An Overview on Chemotherapy-induced Cognitive Impairment and Potential Role of Antidepressants

Effectiveness of smartphone app-based interventions after surgery on quality of recovery among cancer patients: a systematic review and meta-analysis

BACKGROUND

Postoperative recovery in patients with cancer is a complex process that influences quality of life, functional recovery, and mental well-being. Smartphone app-based interventions have emerged as potential tools for improving various aspects of health and well-being in cancer patients. However, the existing literature lacks a consensus on the efficacy of these interventions, leading to conflicting outcomes.

METHODS

We searched multiple databases, including PubMed, Web of Science, Cochrane Library, Scopus, EMBASE, and MEDLINE Complete (EBSCO). We exclusively selected randomized controlled trials meeting the inclusion criteria for our systematic review and meta-analysis. Utilizing a random-effects model, we derived the pooled effect size estimates for the meta-analysis. Where applicable, we calculated the pooled standardized mean difference (SMD) with 95% confidence interval (CI). The Cochrane Collaboration tool (Cochrane ROB) was used to evaluate bias in randomized trials. The primary outcome was the quality of life. The secondary outcomes were psychological symptoms, health conditions, satisfaction, and self-efficacy.

RESULTS

Of 731 screened articles, 15 were included, comprising 1,831 participants. Our meta-analysis revealed that app-based interventions potentially improved quality of life (SMD =  -0.58, 95% CI -1.00 to -0.16), alleviated psychological symptoms (SMD =  -0.43, 95% CI -0.72,-0.15; p = .003), and enhanced self-efficacy (SMD = 0.90, 95% CI 0.26 to 1.53; p  =  0.001). However, there was no statistically significant effect on satisfaction (SMD = 1.25, 95% CI-1.06 to 3.57; p  =  0.23).

CONCLUSIONS

Our findings suggest that mobile health apps hold promise in improving the well-being of cancer patients after surgery by enhancing their quality of life, health status, and self-efficacy, while also reducing anxiety and depression.

Antineoplastics for treating Alzheimer's disease and dementia: Evidence from preclinical and observational studies

As the world population ages, there will be an increasing need for effective therapies for aging-associated neurodegenerative disorders, which remain untreatable. Dementia due to Alzheimer's disease (AD) is one of the leading neurological diseases in the aging population. Current therapeutic approaches to treat this disorder are solely symptomatic, making the need for new molecular entities acting on the causes of the disease extremely urgent. One of the potential solutions is to use compounds that are already in the market. The structures have known pharmacokinetics, pharmacodynamics, toxicity profiles, and patient data available in several countries. Several drugs have been used successfully to treat diseases different from their original purposes, such as autoimmunity and peripheral inflammation. Herein, we divulge the repurposing of drugs in the area of neurodegenerative diseases, focusing on the therapeutic potential of antineoplastics to treat dementia due to AD and dementia. We briefly touch upon the shared pathological mechanism between AD and cancer and drug repurposing strategies, with a focus on artificial intelligence. Next, we bring out the current status of research on the development of drugs, provide supporting evidence from retrospective, clinical, and preclinical studies on antineoplastic use, and bring in new areas, such as repurposing drugs for the prion-like spreading of pathologies in treating AD.

In-vitro and in-vivo studies of two-drug cocktail therapy targeting chemobrain via the Nrf2/NF-κB signaling pathway

Today, we critically need alternative therapeutic options for chemotherapy-induced cognitive impairment (CICI), often known as chemo brain. Mitochondrial dysfunction and oxidative stress are two of the primary processes that contribute to the development of chemobrain. Therefore, the purpose of this study was to investigate how CoQ10 and berberine shield neurons from chemotherapy-induced damage in in-vitro studies and memory loss in vivo studies. For the in-vitro investigation, we employed SH-SY5Y cell lines, and for the in-vivo study, we used female Swiss albino mice divided into seven different groups. Data from in-vitro studies revealed that treatment with coenzyme Q10 (CoQ10) and berberine improved chemotherapy-induced toxicity by reducing mitochondrial and total cellular ROS, as well as apoptosis-elicited markers (caspase 3 and 9). CoQ10 and berberine therapy inhibited the nuclear translocation of NF-κB and, consequently, the subsequent expressions of NLRP3 and IL-1β, implying the prevention of inflammasome formation. Furthermore, CoQ10 and berberine therapy boosted Nrf2 levels. This is a regulator for cellular resistance to oxidants. The in vivo results showed that treatment with CoQ10 (40 mg/kg) and berberine (200 mg/kg) improved the behavioral alterations induced by CAF (40/4/25 mg/kg) in both the Morris Water Maze (MWM) and Novel Object Recognition (NOR) tests. Furthermore, biochemical and molecular evidence revealed the antioxidant, mitochondrial restorative, and anti-inflammatory potential of CoQ10 (40 mg/kg) and berberine (200 mg/kg) against CAF (40/4/25 mg/kg) subjected mice. In addition, the histological analysis using H&E staining and transmission electron microscopy (for mitochondrial morphology) showed that mice treated with the cocktails had an increased number of healthy neurons with intact mitochondria and a reduced presence of autophagic vacuoles in the hippocampal region of the brain. These findings back up our theory about this novel cocktail method for CAF-induced cognitive impairment.

Clinical study of chemotherapy-related cognitive impairment in patients with non-Hodgkin lymphoma

BACKGROUND

Chemotherapy for malignant tumors can cause brain changes and cognitive impairment, leading to chemotherapy-induced cognitive impairment (CICI). Current research on CICI has focused on breast cancer and Hodgkin's lymphoma. Whether patients with non-Hodgkin's lymphoma (NHL) undergoing chemotherapy have cognitive impairment has not been fully investigated.

AIM

To investigate whether NHL patients undergoing chemotherapy had cognitive impairments.

METHODS

The study included 100 NHL patients who were required to complete a comprehensive psychological scale including the Brief Psychiatric Examination Scale (MMSE) at two time points: before chemotherapy and within 2 wk of two chemotherapy courses. A language proficiency test (VFT), Symbol Number Pattern Test (SDMT), Clock Drawing Test (CDT), Abbreviated Daily Cognition Scale (ECog-12), Prospective and Retrospective Memory Questionnaire, and Karnofsky Performance Status were used to assess cognitive changes before and after chemotherapy.

RESULTS

The VFT scores for before treatment (BT) and after treatment (AT) groups were 45.20 ± 15.62, and 42.30 ± 17.53, respectively (t -2.16, P < 0.05). The CDT scores were 8 (3.5-9.25) for BT and 7 (2.5-9) for AT groups (Z -2.1, P < 0.05). Retrospective memory scores were 13.5 (9-17) for BT and 15 (13-18) for AT (Z -3.7, P < 0.01). The prospective memory scores were 12.63 ± 3.61 for BT and 14.43 ± 4.32 for AT groups (t -4.97, P < 0.01). The ECog-12 scores were 1.71 (1.25-2.08) for BT and 1.79 (1.42-2.08) for AT groups (Z -2.84, P < 0.01). The SDMT and MMSE values did not show a significant difference between BT and AT groups.

CONCLUSION

Compared to the AT group, the BT group showed impaired language, memory, and subjective cognition, but objective cognition and execution were not significantly affected.

Patient-reported outcomes in Primary Spinal Intradural Tumours: a systematic review

STUDY DESIGN

Systematic review.

OBJECTIVES

Primary Spinal Intradural Tumours (PSITs) are rare pathologies that can significantly impact quality of life. This study aimed to review patient reported outcomes (PROs) in PSITs.

METHODS

A systematic search of Pubmed and Embase was performed to identify studies measuring PROs in adults with PSITs. PRO results were categorised as relating to Global, Physical, Social, or Mental health. Outcomes were summarised descriptively.

RESULTS

Following review of 2382 records, 11 studies were eligible for inclusion (737 patients). All studies assessed surgically treated patients. Schwannoma was the commonest pathology (n = 190). 7 studies measured PROs before and after surgery, the remainder assessed only post-operatively. For eight studies, PROs were obtained within 12 months of treatment. 21 PRO measurement tools were used across included studies, of which Euro-Qol-5D (n = 8) and the pain visual/numerical analogue scale (n = 5) were utilised most frequently. Although overall QoL is lower than healthy controls in PSITs, improvements following surgery were found in Extramedullary tumours (EMT) in overall physical, social, and mental health. Similar improvements were not significant across studies of Intramedullary tumours (IMT). Overall QoL and symptom burden was higher in IMT patients than in brain tumour patients. No studies evaluated the effect of chemotherapy or radiotherapy.

CONCLUSION

Patients with PSITs suffer impaired PROs before and after surgery. This is particularly true for IMTs. PRO reporting in PSITs is hindered by a heterogeneity of reporting and varied measurement tools. This calls for the establishment of a standard set of PROs as well as the use of registries.

The Genomic Intersection of Oligodendrocyte Dynamics in Schizophrenia and Aging Unravels Novel Pathological Mechanisms and Therapeutic Potentials

Schizophrenia is a significant worldwide health concern, affecting over 20 million individuals and contributing to a potential reduction in life expectancy by up to 14.5 years. Despite its profound impact, the precise pathological mechanisms underlying schizophrenia continue to remain enigmatic, with previous research yielding diverse and occasionally conflicting findings. Nonetheless, one consistently observed phenomenon in brain imaging studies of schizophrenia patients is the disruption of white matter, the bundles of myelinated axons that provide connectivity and rapid signalling between brain regions. Myelin is produced by specialised glial cells known as oligodendrocytes, which have been shown to be disrupted in post-mortem analyses of schizophrenia patients. Oligodendrocytes are generated throughout life by a major population of oligodendrocyte progenitor cells (OPC), which are essential for white matter health and plasticity. Notably, a decline in a specific subpopulation of OPC has been identified as a principal factor in oligodendrocyte disruption and white matter loss in the aging brain, suggesting this may also be a factor in schizophrenia. In this review, we analysed genomic databases to pinpoint intersections between aging and schizophrenia and identify shared mechanisms of white matter disruption and cognitive dysfunction.

Exercise alleviates cisplatin-induced toxicity in the hippocampus of mice by inhibiting neuroinflammation and improving synaptic plasticity

Chemotherapy-induced cognitive impairment is recognized as the most typical symptom in patients with cancer that occurs during and following the chemotherapy treatment. Recently many studies focused on pharmaceutical strategies to control the chemotherapy side effects, however it is far from satisfactory. There may be a need for more effective treatment options. The aim of this study was to investigate the protective effect of exercise on cisplatin-induced neurotoxicity. Eightweek- old C57BL6 mice were separated into three group: normal control (CON, n = 8); cisplatin injection control (Cis-CON, n = 8); cisplatin with aerobic exercise (Cis-EXE, n = 8). Cisplatin was administered intraperitoneally at a dose of 3.5 mg/kg/day. The Cis-EXE group exercise by treadmill running (14-16 m/min for 45 min daily, 3 times/ week) for 12 weeks. Compared to the CON group, the cisplatin injection groups showed significant decrease in body weight and food intake, indicating successful induction of cisplatin toxicity. The Cis-CON group showed significantly increased levels of pro-inflammatory cytokines including IL-6, IL-1β, and TNF-α in the hippocampus, while the Cis-EXE group was significantly decreased in the expression of IL- 6, IL-1β, and TNF-α. In addition, compared to the CON group, the levels of synapserelated proteins including synapsin-1 and -2 were significantly reduced in the Cis- CON group, and there was a significant difference between the Cis-CON and Cis-EXE groups. Antioxidant and apoptosis factors were significantly improved in the Cis-EXE group compared with the Cis-CON group. This study suggest that exercise could be meaningful approach to prevent or improve cisplatin-induced cognitive impairment.

N-acetylcysteine ameliorates chemotherapy-induced impaired anxiety and depression-like behaviors by regulating inflammation, oxidative and cholinergic status, and BDNF release

Mood disorders caused by chemotherapy have become more important as the survival of cancer patients increases, and new studies in this field will contribute to the prevention of this disorder. For this purpose, we used methotrexate, a chemotherapeutic agent frequently preferred in oncological cases. Mtx was administered as a single dose of 100 mg/kg intraperitoneally to male Wistar albino rats. Since oxidative stress plays an important role in chemotherapy-induced emotional impairment, n-acetylcysteine (NAC), a potent antioxidant, was administered at 500 mg/kg in two doses before Mtx administration. We evaluated anxiety and depression-like behaviors 24 h after Mtx administration, as well as some oxidative and inflammatory markers in blood serum and hippocampal tissue, acetylcholinesterase activity (AChE), and brain-derived neurotrophic factor (BDNF) release in hippocampal tissue. In rats, Mtx induced anxiety and depression-like behaviors as well as abnormalities in oxidative and inflammatory markers in blood serum and hippocampal tissue, increased AChE activity in hippocampal tissue, and decreased BDNF release. NAC treatment was found to ameliorate Mtx-induced anxiety and depression-like behaviors, increase antioxidant capacity, reduce oxidative stress and inflammatory response, and regulate AChE activity and BDNF release. In conclusion, the fact that NAC treatment of Mtx was effective is important for revising the treatment strategies for individuals suffering from this disorder, and this effect is thought to be related to the antioxidant and anti-inflammatory power of NAC.

Natural products for the treatment of chemotherapy-related cognitive impairment and prospects of nose-to-brain drug delivery

Chemotherapy-related cognitive deficits (CRCI) as one of the common adverse drug reactions during chemotherapy that manifest as memory, attention, and executive function impairments. However, there are still no effective pharmacological therapies for the treatment of CRCI. Natural compounds have always inspired drug development and numerous natural products have shown potential therapeutic effects on CRCI. Nevertheless, improving the brain targeting of natural compounds in the treatment of CRCI is still a problem to be overcome at present and in the future. Accumulated evidence shows that nose-to-brain drug delivery may be an excellent carrier for natural compounds. Therefore, we reviewed natural products with potential anti-CRCI, focusing on the signaling pathway of these drugs' anti-CRCI effects, as well as the possibility and prospect of treating CRCI with natural compounds based on nose-to-brain drug delivery in the future. In conclusion, this review provides new insights to further explore natural products in the treatment of CRCI.

Cladribine induces apoptosis, neuroinflammation, mitochondrial oxidative stress, tau phosphorylation and Aβ (1-42) pathway in the hippocampus: An in vivo approach

Cladribine is a purine nucleoside found to enhance toxic amyloid protein and cause memory impairment. Patients following chemotherapy treatment commonly suffer from cognitive deficits more prevalent in the elderly than adults. A previous research study revealed that cladribine has a high affinity to the brain, increases the level of amyloid precursor protein, and results in learning deficits. The study was designed to validate an animal model of cladribine administration to rats through mitochondrial oxidative stress, inflammation, apoptosis, tau phosphorylation, and amyloid-β (1-42) accumulation. In this study, all rats were orally given cladribine (0.5 and 1 mg/kg) for 28 days, resulting in impaired spatial memory confirmed by behavioural activity. On day 29, all rats were euthanized, and the hippocampal tissues were isolated and used for the estimation of neuroinflammatory markers, biochemicals parameters (glutathione, catalase, lipid peroxidation, and nitrite), amyloid-β (1-42) level, neurotransmitters, and nuclear factor kappa B analysis. Cladribine administration significantly elevated cytokines release, dysbalanced neurotransmitter concentration, and promoted the Aβ accumulation and hyperphosphorylation of tau protein. Our study outcome confirmed that cladribine produces cognitive impairment via activation of Nuclear factor kappa B, mitochondrial oxidative stress and dysbalanced of the endogenous antioxidant defence system.

Transcranial Magnetic Stimulation for the Treatment of Chemo Brain

This pilot feasibility study aimed to evaluate the effects of transcranial magnetic stimulation (TMS) on chemotherapy-related cognitive impairment (CRCI), and we report here on the first patient.

BACKGROUND

Deleterious cognitive changes due to chemotherapy or CRCI are commonly referred to as "chemo brain". With the increasing survival of cancer patients, this poorly understood and inadequately treated condition will likewise have an increasing toll on individuals and society. Since there is no approved treatment for chemo brain, we have initiated a therapeutic trial using transcranial magnetic stimulation (TMS), a non-invasive brain stimulation technique approved in many countries for the treatment of neurologic and psychiatric conditions like migraine and depression.

CASE PRESENTATION

A 58-year-old woman, diagnosed 7 years prior with left breast cancer, underwent partial mastectomy with sentinel lymph node biopsy. She then received four cycles of adjuvant chemotherapy followed by radiation therapy. Afterwards, she was on tamoxifen for 4 years and then switched to aromatase inhibitors. The patient's CRCI started during chemotherapy and severely impaired her quality of life for an additional two years. In the third year after chemotherapy, the CRCI partially cleared to stabilize to the level at the time of presentation for this trial. The patient continues to have memory difficulties and decreased concentration, which makes multi-tasking very difficult to impossible. She is reliant on memory aids at work and at home. The participant underwent 10 consecutive sessions of TMS during weekdays for 2 weeks. Stimulation was directed to the left dorsolateral prefrontal cortex. After TMS, the participant significantly improved in memory function on neuropsychological testing. While she reported no subjective differences in concentration or memory, she did report an improvement in her sleep. Functional magnetic resonance imaging of the brain before and after TMS showed increased resting-state functional connectivity between the stimulation site and several brain regions. Remarkably, after 6 years of chemo brain and remaining in the same position at work due to her inability to concentrate and multi-task, she applied for and received a promotion 5-6 months after her TMS treatments.

CONCLUSIONS

This first patient in the phase 1 clinical trial testing of TMS for the treatment of "chemo brain" provided important lessons for feasibility and insights into mechanisms of potential benefit.

Protocol for a systematic review of the effects of gardening physical activity on neuroplasticity and cognitive function

Background

The beneficial effects of gardening as a form of physical activity have garnered growing interest in recent years. Existing research suggests that physical activity enhances brain function through modifying synaptic plasticity, growth factor synthesis, and neurogenesis. Gardening physical activity is a promising, cost-effective, non-invasive intervention that can easily be augmented in the rehabilitation of neurodegenerative conditions. However, there is still insufficient literature. This protocol describes a systematic review to be conducted of scientific literature on the benefits of gardening as a physical activity that can promote neuroplasticity and improve cognitive function. This information can be useful as an intervention for persons who experience cognitive impairment brought on by cancer and chemotherapy in developing countries such as South Africa where there is real need to access cognitive rehabilitation.

Methods and analysis

The systematic review strategy will be conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. An electronic literature database search of MEDLINE (PubMed), Embase, Scopus, Cochrane Central Register of Controlled Trials (CENTRAL), and Web of Science will be carried out using medical search terms (MeSH), with English as the only permitted language, during the time period of January 2010 to December 2022. We will search for and review studies on how gardening as a physical activity impacts neuroplasticity and cognition. Two reviewers will read the titles, and abstracts and full text of the studies identified during the search to exclude records that do not meet the inclusion criteria. Data will then be extracted from the remaining studies. Any differences in opinion arising between the reviewers during the procedure will be resolved through discussion with a third reviewer. The Joanna Briggs Institute (JBI) Critical Appraisal Tool checklist will be utilized independently by two reviewers to evaluate the possibility of bias. The included articles will be subjected to narrative synthesis, with the results being presented in a thematic manner.

Ethics and dissemination

There are no need for ethical approval because no patient data will be gathered. The results will be disseminated through an open-access peer-reviewed indexed journal, presented scientific meetings.PROSPERO registration number: CRD42023394493.

CAR t-cell therapy in BOlogNa-NEUrotoxicity TReatment and Assessment in Lymphoma (CARBON-NEUTRAL): proposed protocol and results from an Italian study

OBJECTIVE

To investigate neurotoxicity clinical and instrumental features, incidence, risk factors, and early and long-term prognosis in lymphoma patients who received CAR T-cell therapy.

METHODS

In this prospective study, consecutive refractory B-cell non-Hodgkin lymphoma patients who received CAR T-cell therapy were included. Patients were comprehensively evaluated (neurological examination, EEG, brain MRI, and neuropsychological test) before and after (two and twelve months) CAR T-cells. From the day of CAR T-cells infusion, patients underwent daily neurological examinations to monitor the development of neurotoxicity.

RESULTS

Forty-six patients were included in the study. The median age was 56.5 years, and 13 (28%) were females. Seventeen patients (37%) developed neurotoxicity, characterized by encephalopathy frequently associated with language disturbances (65%) and frontal lobe dysfunction (65%). EEG and brain FDG-PET findings also supported a predominant frontal lobe involvement. The median time at onset and duration were five and eight days, respectively. Baseline EEG abnormalities predicted ICANS development in the multivariable analysis (OR 4.771; CI 1.081-21.048; p = 0.039). Notably, CRS was invariably present before or concomitant with neurotoxicity, and all patients who exhibited severe CRS (grade ≥ 3) developed neurotoxicity. Serum inflammatory markers were significantly higher in patients who developed neurotoxicity. A complete neurological resolution following corticosteroids and anti-cytokines monoclonal antibodies was reached in all patients treated, except for one patient developing a fatal fulminant cerebral edema. All surviving patients completed the 1-year follow-up, and no long-term neurotoxicity was observed.

CONCLUSIONS

In the first prospective Italian real-life study, we presented novel clinical and investigative insights into ICANS diagnosis, predictive factors, and prognosis.

Docetaxel-induced cognitive impairment in rats can be ameliorated by edaravone dexborneol: Evidence from the indicators of biological behavior and anisotropic fraction

Objective

This study aimed to investigate the effect of Edaravone Dexborneol (ED) on impaired learning and memory in docetaxel (DTX)-treated rats using cognitive behavior assessments and magnetic resonance diffusion tensor imaging (DTI).

Materials and methods

In total, 24 male Sprague–Dawley rats were divided into control, low-dose DTX (L-DTX) model, and high-dose DTX(H-DTX) model groups, with eight rats in each group, numbered 1–8. The rats were intraperitoneally injected with 1.5 mL of either normal saline (control group), or 3 mg/kg and 6 mg/kg DTX (L-DTX and H-DTX groups, respectively), once a week for 4 weeks. The learning and memory abilities of each group were tested using a water maze. At the end of the water maze test, rats 1–4 in each group were treated with ED (3 mg/kg, 1 mL), and rats 5–8 were injected with an equal volume of normal saline once a day for 2 weeks. The learning and memory abilities of each group were evaluated again using the water maze test, and the image differences in the hippocampus of each group were analyzed using DTI.

Results

(1) H-DTX group (32.33 ± 7.83) had the longest escape latency, followed by the L-DTX group (27.49 ± 7.32), and the Control group (24.52 ± 8.11) having the shortest, with the difference being statistically significant (p &lt; 0.05). (2) Following ED treatment, compared to rats treated with normal saline, the escape latency of the L-DTX (12.00 ± 2.79 vs. 10.77 ± 3.97, p &lt; 0.05), and the H-DTX (12.52 ± 3.69 vs. 9.11 ± 2.88, p &lt; 0.05) rats were significantly shortened. The residence time in the target quadrant of H-DTX rats was significantly prolonged (40.49 ± 5.82 vs. 55.25 ± 6.78, p &lt; 0.05). The CNS damage in the L-DTX rats was repaired to a certain extent during the interval between the two water maze tests (28.89 ± 7.92 vs. 12.00 ± 2.79, p &lt; 0.05). (3) The fractional anisotropy (FA) value of DTI in the hippocampus of rats in the different groups showed variable trends. After treatment with ED, though the FA values of most areas in the hippocampus of rats in L-DTX and H-DTX groups were higher than before, they did not reach the normal level.

Conclusion

ED can ameliorate the cognitive dysfunctions caused by DTX in rats by improving the learning and memory impairment, which is reflected in the recovery of biological behavior and DTI indicators of the hippocampus.

Diagnostic Accuracy of Machine-Learning Models on Predicting Chemo-Brain in Breast Cancer Survivors Previously Treated with Chemotherapy: A Meta-Analysis

We performed a meta-analysis of chemo-brain diagnostic, pooling sensitivities, and specificities in order to assess the accuracy of a machine-learning (ML) algorithm in breast cancer survivors previously treated with chemotherapy. We searched PubMed, Web of Science, and Scopus for eligible articles before 30 September 2022. We identified three eligible studies from which we extracted seven ML algorithms. For our data, the χ² tests demonstrated the homogeneity of the sensitivity's models (χ² = 7.6987, df = 6, p-value = 0.261) and the specificities of the ML models (χ² = 3.0151, df = 6, p-value = 0.807). The pooled area under the curve (AUC) for the overall ML models in this study was 0.914 (95%CI: 0.891-0.939) and partial AUC (restricted to observed false positive rates and normalized) was 0.844 (95%CI: 0.80-0.889). Additionally, the pooled sensitivity and pooled specificity values were 0.81 (95% CI: 0.75-0.86) and 0.82 (95% CI: 0.76-0.86), respectively. From all included ML models, support vector machine demonstrated the best test performance. ML models represent a promising, reliable modality for chemo-brain prediction in breast cancer survivors previously treated with chemotherapy, demonstrating high accuracy.

Ameliorating effect offluoxetine on tamoxifen-induced memory loss: The role of corticolimbic NMDA receptors and CREB/BDNF/cFos signaling pathways in rats

Tamoxifen-induced cognitive dysfunction may lead to fluoxetine consumption in patients with breast cancer. Since the brain mechanisms are unclear in tamoxifen/fluoxetine therapy, the blockade effect of hippocampal/amygdala/prefrontal cortical NMDA receptors was examined in fluoxetine/tamoxifen-induced memory retrieval. We also assessed the corticolimbic signaling pathways in memory retrieval under the drug treatment in adult male Wistar rats. Using the Western blot technique, the expression levels of the cAMP response element-binding protein (CREB), brain-derived neurotrophic factor (BDNF), and cFos were evaluated in the corticolimbic regions. The results showed that pre-test administration of fluoxetine (3 and 5 mg/kg, i.p.) improved tamoxifen-induced memory impairment in the passive avoidance learning task. Pre-test bilateral microinjection of D-AP5, a selective NMDA receptor antagonist, into the dorsal hippocampal CA1 regions and the central amygdala (CeA), but not the medial prefrontal cortex (mPFC), inhibited the improving effect of fluoxetine on tamoxifen response. It is important to note that the microinjection of D-AP5 into the different sites by itself did not affect memory retrieval. Memory retrieval increased the signaling pathway of pCREB/CREB/BDNF/cFos in the corticolimbic regions. Tamoxifen-induced memory impairment decreased the hippocampal/PFC BDNF level and the amygdala level of pCREB/CREB/cFos. The improving effect of fluoxetine on tamoxifen significantly increased the hippocampal/PFC expression levels of BDNF, the PFC/amygdala expression levels of cFos, and the ratio of pCREB/CREB in all targeted areas. Thus, NMDA receptors' activity in the different corticolimbic regions mediates fluoxetine/tamoxifen memory retrieval. The corticolimbic synaptic plasticity changes likely accompany the improving effect of fluoxetine on tamoxifen response.

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.

COMT rs737865 mediates chemobrain in breast cancer patients with various levels of Ki-67

Previous findings have indicated that catechol-O-methyltransferase (COMT) may be a genetic risk factor for chemobrain. However, the mediation of chemobrain by COMT polymorphisms in breast cancer patients with various levels of Ki-67 remains unknown. The current research assessed the genetic risk across COMT genotypes for chemobrain in breast cancer patients with various levels of Ki-67. Breast cancer patients (65 with Ki-67<14%, 75 with Ki-67>14%) completed cognitive tests before and after adjuvant chemotherapy, and three single-nucleotide polymorphisms (SNPs) of COMT (rs165599, rs4680, rs737865) were genotyped from peripheral blood. Lower cognitive test results in breast cancer patients were displayed in those before chemotherapy. Furthermore, the event-based prospective memory (EBPM) scores of patients in the Ki-67>14% group were worse than those in the patients in the Ki-67<14% group after chemotherapy (z=-7.51, P<0.01), but the time-based prospective memory (TBPM) scores of the two groups were not significantly different. The COMT rs737865 A/G genotype was associated with memory protection (codominant model: adjusted odds ratio (OR)=0.135, 95% CI=0.026-0.706, P=0.018), and A/G genotype carriers exhibited better performance on the EBPM test than the A/A genotype. Levels of Ki-67 were likely to be associated with EBPM decline in breast cancer patients. Taken together, COMT rs737865 polymorphisms are a potential genetic risk factor for chemobrain in breast cancer patients with various levels of Ki-67.

Influencing factors of depressive symptoms in patients with malignant tumour

OBJECTIVE

To assess the influencing factors of depressive symptoms in malignant tumour patients.

METHODS

Participants were 2079 inpatients with malignant tumour (1291: depressive symptoms; 788 no depressive symptoms). Univariable and multivariable logistic regression were used to evaluate sociodemographic and clinical factors influencing depressive symptoms.

RESULTS

Risk factors were family income ≤5000 yuan (odds ratio [OR]: 4.966, 95% confidence interval [CI]: 2.938-8.395) and 5001-10,000 yuan (OR: 3.111, 95% CI: 1.840-5.260); Karnofsky Performance Status of 70 (OR: 2.783, 95% CI: 1.281-6.042) and 80 (OR: 1.834, 95% CI: 1.139-2.953); disease course ≤1 year; palliative treatment (OR: 2.288, 95% CI: 1.292-4.055); progressive disease (OR: 1.876, 95% CI: 1.284-2.739); pain (OR: 1.973, 95% CI: 1.555-2.505); cancer type: lung (OR: 3.199, 95% CI: 1.938-5.279), oesophagus (OR: 3.288, 95% CI: 1.673-6.464), cervix (OR: 1.542, 95% CI: 1.056-2.253) and partial knowledge of disease condition (OR: 2.366, 95% CI: 1.653-3.385). Return to work (OR: 0.503, 95% CI: 0.348-0.727) and physical exercise (OR: 0.437, 95% CI: 0.347-0.551) were protective against depressive symptoms.

CONCLUSIONS

Several factors affected depressive symptoms in malignant tumour patients, including income, disease type and course, palliative treatment, return to work and physical exercise.

Chemotherapy-induced cognitive impairment: focus on the intersection of oxidative stress and TNFα

Chemotherapy-induced cognitive impairment (CICI) has been observed in a large fraction of cancer survivors. Although many of the chemotherapeutic drugs do not cross the blood-brain barrier, following treatment, the structure and function of the brain are altered and cognitive dysfunction occurs in a significant number of cancer survivors. The means by which CICI occurs is becoming better understood, but there still remain unsolved questions of the mechanisms involved. The hypotheses to explain CICI are numerous. More than 50% of FDA-approved cancer chemotherapy agents are associated with reactive oxygen species (ROS) that lead to oxidative stress and activate a myriad of pathways as well as inhibit pathways necessary for proper brain function. Oxidative stress triggers the activation of different proteins, one in particular is tumor necrosis factor alpha (TNFα). Following treatment with various chemotherapy agents, this pro-inflammatory cytokine binds to its receptors at the blood-brain barrier and translocates to the parenchyma via receptor-mediated endocytosis. Once in brain, TNFα initiates pathways that may eventually lead to neuronal death and ultimately cognitive impairment. TNFα activation of the c-jun N-terminal kinases (JNK) and Janus kinase-signal transducer and activator of transcription (JAK/STAT) pathways may contribute to both memory decline and loss of higher executive functions reported in patients after chemotherapy treatment. Chemotherapy also affects the brain's antioxidant capacity, allowing for accumulation of ROS. This review expands on these topics to provide insights into the possible mechanisms by which the intersection of oxidative stress and TNFΑ are involved in chemotherapy-induced cognitive impairment.

Animal models of chemotherapy-induced cognitive decline in preclinical drug development

RATIONALE

Chemotherapy-induced cognitive impairment (CICI), chemobrain, and chemofog are the common terms for mental dysfunction in a cancer patient/survivor under the influence of chemotherapeutics. CICI is manifested as short/long term memory problems and delayed mental processing, which interferes with a person's day-to-day activities. Understanding CICI mechanisms help in developing therapeutic interventions that may alleviate the disease condition. Animal models facilitate critical evaluation to elucidate the underlying mechanisms and form an integral part of verifying different treatment hypotheses and strategies.

OBJECTIVES

A methodical evaluation of scientific literature is required to understand cognitive changes associated with the use of chemotherapeutic agents in different preclinical studies. This review mainly emphasizes animal models developed with various chemotherapeutic agents individually and in combination, with their proposed mechanisms contributing to the cognitive dysfunction. This review also points toward the analysis of chemobrain in healthy animals to understand the mechanism of interventions in absence of tumor and in tumor-bearing animals to mimic human cancer conditions to screen potential drug candidates against chemobrain.

RESULTS

Substantial memory deficit as a result of commonly used chemotherapeutic agents was evidenced in healthy and tumor-bearing animals. Spatial and episodic cognitive impairments, alterations in neurotrophins, oxidative and inflammatory markers, and changes in long-term potentiation were commonly observed changes in different animal models irrespective of the chemotherapeutic agent.

CONCLUSION

Dyscognition exists as one of the serious side effects of cancer chemotherapy. Due to differing mechanisms of chemotherapeutic agents with differing tendencies to alter behavioral and biochemical parameters, chemotherapy may present a significant risk in resulting memory impairments in healthy as well as tumor-bearing animals.

Pathogenesis, Assessments, and Management of Chemotherapy-Related Cognitive Impairment (CRCI): An Updated Literature Review

There are various cancer treatments at present, and chemotherapy is one of the main methods. Chemotherapy-related cognitive impairment (CRCI), as one of the side effects of chemotherapy, has gradually attracted the attention of more and more researchers. CRCI has been verified by subjective reports and objective neuropsychological tests so far. But oncologists' understanding of it and its treatments are still incomplete. In this review, we mainly give a comprehensive overview of the mechanism of CRCI, then describe a variety of evaluation methods, and finally summarize the treatment approaches under current medical conditions and compare it with an excellent article published in 2015 with the aim of providing directions for future research and better understanding of CRCI for clinicians.