Longitudinal study of cognitive dysfunctions induced by adjuvant chemotherapy in colon cancer patients

Quantifying chemotherapy-induced cognitive impairment in gastrointestinal cancer patients: A scoping review of methodological concerns in the literature

PURPOSE

Chemotherapy is one of the common treatments in cancer management. However, chemotherapy-induced cognitive impairment (CICI) is one notable side effect that can greatly impact a patient's quality of life. Literature on CICI in gastrointestinal (GI) cancers are few and inconsistent. This review aims to identify the methodological differences in such studies.

METHODS

A systematic search was performed in four electronic databases. All peer-reviewed primary literature published in English that evaluated cognitive-related functioning scores related to chemotherapy in GI cancer patients were included. Information about each study such as CICI findings, study limitations, methodology, and sample characteristics was extracted and synthesized.

RESULTS

A total of 19 studies were included. Evidence of CICI was found in 50.0% (8 of 16) and 62.5% (5 of 8) studies that used objective and subjective measures, respectively. Methodological differences such as groups used for comparison, instruments used, and assessment from the length of time since chemotherapy were highlighted between studies that did and did not find evidence of CICI.

CONCLUSIONS

This review suggests that the mixed findings can be attributed to the heterogeneous methodologies adopted in the evaluation of CICI in this field.

IMPLICATIONS FOR CANCER SURVIVORS

Further studies are necessary to establish the presence and chronicity of CICI, and in which groups of patients to facilitate targeted interventions and treatments.

Functional network disorganization and cognitive decline following fractionated whole-brain radiation in mice

Cognitive dysfunction following radiotherapy (RT) is one of the most common complications associated with RT delivered to the brain, but the precise mechanisms behind this dysfunction are not well understood, and to date, there are no preventative measures or effective treatments. To improve patient outcomes, a better understanding of the effects of radiation on the brain's functional systems is required. Functional magnetic resonance imaging (fMRI) has shown promise in this regard, however, compared to neural activity, hemodynamic measures of brain function are slow and indirect. Understanding how RT acutely and chronically affects functional brain organization requires more direct examination of temporally evolving neural dynamics as they relate to cerebral hemodynamics for bridging with human studies. In order to adequately study the underlying mechanisms of RT-induced cognitive dysfunction, the development of clinically mimetic RT protocols in animal models is needed. To address these challenges, we developed a fractionated whole-brain RT protocol (3Gy/day for 10 days) and applied longitudinal wide field optical imaging (WFOI) of neural and hemodynamic brain activity at 1, 2, and 3 months post RT. At each time point, mice were subject to repeated behavioral testing across a variety of sensorimotor and cognitive domains. Disruptions in cortical neuronal and hemodynamic activity observed 1 month post RT were significantly worsened by 3 months. While broad changes were observed in functional brain organization post RT, brain regions most impacted by RT occurred within those overlapping with the mouse default mode network and other association areas similar to prior reports in human subjects. Further, significant cognitive deficits were observed following tests of novel object investigation and responses to auditory and contextual cues after fear conditioning. Our results fill a much-needed gap in understanding the effects of whole-brain RT on systems level brain organization and how RT affects neuronal versus hemodynamic signaling in the cortex. Having established a clinically-relevant injury model, future studies can examine therapeutic interventions designed to reduce neuroinflammation-based injury following RT. Given the overlap of sequelae that occur following RT with and without chemotherapy, these tools can also be easily incorporated to examine chemotherapy-related cognitive impairment.

Chemobrain in blood cancers: How chemotherapeutics interfere with the brain's structure and functionality, immune system, and metabolic functions

Cancer treatment brings about a phenomenon not fully clarified yet, termed chemobrain. Its strong negative impact on patients' well-being makes it a trending topic in current research, interconnecting many disciplines from clinical oncology to neuroscience. Clinical and animal studies have often reported elevated concentrations of proinflammatory cytokines in various types of blood cancers. This inflammatory burst could be the background for chemotherapy-induced cognitive deficit in patients with blood cancers. Cancer environment is a dynamic interacting system. The review puts into close relationship the inflammatory dysbalance and oxidative/nitrosative stress with disruption of the blood-brain barrier (BBB). The BBB breakdown leads to neuroinflammation, followed by neurotoxicity and neurodegeneration. High levels of intracellular reactive oxygen species (ROS) induce the progression of cancer resulting in increased mutagenesis, conversion of protooncogenes to oncogenes, and inactivation of tumor suppression genes to trigger cancer cell growth. These cell alterations may change brain functionality, as well as morphology. Multidrug chemotherapy is not without consequences to healthy tissue and could even be toxic. Specific treatment impacts brain function and morphology, functions of the immune system, and metabolism in a unique mixture. In general, a chemo-drug's effects on cognition in cancer are not direct and/or in-direct, usually a combination of effects is more probable. Last but not least, chemotherapy strongly impacts the immune system and could contribute to BBB disruption. This review points out inflammation as a possible mechanism of brain damage during blood cancers and discusses chemotherapy-induced cognitive impairment.

Latent class symptom profiles of colorectal cancer survivors with cancer-related cognitive impairment

PURPOSE

Colorectal cancer (CRC) survivors experience cancer-related cognitive impairment and co-occurring symptoms after cancer treatments. There has been little data to inform the risk factors of complex symptom phenotypes in CRC survivors.

OBJECTIVES

To determine if subgroups of CRC survivors after cancer treatments could be identified based on the cognitive impairment and common co-occurring symptoms (depression, anxiety, sleep disturbance, fatigue, and pain); and to explore risk factors (sociodemographic and clinical characteristics, perceived stress, and social support) of these subgroups.

METHODS

Latent class profile analysis (LCPA) was used to identify subgroups based on self-reported symptoms in 64 CRC survivors. Cognitive impairment was measured by assessing subjective cognitive function using the Patient-Reported Outcome Measurement Information System (PROMIS) measure. The Kruskal-Wallis test and regression analyses were performed.

RESULTS

Three distinct latent classes were identified (Class 1: All Low '28.1%'; Class 2: High Psychological Symptoms (depression/anxiety) '25%'; Class 3: High Somatic Symptoms (fatigue, sleep disturbance, and pain) with High Cognitive Impairment'46.9%'). The pain was the most distinguishable symptom across the latent classes. The high symptom burden group was associated with less time since cancer diagnosis, higher perceived stress levels, and poor emotional social support.

CONCLUSION

Our study adds to the information on interindividual variability in symptom experience of CRC survivors with cognitive impairment. Findings suggest a need for increased attention to screening for co-occurring symptoms (e.g., high pain) and future interventions focused on stress management and social support.

Predictors of cognitive impairment in patients undergoing ileostomy for colorectal cancer: a retrospective analysis

Background

Early detection of cognitive impairment in patients undergoing ileostomy for colorectal cancer may help improve patient outcomes and quality of life. Identifying risk factors and clinically accessible factors is crucial for prevention and treatment.

Objective

This retrospective study aimed to identify risk factors for post-operative cognitive impairment in patients undergoing ileostomy for colorectal cancer and to explore potential factors for its prevention and treatment.

Methods

A total of 108 cases were selected and included in the study. Patient data including general characteristics, disease stage, complications, and chemotherapy status were collected, and sleep quality and cognitive function were assessed using questionnaires and follow-up. Patients were randomly divided into training and validation groups. A random forest model was used to rank clinical features based on their contribution to predicting the prognosis of cancer-related cognitive impairment (CRCI). Nomograms were constructed using the support vector machine-recursive feature elimination (SVM-RFE) method, and the minimal root-mean-square error (RMSE) values were compared to select the best model. Regression analysis was performed to determine independent predictors.

Results

Significant differences were observed in age, body mass index (BMI), alcohol consumption, frequency of physical activity, comorbidity, and cancer-related anemia (CRA) between the CRCI and non-CRCI groups. Random forest analysis revealed that age, BMI, exercise intensity, PSQI scores, and history of hypertension were the most significant predictors of outcome. Univariate logistic regression analysis of 18 variables revealed that age, alcohol consumption, exercise intensity, BMI, and comorbidity were significantly associated with the outcome of CRCI (p < 0.05). Univariate and multivariate models with P-values less than 0.1 and 0.2, respectively, showed better predictive performance for CRCI. The results of univariate analysis were plotted on a nomogram to evaluate the risk of developing CRCI after colorectal cancer surgery. The nomogram was found to have good predictive performance. Finally, regression analysis revealed that age, exercise intensity, BMI, comorbidity, and CRA were independent predictors of CRCI.

Conclusions

This retrospective cohort study revealed that age, exercise intensity, BMI, comorbidity, CRA, and mobility are independent predictors of cognitive impairment in patients undergoing ileostomy for colorectal cancer. Identifying these factors and potential factors may have clinical implications in predicting and managing post-operative cognitive impairment in this patient population.

Effect of cognitive behavioral stress management on anxiety, depression, and quality of life in colorectal cancer patients post tumor resection: a randomized, controlled study

OBJECTIVE

Cognitive behavioral stress management (CBSM) is a psychotherapy helping individuals develop adaptive behaviors, whose application in colorectal cancer (CRC) is rare. This randomized, controlled study intended to explore the effect of CBSM on anxiety, depression, and quality of life in CRC patients post tumor resection.

METHODS

One hundred and sixty CRC patients who received tumor resection were randomized (1:1) to receive weekly CBSM or usual care (UC) for 10 weeks after discharge (120 min for each session). Hospital Anxiety and Depression Scale (HADS) and Quality of Life Questionnaire-Core 30 (QLQ-C30) of each patient were assessed after randomization (M0), one month (M1), three months (M3), and six months (M6).

RESULTS

CBSM realized decreased HADS-anxiety scores at M1 (P = 0.044), M3 (P = 0.020), M6 (P = 0.003) compared to UC, so did anxiety rates at M3 (28.0% vs. 43.6%, P = 0.045), M6 (25.7% vs. 42.5%, P = 0.035), HADS-depression scores at M3 (P = 0.017), M6 (P = 0.005), and depression rates at M3 (25.3% vs. 41.0%, P = 0.040), M6 (22.9% vs. 41.1%, P = 0.020). Concerning the quality of life, CBSM achieved elevated QLQ-C30 global health status scores at M6 (P = 0.008), QLQ-C30 functions scores at M3 (P = 0.047), M6 (P = 0.031), and decreased QLQ-C30 symptoms scores at M3 (P = 0.048) and M6 (P = 0.039) compared with UC. By subgroup analyses, CBSM had a better utility on relieving anxiety, depression and improving quality of life in patients with higher education level and patients receiving adjuvant chemotherapy.

CONCLUSION

CBSM program alleviates anxiety, depression, and elevates quality of life in CRC patients post tumor resection.

A Systematic Review on the Potential Acceleration of Neurocognitive Aging in Older Cancer Survivors

As survival rates increase, more emphasis has gone to possible cognitive sequelae in older cancer patients, which could be explained by accelerated brain aging. In this review, we provide a complete overview of studies investigating neuroimaging, neurocognitive, and neurodegenerative disorders in older cancer survivors (>65 years), based on three databases (Pubmed, Web of Science and Medline). Ninety-six studies were included. Evidence was found for functional and structural brain changes (frontal regions, basal ganglia, gray and white matter), compared to healthy controls. Cognitive decline was mainly found in memory functioning. Anti-hormonal treatments were repeatedly associated with cognitive decline (tamoxifen) and sometimes with an increased risk of Alzheimer's disease (androgen deprivation therapy). Chemotherapy was inconsistently associated with later development of cognitive changes or dementia. Radiotherapy was not associated with cognition in patients with non-central nervous system cancer but can play a role in patients with central nervous system cancer, while neurosurgery seemed to improve their cognition in the short-term. Individual risk factors included cancer subtypes (e.g., brain cancer, hormone-related cancers), treatment (e.g., anti-hormonal therapy, chemotherapy, cranial radiation), genetic predisposition (e.g., APOE, COMT, BDNF), age, comorbidities (e.g., frailty, cognitive reserve), and psychological (e.g., depression, (post-traumatic) distress, sleep, fatigue) and social factors (e.g., loneliness, limited caregiver support, low SES). More research on accelerated aging is required to guide intervention studies.

Exosomes and cancer immunotherapy: A review of recent cancer research

As phospholipid extracellular vesicles (EVs) secreted by various cells, exosomes contain non-coding RNA (ncRNA), mRNA, DNA fragments, lipids, and proteins, which are essential for intercellular communication. Several types of cells can secrete exosomes that contribute to cancer initiation and progression. Cancer cells and the immune microenvironment interact and restrict each other. Tumor-derived exosomes (TDEs) have become essential players in this balance because they carry information from the original cancer cells and express complexes of MHC class I/II epitopes and costimulatory molecules. In the present study, we aimed to identify potential targets for exosome therapy by examining the specific expression and mechanism of exosomes derived from cancer cells. We introduced TDEs and explored their role in different tumor immune microenvironment (TIME), with a particular emphasis on gastrointestinal cancers, before briefly describing the therapeutic strategies of exosomes in cancer immune-related therapy.

Psychometric properties of the Chinese version of the Cognitive Reserve Assessment Scale in Health in patients with cancer

BACKGROUND

Cognitive reserve is a modifiable factor that could prevent cognitive decline in patients with cancer. The Cognitive Reserve Assessment Scale in Health (CRASH) is an instrument used to assess cognitive reserve. This study aims to develop and examine the psychometric properties of the Chinese version of the CRASH for patients with cancer.

METHODS

A cross-sectional survey was conducted with 167 cancer patients from four wards of two hospitals in China. Thirty-one patients were re-assessed to examine the test-retest reliability. Four translators and three reviewers developed the Chinese version of the scale. We assessed its structural validity, concurrent validity, internal consistency, test-retest reliability, measurement error, and floor/ceiling effects.

RESULTS

Confirmatory factor analysis showed a good model fit with the four-factor structure of the original CRASH. The CRASH scores were statistically significantly associated with neuropsychological test scores, indicating sufficient concurrent validity. The internal consistency was acceptable, except for leisure activities, with standardized Cronbach's alphas (0.64-0.94) and standardized Omega (0.66-0.95). There was excellent test-retest reliability, with a high intraclass correlation coefficient (0.914-0.993) of total scores and scores for each domain. The measurement error was acceptable, and no floor or ceiling effects were observed.

CONCLUSIONS

The Chinese version of the CRASH is a valid and reliable instrument to assess cognitive reserve in patients with cancer. Moreover, cognitive reserve measured by the CRASH was associated with low cognitive performance in cancer patients.

A scoping review of cognitive assessment tools and domains for chemotherapy-induced cognitive impairments in cancer survivors

Backgrounds

Cancer survivors suffer from specific symptoms known as chemotherapy-induced cognitive impairments (CICIs). CICIs are difficult to capture with existing assessments such as the brief screening test for dementia. Although recommended neuropsychological tests (NPTs) exist, international consensus and shared cognitive domains of assessment tools are unknown. The aim of this scoping review was as follows: (1) to identify studies that assess CICIs in cancer survivors; (2) to identify shared cognitive assessment tools and domains by mapping the domains reported in studies using the International Classification of Functioning, Disability and Health (ICF) framework.

Methods

The study followed the recommendations made by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews. We searched the following three databases through October 2021: PubMed, CINAHL, and Web of Science. Prospective longitudinal or cross-sectional studies were selected to determine CICI-specific assessment tools for adult cancer survivors.

Results

Sixty-four prospective studies (36 longitudinal studies and 28 cross-sectional studies) were included after checking for eligibility. The NPTs were divided into seven main cognitive domains. The specific mental functions were often used in the order of memory, attention, higher-level cognitive functions, and psychomotor functions. Perceptual functions were used less frequently. In some ICF domains, shared NPTs were not clearly identified. In some different domains, the same NPTs were used, such as the trail making test and the verbal fluency test. When the association between the publishing year and the amount of NPT use was examined, it was found that the amount of tool use tended to decline over the publication years. The Functional Assessment of Cancer Therapy-Cognitive function (FACT-Cog) was a shared consensus tool among the patient-reported outcomes (PROs).

Conclusion

Chemotherapy-induced cognitive impairments are currently gaining interest. Shared ICF domains such as memory and attention were identified for NPTs. There was a gap between the publicly recommended tools and the tools actually used in the studies. For PROs, a clearly shared tool, FACT-Cog, was identified. Mapping the domains reported in studies using the ICF can help in the process of reviewing consensus on which NPTs may be used to target cognitive domains.

Systematic review registration

https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000053710, identifier UMIN000047104.

Neurological Complications of Conventional and Novel Anticancer Treatments

Various neurological complications, affecting both the central and peripheral nervous system, can frequently be experienced by cancer survivors after exposure to conventional chemotherapy, but also to modern immunotherapy. In this review, we provide an overview of the most well-known adverse events related to chemotherapy, with a focus on chemotherapy induced peripheral neurotoxicity, but we also address some emerging novel clinical entities related to cancer treatment, including chemotherapy-related cognitive impairment and immune-mediated adverse events. Unfortunately, efficacious curative or preventive treatment for all these neurological complications is still lacking. We provide a description of the possible mechanisms involved to drive future drug discovery in this field, both for symptomatic treatment and neuroprotection.

What is the impact of targeted therapies given within phase I trials on the cognitive function of patients with advanced cancer: a mixed-methods exploratory study conducted in an early clinical trials unit

INTRODUCTION

Novel therapies such as small protein molecule inhibitors and immunotherapies are tested in early phase trials before moving to later phase trials and ultimately standard practice. A key aim of these clinical trials is to define a toxicity profile, however, the emphasis is often on safety with measurements of organ toxicity. Other subjective side effects can be under-reported because they are not measured formally within the trial protocols. The concern from clinical practice is that cognitive toxicity is poorly studied and may be under-reported in this context. This could lead to toxicity profiles of new treatments not being fully described and patients with unmet need in terms of acknowledgement and support of symptoms. This protocol outlines a framework of an exploratory study with feasibility aspects to investigate the impact and experience of cognitive changes for patients on phase I trials.

METHODS AND ANALYSIS

This is a mixed-methods study, combining quantitative and qualitative approaches. The sample is 30 patients with advanced cancer who are participating in phase I trials of novel therapies in the early clinical trials unit of a specialist cancer centre. A test battery of validated cognitive assessments will be taken alongside patient reported outcome measures at three time points from baseline, day eight and day 28 post start of treatment. At day 28, a semi-structured interview will be conducted and the narrative thematically analysed. Results will be integrated to offer a comprehensive description of cognitive function in this patient group.

ETHICS AND DISSEMINATION

The study has received full HRA and ethical approval. It is the first study to introduce formal cognitive assessments in a cancer phase I trial context. The study has the potential to highlight previously unreported side effects and more importantly unmet need in terms of care for patients who are participating in the trials.

Blood-Based Biomarkers of Cancer-Related Cognitive Impairment in Non-Central Nervous System Cancer: A Scoping Review

This scoping review was designed to synthesize the extant literature on associations between subjective and/or objective measures of cancer-related cognitive impairment (CRCI) and blood-based biomarkers in adults with non-central nervous system cancers. The literature search was done for studies published from the start of each database searched (i.e., MEDLINE, Embase, PsycINFO, Cumulative Index to Nursing and Allied Health Literature, Cochrane Central Register of Controlled Trials, grey literature) through to October 20, 2021. A total of 95 studies are included in this review. Of note, a wide variety of biomarkers were evaluated. Most studies evaluated patients with breast cancer. A variety of cognitive assessment measures were used. The most consistent significant findings were with various subjective and objective measures of CRCI and levels of interleukin-6 and tumor necrosis factor. Overall, biomarker research is in an exploratory phase. However, this review synthesizes findings and proposes directions for future research.

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.

A pilot retrospective study of comprehensive nursing care on psychological disorder in colorectal cancer undergoing chemotherapy

BACKGROUND

This pilot study retrospectively evaluated the effects of comprehensive nursing care (CNC) on psychological disorders in patients with colorectal cancer (CC) undergoing chemotherapy.

METHODS

This study analyzed 70 eligible patients' case records of CC undergoing chemotherapy. These records were allocated to a treatment group (n = 35) or a control group (n = 35). All 70 patients in both groups received routine nursing care. In addition, 35 patients in the treatment group also received CNC. The primary outcomes were anxiety, as measured by Self-rating Anxiety Scale, and depression, as assessed by Self-rating Depression Scale. The secondary outcomes were quality of life, as measured by The 36-Item Short Form Health Survey, and adverse events. All outcome data were analyzed before and 3-month after treatment.

RESULTS

At 3-month after treatment, the patients in the treatment group had better outcomes in the Self-rating Anxiety Scale (P<0.01), Self-rating Depression Scale (P<0.01), and The 36-Item Short Form Health Survey (social function, P = .04; emotional role, P = 0.03) than those in the control group. With regard to safety, no treatment-related adverse events were recorded in either group.

CONCLUSION

The findings of this pilot retrospective study showed promising effects of CNC on psychological disorders and quality of life in patients with CC undergoing chemotherapy. However, more high-quality clinical trials are required to confirm these findings.

Evaluation of mild cognitive impairment and dementia in patients with metastatic renal cell carcinoma

BACKGROUND

Dementia and cancer are both more common in adults as they age. As new cancer treatments become more popular, it is important to consider how these treatments might affect older patients. This study evaluates metastatic renal cell carcinoma (mRCC) as a risk factor for older adults developing mild cognitive impairment or dementia (MCI/D) and the impact of mRCC-directed therapies on the development of MCI/D.

METHODS

We identified patients diagnosed with mRCC in a Surveillance, Epidemiology, and End Results (SEER)-Medicare dataset from 2007 to 2015 and matched them to non-cancer controls. Exclusion criteria included age < 65 years at mRCC diagnosis and diagnosis of MCI/D within the year preceding mRCC diagnosis. The main outcome was time to incident MCI/D within one year of mRCC diagnosis for cases or cohort entry for non-cancer controls. Cox proportional hazards models were used to measure associations between mRCC and incident MCI/D as well as associations of oral anticancer agent (OAA) use with MCI/D development within the mRCC group.

RESULTS

Patients with mRCC (n = 2533) were matched to non-cancer controls (n = 7027). mRCC (hazard ratio [HR] 8.52, p < .001), being older (HR 1.05 per 1-year age increase, p < .001), and identifying as Black (HR 1.92, p = .047) were predictive of developing MCI/D. In addition, neither those initiating treatment with OAAs nor those who underwent nephrectomy were more likely to develop MCI/D.

CONCLUSIONS

Patients with mRCC were more likely to develop MCI/D than those without mRCC. The medical and surgical therapies evaluated were not associated with increased incidence of MCI/D. The increased incidence of MCI/D in older adults with mRCC may be the result of the pathology itself or risk factors common to the two disease processes.

Cyclophosphamide and epirubicin induce high apoptosis in microglia cells while epirubicin provokes DNA damage and microglial activation at sub-lethal concentrations

Chemotherapy Related Cognitive Impairment (CRCI), also called chemobrain, diminishes cancer patient's life quality. Breast cancer (BC) patients have been described to be importantly affected, however, the mechanism leading to CRCI has not been fully elucidated. Recent research proposes microglia as the main architect of CRCI, thus dysregulations in these cells could trigger CRCI. The aim of this research was to evaluate the effects of two drugs commonly used against breast cancer, cyclophosphamide (CTX) and epirubicin (EPI), on the microglia cell line SIM-A9, using the BC cell line, 4T1, as a control. Our results show that CTX and EPI decrease microglia-cell viability and increase cell death on a concentration-dependent manner, being 5 and 2 times more cytotoxic to microglia cell line than to breast cancer 4T1cells, respectively. Both chemotherapies induce cell cycle arrest and a significant increase in p53, p16 and γ-H2AX in breast cancer and microglia cells. Furthermore, mitochondrial membrane potential (ΔΨm) diminishes as cell death increases, and both chemotherapies induce reactive oxygen species (ROS) production on SIM-A9 and 4T1. Moreover, caspase activation increases with treatments and its pharmacological blockade inhibits CTX and EPI induced-cell death. Finally, low concentrations of CTX and EPI induce γ-H2AX, and EPI induces cytokine release, NO production and Iba-1 overexpression. These findings indicate that microglia cells are more sensitive to CTX and EPI than BC cells and undergo DNA damage and cell cycle arrest at very low concentrations, moreover EPI induces microglia activation and a pro-inflammatory profile.

Cognitive adverse effects of chemotherapy and immunotherapy: are interventions within reach?

One in three people will be diagnosed with cancer during their lifetime. The community of cancer patients is growing, and several common cancers are becoming increasingly chronic; thus, cancer survivorship is an important part of health care. A large body of research indicates that cancer and cancer therapies are associated with cognitive impairment. This research has mainly concentrated on chemotherapy-associated cognitive impairment but, with the arrival of immunotherapies, the focus is expected to widen and the number of studies investigating the potential cognitive effects of these new therapies is rising. Meanwhile, patients with cognitive impairment and their healthcare providers are eagerly awaiting effective approaches to intervene against the cognitive effects of cancer treatment. In this Review, we take stock of the progress that has been made and discuss the steps that need to be taken to accelerate research into the biology underlying cognitive decline following chemotherapy and immunotherapy and to develop restorative and preventive interventions. We also provide recommendations to clinicians on how to best help patients who are currently experiencing cognitive impairment.

Effects of cognitive behavior therapy combined with Baduanjin in patients with colorectal cancer

BACKGROUND

Cancer-related fatigue (CRF) is the most common concomitant symptom in the treatment of colorectal cancer (CRC). Such patients often present with subjective fatigue state accompanied by cognitive dysfunction, which seriously affects the quality of life of patients.

AIM

To explore the effects of cognitive behavior therapy (CBT) combined with Baduanjin exercise on CRF, cognitive impairment, and quality of life in patients with CRC after chemotherapy, and to provide a theoretical basis and practical reference for rehabilitation of CRC after chemotherapy.

METHODS

Fifty-five patients with CRC after radical resection and chemotherapy were randomly divided into either an experimental or a control group. The experimental group received the intervention of CBT combined with exercise intervention for 6 mo, and indicators were observed and measured at baseline, 3 mo, and 6 mo to evaluate the intervention effect.

RESULTS

Compared with the baseline values, in the experimental group 3 mo after intervention, cognitive function, quality of life score, and P300 amplitude and latency changes were significantly better (P < 0.01). Compared with the control group, at 3 mo, the experimental group had significant differences in CRF, P300 amplitude, and quality of life score (P < 0.05), as well as significant differences in P300 latency and cognitive function (P < 0.01). Compared with the control group, at 6 mo, CRF, P300 amplitude, P300 latency, cognitive function and quality of life score were further improved in the experimental group, with significant differences (P < 0.01). The total score of CRF and the scores of each dimension were negatively correlated with quality of life (P < 0.05), while the total score of cognitive impairment and the scores of each dimension were positively correlated with quality of life (P < 0.05).

CONCLUSION

CBT combined with body-building Baduanjin exercise can improve CRF and cognitive impairment in CRC patients after chemotherapy, and improve their quality of life.

Long-Term Cognitive Dysfunction in Cancer Survivors

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

Target enzymes in oxaliplatin-induced peripheral neuropathy in Swiss mice: A new acetylcholinesterase inhibitor as therapeutic strategy

In the present study it was hypothesized that 5-((4-methoxyphenyl)thio)benzo[c][1,2,5] thiodiazole (MTDZ), a new acetylcholinesterase inhibitor, exerts antinociceptive action and reduces the oxaliplatin (OXA)-induced peripheral neuropathy and its comorbidities (anxiety and cognitive deficits). Indeed, the acute antinociceptive activity of MTDZ (1 and 10 mg/kg; per oral route) was observed for the first time in male Swiss mice in formalin and hot plate tests and on mechanical withdrawal threshold induced by Complete Freund's Adjuvant (CFA). To evaluate the MTDZ effect on OXA-induced peripheral neuropathy and its comorbidities, male and female Swiss mice received OXA (10 mg/kg) or vehicle intraperitoneally, on days 0 and 2 of the experimental protocol. Oral administration of MTDZ (1 mg/kg) or vehicle was performed on days 2-14. OXA caused cognitive impairment, anxious-like behaviour, mechanical and thermal hypersensitivity in animals, with females more susceptible to thermal sensitivity. MTDZ reversed the hypersensitivity, cognitive impairment and anxious-like behaviour induced by OXA. Here, the negative correlation between the paw withdrawal threshold caused by OXA and acetylcholinesterase (AChE) activity was demonstrated in the cortex, hippocampus, and spinal cord. OXA inhibited the activity of total ATPase, Na⁺ K⁺ - ATPase, Ca²⁺ - ATPase and altered Mg²⁺ - ATPase in the cortex, hippocampus, and spinal cord. OXA exposure increased reactive species (RS) levels and superoxide dismutase (SOD) activity in the cortex, hippocampus, and spinal cord. MTDZ modulated ion pumps and reduced the oxidative stress induced by OXA. In conclusion, MTDZ is an antinociceptive molecule promising to treat OXA-induced neurotoxicity since it reduced nociceptive and anxious-like behaviours, and cognitive deficit in male and female mice.

Four decades of chemotherapy-induced cognitive dysfunction: comprehensive review of clinical, animal and in vitro studies, and insights of key initiating events

Cognitive dysfunction has been one of the most reported and studied adverse effects of cancer treatment, but, for many years, it was overlooked by the medical community. Nevertheless, the medical and scientific communities have now recognized that the cognitive deficits caused by chemotherapy have a strong impact on the morbidity of cancer treated patients. In fact, chemotherapy-induced cognitive dysfunction or 'chemobrain'  (also named also chemofog) is at present a well-recognized effect of chemotherapy that could affect up to 78% of treated patients. Nonetheless, its underlying neurotoxic mechanism is still not fully elucidated. Therefore, this work aimed to provide a comprehensive review using PubMed as a database to assess the studies published on the field and, therefore, highlight the clinical manifestations of chemobrain and the putative neurotoxicity mechanisms.In the last two decades, a great number of papers was published on the topic, mainly with clinical observations. Chemotherapy-treated patients showed that the cognitive domains most often impaired were verbal memory, psychomotor function, visual memory, visuospatial and verbal learning, memory function and attention. Chemotherapy alters the brain's metabolism, white and grey matter and functional connectivity of brain areas. Several mechanisms have been proposed to cause chemobrain but increase of proinflammatory cytokines with oxidative stress seem more relevant, not excluding the action on neurotransmission and cellular death or impaired hippocampal neurogenesis. The interplay between these mechanisms and susceptible factors makes the clinical management of chemobrain even more difficult. New studies, mainly referring to the underlying mechanisms of chemobrain and protective measures, are important in the future, as it is expected that chemobrain will have more clinical impact in the coming years, since the number of cancer survivors is steadily increasing.

Effect of chemotherapy and radiotherapy on cognitive impairment in colorectal cancer: evidence from national representative longitudinal database

Objectives

We aimed to assess the risk of chemotherapy- and radiotherapy-related cognitive impairment in colorectal cancer patients.

Methods

Medical use data of colorectal cancer patients were obtained from Korean National Health Insurance Database (NHID), 2004-2018. We randomly selected 40% of colorectal cancer patients (N=148,848). Cognitive impairment cases were defined as having one or more ICD-10 diagnostic codes for dementia or mild cognitive impairment. Patients aged 18 or younger, patients diagnosed with cognitive impairment before colorectal cancer diagnosis (N=8,225) and those who did not receive primary resection (N=45,320) were excluded. The effects of each chemotherapy regimen on cognitive impairment were estimated. We additionally estimated the effect of radiotherapy in rectal cancer patients. Time-dependent competing risk Cox regression was conducted to estimate overall and age-specific hazard ratios (HR) separately for colon and rectal cancer. Landmark analyses with different lag times were conducted as sensitivity analyses.

Results

Chemotherapy did not increase the risk of cognitive impairment in colorectal cancer (colon cancer: HR=0.92, 95% CI 0.83-1.03; rectal cancer: HR=0.88, 95% CI 0.75-1.04). Radiotherapy was negatively associated with cognitive impairment in rectal cancer (HR=0.01, 95% CI 0.84-0.99). Heterogeneous direction of association by regimen combination was detected. Adverse cognitive effect of certain chemotherapy regimen was more prominent in elderly patients.

Conclusion

Chemotherapy and radiotherapy did not increase the risk of cognitive impairment. Elderly patients with low cognitive reserve could be affected by adverse cognitive effects of chemotherapy. Folate administration showed protective effect against possible cognitive impairment.

Systematic Review of Cognitive Impairment in Colorectal Cancer Survivors Who Received Chemotherapy

PROBLEM IDENTIFICATION

Cognitive impairment is a common and troublesome side effect experienced by many cancer survivors. It can have a significant impact on survivors' ability to function and enjoy a high quality of life. However, most cognitive impairment research has focused on breast cancer survivors, despite the high rates of colorectal cancer and the toxicity of treatment agents in some colorectal cancer chemotherapeutic regimens, which have been linked to cognitive impairment. This review provides a novel synthesis of what is known about cognitive impairment in colorectal cancer survivors.

LITERATURE SEARCH

CINAHL®, Cochrane Library, Embase®, PsycINFO®, and PubMed® were systematically searched by a health sciences librarian.

DATA EVALUATION

Data were extracted across studies; findings about the prevalence, severity, and correlates of cognitive impairment were synthesized.

SYNTHESIS

Across findings from 26 articles representing 24 independent studies, 13%-57% of participants had cognitive impairment. Potential demographic, physiologic, and psychological correlates of cognitive impairment were identified.

IMPLICATIONS FOR PRACTICE

Findings indicate a need to focus research and patient assessments on early identification of risk factors, assessing for existing cognitive deficits and testing interventions to decrease cognitive impairment in colorectal cancer survivors.

Kai-Xin-San Attenuates Doxorubicin-Induced Cognitive Impairment by Reducing Inflammation, Oxidative Stress, and Neural Degeneration in 4T1 Breast Cancer Mice

Objective

This study explored the potential therapeutic effect and possible mechanism of Kai-Xin-San (KXS) on doxorubicin-induced cognitive impairment in 4T1 breast cancer mice.

Methods

A model of chemotherapy-induced cognitive impairment (CICI) was established with the injection of doxorubicin (DOX, 5 mg/kg) at a 7-day interval in a 4T1 breast cancer mouse. KXS was given (1 g/kg) daily by gavage over three weeks starting at the first week while giving DOX. The Morris water maze task was performed to measure the CICI-like behaviors. Oxidative stress markers in the hippocampus, inflammatory cytokines in the serum and hippocampus, Nissl staining, immunofluorescence staining, and analysis for Glial fibrillary acidic protein and ionized calcium-binding adapter molecule 1 of the hippocampus were examined to explore the effect and mechanism of KXS on DOX-induced CICI. Meanwhile, tumor growth and survival time were tested in this study.

Results

CICI-like behaviors induced by DOX occurred earlier and were severer than the cognitive impairment induced by the tumor, and the effect of KXS on improving the cognitive impairment was obvious. KXS protected against DOX-induced neuroinflammation by decreasing levels of proinflammatory cytokines interleukin-6, interleukin-12p70, and tumor necrosis factor-alpha in both serum and brain and interleukin-1β in the brain, increasing the anti-inflammatory cytokines interleukin-4 in the serum and interleukin-10 in the hippocampus, and inhibiting the astrocytic hyperplasia and microglial polarization in the hippocampus. KXS reduced neural degeneration and protected against DOX-induced oxidative stress according to decreased malondialdehyde level, increased glutathione level, and enhanced activities of superoxide dismutase, catalase, and glutathione peroxidase. Moreover, KXS recovered the lost body weights after DOX administration and prolonged the survival times of mice.

Conclusions

KXS may attenuate DOX-induced cognitive impairment by regulating inflammatory responses and reducing oxidative stress and neural degeneration. These findings also presented the role of KXS in improving the quality of life and prolonging survival time in breast cancer mice that received chemotherapy.

Bone marrow mesenchymal stem cells and their derived exosomes resolve doxorubicin-induced chemobrain: critical role of their miRNA cargo

Background

Doxorubicin (DOX), a widely used chemotherapeutic agent, can cause neurodegeneration in the brain, which leads to a condition known as chemobrain. In fact, chemobrain is a deteriorating condition which adversely affects the lives of cancer survivors. This study aimed to examine the potential therapeutic effects of bone marrow mesenchymal stem cells (BMSCs) and their derived exosomes (BMSCs-Exo) in DOX-induced chemobrain in rat models.

Methods

Chemobrain was induced by exposing rats to DOX (2 mg/kg, i.p) once weekly for 4 consecutive weeks. After 48 h of the last DOX dose, a subset of rats was supplied with either an intravenous injection of BMSCs (1 × 10⁶) or a single dose of 150 μg of BMSCs-Exo. Behavioral tests were conducted 7 days post injection. Rats were sacrificed after 14 days from BMSCs or BMSCs-Exo injection.

Results

BMSCs and BMSCs-Exo successfully restored DOX-induced cognitive and behavioral distortion. These actions were mediated via decreasing hippocampal neurodegeneration and neural demyelination through upregulating neural myelination factors (myelin%, Olig2, Opalin expression), neurotropic growth factors (BDNF, FGF-2), synaptic factors (synaptophysin), and fractalkine receptor expression (Cx3cr1). Halting neurodegeneration in DOX-induced chemobrain was achieved through epigenetic induction of key factors in Wnt/β-catenin and hedgehog signaling pathways mediated primarily by the most abundant secreted exosomal miRNAs (miR-21-5p, miR-125b-5p, miR-199a-3p, miR-24-3p, let-7a-5p). Moreover, BMSCs and BMSCs-Exo significantly abrogate the inflammatory state (IL-6, TNF-α), apoptotic state (BAX/Bcl2), astrocyte, and microglia activation (GFAP, IBA-1) in DOX-induced chemobrain with a significant increase in the antioxidant mediators (GSH, GPx, SOD activity).

Conclusions

BMSCs and their derived exosomes offer neuroprotection against DOX-induced chemobrain via genetic and epigenetic abrogation of hippocampal neurodegeneration through modulating Wnt/β-catenin and hedgehog signaling pathways and through reducing inflammatory, apoptotic, and oxidative stress state.

Graphical abstract

Proposed mechanisms of the protective effects of bone marrow stem cells (BMSCs) and their exosomes (BMSCs-Exo) in doxorubicin (DOX)-induced chemobrain. Blue arrows: induce. Red arrows: inhibit.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02384-9.

Oxaliplatin-Induced Neuropathy: Genetic and Epigenetic Profile to Better Understand How to Ameliorate This Side Effect

In the most recent decades, oxaliplatin has been used as a chemotherapeutic agent for colorectal cancer and other malignancies as well. Oxaliplatin interferes with tumor growth predominantly exerting its action in DNA synthesis inhibition by the formation of DNA-platinum adducts that, in turn, leads to cancer cell death. On the other hand, unfortunately, this interaction leads to a plethora of systemic side effects, including those affecting the peripheral and central nervous system. Oxaliplatin therapy has been associated with acute and chronic neuropathic pain that induces physicians to reduce the dose of medication or discontinue treatment. Recently, the capability of oxaliplatin to alter the genetic and epigenetic profiles of the nervous cells has been documented, and the understanding of gene expression and transcriptional changes may help to find new putative treatments for neuropathy. The present article is aimed to review the effects of oxaliplatin on genetic and epigenetic mechanisms to better understand how to ameliorate neuropathic pain in order to enhance the anti-cancer potential and improve patients’ quality of life.

Neurocognitive Effects of Chemotherapy for Colorectal Cancer: A Systematic Review and a Meta-Analysis of 11 Studies

Purpose

Chemotherapy-related cognitive impairment (CRCI) is a controversial concept not much explored on colorectal cancer patients.

Materials and Methods

We identified 11 prospective studies: eight studies on 696 colorectal cancer patients who received chemotherapy and three studies on 346 rectal cancer patients who received neoadjuvant chemoradiotherapy. Standardized mean differences (SMDs) of neuropsychological test results and the cognitive quality-of-life scale were calculated using random effect models. A meta-regression was conducted to investigate the association between mean study population age and effect sizes.

Results

The association between chemotherapy and cognitive impairment was not clear in colorectal cancer patients (SMD, 0.003; 95% confidence interval, −0.080 to 0.086). However, a meta-regression showed that older patients are more vulnerable to CRCI than younger patients (β=–0.016, p < 0.001).

Conclusion

Chemotherapy has an overall positive negligible effect size on the cognitive function of colorectal patients. Age is a significant moderator of CRCI.

Cognitive dysfunction in patients with nasopharyngeal carcinoma after induction chemotherapy

OBJECTIVE

This prospective study aimed to assess the incidence, details of the change of cognitive dysfunction, and predictive factors of cognitive function impairment associated with induction chemotherapy (IC) in nasopharyngeal carcinoma (NPC) patients.

METHOD

We prospectively included NPC patients who treated with IC from December 2018 to January 2020. Montreal cognitive assessment (MoCA) was used to measure cognitive function, and score less than 26 was defined as cognitive dysfunction. Multivariate logistic regression analysis was applied to assess the independent predictors associated with cognitive function impairment.

RESULTS

A total of 76 patients were recruited, 10 patients were excluded due to refusal or unable to finish the questionnaire, and 66 patients were analyzed in this study. The median age of the patients was 48.5 years (range, 24-69 years). There was 89.4% of patients received ≥3 circles of IC. For the entire group, 27.3% had cognitive dysfunction, of which attention, language, short-term memory, and orientation showed significant downward trends, while visuospatial/executive function, naming, and abstraction demonstrated no prominent decrease. In patients having cognitive function impairment, 77.8% of them occurred after the first circle of IC. Gender (P = 0.039) and education (P = 0.03) were significant predictors for cognitive dysfunction. Female patients (female vs. male: 50% vs. 20%) and patients with lower educational levels (lower vs. higher: 37.8% vs. 11.8%) were more likely to suffer cognitive dysfunction. In addition, age (P = 0.572) and chemotherapy circles (P = 0.68) had no association with cognitive dysfunction.

CONCLUSION

Approximately 25% of NPC patients suffered cognitive dysfunction after IC, especially in female patients and patients with lower educational levels.

Chemotherapy-induced cognitive impairment (CICI): An overview of etiology and pathogenesis

Many cancer patients treated with chemotherapy develop chemotherapy-induced cognitive impairment (CICI), often referred to as chemo-brain, which manifest during or post-treatment with variable degrees, onset and duration thereby affecting the patients' quality of life. Several chemotherapeutic agents have been studied to determine its possible association with cognitive impairment and to fully comprehend their contribution to CICI. A vast number of studies have emerged proposing several candidate underlying mechanisms and etiologies contributing to CICI such as direct neurotoxicity, BBB disruption, decreased hippocampal neurogenesis, white matter abnormalities, secondary neuro-inflammatory response and increased oxidative stress; however, the exact underlying mechanisms are still not well defined. This review summarizes CICI associated with most commonly used chemotherapeutic agents with emphasizes the possible underlying pathogenesis in both animal and clinical studies.

Pharmacological modulation of Na+, K+-ATPase as a potential target for OXA-induced neurotoxicity: Correlation between anxiety and cognitive decline and beneficial effects of 7-chloro-4-(phenylselanyl) quinoline

Growing evidence demonstrates that Oxaliplatin (OXA) is commonly associated with neurotoxicity that leads to emotional and cognitive impairments. The aim of the present study was to evaluate the OXA and Na⁺, K⁺-ATPase interaction and to correlate anxious behavior and cognitive impairment induced by this chemotherapeutic in Swiss mice. Also, considering the pharmacological modulation of Na⁺, K⁺-ATPase as a potential target for OXA-induced neurotoxicity, the therapeutic potential of 7-chloro-4-(phenylselanyl) quinoline (4-PSQ) was evaluated. Mice received OXA (10 mg kg^-1) or vehicle by intraperitoneal route (days 0 and 2). Oral administration of 4-PSQ (1 mg kg^-1) or vehicle was performed from days 2-14. Behavioral tasks started from day 12 onwards. On day 15, the animals were sacrificed, and the tissues collected. The effects of OXA and 4-PSQ on activity and expression level of Na⁺, K⁺-ATPase in the hippocampus and cerebral cortex, and the plasmatic corticosterone levels were determined. The findings demonstrated a significant positive correlation between anxious behavior and cognitive impairment induced by OXA. OXA caused an increase on the plasmatic corticosterone levels and reduced activity and expression level of Na⁺, K⁺-ATPase. 4-PSQ reduced both anxious behavior and cognitive impairment induced by OXA. 4-PSQ effect seems to be due to the modulation of Na⁺, K⁺-ATPase and reduction of corticosterone levels. Our results helped to expand knowledge about the mechanisms involved in the physiopathology of the OXA-induced neurotoxicity and strongly indicated that 4-PSQ may be a good prototype for the treatment of anxious behavior and cognitive impairment induced by OXA exposure.

Systematic review of cognitive sequelae of non-central nervous system cancer and cancer therapy

PURPOSE

The aim of this review is to provide an updated overview of chemotherapy-related cognitive impairment (CRCI) in patients with cancer outside central nervous system (CNS), its incidence and prevalence, the cognitive pattern in neuropsychological studies, neuroimaging findings, and the relationship between chemobrain and aging. Methodological limitations of studies are also discussed.

METHODS

This review was guided by the PRISMA statement. The MEDLINE and Scopus databases were employed to search articles about CRCI in non-CNS cancer patients published from January 2004 to September 2019. Two types of research were reviewed: prospective studies addressing the effects of chemotherapy on cognition and systematic reviews about factors related with CRCI, also as neuroimaging findings and current available treatments.

RESULTS

Fifty-nine studies meeting the criteria were analyzed: 47 were longitudinal studies on cancer and cognition and 12 were reviews on risk factors, neuroimaging, and treatment. The majority of studies find cognitive impairment in patients with cancer treated with chemotherapy. The body of the literature on breast cancer is the most abundant, but there are also studies on colorectal, testicular, and lung cancer. Neuroimaging studies show changes in structure and activation in patients undergoing chemotherapy. Non-pharmacological treatment is effective for improving cognition and quality of life.

CONCLUSIONS

The occurrence of CRCI during the course of treatment in people with different types of cancer is frequent. Some risk factors have been identified, but CRCI is a complex phenomenon, with mediating factors related to cancer and treatment and moderating factors related with lifestyle and health.

IMPLICATIONS FOR CANCER SURVIVORS

This review highlights the importance of recognizing that this cognitive dysfunction is frequent, mild to moderate in nature but with great impact on quality of life.

Item-level psychometrics of a brief self-reported memory problem screening measure in breast cancer survivors

Background: We previously developed and psychometrically validated a self-reported memory problem (SRMP) measure using principal component analysis. In the present study, we applied item response theory (IRT) analysis to further examined the construct validity and determine item-level psychometric properties for the SRMP.Methods: The sample included 530 female breast cancer survivors (61% non-Hispanic White, mean age = 57 years) who were recruited from community-based organizations and large health care systems. We examined the construct validity, item-level psychometric properties, and differential item functioning (DIF) of the SRMP using confirmatory factor analysis (CFA), IRT and logistic regression analysis models.Results: The CFA confirmed a one-factor structure for the SRMP (comparative fit index [CFI] = 0.996, root-mean-square-error-approximation [RMSEA] = 0.059). As expected, SRMP scores correlated significantly with pain, mood, and fatigue; but not spiritual health locus of control (SPR). DIF analysis showed no measurement differences based on race/ethnicity and age groups.Conclusion: The CFA and DIF analysis supported the construct validity of the SRMP and its use in an ethnically diverse breast cancer population. These findings provide further evidence of the generalizability for the SRMP, and support its utilization as a psychometrically valid and reliable screening measure of cancer and treatment-related memory difficulties.

A Hypothesis-Generating Study Using Electrophysiology to Examine Cognitive Function in Colon Cancer Patients

INTRODUCTION

The purpose of this study was to describe the trajectory of cognitive function using neuropsychological tests and electrophysiological measures in individuals receiving 5FU/oxaliplatin chemotherapy for colon cancer.

METHODS

A total of 10 participants were tested at baseline (within 3 weeks of starting chemotherapy), 6 months (coinciding with the end of chemotherapy treatment), and 12 months (approximately 6 months post-chemotherapy). Participants completed neuropsychological tests and electrophysiology recordings of P300 event-related potential (ERP) elicited by a sustained attention to response task paired with experience sampling of attentional states (subjective reports of on-task or mind wandering).

RESULTS

No change in mean neuropsychological test performance was observed. Comparison of mean P300 ERP amplitudes as a function of attentional states (on-task vs. mind wandering) revealed no main effect of attentional state observed at baseline or 6 months, but a significant effect of attention was observed at 12 months, consistent with effects observed in healthy individuals.

CONCLUSIONS

Future studies can consider sustained attention constructs when studying cognitive function in colon cancer patients.

Cognitive impairment after cytotoxic chemotherapy

Background

Neurotoxicity is a frequent side effect of cytotoxic chemotherapy and affects a large number of patients. Despite the high medical need, few research efforts have addressed the impact of cytotoxic agents on cognition (ie, postchemotherapy cognitive impairment; PCCI). One unsolved question is whether individual cytotoxic drugs have differential effects on cognition. We thus examine the current state of research regarding PCCI. Neurological symptoms after targeted therapies and immunotherapies are not part of this review.

Methods

A literature search was conducted in the PubMed database, and 1215 articles were reviewed for predefined inclusion and exclusion criteria. Thirty articles were included in the systematic review.

Results

Twenty-five of the included studies report significant cognitive impairment. Of these, 21 studies investigated patients with breast cancer. Patients mainly received combinations of 5-fluorouracil, epirubicin, cyclophosphamide, doxorubicin, and taxanes (FEC/FEC-T). Five studies found no significant cognitive impairment in chemotherapy patients. Of these, 2 studies investigated patients with colon cancer receiving 5-fluorouracil and oxaliplatin (FOLFOX). Independent risk factors for PCCI were patient age, mood alterations, cognitive reserve, and the presence of apolipoprotein E e4 alleles.

Conclusions

There is evidence that certain chemotherapy regimens cause PCCI more frequently than others as evidenced by 21 out of 23 studies in breast cancer patients (mainly FEC-T), whereas 2 out of 3 studies with colon cancer patients (FOLFOX) did not observe significant changes. Further studies are needed defining patient cohorts by treatment protocol in addition to cancer type to elucidate the effects of individual cytotoxic drugs on cognitive functions.

Psychostimulants for cancer-related cognitive impairment in adult cancer survivors: a systematic review and meta-analysis

BACKGROUND

Cognitive impairment is recognized as a common symptom experienced by cancer survivors which impacts on quality of life (QoL) and day-to-day activities. One of the treatment options is the use of psychostimulants but the evidence supporting its use remains unclear.

OBJECTIVES

To identify the level of evidence of psychostimulants' effect on the management of cognitive impairment in adult cancer survivors.

METHODS

Electronic databases (MEDLINE, EMBASE, CENTRAL, CINAHL) and reference lists of relevant reviews were searched from inception to December 2017, with no language restrictions applied. Randomized controlled trials (RCTs), evaluating the effect of psychostimulants on cognitive impairment among cancer patients with no primary or secondary brain tumor or brain radiation, were included. The primary outcome was cognitive function changes, whereas secondary outcomes were adverse events (AEs) and QoL.

RESULTS

Six RCTs were included: three studies investigating methylphenidate and three modafinil, with a total of 244 and 146 patients, respectively. Due to important differences in methodologies between studies, a meta-analysis was assumed inappropriate for the primary outcome. A narrative synthesis was performed. One study using methylphenidate and two using modafinil demonstrated improvements in some cognitive functions as measured by objective cognitive assessment tests. Psychostimulants did not improve QoL and were not associated with more AEs.

CONCLUSION

To date, limited evidence is available to estimate the usefulness (or lack) of psychostimulants on cognitive function in this population.

Cognitive Dysfunction and Its Predictors in Adult Patients With Cancer Receiving Chemotherapy: A Cross-Sectional Correlational Study

BACKGROUND

Chemotherapy-related cognitive dysfunction, one of the most frequently reported symptoms in patients with cancer, has a negative impact on the daily lives of patients. No research has examined cognitive dysfunction and its potential predictors in adult patients with cancer receiving chemotherapy in Saudi Arabia.

PURPOSE

The purpose of this study was to examine the sociodemographic, clinical, and psychological factors associated with cognitive dysfunction in adult patients with cancer receiving chemotherapy.

METHODS

A cross-sectional correlational study was carried out with a convenience sample of 100 adult patients with cancer receiving chemotherapy at a university teaching hospital in Saudi Arabia. The Montreal Cognitive Assessment, the Hospital Anxiety and Depression Scale, and sociodemographic and clinical surveys were completed by participants. Descriptive statistics and linear regression were used to analyze the data.

RESULTS

The data showed that the participants experienced moderate-to-severe cognitive dysfunction. Participants performed poorly in the divided attention and memory cognitive domains. Age, educational level, and depression factors were found to be significant predictors of cognitive dysfunction.

CONCLUSIONS/IMPLICATIONS FOR PRACTICE

Cognitive dysfunction is commonly seen in patients with cancer receiving chemotherapy. Chemotherapy, age, and psychological factors increase susceptibility to cognitive dysfunction in adult patients with cancer. Oncology nurses should be aware that patients with cancer may be extremely vulnerable to cognitive dysfunction. Furthermore, age and psychological factors must be considered when developing symptom management and supportive care intervention programs to reduce the incidence of negative cognitive outcomes in this population.

Validation of a Battery of Neuropsychological Tests for Patients With Metastatic Cancer

This study aimed to investigate the psychometric properties of Trail Making Test (TMT), Continuous Reaction Time (CRT), Finger Tapping Test (FTT), Digit Span Test (DST), and Mini-Mental State Examination (MMSE) in Brazilian patients with metastatic cancer. Cognitive performance of 178 patients with metastatic cancer and 79 controls was assessed using the TMT, CRT, FTT, DST, and MMSE. Discriminant validity, concurrent validity, and reliability (39 patients were retested after 3-7 days) were investigated. Discriminant validity between groups was observed in TMT, DST, and MMSE. Measures of concurrent validity and cognitive performance were positively correlated with physical performance, education level, and better performance on MMSE. Negative correlations were observed between cognitive function, pain, anxiety, and depression. All tests but FTT demonstrated very good reliability. Thus, all neuropsychological tests but FTT showed psychometric properties that permit their use in clinical and research purposes in patients with metastatic cancer.

Chemotherapy and cognition: International cognition and cancer task force recommendations for harmonising preclinical research

Cancer survivors who undergo chemotherapy for non-CNS tumours often report substantial cognitive disturbances that adversely affect quality of life, during and after treatment. The neurotoxic effects of anti-cancer drugs have been confirmed in clinical and pre-clinical research. Work with animals has also identified a range of factors and underlying mechanisms that contribute to chemotherapy-induced cognitive impairment. However, there is a continuing need to develop standard cognitive testing procedures for validation and comparison purposes, broaden the search for biological and neurochemical mechanisms, and develop improved animal models for investigating the combined effects of treatment, the disease, and other potential factors (e.g., age, stress). In this paper, a working group, formed under the auspices of the International Cognition and Cancer Task Force, reviews the state of pre-clinical research, formulates strategic priorities, and provides recommendations to guide animal research that meaningfully informs clinical investigations.

Long-Term Cognitive Functioning in Testicular Germ-Cell Tumor Survivors

BACKGROUND

Treatment for cancer may lead to development of cognitive difficulties in cancer survivors. This study aimed to evaluate long-term cognitive functioning (CogF) in germ-cell tumor (GCT) survivors.

SUBJECTS, MATERIALS, AND METHODS

GCT survivors (n = 155) from the National Cancer Institute of Slovakia completed the Functional Assessment of Cancer Therapy Cognitive Function at a median of 10 years of follow-up (range: 5-32). The study group consisted of survivors receiving a cisplatin-based chemotherapy, radiotherapy to the retroperitoneal lymph nodes, or both, whereas the control group included survivors treated with orchiectomy only.

RESULTS

Of the total survivors, 138 received treatment beyond orchiectomy and 17 controls had orchiectomy alone. Any treatment resulted in significantly greater cognitive difficulties on the overall cognitive function score. Treatment with radiotherapy was associated with cognitive declines in overall cognitive functioning and in subscales for perceived cognitive impairment and cognitive impairment perceived by others (both p < .05). The burden of chemotherapy plus radiotherapy or radiotherapy versus controls resulted in the impairment in all cognitive functioning domains (all p < .05). Overall long-term cognitive impairment was independent of age in the multivariable analysis.

CONCLUSION

This prospective study shows that GCT survivors suffer from a long-term CogF impairment. These results may help guide clinicians' decisions in treatment and follow-up of GCTs.

IMPLICATIONS FOR PRACTICE

In this study, long-term survivors of germ-cell tumors have reported cognitive impairment after curative treatment with radiotherapy and chemotherapy compared with controls who had treatment with orchiectomy only. These data provide an argument against the use of adjuvant radiotherapy for stage I seminoma. Unnecessary overtreatment with chemotherapy and additional radiotherapy after chemotherapy should be avoided.

Long-Term and Latent Side Effects of Specific Cancer Types

Although many cancer survivors diagnosed with early-stage disease will outlive their cancer, they may continue to experience long-term and/or latent side effects due to cancer treatment. Many of these side effects are common and contribute to worse quality of life, morbidity, and mortality for cancer survivors. This article summarizes the treatment side effects for several of the most prevalent cancers in the United States.