Chemotherapy-Related Neurotoxicity

Acute Neurotoxicity in Children Treated for Acute Lymphoblastic Leukemia and Lymphoblastic Lymphoma: A 10-Year Single-Centre Experience

Background: Recent advances in childhood acute lymphoblastic leukemia (ALL) and lymphoblastic lymphoma (LL) management provide higher survival rates at the cost of increased toxicities. Acute neurotoxicity affects up to 10% of patients, requiring rapid recognition and treatment. Methods: A retrospective observational study was performed to determine the frequency, clinical manifestations, radiological characteristics, treatment options and outcome of acute neurological adverse events in pediatric patients with lymphoid malignancies at the Department of Oncology and Hematology, Children's Hospital Zagreb, Croatia. Results: A total of 56 patients (48 ALL and 8 LL, male/female ratio 1:1, average age 5.4 years) were treated mainly according to the ALL-IC BFM 2009 protocol. The B-immunophenotype was the most frequent (85.7%). Most patients were stratified to the intermediate risk group (39.3%), and two were initially diagnosed with central nervous system infiltration. Acute neurotoxic events were registered in 11 patients (19.6%), most commonly in the 6-10-year age group (66.7%), predominately in females (72.7%) and high-risk group (54.5%). The most frequent clinical presentation was seizures (83.3%), with status epilepticus in four cases. We detected electroencephalogram (EEG) irregularities in almost all patients and various morphological changes in the brain magnetic resonance imaging (MRI), most often consistent with posterior reversible encephalopathy syndrome and leukoencephalopathy. Approximately half the patients received prolonged antiepileptic therapy. No apparent residual neurologic manifestations have been observed. Conclusions: Acute neurotoxicity is a rather frequent treatment-related adverse event, associated with high-risk disease. Early recognition and timely management are essential for rapid recovery and optimal outcomes.

Identification of Matrine as a Kirsten rats Arcomaviral oncogene homolog inhibitor alleviating chemotherapy-induced neuropathic pain

BACKGROUND

Chemotherapy-induced peripheral neuropathy (CIPN) represents a prevailing and severe clinical concern, characterized by limited availability of clinically effective treatment strategies. Current evidence endorses matrine's potential as a neuroprotective and analgesic agent for CIPN. Nevertheless, the precise targets and mechanisms of action of matrine remain insufficiently explored, impeding comprehensive pharmacological investigation and clinical application.

OBJECTIVE

This study endeavors to elucidate the analgesic and neuroprotective effects of matrine in mice with vincristine-induced neuropathic pain. A focal point is the identification of matrine's specific target and the underlying molecular mechanisms governing its analgesic and neuroprotective actions.

METHODS

To discern matrine's analgesic effects in CIPN mice, we conducted behavioral experiments encompassing the Von Frey filament test and Hargreaves Test. Furthermore, we conducted electrophysiological and histopathological assessments involving HE staining, Nissl staining, and Fluoro-Jade B staining to evaluate matrine's effects on neuroprotection within dorsal root ganglia and the spinal cord of CIPN mice. Sequentially, thermal shift assay, GTP hydrolysis assay, and nucleotide exchange assay were executed to validate matrine's inhibitory effects on KRAS. Molecular docking and site-directed mutagenesis experiments were implemented to identify the precise binding pocket of matrine on KRAS. Lastly, matrine's inhibitory effects on downstream signaling pathways of KRAS were confirmed through experiments conducted at animal model.

RESULTS

Matrine exhibited a notable increase in mechanical withdrawal threshold and thermal withdrawal latency in vincristine-treated mice. This compound substantially ameliorated the neurofunctional blockade associated with sensory and motor functions induced by vincristine. Moreover, matrine mitigated pathological damage within DRG and the L4-L5 spinal cord regions. The study's MST experiments indicated matrine's substantial elevation of KRAS's melting temperature. The GTP hydrolysis and nucleotide exchange assays revealed concentration-dependent inhibition of KRAS activity by matrine. Molecular docking provided insight into the binding mode of matrine with KRAS, while site-directed mutagenesis verified the specific binding site of matrine on KRAS. Lastly, matrine's inhibition of downstream Raf/Erk1/2 and PI3K/Akt/mTOR signaling pathways of KRAS was confirmed in VCR mice.

CONCLUSION

Compared to previous studies, our research has identified matrine as a natural inhibitor of the elusive protein KRAS, often considered "undruggable." Furthermore, this study has revealed that matrine exerts its therapeutic effects on chemotherapy-induced peripheral neuropathy (CIPN) by inhibiting KRAS activation, subsequently suppressing downstream signaling pathways such as Raf/Erk1/2 and PI3K/Akt/mTOR. This investigation signifies the discovery of a novel target for matrine, thus expanding the potential scope of its involvement in KRAS-related biological functions and diseases. These findings hold the promise of providing a crucial experimental foundation for forthcoming drug development initiatives centered around matrine, thereby advancing the field of pharmaceutical research.

Docetaxel-induced severe neuropathy, a case of breast cancer with GTSP1 polymorphism

INTRODUCTION

Breast cancer, the most prevalent cancer among women, often requires chemotherapy with docetaxel being a key agent. However, docetaxel-inducted peripheral neuropathy (DIPN) can adversely impact patients' quality of life. This case discusses an unusual instance of severe DIPN leading to wheelchair dependence in a 35-years old woman undergoing neoadjuvant treatment for locally advanced breast cancer.

CASE

Following anthracycline and cyclophosphamide cycles without neurological symptoms, docetaxel administration resulted in progressive neuropathy. Despite dose reduction, the patient developed severe paraesthesias, foot weakness, and eventually wheelchair dependence.

MANAGEMENT AND OUTCOME

Docetaxel's microtubule-stabilizing mechanism, vital for cell division, may disrupt axonal structures, causing sensory and motor neuropathy. While rare, severe motor neuropathy, leading to wheelchair dependence, poses a significant challenge. The frequency of DIPN varies, with docetaxel exhibiting lower neuropathy rates than other taxanes. Risk factors include age, diabetes mellitus, cumulative dose, and genetic polymorphisms in GSTP1 and ABCB1. In our case, despite the patient being young, fit and without diabetes, severe DIPN occured, suggesting a potential genetic predisposition. Genetic variations, such as GSTP1 polymorphisms have been associated with DIPN. Our patient carried GSTP1 (I1e105Val) mutations, emphasizing the need for further research to establish their role as risk factors.

DISCUSSION

This case underscores the importance of recognizing severe DIPN, even in atypical patient profiles. Genetic factors, like GSTP1 polymorphisms, may contribute to DIPN risk. Large-scale studies are crucial to establishing the significance of these genetic variations in DIPN susceptibility.

Neuropsychological assessment, intervention, and best practices for women with non-Central nervous system cancer: A scoping review of current standards

Objective: Existing literature has sought to characterize the broad cognitive impact of non-central nervous system cancer and its treatment, including chemotherapy, radiation, surgery, and hormonal regulation. However, despite the frequency of women that are diagnosed with breast and gynecological cancer, there is limited research on the specific cognitive experiences of women undergoing cancer treatment. Presently, the current literature lacks concise guidance for neuropsychologists to support the cognitive health of women facing cancer, despite the acknowledged impact of cancer interventions and chronic illness on cognitive outcomes. Method: Applying scoping review criteria outlined by Peters et al. (2015) and adhering to Preferred Reporting Items for Systemic Reviews and Meta-Analysis (PRISMA) guidelines, we conducted a comprehensive examination of literature spanning multiple databases (Google Scholar, PubMed, PsychINFO) with a focus on the cognitive impact of cancer treatment on women. Conclusions: Women are subject to unique treatment-related outcomes due to the impact of hormonal alterations, differences in metabolization of certain chemotherapies, and psychosocial risk factors. Despite the known impact of cancer intervention, chronic illness, and cancer-related sequelae on cognitive outcomes, the current literature does not parsimoniously outline best practices for neuropsychologists to promote the health of women experiencing cancer. The current paper (1) provides an overview of the cognitive implications of cancer treatment with an intentional focus on cancers that are more prevalent in women versus men, (2) addresses the characteristics of this impact for women undergoing cancer intervention(s), and (3) provides possible intervention and treatment strategies for mental health providers and neuropsychologists.

Toward better understanding and management of chemobrain: the potential utilities of the MemTrax memory test

OBJECTIVE

To study the effects of chemotherapy on cognitive function in breast cancer patients, and to investigate the relationship of MemTrax test of memory and related functions to the FACT-Cog functional self-assessment for the evaluation and management of chemobrain.

METHODS

In this prospective cohort study, clinical information of pathologically confirmed female breast cancer patients who decided to receive chemotherapy were collected in a questionnaire which was developed for this study and provided as a supplementary file. The FACT-Cog self-assessment and MemTrax test were administered before and after the chemotherapy treatments. Patients with chemobrain were identified using published criteria based on FACT-Cog scores, and MemTrax scores from chemobrain patients were analyzed.

RESULTS

Fifty-six patients participated in this study, of which 41 participants completed 4 or more cycles of chemotherapy and were included in the final analyses here. Using the reported high end of minimal clinical differences (10.6 points) of FACT-Cog before and after chemotherapy, 18 patients suffered from chemobrain in this study. In these 18 chemobrain patients, no cognitive impairments were detected by MemTrax, which paradoxically demonstrated an improvement in the normal cognitive range.

CONCLUSION

The cognitive impairment induced by chemotherapy in breast cancer patients is detectable by the FACT-Cog in a Chinese cohort but is not detected by the MemTrax memory test. The fact that the more objective MemTrax could not detect the impairment could alleviate patients' concerns which in turn would be beneficial for patients' mental health.

Surface Modification of Mesoporous Silica Nanoparticles for Application in Targeted Delivery Systems of Antitumour Drugs

The problem of tumour therapy has attracted the attention of many researchers for many decades. One of the promising strategies for the development of new dosage forms to improve oncology treatment efficacy and minimise side effects is the development of nanoparticle-based targeted transport systems for anticancer drugs. Among inorganic nanoparticles, mesoporous silica deserves special attention due to its outstanding surface properties and drug-loading capability. This review analyses the various factors affecting the cytotoxicity, cellular uptake, and biocompatibility of mesoporous silica nanoparticles (MSNs), constituting a key aspect in the development of safe and effective drug delivery systems. Special attention is paid to technological approaches to chemically modifying MSNs to alter their surface properties. The stimuli that regulate drug release from nanoparticles are also discussed, contributing to the effective control of the delivery process in the body. The findings emphasise the importance of modifying MSNs with different surface functional groups, bio-recognisable molecules, and polymers for their potential use in anticancer drug delivery systems.

Nutritional Support of Crocin on Neurobehavioral Disabilities Induced by Cisplatin-Based Chemotherapy in Rats

Cisplatin, a chemotherapy drug containing platinum, is considered a neurotoxic agent. On the other hand, crocin, the primary component of saffron, possesses neuroprotective and antioxidant properties. In this study, 28 healthy adult male Wistar rats weighing 200-250 g were used (6-7 weeks old). Rats were divided into a control group (Ctr), a crocin group (Cro), a cisplatin group (Cis), and a crocin with cisplatin group (Cro + Cis). Rotarod, open field, and shuttle box tests were performed to assess balance, explorative behavior, and avoidance memory. After behavioral testing, the hippocampus was extracted to analyze oxidative stress parameters such as GPx (glutathione peroxidase), SOD (superoxide dismutase), CAT (catalase), and MDA (malondialdehyde) activity. Shuttle box, rotarod, and open field results showed that crocin can substantially mitigate the deleterious effects of cisplatin on avoidance memory, explorative behavior, motor coordination, and balance. Crocin was also able to effectively avoid the negative effects of cisplatin on MDA, GPx, and CAT during the assessment of oxidative indicators, while the beneficial effect of crocin on cisplatin was not statistically significant in terms of SOD level. In conclusion, since free radicals produced by cisplatin are a contributing factor to memory loss and movement disorders, crocin, owing to its antioxidant properties, improved passive avoidance learning as well as motor activity.

Folate conjugated albumin as a targeted nanocarrier for the delivery of fisetin: in silico and in vitro biological studies

Fisetin (FST), a natural flavonoid compound derived from various fruits and vegetables, including apple, strawberry, and onion, demonstrates potential for a wide range of pharmaceutical applications, including potential anticancer properties. However, challenges such as low bioavailability, poor aqueous solubility, and limited permeability restrict the use of FST in the pharmaceutical sector. Nowadays, targeted nanomedicines have garnered attention to overcome limitations associated with phytochemicals, including FST. In the present study, we have designed and successfully prepared folate-targeted FST nanoparticles (FFNPs). Characterization through DLS and FE-SEM revealed the successful preparation of monodisperse (PDI: 0.117), nanoscale-sized (150 nm), and spherical nanoparticles. Physicochemical characterization including FTIR, XRD, DSC, and TGA analysis, confirmed the encapsulation of the FST within the Folic acid (FA) - conjugated nanoparticles (CNPs) and revealed its amorphous nature. Molecular docking analysis revealed the strong binding affinity and specific amino acid interactions involved in the BSA-FST-FA complex, suggesting the potential synergistic effect of FST and FA in enhancing the therapeutic activity of the FFANPs. Cytotoxic assessments by the MTT assay, migration assay, AO-EtBr staining assay, colony formation assay, and cellular uptake study demonstrated enhanced anticancer efficacy, apoptosis induction, and enhanced uptake of FFNPs compared to pure FST. These findings propose prepared FFNPs as a promising targeted drug delivery nanocarrier for effective FST delivery in cancer therapy.

MRI characteristics of chemotherapy-related central neurotoxicity: a pictorial review

The relentless advancement of chemotherapeutic agents has enhanced survival rates among cancer patients. However, this success comes with an increased prevalence of chemotherapy-induced neurotoxicity, which often mimics the symptoms of metastatic disease or paraneoplastic syndromes and poses a diagnostic challenge for clinicians. Imaging, particularly MRI, plays a pivotal role in unraveling this conundrum.This comprehensive review explores the MRI patterns associated with central neurotoxicities induced by various chemotherapeutic agents. Our objective is to provide radiologists and clinicians with illustrative diagrams that offer a structured approach to diagnosing these conditions. By enhancing the understanding of these distinctive MRI patterns, we aim to facilitate accurate and timely diagnosis, ultimately improving patient care in the context of evolving cancer treatments.Critical relevance statementThis article describes the essential role of MRI in identifying distinct patterns of chemotherapy-induced central neurotoxicity, enabling early diagnosis and improved patient care within the field of clinical radiology.Key points• Chemotherapy-induced neurotoxicity is a growing concern for cancer patients, and MRI is a key tool in diagnosis.• This review highlights distinctive MRI patterns associated with various chemotherapy-induced neurotoxicities.• Understanding these patterns improves patient care, ensuring timely intervention and accurate diagnosis in the complex world of cancer treatment.

Longitudinal trajectory of amplitude of low-frequency fluctuation changes in breast cancer patients during neoadjuvant chemotherapy-A preliminary prospective study

There is growing evidence that the amplitude of low-frequency fluctuation (ALFF) changes in breast cancer patients after chemotherapy. However, longitudinal changes in ALFF during chemotherapy are unclear. To assess the trajectory of ALFF changes during chemotherapy, 36 breast cancer patients underwent both resting-state functional magnetic resonance imaging and neuropsychological testing at three time points, including before neoadjuvant chemotherapy (NAC) (time point 0, TP0), after one cycle of NAC (before the second cycle of NAC, TP1), and upon completion of NAC (pre-operation, TP2). Healthy controls (HC) received the same assessments at matching time points. We compared the longitudinal changes of ALFF in the NAC and two HC groups. In the NAC group, compared with TP0, ALFF values in the right orbital part of the inferior frontal gyrus, left medial orbital part of the superior frontal gyrus, right insula, left medial part of the superior frontal gyrus, and right middle frontal gyrus declined significantly at TP1 and TP2. Compared with TP1, there were no significant changes in ALFF values at TP2. In the two HC groups, there were no significant changes in ALFF at corresponding intervals. We concluded that for breast cancer patients receiving NAC, ALFF values declined significantly in some brain regions after one cycle of NAC and then remained stable until the completion of NAC, and most of the brain regions with ALFF changes were located in the frontal lobe.

Imaging Aspects of Toxic and Metabolic Myelopathies

Metabolic and toxic myelopathies usually occurs due to several different causes. Metabolic myelopathy usually occurs due to deficiency of a nutrient, such as vitamin B12. Toxic myelopathy occurs secondary to the exposure to an external toxic agent. Although they may have a difficult diagnosis, determination of the specific cause of myelopathy is of utmost importance, because many causes are amenable to treatment. Although they have many clinical, electrophysiologic, and neuropathologic similarities, imaging may aid in the suspicion of toxic or metabolic myelopathy. The aim of this article, is to review the imaging features of the main toxic and metabolic myelopathies.

Effect of neoadjuvant chemotherapy on effect-site concentration of propofol for sedation in patients with breast cancer

BACKGROUND

Some studies have demonstrated that chemotherapy drugs enhance sensitivity to anesthetics owing to its systemic toxicity, while others have demonstrated that chemotherapy drugs have no effect. This study aimed to determine whether neoadjuvant chemotherapy influences the effect-site concentration (Ce) of propofol for sedation in patients withbreast cancer.

METHODS

This study included patients aged 19-75 years who were scheduled to undergobreast cancer surgery under general anesthesia. Patients who received neoadjuvant chemotherapy were assigned to group C, whereas those who never received chemotherapy wereassigned to group N. Propofol was administered through an effect-site target-controlled infusion, and the Modified Observer's Assessment of Alertness/Sedation scale (MOAA/S) scoreand Bispectral Index (BIS) were recorded. When the plasma concentration and Ce wereequal to the target Ce, and if the MOAA/S score did not change, the target Ce was increasedby 0.2 μg/ml; otherwise, the Ce was maintained for 2 min and then increased. This processwas repeated until the MOAA/S score became 0.

RESULTS

No significant differences were observed in Ce values at each sedation level between both groups. Ce values for loss of consciousness (LOC) of groups C and N were 2.76± 0.29 and 2.67 ± 0.27 μg/ml (P = 0.285), respectively. However, the BIS value at LOC ofgroup C (63.87 ± 7.04) was lower than that (68.44 ± 6.01) of group N (P = 0.018).

CONCLUSIONS

Neoadjuvant chemotherapy for breast cancer has no effect on the Ce ofpropofol for sedation.

Paclitaxel Regulates TRPA1 Function and Expression Through PKA and PKC

Paclitaxel (PTX) is a frequently used anticancer drug that causes peripheral neuropathy. Transient receptor potential ankyrin 1 (TRPA1), a plasma membrane calcium channel, has been associated with PTX toxicity and with other chemotherapy agents such as oxaliplatin and vincristine. However, the effect of PTX on the functional expression and calcium currents of TRPA1 has not been determined. The present study shows the effect of PTX on TRPA1 activity in a neuronal cell line (SH-SY5Y). The effect of PTX on the expression of TRPA1 was assessed through quantitative PCR and Western blot analyses to determine the relative mRNA and protein expression levels. To assess the effect on calcium flux and currents, cells were exposed to PTX; simultaneously, a specific agonist and antagonist of TRPA1 were added to evaluate the differential response in exposed versus control cells. To assess the effect of PKA, PKC and PI3K on PTX-induced TRPA1 increased activity, selective inhibitors were added to these previous experiments. PTX increased the mRNA and protein expression of TRPA1 as well as the TRPA1-mediated Ca2+ currents and intracellular Ca2+ concentrations. This effect was dependent on AITC (a selective specific agonist) and was abolished with HC-030031 (a selective specific antagonist). The inhibition of PKA and PKC reduced the effect of PTX on the functional expression of TRPA1, whereas the inhibition of PI3K had no effects. PTX-induced neuropathy involves TRPA1 activity through an increase in functional expression and is regulated by PKA and PKC signaling. These findings support the role of the TRPA1 channel in the mechanisms altered by PTX, which can be involved in the process that lead to chemotherapy-induced neuropathy.

Anticancer potential of Marina Crystal Minerals (MCM) against the growth of murine mammary adenocarcinoma cells in vivo

In vitro studies have shown that Marina Crystal Minerals (MCM), a crystallized mixture of minerals and trace elements from sea water, possesses apoptotic and immune modulatory effects in human breast cancer cells MDA-MB-231. The current study aimed to evaluate MCM's anticancer effect in vivo against murine mammary adenocarcinoma cells and to explore its underlying mechanisms. Mice were inoculated intramuscularly with Ehrlich ascites carcinoma (EAC) cells, a breast adenocarcinoma. Tumors became palpable within 9 days. Tumor-bearing mice were injected with MCM intraperitoneally (IP) or intratumorally (IT) at a dose of 40 mg/kg BW for 6 days/week until day 28 post-inoculation. Tumor growth, cell cycle progression, cell cycle regulatory proteins, apoptosis, apoptotic regulatory markers, mitochondrial membrane potential (MMP), natural killer (NK) cell activity, and histopathological effects were investigated. Treatment with MCM reduced tumor volume by 49.4% for IP and 59.5% for IT injection. MCM induced cancer cell apoptosis, as indicated by a sub-G1 peak and confirmed by Annexin V/PI assay and histopathological examination. This was mediated by increased Bax expression, caspase-3 activation, decreased Bcl-2 expression, and MMP disruption. Furthermore, MCM treatment induced G1 cell cycle arrest, mediated through significantly increased expression of p53, p21, and p27 and decreased expression of cyclin D1 and PCNA in cancer cells. Finally, MCM treatment markedly enhanced NK cell cytotoxicity. MCM possesses chemopreventive potential to reduce tumor growth by suppressing cell proliferation, inducing apoptosis in EAC cells via a mitochondrial dependent pathway, and activating the immune system. Our results suggest MCM's beneficial potential for treating breast adenocarcinoma.

Resveratrol Improves Paclitaxel-Induced Cognitive Impairment in Mice by Activating SIRT1/PGC-1α Pathway to Regulate Neuronal State and Microglia Cell Polarization

Objective

This study aimed to investigate the effect of resveratrol (Res) on paclitaxel (PTX)-induced cognitive impairment and elucidate the underlying molecular mechanisms.

Methods

Morris Water Maze (MWM) test was used to evaluate the mice's spatial learning and memory abilities. Western blotting was applied to detect protein expression of receptor-interacting protein (RIP3), mixed lineage kinase domain-like protein (MLKL), silencing information regulator 2 related enzyme 1 (SIRT1), peroxisome proliferator activated receptor coactivator-1 (PGC-1α), NADPH oxidase 2 (NOX2), NOX4, postsynaptic density zone 95 (PSD95), arginase-1 (Arg-1) and inducible nitric oxide synthase (iNOS). Immunofluorescence of RIP3, MLKL, Arg-1, Iba-1 and iNOS was conducted to observe the apoptosis of hippocampal cells and the polarization of microglia. qRT-PCR was performed to detect BDNF mRNA expressions. DHE staining was used to assess the level of oxidative stress response. Golgi-Cox staining and dendritic spine counting were applied to visualize synaptic structural plasticity. Postsynaptic density was performed by transmission electron microscope. ELISA was used to detect the contents of tumour necrosis factor alpha (TNF-α), IL-1β, IL-4, and IL-10.

Results

PTX-induced cognitive impairment model was constructed after the application of PTX, represented as longer latency to platform and less platform crossing times over the whole period in PTX group. After Res treatment, the above indicators were reversed, indicating that cognitive function was improved. Moreover, Res reduced neuronal apoptosis and oxidative stress through SIRT1/PGC-1α pathway in mice, manifesting as down-regulated expression of RIP3, MLKL, NOX2 and NOX4. Meanwhile, Res increased the density of dendritic spines and the expression of PSD95 and BDNF, thereby ameliorating the PTX induced synaptic damage. Besides, M2 microglia was in the majority, eliciting the expression of anti-inflammatory cytokines IL-4 and IL-10 after Res treatment in PTX+Res group, while immunofluorescence images results demonstrated an decrease in the proportion of M2 microglia a following SIRT1 inhibitor EX-527.

Conclusion

Res improves PTX-induced cognitive impairment in mice by activating SIRT1/PGC-1α pathways to regulate neuronal state and microglia cell polarization.

Associations between disrupted functional brain network topology and cognitive impairment in patients with rectal cancer during chemotherapy

Introduction

Cognitive impairment has been identified in patients with non-central nervous system cancer received chemotherapy. Chemotherapy-induced changes in the brain are considered as the possible causes of the cognitive deficits of patients. This study aimed to explore chemotherapy-related functional brain changes and cognitive impairment in rectal cancer (RC) patients who had just finished chemotherapy treatment.

Methods

In this study, RC patients after chemotherapy (on the day patients received the last dose of chemotherapy) (n=30) and matched healthy controls (HCs) (n=30) underwent cognitive assessments, structural magnetic resonance imaging (MRI) and resting-state functional MRI. The functional brain networks were constructed by thresholding the partial correlation matrices of 90 brain regions in the Anatomical Automatic Labeling template and the topologic properties were evaluated by graph theory analysis. Moreover, correlations between altered topological measures and scores of cognitive scales were explored in the patient group.

Results

Compared with HCs, RC patients had lower scores of cognitive scales. The functional brain network had preserved small-world topological features but with a tendency towards higher path length in the whole network. In addition, patients had decreased nodal global efficiency (E_glo(i)) in the left superior frontal gyrus (dorsolateral), superior frontal gyrus (orbital part), inferior frontal gyrus (opercular part), inferior frontal gyrus (triangular part) and right inferior frontal gyrus (triangular part). Moreover, values of E_glo(i) in the superior and inferior frontal gyrus were positively associated with cognitive function in the patient group.

Conclusion

These results suggested that cognitive impairment was associated with disruptions of the topological organization in functional brain networks of RC patients who had just finished chemotherapy, which provided new insights into the pathophysiology underlying acute effects of chemotherapy on cognitive function.

Association of Taxane Type With Patient-Reported Chemotherapy-Induced Peripheral Neuropathy Among Patients With Breast Cancer

IMPORTANCE

Understanding the detailed symptom spectrum of chemotherapy-induced peripheral neuropathy (CIPN) could facilitate shared decision-making and promote early intervention.

OBJECTIVE

To compare the symptom spectrum of patient-reported CIPN associated with nab-paclitaxel, paclitaxel, and docetaxel treatments among patients with breast cancer.

DESIGN, SETTING, AND PARTICIPANTS

This prospective cohort study was conducted at 9 medical centers across China from 2019 to 2021. Participants included hospitalized women diagnosed with invasive breast cancer, assessed with overlap propensity score weighting. Data were analyzed from from December 2021 to May 2022.

EXPOSURES

Treatment with nab-paclitaxel-, paclitaxel-, or docetaxel-based regimens.

MAIN OUTCOMES AND MEASURES

Patient-reported CIPN on the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire: CIPN 20-item instruments, consisting of sensory, motor, and autonomic scales. Multiple regression models were adjusted for baseline patient, tumor, and treatment characteristics.

RESULTS

Of 1234 participants, the mean (SD) age was 50.9 (10.4) years, and 295 patients (23.9%) received nab-paclitaxel, 514 patients (41.7%) received paclitaxel, and 425 patients (34.4%) received docetaxel. The nab-paclitaxel group mostly reported numbness in hands or feet related to sensory symptoms (83 patients [81.4%]), while the paclitaxel and docetaxel groups reported mainly motor (eg, weakness in legs: 60 patients [47.2%] in the paclitaxel group; 52 patients [44.4%] in the docetaxel group) and autonomic (eg, blurred vision: 58 patients [45.7%] in the paclitaxel group; 51 patients [43.6%] in the docetaxel group) symptoms. Patients reported motor symptoms earlier than sensory abnormalities, with a median of 0.4 (95% CI, 0.4-2.3) weeks in the nab-paclitaxel group, 2.7 (95% CI, 1.7-3.4) weeks in the paclitaxel group, and 5.6 (95% CI, 3.1-6.1) weeks in the docetaxel group. After overlap propensity score weighting and compared with the nab-paclitaxel group, the risks of patient-reported CIPN were lower in the paclitaxel (hazard ratio [HR], 0.59 [95% CI, 0.41-0.87]; P = .008) and the docetaxel (HR, 0.65 [95% CI, 0.45-0.94]; P = .02) groups. Similarly, patients who received paclitaxel (HR, 0.44 [95% CI, 0.30-0.64]; P < .001) or docetaxel (HR, 0.52 [95% CI, 0.36-0.75]; P < .001) reported less sensory discomfort compared with those who received nab-paclitaxel. However, the risk of patients in the paclitaxel or docetaxel groups reporting motor (paclitaxel: HR, 0.76 [95% CI, 0.52-1.11]; P = .15; docetaxel: HR, 0.69 [95% CI, 0.47-1.01]; P = .05) and/or autonomic (paclitaxel: HR, 1.00 [95% CI, 0.68-1.49]; P = .98; docetaxel: HR, 0.88 [95% CI, 0.59-1.30]; P = .52) symptoms was not lower than that in the nab-paclitaxel group.

CONCLUSIONS AND RELEVANCE

In this cohort study of women with invasive breast cancer, nab-paclitaxel was associated with more severe CIPN than either paclitaxel or docetaxel. In addition to sensory symptoms, the risk of motor and autonomic abnormalities was not low among these 3 taxanes, and patients-reported motor symptoms even earlier than sensory symptoms. These findings may facilitate early detection and intervention for CIPN in taxane treatments for breast cancer.

Role of inflammation and oxidative stress in chemotherapy-induced neurotoxicity

Chemotherapeutic agents may adversely affect the nervous system, including the neural precursor cells as well as the white matter. Although the mechanisms are not completely understood, several hypotheses connecting inflammation and oxidative stress with neurotoxicity are now emerging. The proposed mechanisms differ depending on the class of drug. For example, toxicity due to cisplatin occurs due to activation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), which alters hippocampal long-term potentiation. Free radical injury is also involved in the cisplatin-mediated neurotoxicity as dysregulation of nuclear factor erythroid 2-related factor 2 (Nrf2) has been seen which protects against the free radical injury by regulating glutathione S-transferases and hemeoxygenase-1 (HO-1). Thus, correcting the imbalance between NF-κB and Nrf2/HO-1 pathways may alleviate cisplatin-induced neurotoxicity. With newer agents like bortezomib, peripheral neuropathy occurs due to up-regulation of TNF-α and IL-6 in the sensory neurons. Superoxide dismutase dysregulation is also involved in bortezomib-induced neuropathy. This article reviews the available literature on inflammation and oxidative stress in neurotoxicity caused by various classes of chemotherapeutic agents. It covers the conventional medicines like platinum compounds, vinca alkaloids, and methotrexate, as well as the newer therapeutic agents like immunomodulators and immune checkpoint inhibitors. A better understanding of the pathophysiology will lead to further advancement in strategies for management of chemotherapy-induced neurotoxicity.

Chemotherapy-induced functional brain abnormality in colorectal cancer patients: a resting‐state functional magnetic resonance imaging study

Introduction

Chemotherapy-induced cognitive impairment (i.e., “chemobrain”) is a common neurotoxic side-effect experienced by many cancer survivors who undergone chemotherapy. However, the central mechanism underlying chemotherapy-related cognitive impairment is still unclear. The purpose of this study was to investigate the changes of intrinsic brain activity and their associations with cognitive impairment in colorectal cancer (CRC) patients after chemotherapy.

Methods

Resting‐state functional magnetic resonance imaging data of 29 CRC patients following chemotherapy and 29 matched healthy controls (HCs) were collected in this study, as well as cognitive test data including Mini Mental State Exam (MMSE), Montreal Cognitive Assessment (MoCA) and Functional Assessment of Cancer Therapy-Cognitive Function (FACT-Cog). The measure of fractional amplitude of low-frequency fluctuation (fALFF) was calculated and compared between groups. The correlations between the fALFF of impaired brain region and cognitive performance were also analyzed.

Results

Compared with HCs, CRC patients following chemotherapy showed decreased fALFF values in the left anterior cingulate gyrus (ACG) and middle frontal gyrus, as well as increased fALFF values in the left superior frontal gyrus (orbital part) and middle occipital gyrus. Moreover, positive associations were identified between fALFF values of the left ACG and the total scores of MMSE, MoCA and FACT-Cog in the patient group.

Conclusion

These findings indicated that CRC patients after chemotherapy had decreased intrinsic brain activity in the left ACG, which might be vulnerable to the neurotoxic side-effect of chemotherapeutic drugs and related to chemotherapy-induced cognitive impairment.

Early alterations in cortical morphology after neoadjuvant chemotherapy in breast cancer patients: A longitudinal magnetic resonance imaging study

There is growing evidence that chemotherapy may have a significant impact on the brains of breast cancer patients, causing changes in cortical morphology. However, early morphological alterations induced by chemotherapy in breast cancer patients are unclear. To investigate the patterns of those alterations, we compared female breast cancer patients (n = 45) longitudinally before (time point 0, TP0) and after (time point 1, TP1) the first cycle of neoadjuvant chemotherapy, using voxel‐based morphometry (VBM) and surface‐based morphometry (SBM). VBM and SBM alteration data underwent correlation analysis. We also compared cognition‐related neuropsychological tests in the breast cancer patients between TP0 and TP1. Reductions in gray matter volume, cortical thickness, sulcal depth, and gyrification index were found in most brain areas, while increments were found to be mainly concentrated in and around the hippocampus. Reductions of fractal dimension mainly occurred in the limbic and occipital lobes, while increments mainly occurred in the anterior and posterior central gyrus. Significant correlations were found between altered VBM and altered SBM mainly in the bilateral superior frontal gyrus. We found no significant differences in the cognition‐related neuropsychological tests before and after chemotherapy. The altered brain regions are in line with those associated with impaired cognitive domains in previous studies. We conclude that breast cancer patients showed widespread morphological alterations soon after neoadjuvant chemotherapy, despite an absence of cognitive impairments. The affected brain regions may indicate major targets of early brain damage after chemotherapy.

Gabapentinoid Use Is Associated With Reduced Occurrence of Hyperactive Delirium in Older Cancer Patients Undergoing Chemotherapy: A Nationwide Retrospective Cohort Study in Japan

BACKGROUND

It is unclear whether gabapentinoids affect the development of delirium. We aimed to determine the association between gabapentinoid use and hyperactive delirium in older cancer patients undergoing chemotherapy.

METHODS

We conducted propensity score-matched analyses using data from a nationwide inpatient database in Japan. We included cancer patients with pain ≥70 years of age undergoing chemotherapy between April 2016 and March 2018. Patients receiving gabapentinoids were matched with control patients using propensity scores. The primary outcome was occurrence of hyperactive delirium during hospitalization, and the secondary outcomes were length of hospital stay, in-hospital fractures, and in-hospital mortality. Hyperactive delirium was identified by antipsychotic use or discharge diagnoses from the International Classification of Diseases, 10th Revision.

RESULTS

Among 143,132 identified patients (59% men; mean age, 76.3 years), 14,174 (9.9%) received gabapentinoids and 128,958 (90.1%) did not (control group). After one-to-one propensity score matching, 14,173 patients were included in each group. The occurrence of hyperactive delirium was significantly lower (5.2% vs 8.5%; difference in percent, -3.2% [95% confidence interval, -3.8 to -2.6]; odds ratio, 0.60 [0.54-0.66]; P < .001), the median length of hospital stay was significantly shorter (6 days [interquartile range, 3-15] vs 9 days [4-17]; subdistribution hazard ratio, 1.22 [1.19-1.25]; P < .001), and the occurrence of in-hospital mortality was significantly lower in the gabapentinoid group than in the control group (1.3% vs 1.8%; difference in percent, -0.6% [-0.9 to -0.3]; odds ratio, 0.69 [0.57-0.83]; P < .001). Gabapentinoid use was not significantly associated with the occurrence of in-hospital fractures (0.2% vs 0.2%; difference in percent, 0.0% [-0.1 to 0.1]; odds ratio, 1.07 [0.65-1.76]; P = .799). The results of sensitivity analyses using stabilized inverse probability of treatment weighting were consistent with the results of the propensity score-matched analyses.

CONCLUSIONS

Our findings suggest that gabapentinoid use is associated with reduced hyperactive delirium in older cancer patients undergoing chemotherapy, with no evidence of an increase in the fracture rate, length of hospital stay, or in-hospital death.

Mechanisms of Chemotherapy-Induced Neurotoxicity

Since the first clinical trials conducted after World War II, chemotherapeutic drugs have been extensively used in the clinic as the main cancer treatment either alone or as an adjuvant therapy before and after surgery. Although the use of chemotherapeutic drugs improved the survival of cancer patients, these drugs are notorious for causing many severe side effects that significantly reduce the efficacy of anti-cancer treatment and patients’ quality of life. Many widely used chemotherapy drugs including platinum-based agents, taxanes, vinca alkaloids, proteasome inhibitors, and thalidomide analogs may cause direct and indirect neurotoxicity. In this review we discuss the main effects of chemotherapy on the peripheral and central nervous systems, including neuropathic pain, chemobrain, enteric neuropathy, as well as nausea and emesis. Understanding mechanisms involved in chemotherapy-induced neurotoxicity is crucial for the development of drugs that can protect the nervous system, reduce symptoms experienced by millions of patients, and improve the outcome of the treatment and patients’ quality of life.

Targeting the A3 adenosine receptor to prevent and reverse chemotherapy-induced neurotoxicities in mice

Cisplatin is used to combat solid tumors. However, patients treated with cisplatin often develop cognitive impairments, sensorimotor deficits, and peripheral neuropathy. There is no FDA-approved treatment for these neurotoxicities. We investigated the capacity of a highly selective A₃ adenosine receptor (AR) subtype (A₃AR) agonist, MRS5980, to prevent and reverse cisplatin-induced neurotoxicities. MRS5980 prevented cisplatin-induced cognitive impairment (decreased executive function and impaired spatial and working memory), sensorimotor deficits, and neuropathic pain (mechanical allodynia and spontaneous pain) in both sexes. At the structural level, MRS5980 prevented the cisplatin-induced reduction in markers of synaptic integrity. In-situ hybridization detected Adora3 mRNA in neurons, microglia, astrocytes and oligodendrocytes. RNAseq analysis identified 164 genes, including genes related to mitochondrial function, of which expression was changed by cisplatin and normalized by MRS5980. Consistently, MRS5980 prevented cisplatin-induced mitochondrial dysfunction and decreased signs of oxidative stress. Transcriptomic analysis showed that the A₃AR agonist upregulates genes related to repair pathways including NOTCH1 signaling and chromatin modification in the cortex of cisplatin-treated mice. Importantly, A₃AR agonist administration after completion of cisplatin treatment resolved cognitive impairment, neuropathy and sensorimotor deficits. Our results highlight the efficacy of a selective A₃AR agonist to prevent and reverse cisplatin-induced neurotoxicities via preventing brain mitochondrial damage and activating repair pathways. An A₃AR agonist is already in cancer, clinical trials and our results demonstrate management of neurotoxic side effects of chemotherapy as an additional therapeutic benefit.

Ginsenosides in central nervous system diseases: Pharmacological actions, mechanisms, and therapeutics

The nervous system is one of the most complex physiological systems, and central nervous system diseases (CNSDs) are serious diseases that affect human health. Ginseng (Panax L.), the root of Panax species, are famous Chinese herbs that have been used for various diseases in China, Japan, and Korea since ancient times, and remain a popular natural medicine used worldwide in modern times. Ginsenosides are the main active components of ginseng, and increasing evidence has demonstrated that ginsenosides can prevent CNSDs, including neurodegenerative diseases, memory and cognitive impairment, cerebral ischemia injury, depression, brain glioma, multiple sclerosis, which has been confirmed in numerous studies. Therefore, this review summarizes the potential pathways by which ginsenosides affect the pathogenesis of CNSDs mainly including antioxidant effects, anti-inflammatory effects, anti-apoptotic effects, and nerve protection, which provides novel ideas for the treatment of CNSDs.

Chemotherapy Side-Effects: Not All DNA Damage Is Equal

Recent advances have increased survival rates of children and adults suffering from cancer thanks to effective anti-cancer therapy, such as chemotherapy. However, during treatment and later in life they are frequently confronted with the severe negative side-effects of their life-saving treatment. The occurrence of numerous features of accelerated aging, seriously affecting quality of life, has now become one of the most pressing problems associated with (pediatric) cancer treatment. Chemotherapies frequently target and damage the DNA, causing mutations or genome instability, a major hallmark of both cancer and aging. However, there are numerous types of chemotherapeutic drugs that are genotoxic and interfere with DNA metabolism in different ways, each with their own biodistribution, kinetics, and biological fate. Depending on the type of DNA lesion produced (e.g., interference with DNA replication or RNA transcription), the organ or cell type inflicted (e.g., cell cycle or differentiation status, metabolic state, activity of clearance and detoxification mechanisms, the cellular condition or micro-environment), and the degree of exposure, outcomes of cancer treatment can largely differ. These considerations provide a conceptual framework in which different classes of chemotherapeutics contribute to the development of toxicities and accelerated aging of different organ systems. Here, we summarize frequently observed side-effects in (pediatric) ex-cancer patients and discuss which types of DNA damage might be responsible.

Effects of combined chemotherapy and anti-programmed cell death protein 1 treatment on peripheral neuropathy and neuroinflammation in mice

ABSTRACT

A modern approach for cancer treatment is the use of immunotherapy, and particularly immune checkpoint inhibitors, such as anti-programmed cell death protein 1 (PD-1), alone and in combination with chemotherapy. The PD-1 pathway plays a crucial role in inhibiting immune responses and recently has been shown to modulate neuronal activity. However, the impact of PD-1 blockade on the development of chemotherapy-induced peripheral neuropathy is currently unknown. In this study, we show that C57BL/6 mice treated with the chemotherapeutic drug paclitaxel or cotherapy (paclitaxel and anti-PD-1), but not with anti-PD-1 alone, exhibited increased mechanical sensitivity of the hind paw. Both chemotherapy and immunotherapy caused a reduction in neurite outgrowth of dorsal root ganglion (DRG) explants derived from treated mice, whereas only paclitaxel reduced the neurite outgrowth after direct in vitro treatment. Mice treated with anti-PD-1 or cotherapy exhibited distinct T-cell changes in the lymph nodes and increased T-cell infiltration into the DRG. Mice treated with paclitaxel or cotherapy had increased macrophage presence in the DRG, and all treated groups presented an altered expression of microglia markers in the dorsal horn of the spinal cord. We conclude that combining anti-PD-1 immunotherapy with paclitaxel does not increase the severity of paclitaxel-induced peripheral neuropathy. However, because anti-PD-1 treatment caused significant changes in DRG and spinal cord immunity, caution is warranted when considering immune checkpoint inhibitors therapy in patients with a high risk of developing neuropathy.

Central Nervous System Complications Among Oncology Patients

Cancer treatment related injury to the central nervous system (CNS) is well-recognized in the setting of brain-directed radiation therapies and conventional and novel systemic anticancer therapies. Late-delayed treatment-induced CNS complications frequently result in permanent neurologic disability. Therapeutic options are supportive with limited clinical benefit, whereby alteration or discontinuation of the overall antineoplastic treatment plan is frequently necessary to prevent further neurologic injury. Better identification of patients at high risk for developing late CNS toxicities, neuroprotective strategies with modification of existing antineoplastic treatment regimens, and research efforts directed at earlier recognition and improved treatment of central neurologic complications are paramount.

Behavioral and morphological effects of resveratrol and curcumin in rats submitted to doxorubicin-induced cognitive impairment

Doxorubicin (DOX) is known to cause cognitive impairments in patients submitted to long-term chemotherapy (deficits also known as chemobrain). Therefore, there is an urgent need for therapeutic strategies capable of returning cancer survivors back to their previous quality of life. The present study investigated whether resveratrol (RSV) or curcumin (CUR) administration could affect mnemonic function and brain morphological changes following DOX administration in rats. Male Wistar rats were divided into 4 groups: DOX group (2.5 mg/kg/week for 4 weeks, i.p., plus distilled water for 28 days, oral gavage - OG), DOX + RSV group (DOX, 2.5 mg/kg/week for 4 weeks, i.p., plus RSV, 10 mg/kg/day for 28 days, OG), DOX + CUR group (DOX, 2.5 mg/kg/week for 4 weeks, i.p., plus CUR, 100 mg/kg/day for 28 days, OG) and control (CTR) group (0.9% saline solution weekly for 4 weeks, i.p., plus distilled water for 28 days, OG). Behavioral analyses (open field - OF - and the novel object recognition test - NORT) were performed. Brains were collected and analyzed by hematoxylin-eosin and luxol fast blue staining techniques and by immunohistochemistry for GFAP (glial fibrillary acidic protein) expression in astrocytes and Iba1 (ionized calcium-binding adaptor molecule 1) expression in microglia. DOX-injected rats presented short-term and long-term memory impairments as seen in the NORT at 3 and 24 h after habituation and increased GFAP and Iba1 expression, respectively, in astrocytes and microglia of the frontal cortex, hypothalamus and hippocampus. Such cognitive deficits were prevented by CUR at both periods and by RSV at 24 h. DOX-induced astrogliosis and microgliosis were avoided by RSV and CUR. No signs of demyelination or neuronal loss were found in any group. Thus, CUR and RSV prevented memory loss, astrogliosis and microgliosis induced by DOX monotherapy.

Effect of chemotherapy on effect-site concentration of propofol for loss of consciousness in colorectal cancer patients

Background

The depth of anesthesia is an essential factor in surgical prognosis. The neurotoxic effect of chemotherapeutic drugs affects the sensitivity to anesthetics. This study was conducted to determine whether the effect-site concentration (Ce) of propofol for loss of consciousness (LOC) differs in patients undergoing preoperative chemotherapy.

Methods

A total of 60 patients scheduled for surgery for colorectal cancer under general anesthesia were included in this study. Patients who had received chemotherapy comprised the experimental (C) group, and those without a previous history of chemotherapy comprised the control (N) group. Propofol was administered as an effect-site target-controlled infusion, and the Modified Observer’s Assessment of Alertness/Sedation (MOAA/S) scores were evaluated. When the plasma concentration and Ce were similar, and if the MOAA/S score did not change, the target Ce was increased by 0.2 μg/ml; otherwise, the Ce was maintained for 2 min and then increased.

Results

The Ce values of propofol for loss of verbal contact (LVC) in groups C and N were 2.40 ± 0.39 and 2.29 ± 0.39 μg/ml (P = 0.286), respectively, and those for LOC in groups C and N were 2.69 ± 0.43 and 2.50 ± 0.36 μg/ml (P = 0.069), respectively. No significant difference was observed in Ce values between the two groups.

Conclusions

Chemotherapy had no effect on the Ce of propofol for LVC and LOC in patients with colorectal cancer. We do not recommend reducing the dose of propofol for the induction of LOC in patients with colorectal cancer undergoing chemotherapy.

Mechanisms of peripheral neurotoxicity associated with four chemotherapy drugs using human induced pluripotent stem cell-derived peripheral neurons

The awareness of the long-term toxicities of cancer survivors after chemotherapy treatment has been gradually strengthened as the population of cancer survivors grows. Generally, chemotherapy-induced peripheral neurotoxicity (CIPN) is studied by animal models which are not only expensive and time-consuming, but also species-specific differences. The generation of human induced pluripotent stem cells (hiPSCs) and differentiation of peripheral neurons have provided an in vitro model to elucidate the risk of CIPN. Here, we developed a drug-induced peripheral neurotoxicity model using hiPSC-derived peripheral neurons (hiPSC-PNs) to study the mechanisms of different chemotherapeutic agents on neuronal viability using LDH assay, a cell apoptosis assay determined by caspase 3/7 activation, neurite outgrowth, ion channel expression and neurotransmitter release following treatment of cisplatin, bortezomib, ixabepilone, or pomalidomide. Our data showed that the multiple endpoints of the hiPSC-PNs model had different sensitivity to various chemotherapeutic agents. Furthermore, the chemotherapeutics separated cell viability from the decrease in neurite lengthand changed levels of ion channels and neurotransmitters to a certain extent. Thus, we study the mechanisms of peripheral neurotoxicity induced by chemotherapeutic agents through changes in these indicators.

Reporting in rodent models of 'chemobrain': a systematic review assessing compliance with the ARRIVE guidelines

Patients diagnosed with cancer are often plagued with debilitating side effects post-chemotherapy treatment. One such side effect is chemotherapy-induced cognitive impairment or 'chemobrain'. Rodent models are commonly used to investigate pathogenesis and potential therapeutic strategies. However, concerns have been raised regarding inadequacies in reporting of animal studies rendering them unreliable and irreproducible. The aim of this systematic review was to assess compliance with the ARRIVE reporting guidelines in peer-reviewed publications evaluating chemotherapy-induced cognitive changes in rodent models, and to determine if the introduction of the ARRIVE guidelines has improved quality of reporting. A comprehensive search was conducted to identify relevant peer-reviewed publications. Ninety-seven studies met the eligibility criteria, and publication compliance with the ARRIVE guideline reporting was assessed. No studies achieved full adherence with the ARRIVE guidelines. Furthermore, no significant improvement was demonstrated in the overall compliance score post-ARRIVE. Given the lack of standardisation of animal models in this research area, these results pose particular threat to future progress and translation of findings in this area of research. These results highlight the need for stricter adherence to the ARRIVE guidelines by journal editors and reviewers. Animal Ethics Committees also have an important educative role in improving knowledge and awareness of the guidelines amongst researchers.

Neuroimmune reactivity marker expression in rodent models of chemotherapy-induced cognitive impairment: A systematic scoping review

BACKGROUND

Chemotherapy-induced cognitive impairment (CICI) is a debilitating side effect arising from chemotherapy treatments. The condition is characterised by a range of cognitive deficits including impairment to memory, attention, and concentration. Whilst the underlying mechanisms that contribute to CICI remain unclear, neuroinflammation has been suggested as one key contributor.

METHOD

A comprehensive systematic search of EMBASE and Medline via PubMed was conducted to identify studies on neuroimmune reactivity marker expression changes and resulting cognitive changes in preclinical rodent models of CICI.

RESULTS

A total of twenty studies met the eligibility criteria and were included in the scoping review. There was significant heterogeneity in the methodology employed in the included studies. Our findings demonstrate that widespread changes in cytokines, chemokines, microglia reactivity, and astrocyte reactivity are observed in CICI in the brain regions expected to be affected, given the nature of the cognitive impairment observed in CICI.

CONCLUSIONS

Although there was considerable heterogeneity in study design that made comparisons between studies difficult, our findings suggest that neuroinflammation commonly occurs in CICI preclinical rodent models and shows an association with cognitive impairment.

Visual Pathway Degeneration in Chemotherapy-Related Neurotoxicity: A Review and Directions for Future Research

Chemotherapy-related neurotoxicity (CRNT) is an emerging public health concern. Visual pathway degeneration may be a symptom of CRNT. We surveyed the current literature for evidence of visual pathway degeneration in cancer patients receiving chemotherapy. A systematic review was conducted in PubMed. Six published articles met our inclusion criteria. The studies showed reduced retinal thickness, primarily in the retinal nerve fibre layer, and impaired inner retinal function in patients receiving chemotherapy. In summary, the current literature suggests chemotherapy may induce visual pathway degeneration. Future research may benefit from improving study design, exploring mechanisms of chemotherapy-related visual pathway degeneration, and incorporating these findings into biomarker development.

Case of neuromyelitis optica: bilateral sensorineural hearing loss and transverse myelopathy following intrathecal chemotherapy

Neurotoxicity from intrathecally administered chemotherapeutic drugs is frequent, particularly with some agents like methotrexate, which are more prone to developing adverse effects. Myelopathy ranks among the most frequently reported neurological entities; with the diagnosis being straightforward, after ruling out infectious, metabolic, autoimmune or paraneoplastic causes. Scarcity of cases precludes evidence-based recommendations for the management of these complications. The most common therapeutic approach consists of the suspension of chemotherapy, exclusion of infectious and neoplastic causes, with prompt administration of high-dose steroids. We report a 21-year-old patient with acute lymphoblastic leukaemia, who developed acute transverse myelitis and bilateral sensorineural hearing loss, after five rounds of intrathecal methotrexate and cytarabine. Although neurotoxicity from both agents has been documented, this combination has not been previously reported.

Post-chemotherapy cognitive impairment in hematological patients: current understanding of chemobrain in hematology

Introduction: Cognitive impairment caused by chemotherapies, a condition known as chemobrain, is a possible side effect that affects alertness, learning, memory, and concentration.Areas covered: Chemobrain has been principally investigated as a possible side-effect among cancer patients. However, numerous drugs used to treat hematological malignancies can determine the appearance of chemobrain. In this review, we have examined some commonly used drugs for the treatment of hematological malignancies which are known to have a deleterious action on cognitive functions.Numerous mechanisms have been suggested, comprising the direct neurotoxicity of chemotherapeutic drugs, oxidative stress, genetic predisposition, cytokine-provoked damage, histone modifications, immune alteration, and the action of chemotherapeutic on trophic factors and structural proteins of brain cells.Expert commentary: Cognitive dysfunction provoked by the treatment of hematological diseases is an actual challenge in clinical practice. Actually, there are no totally efficient and innocuous treatments for this syndrome. It is important that further investigations specify the existence of predictors and gravity factors to pre- and post-therapy cognitive change and identify the influence of tumor treatments on the cognitive alterations in long-term, cancer survivors. Moreover, future studies are needed to analyze the interactions between genetic risk, amyloid accumulation, intrinsic brain networks, and chemotherapy.

Premature ageing following allogeneic hematopoietic stem cell transplantation

Survivors of hematopoietic cell transplantation (HCT) have been shown to exhibit both clinical and biological features of accelerated ageing. Most studies used frailty measures, comorbidities for clinical assessment and several biological assessment of premature ageing. However, these tests are less suitable for age determination of individual patients. Recently, DNA methylation has emerged as a novel test to measure cellular age. In the present study, we assessed ageing in a cohort of 26 survivors of allogeneic HCT by frailty tests comprising the handgrip and 6 min walk tests and by biological tests including DNA methylation, telomere length and expression of p16INK^4A and serum levels of IL-6. DNA methylation was evaluated both in blood and buccal epithelial cells. Physiological reserve was markedly reduced in transplant survivors, reflected by 6 min walk test. Increased IL-6 serum levels and p16^ink4A correlated with accelerated ageing. Overall, the measured age of donor blood cells was significantly higher than these blood cells residing in their respective donors, as reflected by DNA methylation and by buccal epithelium methylation status. These clinical and biological observations suggest that allogeneic HCT is associated with accelerated ageing.

Management of Peripheral Neuropathy Induced by Chemotherapy

BACKGROUND

Chemotherapy-induced peripheral neuropathy (CIPN) is considered a severe side effect of therapeutic agents with limited treatment options. The incidence of CIPN in cancer patients is approximately 3-7% in cytostatic monotherapy and as high as 38% in cases of polychemotherapy. The prevalence of CIPN was found to be 68% within the first month of chemotherapy treatment. In some cases, CIPN can resolve, partially or completely, after completion of the treatment; in other cases, it can remain for a long time and affect the patient's quality of life.

OBJECTIVE

The aim of this study is to present up-to-date data regarding available treatment options for the management of CIPN.

MATERIALS AND METHODS

The up-to-date guidelines of ESMO (European Society for Medical Oncology), ASCO (American Society of Clinical Oncology), ONS (Oncology Nursing Society), NCI (National Cancer Institute), and NCCN (National Comprehensive Cancer Network) were reviewed and included in the manuscript.

RESULTS

The use of tricyclic antidepressant (TCA), selective serotonin norepinephrine reuptake inhibitor (SSNRI), pregabalin, and gabapentin are recommended as first-line treatment. Other treatment options were offered as second and third lines of treatment (lidocaine patches, capsaicin high-concentration patches, tramadol, and strong opioids, respectively); however, lower significance was demonstrated. Inconclusive results were found in the use of cannabinoids, drug combinations, antiepileptics, antidepressants, and topical drugs.

CONCLUSION

TCA, other antidepressants, and opioids could be recommended as treatment. Yet, we could not recommend an ideal therapeutic agent for the prevention or treatment of CIPN. Therefore, CIPN continues to be a challenge to clinicians and our patients.

Emergent Nanotechnological Strategies for Systemic Chemotherapy against Melanoma

Melanoma is an aggressive form of skin cancer, being one of the deadliest cancers in the world. The current treatment options involve surgery, radiotherapy, targeted therapy, immunotherapy and the use of chemotherapeutic agents. Although the last approach is the most used, the high toxicity and the lack of efficacy in advanced stages of the disease have demanded the search for novel bioactive molecules and/or efficient drug delivery systems. The current review aims to discuss the most recent advances on the elucidation of potential targets for melanoma treatment, such as aquaporin-3 and tyrosinase. In addition, the role of nanotechnology as a valuable strategy to effectively deliver selective drugs is emphasized, either incorporating/encapsulating synthetic molecules or natural-derived compounds in lipid-based nanosystems such as liposomes. Nanoformulated compounds have been explored for their improved anticancer activity against melanoma and promising results have been obtained. Indeed, they displayed improved physicochemical properties and higher accumulation in tumoral tissues, which potentiated the efficacy of the compounds in pre-clinical experiments. Overall, these experiments opened new doors for the discovery and development of more effective drug formulations for melanoma treatment.

Chemobrain in rats: Behavioral, morphological, oxidative and inflammatory effects of doxorubicin administration

Doxorubicin (DOX) is known to cause cognitive impairments in patients submitted to long-term chemotherapy (deficits also known as chemobrain). The present study investigated whether DOX administration could affect behavior and brain morphology, as well as oxidative and inflammatory status in rats. Male Wistar rats were injected with DOX (2.5 mg/kg/week, 4 weeks, i.p.) or saline. Behavioral analyses were performed. Brains were collected and analyzed by hematoxylin-eosin and luxol fast blue staining techniques and by immunohistochemistry (for glial fibrillary acidic protein expression in astrocytes; GFAP). Serum and brain levels of TNF-α, IL-1β, IL-6, IL-8, IL-10 and CXCL-1 were determined. Oxidative parameters, such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), nitric oxide (NO•), brain iron and ferritin levels, as well as reduced and oxidized glutathione (GSH and GSSG, respectively) and thiobarbituric acid reactive substances (TBARS) were also assessed in brain. DOX-injected rats presented cognitive/memory impairments, increased GFAP expression, increased levels of TBARS, NO and GR, but decreased GSSG and ferritin levels in brain homogenate. In addition, increased serum and brain levels of IL-6, IL-8 and CXCL1 were noted in the DOX group, although IL-10 decreased. As DOX has a poor penetration across the blood-brain barrier (BBB), it is proposed that this drug elicits a systemic proinflammatory response with increase of proinflammatory cytokines which cross the BBB and can be involved in the induction of oxidative molecules and proinflammatory cytokines that altogether induce astrogliosis all over the brain. These events may be responsable for chemotherapy-induced cognitive/memory deficits.

Chemotherapy-induced posterior reversible encephalopathy syndrome: Three case reports

RATIONALE

Posterior reversible encephalopathy syndrome (PRES) has been associated with the use of several medications, including chemotherapeutic agents.

PATIENT CONCERNS

A 65-year-old woman was diagnosed with adenocarcinoma of the ovary, after sixth-line treatment with topotecan, at the beginning of the fourth cycle, she was admitted to the emergency room for presenting tonic-clonic seizures, visual disturbance, and hypertension. A 66-year-old woman was diagnosed with bilateral breast cancer; due to disease progression, treatment with paclitaxel and gemcitabine was started, 1 month after the last dose of chemotherapy, she was admitted to the emergency room for suffering severe headache, altered mental status, tonic-clonic seizures, and hypertension. A 60-year-old patient diagnosed with breast cancer on the left side, underwent second-line chemotherapy with gemcitabine, carboplatin, and bevacizumab, and 1 month after the last dose of chemotherapy, she was also admitted to the emergency room due to altered mental status, vomiting, tonic-clonic seizures, and hypertension.

DIAGNOSIS

They were diagnosed as PRES based on physical examination, laboratory findings, and imaging techniques that revealed diffuse lesions and edema within the parieto-occipital regions.

INTERVENTIONS

They received support treatment with blood pressure (BP) control, seizures were controlled with a single anti-epileptic agent, and chemotherapeutic agents from the onset of PRES to its resolution were discontinued.

OUTCOMES

All these patients improved after medical treatment was started.

LESSONS

Medical personnel and therapeutic establishments need to be made aware about this chemotherapy-induced neurologic complication.

Duloxetine, a Balanced Serotonin-Norepinephrine Reuptake Inhibitor, Improves Painful Chemotherapy-Induced Peripheral Neuropathy by Inhibiting Activation of p38 MAPK and NF-κB

Chemotherapy-induced peripheral neuropathy (CIPN) is a severe, toxic side effect that frequently occurs in anticancer treatment and may result in discontinuation of treatment as well as a serious reduction in life quality. The CIPN incidence rate is as high as 85–90%. Unfortunately, there is currently no standard evidence-based CIPN treatment. In several clinical trials, it has been reported that duloxetine can improve CIPN pain induced by oxaliplatin (OXA) and paclitaxel (PTX); thus, The American Society of Clinical Oncology (ASCO) recommends duloxetine as the only potential treatment for CIPN. However, this guidance lacks the support of sufficient evidence. Our study shows that duloxetine markedly reduces neuropathic pain evoked by OXA or PTX. Duloxetine acts by inhibiting the activation of p38 phosphorylation, thus preventing the activation and nuclear translocation of the NF-κB transcription factor, reducing the inflammatory response and inhibiting nerve injury by regulating nerve growth factor (NGF). Furthermore, in this study, it is shown that duloxetine does not affect the antitumor activity of OXA or PTX. This study not only provides biological evidence to support the use of duloxetine as the first standard CIPN drug but will also lead to potential new targets for CIPN drug development.

Axonal Degeneration Is Mediated by Necroptosis Activation

Axonal degeneration, which contributes to functional impairment in several disorders of the nervous system, is an important target for neuroprotection. Several individual factors and subcellular events have been implicated in axonal degeneration, but researchers have so far been unable to identify an integrative signaling pathway activating this self-destructive process. Through pharmacological and genetic approaches, we tested whether necroptosis, a regulated cell-death mechanism implicated in the pathogenesis of several neurodegenerative diseases, is involved in axonal degeneration. Pharmacological inhibition of the necroptotic kinase RIPK1 using necrostatin-1 strongly delayed axonal degeneration in the peripheral nervous system and CNS of wild-type mice of either sex and protected in vitro sensory axons from degeneration after mechanical and toxic insults. These effects were also observed after genetic knock-down of RIPK3, a second key regulator of necroptosis, and the downstream effector MLKL (Mixed Lineage Kinase Domain-Like). RIPK1 inhibition prevented mitochondrial fragmentation in vitro and in vivo, a typical feature of necrotic death, and inhibition of mitochondrial fission by Mdivi also resulted in reduced axonal loss in damaged nerves. Furthermore, electrophysiological analysis demonstrated that inhibition of necroptosis delays not only the morphological degeneration of axons, but also the loss of their electrophysiological function after nerve injury. Activation of the necroptotic pathway early during injury-induced axonal degeneration was made evident by increased phosphorylation of the downstream effector MLKL. Our results demonstrate that axonal degeneration proceeds by necroptosis, thus defining a novel mechanistic framework in the axonal degenerative cascade for therapeutic interventions in a wide variety of conditions that lead to neuronal loss and functional impairment.SIGNIFICANCE STATEMENT We show that axonal degeneration triggered by diverse stimuli is mediated by the activation of the necroptotic programmed cell-death program by a cell-autonomous mechanism. This work represents a critical advance for the field since it identifies a defined degenerative pathway involved in axonal degeneration in both the peripheral nervous system and the CNS, a process that has been proposed as an early event in several neurodegenerative conditions and a major contributor to neuronal death. The identification of necroptosis as a key mechanism for axonal degeneration is an important step toward the development of novel therapeutic strategies for nervous-system disorders, particularly those related to chemotherapy-induced peripheral neuropathies or CNS diseases in which axonal degeneration is a common factor.