cancer diagnosis in children with lymphoma and rhabdomyosarcoma may provide information that could identify those at risk for serious side effects from chemotherapy. Routinely used measures such as body mass index and body surface area show poor correlations with body composition assessed via computed tomography scans.

Methotrexate-Induced Septicemia With Severe Pancytopenia and Diffuse Cutaneous Ulcerative Lesions

Methotrexate, a folate antimetabolite and one of the first few anti-neoplastic drugs, is now a commonly used drug in the treatment of many inflammatory disorders ranging from diseases like rheumatoid arthritis to psoriasis. The life-threatening toxicity of methotrexate in inflammatory diseases is not commonly encountered. Here we report a case of life-threatening multiorgan failure from methotrexate toxicity, which was given for skin lesions suspected to be psoriasis.

Neurologic Complications in Patients with Cancer

Neurologic symptoms are commonly seen in patients with cancer and can be among the most challenging to diagnose and manage. It is often difficult to determine if new neurologic symptoms are secondary to direct effects of a malignant lesion, systemic complications of disease, paraneoplastic disorders, or side effects of cancer treatment itself. However, early diagnosis and treatment of each of these conditions can improve patients' quality of life and long-term functional outcomes. In this review, we describe a systematic approach to the diagnosis of new neurologic symptoms in patients with known malignancy. We have categorized the neurologic complications of cancer through a mechanistic approach, with an emphasis on ascertaining underlying pathophysiology to guide treatment choice. This review focuses on the acute neurologic complications of cancer that require hospital admission.

Chemotherapy-induced autoimmune-mediated encephalitis during germinoma treatment

BACKGROUND

Autoimmune mediated encephalitis (AME), which includes autoantibody-associated encephalitis and acute disseminated encephalomyelitis, is a common cause of encephalitis as well as infectious encephalitis in children. AME may be triggered by autoimmune responses to paraneoplastic syndromes and infections. Infectious encephalitis associated with an immunocompromised status caused by anti-cancer chemotherapy is well recognized; however, there have been few reports on the relationship between AME and chemotherapy.

CASE REPORT

A ten-year-old previously healthy, developmentally normal girl was diagnosed with a pure germinoma in the suprasellar region. Following 30 days of induction chemotherapy, she developed a depressed level of consciousness with accompanying right hemiplegia, aphasia, and unexplained fever. Cerebrospinal fluid (CSF) analysis revealed positive oligoclonal bands and elevated neopterin levels. Neither atypical cells suggesting tumor exacerbation nor pathogens known to cause encephalitis were identified in the CSF. She was administrated immunosuppressive therapy and her symptoms rapidly improved. No known autoantibodies associated with autoantibody-associated encephalitis were identified in blood or CSF. However, the presence of oligoclonal bands and elevated neopterin levels in the CSF, and the favorable response to immunosuppressive therapy were consistent with an AME diagnosis. Thirteen days after the third course of chemotherapy, the patient developed a depressed level of consciousness again. Due to the recurrence of encephalitis, re-administration of immunosuppressive therapy was performed, which led to improvement in her symptoms. Recurrence of encephalitis has not occurred for 1 year after completion of chemotherapy.

CONCLUSION

The chemotherapy-induced abnormal immune response might have triggered the AME.

Biological Aspects of Inflamm-Aging in Childhood Cancer Survivors

Anti-cancer treatments improve survival in children with cancer. A total of 80% of children treated for childhood cancer achieve 5-year survival, becoming long-term survivors. However, they undergo several chronic late effects related to treatments. In childhood cancer survivors a chronic low-grade inflammation, known as inflamm-aging, is responsible for frailty, a condition characterized by vital organ failure and by premature aging processes. Inflamm-aging is closely related to chemotherapy and radiotherapy, which induce inflammation, accumulation of senescent cells, DNA mutations, and the production of reactive oxygen species. All these conditions are responsible for the onset of secondary diseases, such as osteoporosis, cardiovascular diseases, obesity, and infertility. Considering that the pathobiology of frailty among childhood cancer survivors is still unknown, investigations are needed to better understand frailty's biological and molecular processes and to identify inflamm-aging key biomarkers in order to facilitate the screening of comorbidities and to clarify whether treatments, normally used to modulate inflamm-aging, may be beneficial. This review offers an overview of the possible biological mechanisms involved in the development of inflamm-aging, focusing our attention on immune system alteration, oxidative stress, cellular senescence, and therapeutic strategies.

Population Pharmacokinetics of High-Dose Methotrexate in Chinese Pediatric Patients With Acute Lymphoblastic Leukemia

High-dose methotrexate (HD-MTX) is widely used in pediatric acute lymphoblastic leukemia (ALL) treatment regimens. In this study, we aimed to develop a population pharmacokinetic (PK) model of HD-MTX in Chinese pediatric patients with ALL for designing personalized dosage regimens. In total, 4,517 MTX serum concentration data for 311 pediatric patients with ALL, aged 0.75–15.2 years and under HD-MTX treatment, were retrospectively collected at a tertiary Children’s Hospital in China. The non-linear mixed-effect model was used to establish the population PK model, using NONMEM software. The potential covariate effects of age, body weight, and biochemical measurements (renal and liver function) on MTX PK disposition were investigated. The model was then evaluated using goodness-of-fit, visual predictive check. MTX PK disposition was described using a three-compartment model reasonable well. Body weight, implemented as a fixed allometric function on all clearance and volume of distribution parameters, showed a substantial improvement in model fit. The final population model demonstrated that the MTX clearance estimate in a typical child with body weight of 19 kg was 6.9 L/h and the central distribution of volume estimate was 20.7 L. The serum creatinine significantly affected the MTX clearance, with a 0.97% decrease in clearance per 1 μmol/L of serum creatinine. Other covariates (e.g., age, sex, bilirubin, albumin, aspartate transaminase, concomitant medication) did not significantly affect PK properties of MTX. The proposed population PK model could describe the MTX concentration data in Chinese pediatric patients with ALL. This population PK model combined with a maximum a posteriori Bayesian approach could be used to estimate individual PK parameters, and optimize personalized MTX therapy in target patients, thus aiming to reduce toxicity and improve treatment outcomes.

Reduced dose folinic acid rescue after rapid high-dose methotrexate clearance is not associated with increased toxicity in a pediatric cohort

Purpose

Low doses of folinic acid (FA) rescue after high-dose methotrexate (HD-MTX) have been associated with increased toxicity, whereas high doses may be related to a decreased antileukemic effect. The optimal dosage and duration of FA rescue remain controversial. This study was designed to investigate, whether a shorter duration of FA rescue in the setting of rapid HD-MTX clearance is associated with increased toxicity.

Methods

We reviewed the files of 44 children receiving a total of 350 HD-MTX courses during treatment for acute lymphoblastic leukemia according to the NOPHO ALL-2000 protocol. Following a 5 g/m2 HD-MTX infusion, pharmacokinetically guided FA rescue commenced at hour 42. As per local guidelines, the patients received only one or two 15 mg/m² doses of FA in the case of rapid MTX clearance (serum MTX ≤ 0.2 μmol/L at hour 42 or hour 48, respectively). Data on MTX clearance, FA dosing, inpatient time, and toxicities were collected.

Results

Rapid MTX clearance was observed in 181 courses (51.7%). There was no difference in the steady-state MTX concentration, nephrotoxicity, hepatotoxicity, neutropenic fever, or neurotoxicity between courses followed by rapid MTX clearance and those without. One or two doses of FA after rapid MTX clearance resulted in a 7.8-h shorter inpatient time than if a minimum of three doses of FA would have been given.

Conclusion

A pharmacokinetically guided FA rescue of one or two 15 mg/m² doses of FA following HD-MTX courses with rapid MTX clearance results in a shorter hospitalization without an increase in toxic effects.

Toxicity and effectiveness of CD19 CAR T therapy in children with high-burden central nervous system refractory B-ALL

INTRODUCTION

Although recent clinical trials have demonstrated the efficacy of CD19-directed chimeric antigen receptor (CAR) T-cell therapy for refractory or relapsed B acute lymphoblastic leukemia (r/r B-ALL), most trials exclude patients with high-burden CNS leukemia (CNSL) to avoid the risk of severe neurotoxicity. There were only sparse cases describing the effect of CAR T cells on low-burden CNSL, and the safety and effectiveness of CAR T cells in high-burden CNSL remains unknown.

METHODS

Here, we retrospectively analyzed the results of CD19 CAR T-cell therapy in 12 pediatric patients that had low (Blasts < 20/μL in CSF) or high-burdens (Blasts or intracranial solid mass) of CNS B-ALL, that are enrolled in three clinical trials and one pilot study at Beijing Boren Hospital RESULTS: Eleven patients (91.7%) achieved complete remission (CR) on day 30, and one patient got CR on day 90 after infusion. Most patient experienced mild cytokine-release syndrome. However, of the five patients who retained > 5/μL blasts in CSF or a solid mass before CAR T-cell expansion, four developed severe (grade 3-4) neurotoxicity featured by persistent cerebral edema and seizure, and they fully recovered after intensive managements. Sustained remission was achieved in 9 of the 12 patients, resulted in a 6-month leukemia-free survival rate of 81.8% (95% CI 59.0-100). Only one patient has CNS relapse again.

CONCLUSION

Our study demonstrates that CAR T cells are effective in clearing both low- and high-burden CNSL, but a high CNSL burden before CAR T-cell expansion may cause severe neurotoxicity requiring intense intervention.

[Intellectual disability and cancer in children: An analysis of the decision-making process]

AIM

The aim was to describe and to analyze the ethics of decision-making in situations involving children with intellectual disability and cancer, from the referent-doctor's point-of-view, in pediatric oncology units in France.

METHODS

Pediatricians working in pediatric oncology units were interviewed through an online questionnaire and a semi-directive interview was systematically proposed. We analyzed the ethical issues that arose during the process of decision-making and we made suggestions in order to address them.

RESULTS

Sixteen doctors reported twenty-one clinical cases. Of these cases, one third of the children had a change in their oncologic treatment, with a risk of pejorative outcome on the prognosis. Despite the fact that ethical issues appeared in 80 % of the cases, there were few consultations with ethical committees. Decision-making process showed no difference compared to children without intellectual disability, thus raising ethical issues in the medical team. Our study showed discrepancy between frequently reported ethical issues, high consensus rate regarding treatment decision and lack of consultation with ethical committees.

DISCUSSION

We propose three steps to guide the decision-making process in situations involving children with intellectual disability and cancer: 1/deeper understanding of the child through reinforced interactions with their caregivers, 2/better cross-boundary discussions, to improve the effectiveness of the multidisciplinary staff, and 3/more systematic ethical committees consultation.

Emergent Radiotherapy for Leukemia-Induced Cranial Neuropathies Refractory to Intrathecal Therapy

Neurologic symptoms from leukemic infiltration of the central nervous system are an oncologic emergency, and expeditious treatment is required to preserve function. We report the case of a 44-year-old patient with relapsed acute myeloid leukemia (AML) who developed sub-acute cranial neuropathies refractory to treatment with intrathecal (IT) chemotherapy. The patient was therefore treated with an emergent course of whole-brain radiotherapy, resulting in immediate improvement and subsequent resolution of cranial neuropathies. This case illustrates that while central nervous system involvement by AML is rare, radiotherapy remains an effective modality to avoid long-term morbidity in patients failing to respond to systemic or IT chemotherapy.

Machine learning to predict high-dose methotrexate-related neutropenia and fever in children with B-cell acute lymphoblastic leukemia

Methotrexate (MTX), an antimetabolite for the treatment of leukemia, could cause neutropenia and subsequently fever, which might lead to treatment delay and affect prognosis. Here, we aimed to predict neutropenia and fever related to high-dose MTX using artificial intelligence. This study included 139 pediatric patients newly diagnosed with standard- or intermediate risk B-cell acute lymphoblastic leukemia. Fifty-seven SNPs of 16 genes were genotyped. Univariate and multivariate analysis were used to select SNPs and clinical covariates for model developing. Five machine learning algorithms combined with four resampling techniques were used to build optimal predictive model. The combination of random forest with adaptive synthetic appeared to be the best model for neutropenia (sensitivity = 0.935, specificity = 0.920, AUC = 0.927) and performed best for fever (sensitivity = 0.818, specificity = 0.924, AUC = 0.870). By machine learning, we have developed and validated comprehensive models to predict the risk of neutropenia and fever. Such models may be helpful for medical oncologists in quick decision-making.

Age- and Intravenous Methotrexate-Associated Leukoencephalopathy and Its Neurological Impact in Pediatric Patients with Lymphoblastic Leukemia

Simple Summary

In this study, we investigated standardized post-chemotherapy magnetic resonance (MR) scans for leukoencephalopathy and patient- and treatment-related risk factors in childhood leukemia patients. As prevalence numbers are limited, our study provides the required estimations for this population. Furthermore, we demonstrate that younger patients might be more at-risk for development of leukoencephalopathy (LE), and that a higher intravenous methotrexate (IV-MTX) dose has a cumulative toxic effect, while the number of intrathecal administrations was not significantly associated with the extent of LE. This can suggest we should modify chemotherapeutic treatment regimens by decreasing the number of IV-MTX applications, with special attention for younger patients.

Abstract

Methotrexate (MTX) is associated with leukoencephalopathy (LE) in children treated for lymphoblastic leukemia/lymphoma (ALL/LBL). However, large-scale studies with systematic MR acquisition and quantitative volumetric lesion information remain limited. Hence, the prevalence of lesion burdens and the potential risk factors of LE in this population are still inconclusive. FLAIR-MRI scans were acquired at the end of treatment in children who were treated for ALL/LBL, which were quantitatively analyzed for LE. Voxels were assigned to the lesion segmentation if indicated by two raters. Logistic and linear regression models were used to test whether lesion presence and size were predicted by risk factors such as age at diagnosis, gender, intrathecal (IT-) or intravenous (IV-)MTX dose, CNS invasion, and acute neurological events. Patients with a pre-existing neurological condition or low-quality MR scan were excluded from the analyses. Of the 129 patients, ten (8%) suffered from CNS invasion. Chemotherapy-associated neurological events were observed in 13 patients (10%) during therapy, and 68 patients (53%) showed LE post-treatment. LE was more frequent in cases of lower age and higher cumulative IV-MTX doses, while the extent of LE and neurological symptoms were associated only with IV-MTX doses. Neurological events were not significantly associated with LE, even though symptomatic patients demonstrated a higher ratio of LE (n = 9/13) than asymptomatic patients (n = 59/116). This study suggests leukoencephalopathy frequently occurs in both symptomatic and asymptomatic leukemia patients. Younger children and patients treated with higher cumulative IV-MTX doses might need more regular screening for early detection and follow-up of associated sequelae.

Long-term clinically relevant rodent model of methotrexate-induced cognitive impairment

BACKGROUND

With the enhanced use of chemotherapy and the advent of increased patient survival rates, there are an increasing number of cancer survivors living with chemotherapy-induced cognitive impairment. A growing number of clinical studies have brought to light the association of agents like methotrexate in generating these neurological sequelae, although mechanisms remain unclear.

METHODS

Here, we use a clinically relevant regimen of several cycles of methotrexate and leucovorin rescue to develop a model of chemotherapy-induced cognitive impairment, and investigate the in vivo long-term (16 mo) impact of high-dose systemic methotrexate on white matter cellular dynamics as assessed by stereology, animal behavior, and diffusion tensor imaging.

RESULTS

Our results indicate that at 6 and 16 months post-chemotherapy, methotrexate-treated rats exhibit a significant and permanent decrease in the number of oligodendrocytes and their progenitors in the white matter, in corpus callosum volumes, and myelin basic protein. These findings are associated with mostly delayed deficits in performance on Morris Water Maze and Novel Object Recognition tasks. Diffusion tensor imaging demonstrates significantly decreased fractional anisotropy values in the callosum genu, body, and splenium, as well as previously unassessed areas like the fimbria. Interestingly, these white matter changes are preceded by an earlier, transient decrement in white matter microglia at 3 months, and hippocampal neural progenitors at 3 and 6 months.

CONCLUSION

These results demonstrate a significant negative impact of methotrexate on the oligodendrocyte compartment and white matter, associated with cognitive impairment. The data also support the use of diffusion tensor imaging in monitoring white matter integrity in this context.

Dextromethorphan Administration on Day 0 and Day 7 for Secondary Prevention of Methotrexate-induced Neurotoxicity in Childhood Acute Lymphoblastic Leukemia: A Retrospective Case Series

Acute lymphoblastic leukemia is the most common malignancy in children. Long-term survival exceeds 90%; however, therapy-induced toxicity remains a concern. Methotrexate neurotoxicity (MTX-NT) is common, often necessitating alterations in chemotherapy regimens. Dextromethorphan has been used as an abortive and prophylactic treatment for MTX-NT. The authors report a case series of 7 pediatric patients with acute lymphoblastic leukemia with prior episodes of MTX-NT given a single dose of dextromethorphan (1 to 2 mg/kg) on the day of MTX administration and 7 days later. No subsequent episodes of MTX-NT occurred after 40 intravenous and 81 intrathecal administrations. This specific regimen of secondary prophylaxis may prevent MTX-NT.

Ambulatory high-dose methotrexate administration as central nervous system prophylaxis in patients with aggressive lymphoma

High-dose methotrexate (HD-MTX) at 3 g/m² is one of the strategies for central nervous system (CNS) prophylaxis in the first-line treatment of aggressive lymphomas, especially in diffuse large B cell lymphoma patients with high-risk CNS-International Prognostic Index. The objective of our study was to retrospectively analyze the safety of 2 cycles of systemic HD-MTX administered as an ambulatory regimen. Between January 2013 and December 2016, 103 patients were carefully selected on 6 criteria, including age < 60, albumin > 34, performance status 0 or 1, normal renal and hepatic functions, good understanding of practical medical guidance, and no loss of weight. Strict procedures of HD-MTX infusion were observed including alkalinization, urine pH monitoring, and leucovorin rescue. Renal and hepatic functions were monitored at days 2 and 7. MTX clearance was not monitored. Toxicities and grades of toxicity were collected according to the NCI-CTCAE (version 4.0). Among the 103 selected patients, 92 (89%) patients successfully completed the planned 2 cycles of HD-MTX on an outpatient basis. Eleven patients completed only 1 cycle, 3 because of lymphoma progression and 8 because of toxicity including 3 grade II hepatotoxicity, 2 grade I/II renal toxicity, 1 grade III neutropenia, 1 active herpetic infection, and 1 grade III ileus reflex. Reported adverse events (AE) included 92 (84%) grade I/II and 18 (16%) grade III/IV. Grade III hepatotoxicity, mostly cytolysis, was the most frequent AE observed with 8 (8%) events. Grade III/IV hematologic toxicities concerned 9 patients with 8 grade III/IV neutropenia and 1 thrombocytopenia. Renal toxicity was rare, mild, and transient, observed with 4 (4%) grade I/II events. Ambulatory administration of HD-MTX at 3 g/m² without MTX clearance monitoring is safe with strict medical guidance. It requires careful selection of patients before administration, and a renal and hepatic monitoring after the administration.

Methotrexate-related central neurotoxicity: clinical characteristics, risk factors and genome-wide association study in children treated for acute lymphoblastic leukemia

Symptomatic methotrexate-related central neurotoxicity, 'MTX neurotoxicity', is a severe toxicity experienced during acute lymphoblastic leukemia (ALL) therapy with potential long-term neurologic complications. Risk factors and long-term outcomes require further study. We conducted a systematic, retrospective review of 1251 consecutive Australian children enrolled on BFM or COG-based protocols between 1998-2013. Clinical risk predictors for MTX neurotoxicity were analyzed using regression. A genome-wide association study (GWAS) was performed on 48 cases and 537 controls. The incidence of MTX neurotoxicity was 7.6% (n=95/1251), at a median of 4 months from ALL diagnosis and 8 days after intravenous or intrathecal MTX. Grade 3 elevation of serum aspartate aminotransferase (P=0.005, OR 2.31 (1.28-4.16)) in induction/consolidation was associated with MTX neurotoxicity, after accounting for the only established risk factor, age a10 years. Cumulative incidence of CNS relapse was increased in children where intrathecal MTX was omitted following symptomatic MTX neurotoxicity (n=48) compared to where intrathecal MTX was continued throughout therapy (n=1174) (P=0.047). Five-year CNS relapsefree survival was 89.2%±4.6% when intrathecal MTX was ceased compared to 95.4%±0.6% when intrathecal MTX was continued. Recurrence of MTX neurotoxicity was low (12.9%) for patients whose intrathecal MTX was continued after their first episode. The GWAS identified SNPs associated with MTX neurotoxicity near genes regulating neuronal growth, neuronal differentiation and cytoskeletal organization (P>1E-06). In conclusion, increased serum aspartate aminotransferase and age a10 years at diagnosis were independent risk factors for MTX neurotoxicity. Our data do not support cessation of intrathecal MTX after a first MTX neurotoxicity event.

The safety of current pharmacotherapeutic strategies for osteosarcoma

Introduction: Peri-operative chemotherapy is the backbone of treatment for patients with osteosarcoma. Methotrexate, cisplatinum, doxorubicin and ifosfamide are the main drugs used in chemotherapy regimens used for osteosarcoma.Areas covered: We have reviewed here the relevant literature related to the incidence and management of acute and late toxicities of systemic treatment used for the management of patients with osteosarcoma.Expert opinion: Early diagnosis and appropriate management of acute and late toxicities of chemotherapy is crucial for an efficient care of osteosarcoma patients. Although the incidence and management of chemotherapy-related acute toxicities are well known by most oncologists, the use of high doses of methotrexate have the potential to cause fatal toxicities and, therefore, needs careful monitoring. Moreover, the diagnosis of late toxicities is more challenging and requires long-term follow-up for an appropriate management.

Characterization of Leukoencephalopathy and Association With Later Neurocognitive Performance in Pediatric Acute Lymphoblastic Leukemia

OBJECTIVES

The most common form of pediatric cancer is acute lymphoblastic leukemia (ALL). Magnetic resonance (MR) neuroimaging studies have revealed leukoencephalopathy (LE) in pediatric ALL, but the impact of LE on long-term neurocognitive performance remains unknown. This study aims to objectively characterize the prevalence, extent, and intensity of LE, and their association with later neurocognitive performance.

MATERIALS AND METHODS

Pediatric patients (N = 377) treated for ALL without irradiation underwent MR neuroimaging at 4 time points throughout therapy (end of remission induction [MR1], end of consolidation [MR2], and week 31 [MR3] and week 120 [end therapy, MR4] of continuation treatment) and neurocognitive evaluations at the end of therapy and 2 years later. Generalized estimation equation models with logit link were developed to explore the association between LE prevalence and extent with time points throughout therapy, age at diagnosis (≤5 years or >5 years), treatment risk arm (low risk or standard/high risk), and sex. General linear models were also developed to investigate the association between neuroimaging metrics during treatment and neurocognitive performance at 2-year follow-up.

RESULTS

The prevalence of LE was greatest (22.8%, 74/324) after consolidation therapy. The prevalence of LE increased at MR2 relative to MR1 regardless of treatment risk arm (both P's < 0.001), age group (both P's < 0.001), or sex (male, P < 0.001; female, P = 0.013). The extent of white matter affected also increased at MR2 relative to MR1 regardless of treatment risk arm (standard/high risk, P < 0.001; low risk, P = 0.004), age group (both P's < 0.001), or sex (male, P < 0.001; female, P = 0.001). Quantitative relaxation rates were significantly longer in LE compared with that in normal-appearing white matter in the same examination (T1, P < 0.001; T2, P < 0.001). The LE prevalence early in therapy was associated with increased parent ratings of conduct problems (P = 0.039) and learning difficulties (P = 0.036) at 2-year follow-up compared with that at the end of therapy. A greater extent of LE early in therapy was associated with decreasing performance on a measure of processing speed (P = 0.003) from the end of therapy to 2-year follow-up. A larger extent of LE at the end of therapy was associated with decreased performance in reading (P = 0.004), spelling (P = 0.003), and mathematics (P = 0.019) at 2-year follow-up and increasing problems with attention (omissions, P = 0.045; β, P = 0.015) and memory (list A total recall, P = 0.010) at 2-year follow-up compared with that at the end of therapy.

CONCLUSIONS

In this large cohort of pediatric patients treated for ALL without irradiation, asymptomatic LE during therapy can be seen in almost a quarter of patients, involves as much as 10% of the white matter volume, and is associated with decreasing neurocognitive performance, increasing parent reports of conduct problems, and learning difficulties in survivors.

Characterizing the phenotype of drug-resistant childhood epilepsy associated with leukemia: A case series

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Two phenotypes of drug-resistant epilepsy were noted in children with prior leukemia, focal epilepsy, and epileptic encephalopathy in the form of Lennox-Gastaut syndrome.

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Temporal lobectomy was effective in two children with mesial temporal sclerosis.

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Corpus callosotomy and vagus nerve stimulation was tried in children with epileptic encephalopathy with variable outcomes.

Children with leukemia are at risk for epilepsy due to primary disease or neurotoxic therapies. We describe the phenotypes of drug-resistant epilepsy in 10 children with history of leukemia.

Of 10 cases, 6 had features of Lennox-Gastaut syndrome, and 4 had focal epilepsy. Mean age of epilepsy onset was 5 years in Lennox-Gastaut cases and 6.5 years in focal epilepsy cases. Mean latency between leukemia diagnosis and seizure onset was about 3 years. Brain MRI of 2 patients with epileptic encephalopathy had structural abnormalities – unclear if causative for epilepsy, and 4 had no overt structural abnormalities. In focal epilepsy group, 3 had temporal lobe epilepsy and one had fronto-temporal localization. All 10 patients had received intrathecal chemotherapy; 2 also had received whole brain irradiation. Seizures were poorly controlled in the epileptic encephalopathy group. Three underwent corpus callosotomy with variable response. Two patients with temporal lobe epilepsy had temporal lobectomy with Engel 1 outcome at 2 year follow-up in both.

Two phenotypes of refractory epilepsy were observed in children with previous history of leukemia, focal epilepsy and epileptic encephalopathy. Children with temporal lobe epilepsy had good response to temporal lobectomy; response to palliative surgery was variable.

Cerebrospinal Fluid Biomarkers in Childhood Leukemias

Involvement of the central nervous system (CNS) in childhood leukemias remains a major cause of treatment failures. Analysis of the cerebrospinal fluid constitutes the most important diagnostic pillar in the detection of CNS leukemia and relies primarily on cytological and flow-cytometry studies. With increasing survival rates, it has become clear that treatments for pediatric leukemias pose a toll on the developing brain, as they may cause acute toxicities and persistent neurocognitive deficits. Preclinical research has demonstrated that established and newer therapies can injure and even destroy neuronal and glial cells in the brain. Both passive and active cell death forms can result from DNA damage, oxidative stress, cytokine release, and acceleration of cell aging. In addition, chemotherapy agents may impair neurogenesis as well as the function, formation, and plasticity of synapses. Clinical studies show that neurocognitive toxicity of chemotherapy is greatest in younger children. This raises concerns that, in addition to injury, chemotherapy may also disrupt crucial developmental events resulting in impairment of the formation and efficiency of neuronal networks. This review presents an overview of studies demonstrating that cerebrospinal fluid biomarkers can be utilized in tracing both CNS disease and neurotoxicity of administered treatments in childhood leukemias.

Oral Health, Caries Risk Profiles, and Oral Microbiome of Pediatric Patients with Leukemia Submitted to Chemotherapy

Background

Chemotherapy is the primary treatment modality used for patients with acute lymphoblastic leukemia (ALL), but inevitably causes microbiota-related oral complications. This study is aimed at investigating the effects of chemotherapy on oral health status, caries risk, and oral microbiome in pediatric patients with ALL.

Methods

Thirty-nine children with ALL receiving chemotherapy were enrolled, and a gender-, age-, dentition stage, and socioeconomic class matched healthy counterpart were recruited. Demographic information and overall health condition were obtained through the questionnaire and medical records. Oral examination was performed to assess caries and salivary status, plaque index, and other oral manifestations. Cariogram was used to assess the overall caries risk. Supragingival samples of thirteen ALL subjects and their counterparts were randomly selected to perform a 16S ribosomal RNA gene 454 pyrosequencing. Raw sequence data were screened, trimmed, and filtered using Seqcln and MOTHUR.

Results

The prevalence of dental caries, gingivitis, oral mucositis, xerostomia, and candidiasis in ALL groups was higher than that of the control group (p < 0.05). Children with ALL demonstrated higher caries risk compared to healthy controls (HC) based upon Cariogram (p < 0.05). The oral microbial structure of ALL patients receiving chemotherapy is different from that of healthy controls. Oral microbiota of ALL groups showed less alpha diversity and significant differences in the composition of the oral microbiome compared to healthy controls.

Conclusions

ALL patients receiving chemotherapy demonstrated compromised oral health, high caries risk, alteration of caries-related factors, and dysbiosis of oral microbiota. These findings may be of clinical importance in developing better strategies for personalized preventive management of oral diseases for pediatric children with ALL.

Effect of Body Fat on Population Pharmacokinetics of High-Dose Methotrexate in Pediatric Patients With Acute Lymphoblastic Leukemia

Nearly all international regimens for pediatric acute lymphoblastic leukemia (ALL) incorporate intravenous "high-dose" methotrexate (HDMTX, ≥1 g/m² ) to penetrate the central nervous system. Dosing is routinely adjusted for body surface area (BSA), but limited data describe the pharmacokinetics of HDMTX, particularly in obese and/or large patients. To understand the impact of body size (BSA) and body fat percentage (BFP) on HDMTX pharmacokinetics, we performed a secondary analysis of 36 children and adolescents 10-21 years old treated for newly diagnosed ALL and who were enrolled in a prospective study examining body composition. All patients received 5 g/m² of HDMTX infused over 24 hours. Plasma methotrexate concentrations were measured at 24, 42, and 48 hours. At 48 hours, ≥0.4 μmol/L was defined as "delayed elimination," necessitating prolonged supportive care. BFP was measured using dual-energy x-ray absorptiometry. A nonparametric population pharmacokinetic model was constructed with subsequent simulations to explore effects of BSA and BFP extremes. Despite standard BSA-adjusted dosing, we found significant intrapatient variability in mean MTX concentration (38%; range, 1.2%-86%). BSA and BFP were not linearly associated with increased area under the curve (AUC, P = 0.74 and P = 0.12), but both larger size (BSA) and greater obesity (BFP) were associated with an approximately 2-fold higher risk for delayed elimination at 48 hours. HDMTX AUC was not associated with toxicity. MTX pharmacokinetics vary among and even within patients despite BSA-adjusted dosing. Obesity and large size are identified as new risk factors for delayed elimination, requiring further investigation.

Connectivity of the Cerebello-Thalamo-Cortical Pathway in Survivors of Childhood Leukemia Treated With Chemotherapy Only

IMPORTANCE

Treatment with contemporary chemotherapy-only protocols is associated with risk for neurocognitive impairment among survivors of childhood acute lymphoblastic leukemia (ALL).

OBJECTIVE

To determine whether concurrent use of methotrexate and glucocorticoids is associated with interference with the antioxidant system of the brain and damage and disruption of glucocorticoid-sensitive regions of the cerebello-thalamo-cortical network.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study was conducted from December 2016 to July 2019 in a single pediatric cancer tertiary care center. Participants included survivors of childhood ALL who were more than 5 years from cancer diagnosis, age 8 years or older, and treated on an institutional chemotherapy-only protocol. Age-matched community members were recruited as a control group. Data were analyzed from August 2017 to August 2020.

EXPOSURE

ALL treatment using chemotherapy-only protocols.

MAIN OUTCOMES AND MEASURES

This study compared brain volumes between survivors and individuals in a community control group and examined associations among survivors of methotrexate and dexamethasone exposure with neurocognitive outcomes. Functional and effective connectivity measures were compared between survivors with and without cognitive impairment. The Rey-Osterrieth complex figure test, a neurocognitive evaluation in which individuals are asked to copy a figure and then draw the figure from memory, was scored according to published guidelines and transformed into age-adjusted z scores based on nationally representative reference data and used to measure organization and planning deficits. β values for neurocognitive tests represented the amount of change in cerebellar volume or chemotherapy exposure associated with 1 SD change in neurocognitive outcome by z score (mm3/1 SD in z score for cerebellum, mm3/[g×hr/L] for dexamethasone and methotrexate AUC, and mm3/intrathecal count for total intrathecal count).

RESULTS

Among 302 eligible individuals, 218 (72%) participated in the study and 176 (58%) had usable magnetic resonance imaging (MRI) results. Among these, 89 (51%) were female participants and the mean (range) age was 6.8 (1-18) years at diagnosis and 14.5 (8-27) years at evaluation. Of 100 community individuals recruited as the control group, 82 had usable MRI results; among these, 35 (43%) were female individuals and the mean (range) age was 13.8 (8-26) years at evaluation. There was no significant difference in total brain volume between survivors and individuals in the control group. Survivors of both sexes showed decreased mean (SD) cerebellar volumes compared with the control population (female: 70 568 [6465] mm3 vs 75 134 [6780] mm3; P < .001; male: 77 335 [6210] mm3 vs 79 020 [7420] mm3; P < .001). In female survivors, decreased cerebellar volume was associated with worse performance in Rey-Osterrieth complex figure test (left cerebellum: β = 55.54; SE = 25.55; P = .03; right cerebellum: β = 52.57; SE = 25.50; P = .04) and poorer dominant-hand motor processing speed (ie, grooved pegboard performance) (left cerebellum: β = 82.71; SE = 31.04; P = .009; right cerebellum: β = 91.06; SE = 30.72; P = .004). In female survivors, increased number of intrathecal treatments (ie, number of separate injections) was also associated with Worse Rey-Osterrieth test performance (β = -0.154; SE = 0.063; P = .02), as was increased dexamethasone exposure (β = -0.0014; SE = 0.0005; P = .01). Executive dysfunction was correlated with increased global efficiency between smaller brain regions (Pearson r = -0.24; P = .01) compared with individuals without dysfunction. Anatomical connectivity showed differences between impaired and nonimpaired survivors. Analysis of variance of effective-connectivity weights identified a significant interaction association (F = 3.99; P = .02) among the direction and strength of connectivity between the cerebellum and DLPFC, female sex, and executive dysfunction. Finally, no effective connectivity was found between the precuneus and DLPFC in female survivors with executive dysfunction.

CONCLUSIONS AND RELEVANCE

These findings suggest that dexamethasone exposure was associated with smaller cerebello-thalamo-cortical regions in survivors of ALL and that disruption of effective connectivity was associated with impairment of executive function in female survivors.

Real-time intracranial pressure monitoring during high-dose methotrexate treatment for primary central nervous system lymphoma

BACKGROUND

Primary central nervous system lymphoma (PCNSL) is an aggressive non-Hodgkin lymphoma with exclusive central nervous system (CNS) and/or ocular involvement. Increased intracranial pressure (ICP) from cerebral edema can commonly presents secondary to the mass effect of PCNSL. Methotrexate-based induction chemotherapy is the gold standard for treatment, however, several neurotoxic complications have been associated with high-dose methotrexate (HD-MTX) treatment. Tumor lysis and other biochemical disruptions following administration of HD-MTX are postulated to increase cerebral edema and ICP in predisposed patients, therefore, in the setting of ring-enhancing lesions with significant mass effect, monitoring of ICP to prevent cerebral herniation may be necessary.

PRESENTATION OF CASE

We present the case of a patient with diffuse cerebral edema secondary to PCNSL, who was treated with methotrexate-based induction chemotherapy and underwent real-time ICP monitoring to allow for early recognition, and management with aggressive medical therapy to prevent worsening cerebral edema and potential fatal herniation.

DISCUSSION AND CONCLUSIONS

Treatment of patients with high tumor burden PCNSL can prove to be challenging, particularly at the time of initiation of methotrexate based induction chemotherapy in the setting of impending cerebral herniation, as in the case presented. Close monitoring of the patient's ICP proved advantageous in rapidly recognizing, and successfully treating elevations in ICP that could have worsened mass effect and lead to fatal herniation.

Neurological complications of pediatric cancer

Both the onset of various malignancies as well as the treatment of cancer can lead to neurologic symptoms which can be difficult to diagnose. In this review, we highlight the varied ways in which neurologic sequelae of cancer and its treatment manifest in children. Initial neurologic presentation may be secondary to mass effect or to immune-mediated paraneoplastic syndromes. Treatment effects on the nervous system may arise from surgery, chemotherapy, radiation, or bone marrow transplantation. In addition, the rapidly expanding field of immunotherapies for cancer has generated numerous new approaches to eradicating cancer including monoclonal antibodies, checkpoint inhibitors, and chimeric antigen receptor T cells (CAR-T cells), which have neurologic side effects mediated by immune responses that are also being recognized. Here we review common consult questions to the neurologist and our general approach to these scenarios including altered mental status, headaches, seizures, and sensorimotor complaints, considering the multifactorial nature of each.