Neurologic complications of chemotherapy for children with cancer

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

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

Optic pathway tumor in children: Toward a new classification for neurosurgical use

OBJECT

Optic pathway tumors (OPT) represent a challenge for pediatric neurosurgeons. Role of surgery is debated due to the high risk of iatrogenic damage, and in lasts decades it lost its importance in favor of chemotherapy. However, in some cases surgery is necessary to make biomolecular and histological diagnosis, to manage intracranial hypertension (IH) and to cooperate with medical therapies in controlling tumor relapse. With the aim to standardize selection of surgical OPT cases, we propose a simple, practical and reproducible classification.

METHODS

We retrospectively analyzed data of 38 patients with OPT treated at our institution (1990-2018). After careful analysis of MRI images, we describe a new classification system. Group 1: lesion limited to one or both optic nerve(s). Group 2: chiasmatic lesions extending minimally to hypothalamus. Group 3: hypothalamo-chiasmatic exophitic lesions invading the third ventricle; they can be further divided on the base of concomitant hydrocephalus. Group 4: hypothalamo-chiasmatic lesions extending widely in lateral direction, toward the temporal or the frontal lobes. Patients' data and adopted treatment are reported and analyzed, also depending on this classification.

RESULTS

Twenty children were operated on for treatment of OPT during the study period. Permanent clinical impairment was noted in 5 (25%) of operated patients, while visual improvement was noted in 1 patient. OS rate was 100% at 5 years, with a median follow up of 9 years (ranging from 2 to 23). Prevalence of intracranial hypertension and proportion of first-line surgical treatment decision were significantly higher in groups 3-4 compared to groups 1-2 (P<0.001 for both tests).

CONCLUSION

Surgery can offer a valuable therapeutic complement for OPT without major risk of iatrogenic damage. Surgery is indispensable in cases presenting with IH, as in groups 3 and 4 lesions. Eligibility of patients to surgery can be based on this new classification system.

[White matter alterations after chemotherapy and radiation]

Nowadays chemotherapy and radiotherapy are fundamental therapy concepts in the guidelines of malignant tumors of the central nervous system. Both therapy concepts can cause neurological symptoms or white matter alterations can occur, which can be classified into acute, subacute and chronic. Both symptoms and white matter alterations during acute and subacute phases are in most cases completely reversible, whereas chronic white matter alterations can lead to severe neurological limitations and further impair the quality of life of cancer patients.

Progressive myelopathy mimicking subacute combined degeneration after intrathecal chemotherapy

Intrathecal chemotherapy including methotrexate is well documented for neurotoxicity of diverse clinical manifestation. Acute or chronic leukoencephalopathy is the most common type of methotrexate-induced neurotoxicity, and subacute myelopathy is rare. Although its pathogenesis is not fully understood, it is postulated that direct damage of methotrexate to the central nervous system plays a major part and elevated levels of homocysteine and its excitatory amino acid neurotransmitter metabolites (homocysteic acid and cysteine sulfinic acid) could mediate, in part, MTX-associated neurotoxicity. On the while, subacute combined degeneration is a progressive degeneration of the dorsal and lateral columns of the spinal cord, mostly due to vitamin B12 deficiency. The authors report a case of a 15-year-old boy with Burkitt leukemia who developed progressive myelopathy after intrathecal triple therapy (methotrexate, cytarabine, and hydrocortisone) whose clinical and radiologic features were compatible with subacute combined degeneration. The pathogenic mechanism could be explained by biochemical alteration by methotrexate and a possible treatment strategy was discussed.

Neurotoxicity of cancer chemotherapy

There is accumulating clinical evidence that chemotherapeutic agents induce neurological side effects, including memory deficits and mood disorders, in cancer patients who have undergone chemotherapeutic treatments. This review focuses on chemotherapy-induced neurodegeneration and hippocampal dysfunctions and related mechanisms as measured by in vivo and in vitro approaches. These investigations are helpful in determining how best to further explore the causal mechanisms of chemotherapy-induced neurological side effects and in providing direction for the future development of novel optimized chemotherapeutic agents.

Anesthesia for the child with cancer

Children with cancer undergo a host of surgeries and procedures that require anesthesia during the various phases of the disease. A safe anesthetic plan includes consideration of the direct effects of tumor, toxic effects of chemotherapy and radiation therapy, the specifics of the surgical procedure, drug-drug interactions with chemotherapy agents, pain syndromes, and psychological status of the child. This article provides a comprehensive overview of the anesthetic management of the child with cancer, focuses on a systems-based approach to the impact from both tumor and its treatment in children, and presents a discussion of the relevant anesthetic considerations.

Hemorrhagic and ischemic stroke in children with cancer

BACKGROUND

Adult survivors of childhood cancer have an increased risk of cerebrovascular disease; little is known about early stroke risk in childhood cancer. Our objectives were to assess stroke prevalence in children with cancer, to establish cancer and stroke type, and to determine if modifiable risk factors for stroke were present.

METHODS

Children with stroke and cancer were compared with all children seen for cancer at a single institution between 2000 and 2009. An International Classification of Disease, 9th version, code search and search of existing pediatric oncology and stroke databases identified children <18 years with ischemic stroke, intracerebral hemorrhage, and cerebral sinovenous thrombosis.

RESULTS

Of 1411 children with cancer, 15 had a stroke (1.1%, 95% CI: 0.6-1.7%). Stroke classifications were seven intracerebral hemorrhages, five ischemic strokes (one of which was followed by intracerebral hemorrhage), and three sinovenous thromboses. Stroke occurred at a median of 5 months after cancer diagnosis. Ten children with strokes had hematologic malignancies and five had brain tumors. Thirteen patients died poststroke, eight because of withdrawal of care. White blood cell count ≥48,000/mm3 was found in four children, all with intracerebral hemorrhage. Five of seven children with intracerebral hemorrhage had platelets <50,000/mm3.

CONCLUSIONS

Stroke has a prevalence of approximately 1% in children with cancer. Hemorrhagic stroke and ischemic stroke occur with approximately equal frequency; children with leukemia and brain tumors are at greatest risk.

Ages and Stages Questionnaires-3 developmental screening of infants and young children with cancer

The Ages and Stages Questionnaires-3® (ASQ-3) for developmental screening in our young oncology patients was pilot tested in children 4 to 48 months of age with newly diagnosed cancer. Subjects were screened within 28 days of diagnosis (baseline), at 6 and 12 months. Twenty-six of 30 enrolled parents (87%) completed all 3 screens. Screens were completed by parents within 15 minutes. ASQ-3 screening identified unsuspected developmental delays as follows: 7 at baseline, 4 at 6 months, and 3 at 12 months. ASQ-3 developmental screening is feasible, identifies early developmental delays in young children with cancer, and helps initiate appropriate referrals.

Nicotinamide inhibits alkylating agent-induced apoptotic neurodegeneration in the developing rat brain

BACKGROUND

Exposure to the chemotherapeutic alkylating agent thiotepa during brain development leads to neurological complications arising from neurodegeneration and irreversible damage to the developing central nerve system (CNS). Administration of single dose of thiotepa in 7-d postnatal (P7) rat triggers activation of apoptotic cascade and widespread neuronal death. The present study was aimed to elucidate whether nicotinamide may prevent thiotepa-induced neurodegeneration in the developing rat brain.

METHODOLOGY/PRINCIPAL FINDINGS

Neuronal cell death induced by thiotepa was associated with the induction of Bax, release of cytochrome-c from mitochondria into the cytosol, activation of caspase-3 and cleavage of poly (ADP-ribose) polymerase (PARP-1). Post-treatment of developing rats with nicotinamide suppressed thiotepa-induced upregulation of Bax, reduced cytochrome-c release into the cytosol and reduced expression of activated caspase-3 and cleavage of PARP-1. Cresyl violet staining showed numerous dead cells in the cortex hippocampus and thalamus; post-treatment with nicotinamide reduced the number of dead cells in these brain regions. Terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end-labeling (TUNEL) and immunohistochemical analysis of caspase-3 show that thiotepa-induced cell death is apoptotic and that it is inhibited by nicotinamide treatment.

CONCLUSION

Nicotinamide (Nic) treatment with thiotepa significantly improved neuronal survival and alleviated neuronal cell death in the developing rat. These data demonstrate that nicotinamide shows promise as a therapeutic and neuroprotective agent for the treatment of neurodegenerative disorders in newborns and infants.

Neurotoxicity of methotrexate to hippocampal cells in vivo and in vitro

This study investigated whether methotrexate (MTX) is neurotoxic to neural progenitor cells in the hippocampus of adult mice and whether it affects hippocampus-dependent behaviors. In addition, the cytotoxicity of MTX was elucidated in rat immature and mature hippocampal cultured cells. The number of Ki-67 (proliferating cell marker)- and doublecortin (immature progenitor neuron marker)-positive cells were significantly time- and dose-dependently changed in the dentate gyrus of adult hippocampi after MTX treatment. A learning and memory task (object recognition memory test) and depression-like behavior test (tail-suspension test) were performed after MTX treatment to assess hippocampal neurogenesis-related behavioral dysfunction. MTX-treated mice showed significant depression-like behaviors and memory defects. The cytotoxicity of MTX in immature hippocampal cells varied in a dose-dependent pattern, but was not changed in the mature cells. MTX induced marked apoptotic changes in immature hippocampal cells, with increase in active caspase-3 and cleaved poly (ADP-ribose) polymerase expressions. Results of this study suggest that the neurotoxic effect of MTX inhibits the proliferation of hippocampal progenitor cells and can cause hippocampal dysfunction, such as depression and cognitive impairment. Additionally, the significantly greater caspase-dependent MTX sensitivity of immature hippocampal cells suggests that the susceptibility of such hippocampal cells depends on their maturation.

The developmental neurotoxicity study of platinum compounds. Effects of cisplatin versus a novel Pt(II) complex on rat cerebellum

In the field of experimental oncology, many efforts are being carried out to search new platinum-based drugs overcoming the CNS toxicity and drug resistance. One of the adopted strategies is the synthesis of platinum compounds able to form Pt-DNA adducts different from the cisplatin ones or to react with other subcellular targets. In this context a novel Pt(II) complex, [Pt(O,O'-acac)(γ-acac)(DMS)](PtAcacDMS), was synthesized which reacts preferentially with protein thiols or thioethers. In this work we investigated the in vivo effects of cisplatin and PtAcacDMS on normal development. Moreover, to verify the dose-dependence of the effects, different groups of animals were treated with 5 μg/g or 10 μg/g body weight of cisPt and PtAcacDMS. We have focused our attention on the cerebellum because it provides a useful model system to evaluate the outcomes of perinatal treatment with chemotherapeutic agents on key CNS developmental processes such as neural cells proliferation, migration and differentiation. We have demonstrated the ability of both cisPt and PtAcacDMS to reach the brain tissue once injected. The brain platinum content after PtAcacDMS treatment was notably higher (approximately 4-fold as much) than after cisPt. The platinum accumulation in the brain was still considerable 7 days after PtAcacDMS administration. However, compared with cisplatin, PtAcacDMS induces less severe changes on fundamental events of neuroarchitecture development, such as no high apoptotic events, less altered granule cell migration and Purkinje cell dendrite growth, suggesting a low neurotoxicity of this new Pt complex for normal CNS. The mild damages could be attributable to the different subcellular target of this compound as well as to a greater efficiency of the cell repair system to recognize the drug-target adducts and to repair them. Together with the previously demonstrated antineoplastic effectiveness in vitro, the findings here reported suggest PtAcacDMS as a potential alternative to cisplatin indicating, at the same time, that the choice of platinum compounds with new subcellular targets could be a strategy to prevent neurotoxicity induced by cisplatin and overcome drug resistance induced by mutations in the intrinsic apoptotic pathway.

Anesthetic considerations for the pediatric oncology patient--part 2: systems-based approach to anesthesia

One of the prices paid for chemo- and radiotherapy of cancer in children is damage to the vulnerable and developing healthy tissues of the body. Such damage can exist clinically or subclinically and can become apparent during active antineoplastic treatment or during remission decades later. Furthermore, effects of the tumor itself can significantly impact the physiologic state of the child. The anesthesiologist who cares for children with cancer or for survivors of childhood cancer should understand what effects cancer and its therapy can have on various organ systems. In part two of this three-part review, we review the anesthetic issues associated with childhood cancer. Specifically, this review presents a systems-based approach to the impact from both tumor and its treatment in children, followed by a discussion of the relevant anesthetic considerations.

Leucoencephalopathy, transverse myelopathy, and peripheral neuropathy in association with glutamic acid decarboxylase-65 (GAD) antibodies in children with cancer

Neurologic toxicity may occur as a direct effect of cancer and its therapy or indirectly because of a dysfunctional immune system. The authors report the development of axonal neuropathy, myelopathy, and leucoencephalopathy associated with glutamic acid decarboxylase-65 (GAD) antibodies in 4 children with progressive cancer who were heavily pretreated. Three patients with refractory leukemia and 1 with Ewing sarcoma developed paraplegia with sensory level and dorsal column dysfunction. Three developed leucoencephalopathy and 1 died of neurologic disease. All had high serum titers of GAD antibodies during the progressive phase of the illness, and the antibody levels returned to normal with the stability of the neurologic disease. Three survivors are showing gradual recovery. This syndrome of central and peripheral nervous system toxicity may have resulted from chemotherapy toxicity or from immune dysfunction, as suggested by the high GAD antibody titers.

Systemic 5-fluorouracil treatment causes a syndrome of delayed myelin destruction in the central nervous system

BACKGROUND

Cancer treatment with a variety of chemotherapeutic agents often is associated with delayed adverse neurological consequences. Despite their clinical importance, almost nothing is known about the basis for such effects. It is not even known whether the occurrence of delayed adverse effects requires exposure to multiple chemotherapeutic agents, the presence of both chemotherapeutic agents and the body's own response to cancer, prolonged damage to the blood-brain barrier, inflammation or other such changes. Nor are there any animal models that could enable the study of this important problem.

RESULTS

We found that clinically relevant concentrations of 5-fluorouracil (5-FU; a widely used chemotherapeutic agent) were toxic for both central nervous system (CNS) progenitor cells and non-dividing oligodendrocytes in vitro and in vivo. Short-term systemic administration of 5-FU caused both acute CNS damage and a syndrome of progressively worsening delayed damage to myelinated tracts of the CNS associated with altered transcriptional regulation in oligodendrocytes and extensive myelin pathology. Functional analysis also provided the first demonstration of delayed effects of chemotherapy on the latency of impulse conduction in the auditory system, offering the possibility of non-invasive analysis of myelin damage associated with cancer treatment.

CONCLUSIONS

Our studies demonstrate that systemic treatment with a single chemotherapeutic agent, 5-FU, is sufficient to cause a syndrome of delayed CNS damage and provide the first animal model of delayed damage to white-matter tracts of individuals treated with systemic chemotherapy. Unlike that caused by local irradiation, the degeneration caused by 5-FU treatment did not correlate with either chronic inflammation or extensive vascular damage and appears to represent a new class of delayed degenerative damage in the CNS.

CNS complications in children receiving chemotherapy or hematopoietic stem cell transplantation: retrospective analysis and clinical study of survivors

BACKGROUND

Clinical studies analyzing CNS complications in pediatric oncology systematically are rare.

PROCEDURE

In a single center retrospective analysis, CNS complications in 950 subsequent pediatric patients treated between 1992 and 2004 by chemotherapy or hematopoietic stem cell transplantation (HSCT) were studied. Forty-six patients had pre-existing CNS diseases and were excluded. Out of the 904 remaining, 76 (8.4%) had 82 CNS complications.

RESULTS

The most common manifestations were seizures (in 50.6% of the CNS episodes), altered states of consciousness, and motor deficits (in 47.5% of the episodes each). CNS complications were caused by infections (26.8%), toxicity (25.6%), neoplasma (13.4%), vascular (10.9%), and metabolic disturbances (8.5%). In 14.6%, the mechanism remained unclear. Patients (23.7%) died from the CNS event. Neoplastic disorders had the worst (50%) while metabolic the best (0% mortality) prognosis. Imaging techniques were the most effective diagnostic measures, followed by laboratory analysis, clinical examination, and CSF analysis. A neuro-psychological (CBCL, CFT-1/-20-testing) examination could be done in 21 of 32 long-term survivors. Seven had a major, 3 minor neurological impairment, 11 were normal in all tests.

CONCLUSIONS

These data show that there is not one typical CNS complication, but a wide variety. There is no close connection between either underlying disease or symptoms and cause of the complication. Prognosis is variable. About two thirds of the long-term survivors could lead a normal life.

Management of optic-hypothalamic gliomas in children: still a challenging problem

Optic pathway-hypothalamic gliomas (OPHGs) are rare, often unresectable tumors that mostly occur in childhood. Their biological behavior is unpredictable, although they tend to follow an aggressive clinical course in infants and a benign course in children with neurofibromatosis type 1. Optimal management is still controversial. Nonprogressing OPHGs are usually followed by surveillance alone. Surgery is advocated for progressing tumors to decompress the optic pathways, obtain a quick relief from intracranial hypertension and allow histologic examination (when needed). The current trend is in favor of conservative surgical behavior, except for resectable tumors. Chemotherapy is increasingly used in the management of OPHGs, especially in infants, to delay radiotherapy. Carboplatin and vincristine are the most frequently used drugs, although several chemotherapeutic agents in different combinations are currently employed with good results. Radiotherapy is utilized in children over 5 years of age as an adjuvant or as an alternative to surgery. The prognosis of OPHGs is quite good, with regard to the overall survival rate (70-100% at 5 years), but less favorable in terms of late morbidity.

CNS progenitor cells and oligodendrocytes are targets of chemotherapeutic agents in vitro and in vivo

Background

Chemotherapy in cancer patients can be associated with serious short- and long-term adverse neurological effects, such as leukoencephalopathy and cognitive impairment, even when therapy is delivered systemically. The underlying cellular basis for these adverse effects is poorly understood.

Results

We found that three mainstream chemotherapeutic agents – carmustine (BCNU), cisplatin, and cytosine arabinoside (cytarabine), representing two DNA cross-linking agents and an antimetabolite, respectively – applied at clinically relevant exposure levels to cultured cells are more toxic for the progenitor cells of the CNS and for nondividing oligodendrocytes than they are for multiple cancer cell lines. Enhancement of cell death and suppression of cell division were seen in vitro and in vivo. When administered systemically in mice, these chemotherapeutic agents were associated with increased cell death and decreased cell division in the subventricular zone, in the dentate gyrus of the hippocampus and in the corpus callosum of the CNS. In some cases, cell division was reduced, and cell death increased, for weeks after drug administration ended.

Conclusion

Identifying neural populations at risk during any cancer treatment is of great importance in developing means of reducing neurotoxicity and preserving quality of life in long-term survivors. Thus, as well as providing possible explanations for the adverse neurological effects of systemic chemotherapy, the strong correlations between our in vitro and in vivo analyses indicate that the same approaches we used to identify the reported toxicities can also provide rapid in vitro screens for analyzing new therapies and discovering means of achieving selective protection or targeted killing.

Anticancer, neuroprotective activities and computational studies of 2-amino-1,3,4-thiadiazole based compound

Anticancer activity studies of 2-(4-fluorophenylamino)-5-(2,4-dihydroxyphenyl)-1,3,4-thiadiazole (FABT), as one of the most promising derivatives from the N-substituted 2-amino-5-(2,4-dihydroxyphenyl)-1,3,4-thiadiazole set, have been continued. The tested compound inhibited proliferation of tumor cells derived from cancers of nervous system (medulloblastoma/rhabdosarcoma, neuroblastoma, and glioma) and peripheral cancers including colon adenocarcinoma and lung carcinoma. The anticancer effect of FABT was attributed to decreased cell division and inhibited cell migration. Furthermore, in anticancer concentrations it exerted a trophic effect in neuronal cell culture and had no influence on viability of normal cells including astrocytes, hepatocytes, and skin fibroblasts. Moreover, a prominent neuroprotective activity of FABT was observed in the neuronal cultures exposed to neurotoxic agents like serum deprivation and glutamate. To determine probability of tautomeric transition and indicate potential sites of interactions of FABT molecule with the receptor, quantum-chemical calculations with the ab initio Hartree-Fock model were made.

[Acute central nervous symptoms in oncologic patients]

Oncologic patients may suffer from acute central nervous system disorders either related to the disease itself or to its therapy. These disorders may present as a disturbance of consciousness, as mental changes, as focal neurological signs, as epileptic seizures or as a combination of these. Symptoms may be caused by cerebral metastases, hemorrhage, ischemia or infectious complication, by metabolic changes or by treatment sequealae. This article will focus on clinical presentation, diagnostic workup and possible therapy or prophylaxis of these complications.

Anticancer agents are potent neurotoxins in vitro and in vivo

Neurotoxicity of anticancer agents complicates treatment of children with cancer. We investigated neurotoxic effects of common cytotoxic drugs in neuronal cultures and in the developing rat brain. When neurons were exposed to cisplatin (5-100 microM), cyclophosphamide (5-100 microM), methotrexate (5-100 microM), vinblastin (0.1-1 microM), or thiotepa (5-100 microM), a concentration-dependent neurotoxic effect was observed. Neurotoxicity was potentiated by nontoxic glutamate concentrations. The N-methyl-D-aspartate receptor antagonist MK 801 (10 microM), the AMPA receptor antagonists GYKI 52466 (10 microM) and NBQX (10 microM), and the pancaspase inhibitor Ac-DEVD-CHO (1 nM) ameliorated neurotoxicity of cytotoxic drugs. To investigate neurotoxicity in vivo, we administered to 7-day-old rats the following: cisplatin (5-15 mg/kg i.p.), cyclophosphamide (200-600 mg/kg i.p.), thiotepa (15-45 mg/kg), or ifosfamide (100-500 mg/kg) and their brains were analyzed at 4 to 24 hours. Cytotoxic drugs produced widespread lesions within cortex, thalamus, hippocampal dentate gyrus, and caudate nucleus in a dose-dependent fashion. Early histological analysis demonstrated dendritic swelling and relative preservation of axonal terminals, which are morphological features indicating excitotoxicity. After longer survival periods, degenerating neurons displayed morphological features consistent with active cell death. These results demonstrate that anticancer drugs are potent neurotoxins in vitro and in vivo; they activate excitotoxic mechanisms but also trigger active neuronal death.