Chemotherapy-Related Cognitive Impairment: The Breast Cancer Experience

Subjective Cognitive Dysfunction in Chronic Illness: A Systematic Review and Meta-Synthesis

BACKGROUND

Qualitative studies have examined the experiences of subjective cognitive dysfunction in specific populations or specific disease stages, but there has not yet been a systematic synthesis and evaluation of findings related to perceptions of subjective cognitive dysfunction in nondementia-related chronic illnesses.

OBJECTIVE

The aim of this study was 2-fold: (1) to undertake a systematic review of experiences of subjective cognitive dysfunction in people with nondementia-related chronic disease and (2) to develop an explanatory framework to describe the experiences of living with subjective cognitive dysfunction.

METHODS

Four databases were systematically searched for studies on subjective cognitive dysfunction up to June 2023. Qualitative synthesis was conducted on the final sample (N = 25) using Sandelowski's adaptation of Nobilt and Hare's reciprocal transactional analysis method. Critical appraisal was completed using the Critical Appraisal Skills Programme checklist.

RESULTS

Through constant comparison of key concepts, findings were organized within 4 interrelated themes that informed a conceptual explanatory model of adapting to living with subjective cognitive dysfunction: (1) symptoms, (2) health care, (3) perceptions of self, and (4) relationships. Participants highlighted how subjective cognitive dysfunction affected interactions in health care settings and involved other symptoms that in turn complicated meaning, self-enhancement, and mastery.

CONCLUSIONS

Our model of the process of adapting provides a new way to conceptualize cognitive dysfunction in chronic illness and suggests opportunities for health care professionals to support patients and their families. The results highlight the need for more research to better understand the role of subjective cognitive dysfunction in nondementia-related chronic illnesses.The review protocol was registered in PROSPERO (CRD42021231410).

Cancer-related cognitive impairment in older adults with acute myeloid leukemia treated with hypomethylating agents and venetoclax chemotherapy: a longitudinal descriptive study

PURPOSE

To explore cancer-related cognitive impairment (CRCI) in older adults with acute myeloid leukemia (AML) receiving venetoclax in combination with hypomethylating agents or low-dose cytarabine chemotherapy.

METHODS

This study is a longitudinal, qualitative descriptive study. Participants were recruited using purposive sampling. Semi-structured interviews were conducted among 11 older adults with AML at cycle 2, cycle 4, and cycle 7 of chemotherapy. An early end-of-study interview was conducted for those who changed treatment plans during the study follow-up.

RESULTS

A total of 22 transcripts were included for thematic analysis. Four themes emerged: (1) CRCI experiences, (2) impact of CRCI, (3) CRCI coping strategies, and (4) perceived CRCI-related factors. Older adults with AML experienced challenges in memory, language, and attention both intermittently and daily. These cognitive changes impacted their emotion, daily activities, social connection, and their caregivers' responsibilities. Hence, these older adults with AML developed problem-solving and emotional coping strategies to cope with CRCI. Older adults with AML also identified demographic, physiology/clinical, psychological, and other factors that might contribute to CRCI.

CONCLUSION

This study offers important insight for clinicians to understand how older adults with AML experience CRCI and how it impacts their daily routines. It indicates that clinicians should ask patients about their experience with cognitive changes at each encounter to provide support or coping strategies as needed to prevent CRCI from further hindering their quality of life.

Characterization of cancer survivors clustered by subjective and objective cognitive function scores

BACKGROUND

Cancer-related cognitive impairment (CRCI) is a prevalent condition that significantly impacts the quality of life of individuals who receive cancer treatment. Clinical management of CRCI presents challenges due to the absence of a standardized assessment. This study identified clinically relevant phenotypic clusters of CRCI based on subjective and objective cognitive function scores.

METHODS

In this cross-sectional study, participants were clustered using the VARCLUS™ based on subjective cognitive impairment assessed through the PROMIS® version 1.0 short-form subscales of cognitive abilities and cognitive concerns and the CANTAB Cambridge Cognition® scores, which included measures of visuospatial working memory capacity, visual episodic memory, new learning, working memory, executive function, and sustained attention. Each cluster's characteristics were described using demographics, physical and psychosocial factors (physical function, affect, optimism, and social support), and psychoneurological symptoms (anxiety, depression, fatigue, neuropathic pain, and sleep disturbance).

RESULTS

We obtained five clusters from a total of 414 participants, where 99% were female, and 93% were self-reported white. Clusters 4 and 5 showed the highest PROMIS® cognitive abilities and the lowest measures of cognitive concern, while Clusters 1 and 2 showed the lowest cognitive abilities and the highest cognitive concerns. Clusters 4 and 5 had higher education, income, employment, and higher scores in physical function, positive affect, optimism, and social support. Additionally, individuals in these clusters were less prone to experience severe cancer-related psychoneurological symptoms.

CONCLUSION

Our clustering approach, combining subjective and objective cognitive function information, shows promise in identifying phenotypes that hold clinical relevance for categorizing patient presentation of CRCI and facilitating individualized management strategies.

The Experience of Cancer-Related Cognitive Impairment Across Common Cancers: Protocol for a Qualitative Systematic Review

BACKGROUND

Cancer-related cognitive impairment (CRCI) is commonly experienced by patients with cancer during treatment, and 35% of patients experience cognitive impairment after treatment completion. Impairments in memory, attention, executive functioning, and information processing speed are most reported and often negatively impact daily functioning and quality of life (QoL). Despite the large scale of reports, this adverse side effect is underinvestigated across common cancer types, and there is a lack of insight into the CRCI experience.

OBJECTIVE

This qualitative synthesis aims to explore the evidence in relation to the experience of CRCI across common cancers. It also aims to understand the prevalence of CRCI across various cancer types, cognitive domains, and its impact on QoL and functional ability.

METHODS

A comprehensive search of databases, including PubMed, American Psychological Association PsycINFO, CINAHL, and Scopus, will be conducted. A total of 2 independent reviewers will screen titles and abstracts for inclusion, followed by full-text screening. A third reviewer will resolve any arising conflicts in the process of data screening and inclusion. Subsequently, data extraction and quality assessment using the Critical Appraisal Skills Programme (CASP) tool will be conducted. The results will be analyzed using thematic analysis.

RESULTS

This review is part of a PhD program funded in January 2023. The review commenced in June 2023, and data analysis is currently in progress. The qualitative synthesis will explore the experiences of CRCI across common cancers. The included studies are expected to report on numerous cancer types such as breast cancer, prostate cancer, leukemia, and lung cancer. The included study types are most likely to be interviews, focus groups, and surveys with qualitative components.

CONCLUSIONS

This protocol highlights the need for a qualitative synthesis that will explore the experience of CRCI across common cancer types. It will provide valuable insight into the lived experience of CRCI and the cognitive domains that may be disproportionately affected. There is a growing demand for further management interventions and clinically tested treatments of CRCI and the qualitative exploration of patient experience is crucial for their development. This qualitative synthesis will inform future developments and will contribute to improving QoL after cancer.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/56888.

Changes in physical activity, sedentary behavior, and self-reported cognitive function in cancer survivors before and during the COVID-19 pandemic: A cross-sectional study

BACKGROUND

Physical activity (PA) and reductions in sedentary behavior (SED) may mitigate cancer-related cognitive impairment. The purpose of this study was to examine (a) the associations between changes in PA, SED, and cognitive function in cancer survivors before and during the coronavirus disease 2019 (COVID-19) pandemic; and (b) clinical subgroups that moderate this association.

METHODS

A cross-sectional survey was administered online to adult cancer survivors globally between July and November of 2020. This was a secondary analysis of a cross-sectional survey examining changes in self-reported PA and quality of life in cancer survivors before and during the COVID-19 pandemic. Self-reported Questionnaires assessed moderate-to-vigorous PA (MVPA) using the modified Godin Leisure Time Exercise Questionnaire, cognitive function using the Functional Assessment of Cancer Therapy-Cognitive Function (FACT-Cog) scale, and SED using the Domain-specific Sitting Time questionnaire. Cancer survivors were classified into no change in behavior, desirable change (i.e., increase MVPA to meet PA guidelines or decrease SED by ≥60 min/day), and undesirable change (i.e., decrease MVPA to <150 min/week or increase SED by ≥60 min/day). Analysis of covariance examined differences in FACT-Cog scores across the activity change categories. Planned contrasts compared differences in FACT-Cog scores between cancer survivors with (a) no meaningful change vs. any change, and (b) a desirable change vs. an undesirable change.

RESULTS

There were no significant differences in FACT-Cog scores across activity-change categories in the full sample of cancer survivors (n = 371; age = 48.6 ± 15.3 years (mean ± SD)). However, cancer survivors who were diagnosed ≥5 years ago (t(160) = -2.15, p = 0.03) or who received treatment ≥5 years ago (t(102) = -2.23, p = 0.03) and who had a desirable change in activity reported better perceived cognitive abilities than those who had an undesirable change.

CONCLUSION

PA promotion efforts should consider reducing SED in addition to maintaining MVPA in long-term cancer survivors to mitigate cancer-related cognitive impairment during the COVID-19 pandemic.

Cancer-related cognitive impairment in racial and ethnic minority groups: a scoping review

PURPOSE

Disparities in cognitive function among racial and ethnic groups have been reported in non-cancer conditions, but cancer-related cognitive impairment (CRCI) in racial and ethnic minority groups is poorly understood. We aimed to synthesize and characterize the available literature about CRCI in racial and ethnic minority populations.

METHODS

We conducted a scoping review in the PubMed, PsycInfo, and Cumulative Index to Nursing and Allied Health Literature databases. Articles were included if they were published in English or Spanish, reported cognitive functioning in adults diagnosed with cancer, and characterized the race or ethnicity of the participants. Literature reviews, commentaries, letters to the editor, and gray literature were excluded.

RESULTS

Seventy-four articles met the inclusion criteria, but only 33.8% differentiated the CRCI findings by racial or ethnic subgroups. There were associations between cognitive outcomes and the participants' race or ethnicity. Additionally, some studies found that Black and non-white individuals with cancer were more likely to experience CRCI than their white counterparts. Biological, sociocultural, and instrumentation factors were associated with CRCI differences between racial and ethnic groups.

CONCLUSIONS

Our findings indicate that racial and ethnic minoritized individuals  may be disparately affected by CRCI. Future research should use standardized guidelines for measuring and reporting the self-identified racial and ethnic composition of the sample; differentiate CRCI findings by racial and ethnic subgroups; consider the influence of structural racism in health outcomes; and develop strategies to promote the participation of members of racial and ethnic minority groups.

Young Adults' Lived Experiences with Cancer-Related Cognitive Impairment: An Exploratory Qualitative Study

Cancer-related cognitive impairment (CRCI; e.g., disrupted memory, executive functioning, and information processing) affects many young adults, causing significant distress, reducing quality of life (QoL), and thwarting their ability to engage in professional, recreational, and social experiences. The purpose of this exploratory qualitative study was to investigate young adults' lived experiences with CRCI, and any strategies (including physical activity) they use to self-manage this burdensome side effect. Sixteen young adults (M_age = 30.8 ± 6.0 years; 87.5% female; M_{years since diagnosis} = 3.2 ± 3) who reported clinically meaningful CRCI whilst completing an online survey were interviewed virtually. Four themes comprising 13 sub-themes were identified through an inductive thematic analysis: (1) descriptions and interpretations of the CRCI phenomenon, (2) effects of CRCI on day-to-day and QoL, (3) cognitive-behavioural self-management strategies, and (4) recommendations for improving care. Findings suggest CRCI is detrimental to young adults' QoL and must be addressed more systematically in practice. Results also illuminate the promise of PA in coping with CRCI, but research is needed to confirm this association, test how and why this may occur, and determine optimal PA prescriptions for young adults to self-manage their CRCI.

Driving Assessment for Persons with Dementia: How and when?

Dementia is a progressive neurodegenerative disease leading to deterioration in cognitive and physical skills. Driving is an important instrumental activity of daily living, essential for independence. However, this is a complex skill. A moving vehicle can be a dangerous tool in the hand of someone who cannot maneuver it properly. As a result, the assessment of driving capacity should be part of the management of dementia. Moreover, dementia comprises of different etiologies and stages consisting of different presentations. As a result, this study aims to identify driving behaviors common in dementia and compare different assessment methods. A literature search was conducted using the PRISMA checklist as a framework. A total of forty-four observational studies and four meta-analyses were identified. Study characteristics varied greatly with regards to methodology, population, assessments, and outcome measures used. Drivers with dementia performed generally worse than cognitively normal drivers. Poor speed maintenance, lane maintenance, difficulty managing intersections and poor response to traffic stimuli were the most common behaviors in drivers with dementia. Naturalistic driving, standardized road assessments, neuropsychological tests, participant self-rating and caregiver rating were the most common driving assessment methods used. Naturalistic driving and on-road assessments had the highest predictive accuracy. Results on other forms of assessments varied greatly. Both driving behaviors and assessments were influenced by different stages and etiologies of dementia at varying degrees. Methodology and results in available research are varied and inconsistent. As a result, better quality research is required in this field.

First-Line Immunotherapy with Check-Point Inhibitors: Prospective Assessment of Cognitive Function

Approximately 40% of patients with cancer are eligible for check-point inhibitor (CPI) therapy. Little research has examined the potential cognitive impact of CPIs. First-line CPI therapy offers a unique research opportunity without chemotherapy-related confounders. The purpose of this prospective, observational pilot was to (1) demonstrate the feasibility of prospective recruitment, retention, and neurocognitive assessment for older adults receiving first-line CPI(s) and (2) provide preliminary evidence of changes in cognitive function associated with CPI(s). Patients receiving first-line CPI(s) (CPI Group) were assessed at baseline (n = 20) and 6 months (n = 13) for self-report of cognitive function and neurocognitive test performance. Results were compared to age-matched controls without cognitive impairment assessed annually by the Alzheimer's Disease Research Center (ADRC). Plasma biomarkers were measured at baseline and 6 months for the CPI Group. Estimated differences for CPI Group scores prior to initiating CPIs (baseline) trended to lower performance on the Montreal Cognitive Assessment-Blind (MOCA-Blind) test compared to the ADRC controls (p = 0.066). Controlling for age, the CPI Group's 6-months MOCA-Blind performance was lower than the ADRC control group's 12-months performance (p = 0.011). No significant differences in biomarkers were detected between baseline and 6 months, although significant correlations were noted for biomarker change and cognitive performance at 6 months. IFNγ, IL-1β, IL-2, FGF2, and VEGF were inversely associated with Craft Story Recall performance (p < 0.05), e.g., higher levels correlated with poorer memory performance. Higher IGF-1 and VEGF correlated with better letter-number sequencing and digit-span backwards performance, respectively. Unexpected inverse correlation was noted between IL-1α and Oral Trail-Making Test B completion time. CPI(s) may have a negative impact on some neurocognitive domains and warrant further investigation. A multi-site study design may be crucial to fully powering prospective investigation of the cognitive impact of CPIs. Establishment of a multi-site observational registry from collaborating cancer centers and ADRCs is recommended.

Combined Exercise and Game-Based Cognitive Training Intervention: Correlative Pilot Study of Neurotrophic and Inflammatory Biomarkers for Women With Breast Cancer

BACKGROUND

Interventions that increase neuroprotective factors and/or decrease inflammatory biomarkers may be effective in improving cognitive function for cancer survivors. Concurrent investigation of potential mechanism(s) to fully understand and refine effective interventions is needed.

OBJECTIVE

This correlative prospective substudy was conducted to investigate biomarkers related to potential mechanism(s) for a combined exercise and game-based brain training intervention designed to improve cognitive function in breast cancer survivors.

INTERVENTIONS/METHODS

Fingerstick bloodspot samples were collected at 3 time points during the randomized, wait-list controlled interventional parent study. Samples were analyzed for neuroprotective factors and inflammatory biomarker levels.

RESULTS

Insulinlike growth factor 1 (IGF-1) levels significantly increased (P < .01) for the intervention group from baseline to 4 and 16 weeks postintervention. Insulinlike growth factor 1 levels correlated with neurocognitive test performace improvement for Trail Making Test B (r = 0.31, P = .02). This association was not significant in the mixed model. No significant correlation was seen between IGF-1 levels and changes in self-report of cognitive function, activity level, or intervention dose.

CONCLUSIONS

Further investigation of IGF-1 levels is warranted as related to potential mechanisms for the Combined Exercise and Game-based Cognitive Training intervention. Future investigations should involve a larger sample cohort and incorporate objective measures of physical activity and prescribed sampling time in relationship to the most recent performance of the intervention.

IMPLICATIONS FOR PRACTICE

Fingerstick bloodspot sample collection is feasible, acceptable, and effective for conducting biomarker research. This methodology minimizes participant burden and discomfort; increases clinical trial access for home, off-site, or rural settings; and facilitates research efforts during times of pandemic restrictions.

Neural correlates in functional brain mapping among breast cancer survivors receiving different chemotherapy regimens: a qEEG/HEG-based investigation

BACKGROUND

Post-chemotherapy cognitive impairment commonly known as 'chemobrain' or 'chemofog' is a well-established clinical disorder affecting various cognitive domains including attention, visuospatial working memory, executive function, etc. Although several studies have confirmed the chemobrain in recent years, scant experiments have evaluated the potential neurotoxicity of different chemotherapy regimens and agents. In this study, we aimed to evaluate the extent of attention deficits, one of the commonly affected cognitive domains, among breast cancer patients treated with different chemotherapy regimens through neuroimaging techniques.

METHODS

Breast cancer patients treated with two commonly prescribed chemotherapy regimens, Adriamycin, Cyclophosphamide and Taxol and Taxotere, Adriamycin and Cyclophosphamide, and healthy volunteers were recruited. Near-infrared hemoencephalography and quantitative electroencephalography assessments were recorded for each participant at rest and during task performance to compare the functional cortical changes associated with each chemotherapy regimen.

RESULTS

Although no differences were observed in hemoencephalography results across groups, the quantitative electroencephalography analysis revealed increased power of high alpha/low beta in left fronto-centro-parietal regions involved in dorsal and ventral attention networks in the Adriamycin, Cyclophosphamide and Taxol-treated group compared with the Taxotere, Adriamycin and Cyclophosphamide and control group. The Adriamycin, Cyclophosphamide and Taxol-treated cases had the highest current source density values in dorsal attention network and ventral attention network and ventral attention network-related centers in 10 and 15 Hz associated with the lowest Z-scored Fast Fourier Transform coherence in the mentioned regions.

CONCLUSIONS

The negatively affected neurocognitive profile in breast cancer patients treated with the Adriamycin, Cyclophosphamide and Taxol regimen proposes presumably neurotoxic sequelae of this chemotherapy regimen as compared with the Taxotere, Adriamycin and Cyclophosphamide regimen.

Sex Differences in Taxane Toxicities

Simple Summary

Clinically observed sex differences in acute and long-term taxane chemotherapy-induced normal tissue toxicity are routinely documented but remain poorly understood despite the significant impact such toxicities have on treatment tolerance and quality of life outcomes in cancer survivors. This review draws from pre-clinical and clinical literature to highlight sex-specific mechanisms of action in taxane drug toxicity and proposes hypotheses for sex-specific clinical discrepancies in taxane-induced acute and long-term toxicities. To our knowledge, this is the first review exploring how sex as a biological variable impacts taxane-mediated mechanisms of action and clinical outcomes. In doing so, we have provided a novel framework to investigate and understand common sex differences observed in clinical and pre-clinical research.

Abstract

The taxane family of microtubule poisons and chemotherapeutics have been studied for over 50 years and are among the most frequently used antineoplastic agents today. Still, limited research exists characterizing taxane-induced sex-specific mechanisms of action and toxicities in cancer and non-cancerous tissue. Such research is important to advance cancer treatment outcomes as well as to address clinically observed sex-differences in short- and long-term taxane-induced toxicities that have disproportionate effects on female and male cancer patients. To gain more insight into these underlying differences between the sexes, the following review draws from pre-clinical and clinical paclitaxel and taxane oncology literature, examines sex-discrepancies, and highlights uncharacterized sex-dependent mechanisms of action and clinical outcomes. To our knowledge, this is the first literature review to provide a current overview of the basic and clinical sex dimorphisms of taxane-induced effects. Most importantly, we hope to provide a starting point for improving and advancing sex-specific personalized chemotherapy and cancer treatment strategies as well as to present a novel approach to review sex as a biological variable in basic and clinical biology.

Return to Work and Work Productivity During the First Year After Cancer Treatment

Objectives

Working-age cancer patients face barriers to resuming work after treatment completion. Those resuming work contend with reduced productivity arising from persisting residual symptoms. Existing studies of return to work (RTW) after cancer diagnosis were done predominantly in Western countries. Given that employment and RTW in cancer survivors likely vary regionally due to healthcare provision and social security differences, we documented rates and correlates of RTW, work productivity, and activity impairment among Chinese cancer survivors in Hong Kong at one-year post-treatment.

Methods

Of 1,106 cancer patients assessed at six-months post-cancer treatment (baseline), 593 previously worked; detailed work status, psychological distress (HADS), physical symptom distress (MSAS-SF), supportive care needs (SCNS-SF34-C), health-related quality of life (SF12), and illness perception (B-IPQ) were assessed. Six months later (follow-up), work productivity and activity impairment were assessed (WPAI; n = 402). Descriptive analyses examined RTW rate. Fully adjusted regressions determined RTW, work productivity, and activity impairment predictors.

Results

At baseline, 39% (232/593) were working, 26% (153/593) on sick leave, and 35% (208/593) were unemployed. Compared to patients returning to work, unemployed participants were older, likely manual/service-oriented workers, and had lower family income, chemotherapy, fewer unmet health system and information needs, poorer physical functioning, and negative illness perceptions. Sick leave participants were likely service-oriented workers, who had head and neck cancer, chemotherapy, and poor physical functioning. At FU, baseline depressive symptoms, physical symptom distress, and negative illness perceptions predicted presenteeism and work productivity loss; gynecological cancer, fewer unmet health system and information needs, and greater unmet sexuality needs predicted absenteeism; physical symptom distress, negative illness perception, and poor physical functioning predicted activity impairment.

Conclusion

Cancer survivors who had more physically demanding jobs and poorer physical functioning delayed RTW. Unmanaged physical symptom and psychological distress hindered work productivity.

Chemotherapy-Related Cognitive Impairment in Patients with Breast Cancer Based on Functional Assessment and NIRS Analysis

Background: Chemotherapy-related cognitive impairment (CRCI), or “chemobrain,” isdefined as a phenomenon of cognitive deficits in cancer patients after chemotherapy and is characterized by deficits in areas of cognition, including memory, attention, speed of processing, and executive function, which seriously affect quality of life. The purpose of this study is to investigate the impact of CRCI in breast cancer (BC) patients in chemotherapy treatment (CT+) or not (CT−) and to analyze their relationship with detectable objective changes in cerebral activity during the execution of a phonological and semantic verbal fluency task (PVF and SVF). Methods: An observational, cross-sectional study was carried out at Badajoz University Hospital (Spain). A total of 180 women with BC were included. We used Cognitive Scale (FACT-Cog) for neuropsychological subjective assessment, obtaining scores of perceived cognitive impairment (PCI), and near-infrared spectroscopy system (NIRS) for neuropsychological objective assessment during a verbal fluency task (PVF and SVF), determining alterations in the prefrontal cortex (PFC) assessed as changes in regional saturation index (rSO2). Results: A total of 41.7% percent of the patients in the sample had PCI. CT+ was significantly associated with a worse impact in PCI (X¯ = 50.60 ± 15.64 vs. X¯ = 55.01 ± 12.10; p = 0.005). Average rSO2 decreased significantly in CT+ (X¯ = 63.30 ± 8.02 vs. X¯ = 67.98 ± 7.80; p < 0.001), and BC patients showed a significant decrease in PVF and SVF on average (X¯ = 41.99 ± 9.52 vs. X¯ = 47.03 ± 9.31, and X¯ = 33.43 ± 11.0 vs. X¯ = 36.14 ± 10.68, respectively; p < 0.001). Conclusions: Our findings suggest that cognitive impairments in the domain of executive functioning exist among patients with BC who received CT. The results corroborate the hypothesis that CT is an important factor in cognitive impairment in patients with BC, which has been demonstrated by both subjective (PCI) and objective (PVF, SVF, and rSO2) neuropsychological measures. The combination of doxorubicin, cyclophosphamide, and docetaxel induce cognitive impairment.

Mapping cognitive deficits in cancer patients after chemotherapy: An Activation Likelihood Estimation meta-analysis of task-related fMRI studies

Recent neuroimaging studies have reported alterations in brain activation during cognitive tasks in cancer patients who have undergone chemotherapy treatment. However, the location of these altered brain activation patterns after chemotherapy varies considerably across studies. The aim of the present meta-analysis was to quantitatively synthesise this body of evidence using Activation Likelihood Estimation to identify reliable regions of altered brain activation in cancer patients treated with chemotherapy, compared to healthy controls and no chemotherapy controls. Our systematic search identified 12 studies that adopted task-related fMRI on non-central nervous system cancer patients who received chemotherapy relative to controls. All studies were included in the analyses and were grouped into four contrasts. Cancer patients treated with chemotherapy showed reduced activation in the left superior parietal lobe/precuneus (family-wise error corrected p < .05) compared to no chemotherapy controls. No significant clusters were found in three of our contrasts. The majority of studies did not support an association between altered brain activation and cognitive performance after chemotherapy. Findings point towards a possible chemotherapy-induced alteration, which could inform targeted treatment strategies. With continued work in this field using homogenous task-related protocols and cancer populations, fMRI may be used as a biomarker of cognitive deficits in the future.

Effective non-pharmacological interventions for cancer related cognitive impairment in adults (excluding central nervous system or head and neck cancer): systematic review and meta-analysis

INTRODUCTION

Cancer-related cognitive impairment (CRCI) is prevalent in cancer survivors, and impairments affect daily living tasks and overall wellbeing. This review aimed to identify and evaluate published randomized controlled trials (RCTs) of interventions to manage CRCI in adult populations, to analyze their effectiveness and to investigate the quality of the studies.

EVIDENCE ACQUISITION

Seven databases were searched (Medline, Scopus, CINAHL, AMED, PsychINFO, OTseeker, and the Cochrane Database of Systematic Reviews), including years 2005-2020, for randomized controlled trials (RCTs) investigating interventions to address cognition for adults with cancer. The final search was conducted in February 2021. The quality of studies was assessed using the Joanna Briggs Institute (JBI) Critical Appraisal Checklist for RCTs. Meta-analysis used comprehensive meta-analysis software. The study protocol was registered with PROSPERO (registration N. CRD42017076868).

EVIDENCE SYNTHESIS

A total of 45 studies involving 4727 participants examined interventions for CRCI and met selection criteria. Categories of interventions included cognitive training-based intervention (N.=15), cognitive behavior therapy (CBT) (N.=4), physical activity (N.=16) and other supportive therapies (N.=10). Meta-analysis indicated beneficial overall effects for all categories of interventions: cognitive training (standardized mean difference [SMD]=0.41, 95% CI: 0.28-0.53, I2=88.87%); CBT (SMD=0.30, 95% CI: 0.14-0.46, I2=44.86%); physical activity (SMD=0.27, 95% CI: 0.20-0.35, I2=37.67%); and supportive therapies (SMD=0.27, 95% CI: 0.16-0.39, I2=64.94%). Studies used self-report cognitive outcome measures and neurocognitive testing, or a mixture.

CONCLUSIONS

Findings suggest that effective intervention for CRCI exist, and cognitive training is consistently supported as an effective intervention; however, a high level of heterogeneity was found. CRCI research is currently dominated by breast cancer survivors, and quality research is also needed to address the broader population of cancer survivors who experience CRCI.

Neuroimmunological complications arising from chemotherapy-induced gut toxicity and opioid exposure in female dark agouti rats

Cancer patients may experience symptom clusters, including chemotherapy-induced (CI) gut toxicity (CIGT) and cognitive impairment. Analgesic selection for pain associated with CIGT is difficult as opioids induce glial reactivity and unwanted side effects. This study quantified central glial reactivity and proinflammatory effects in rats with CIGT using three mechanistically different analgesics. Regional adaptations were indicative of immune-to-brain signaling routes. Utilizing a 5-fluorouracil-induced GT (5IGT) rat model and analgesic intervention (carprofen (CAR), buprenorphine (BUP), and tramadol (TRAM)), spinal and brain neuroimmune modulation was examined via microglial, astrocyte, and proinflammatory (cluster of differentiation molecule 11b; CD11b, glial fibrillary associated protein; GFAP, and interleukin-1 beta; IL1β) reactivity marker expression changes by western blot analysis. 5IGT significantly increased thoracic GFAP (p < 0.05) and IL-1β (p < 0.0001) expression, CAR and BUP ameliorated these effects. BUP and TRAM with 5-FU synergistically increased hippocampal GFAP expression. CAR administered with 5IGT significantly elevated hippocampal and thoracic CD11b expression levels (p < 0.05). The neuroimmune responses observed in this study suggest activation of peripheral-to-central immune signaling pathways. We speculate that the opioid-induced hippocampal changes inferred a humorally mediated mechanism, whereas thoracic neuroimmune modifications indicated activation of an indirect neural route. Although TRAM ameliorated 5IGT-intestinal inflammation, this opioid presents complications relating to bodyweight and regional glial dysregulation (neuroinflammation) and may not be optimal in the management of pain associated with 5IGT. The chemotherapy-induced gut-derived neuroimmune consequences observed suggest a potential mechanistic contribution to central components of the cancer symptom cluster experience, while the opioid-related glial changes have implications for optimal pain management in this setting warranting further investigation.

Cognitive Dysfunction in Older Breast Cancer Survivors: An Integrative Review

BACKGROUND

Approximately 60% of the more than 3.8 million breast cancer survivors (BCSs) living in the United States are 60 years or older. Breast cancer survivors experience many symptoms including cognitive dysfunction; however, little is known regarding how age affects these symptoms.

OBJECTIVE

This integrative review was conducted to synthesize the literature on cognitive dysfunction in older BCSs. The purpose was to (1) describe the prevalence of objective and subjective cognitive dysfunctions and (2) examine factors associated with cognitive dysfunction in older BCSs.

METHODS

Whittemore and Knafl's integrative review methodology was used to examine cognitive dysfunction in BCSs 60 years or older.

RESULTS

Twelve quantitative studies were included. Up to 41% of older BCSs experienced cognitive dysfunction on neuropsychological examination, and up to 64% reported cognitive dysfunction on subjective measures pretreatment. Approximately half of older BCSs experienced cognitive decline from pretreatment to posttreatment regardless of cognitive measure. The domains most impacted were memory, executive functioning, and processing speed. Objective and subjective cognitive dysfunctions were associated with age, comorbidities, chemotherapy receipt, sleep, neuropsychological symptom cluster, frailty, and quality of life.

CONCLUSIONS

Cognitive dysfunction among older BCSs was common both prior to and following treatment. Cognitive dysfunction was associated with multiple factors that are compounded in the aging population and could be detrimental to quality of life and independent living.

IMPLICATIONS TO PRACTICE

Early assessment and intervention by healthcare providers, including nurses, for cognitive dysfunction in older BCSs are essential. Future research should focus on evidence-based interventions for cognitive dysfunction incorporating the unique needs of older BCSs.

Cognitive effects of chemotherapy: An integrative review

PURPOSE

An estimated 18.1 million new cancer cases (excluding nonmelanoma skin cancers) were diagnosed worldwide in 2020. Despite a rising incidence of cancers worldwide, in developed countries with strong healthcare systems, survival rates are improving as a result of early detection, improved treatments and survivorship care (World Health Organisation (WHO), 2021). Whilst living longer, cancer survivors are often living with side effects of treatment, including chemotherapy related cognitive impairment, often termed "chemobrain".

METHOD

An integrative review of contemporary literature answering the research question how does chemotherapy affect cognitive function? was undertaken utilising three computerised databases CINAHL, Medline and PUBMED, between 2015 and 2021. Data was thematically analysed to identify themes within published literature.

RESULTS

Thematic analysis identified four broad themes within the literature regarding chemotherapy induced cognitive impairment. Identified themes included; cognition as part of a complex scenario, proof of existence and searching for the cause, learning to play the game and timing of cognitive impairment.

CONCLUSIONS

Aggressive treatment with chemotherapy in the adjuvant setting has drastically improved the survival of cancer patients. Subsequent to aggressive treatments, side effects such as cognitive impairment have presented, which may persist in the long term. Despite the exact aetiology of chemotherapy induced cognitive impairment being largely unknown, the consequences of the condition are impacting cancer survivors and their quality of life.

Trajectories of cognitive performance over five years in a prospective cohort of patients with breast cancer (NEON-BC)

Purpose

To identify trajectories of cognitive performance up to five years since diagnosis and their predictors, in a cohort of patients with breast cancer (BCa).

Methods

A total of 464 women with BCa admitted to the Portuguese Institute of Oncology, Porto, during 2012, were evaluated with the Montreal Cognitive Assessment (MoCA) before any treatment, and after one, three and five years. Probable cognitive impairment (PCI) at baseline was defined based on normative age- and education-specific reference values. Mclust was used to define MoCA trajectories. Receiver Operating Characteristic curves were used to assess the predictive accuracy for cognitive trajectories.

Results

Two trajectories were identified, one with higher scores and increasing overtime, and the other, including 25.9% of the participants, showing a continuous decline. To further characterize each trajectory, participants were also classified as scoring above or below the median baseline MoCA scores. This resulted in four groups: 1) highest baseline scores, stable overtime (0.0% with PCI); 2) lowest baseline scores (29.5% with PCI); 3) mid-range scores at baseline, increasing overtime (10.5% with PCI); 4) mid-range scores at baseline, decreasing overtime (0.0% with PCI). Adding the change in MoCA during the first year to baseline variables significantly increased the accuracy to predict the downward trajectory (area under the curve [AUC] = 0.732 vs. AUC = 0.841, P < 0.001).

Conclusion

Four groups of patients with BCa with different cognitive performance trends were identified. The assessment of cognitive performance before treatments and after one year allows for the identification of patients more likely to have cognitive decline in the long term.

•

5-year cognitive trajectories since diagnosis of breast cancer were identified.

•

25.9% of breast cancer survivors had a declining cognitive trajectory.

•

Cognitive performance during the 1st year predicted the 5-year trajectory.

Chemotherapy-induced grey matter abnormalities in cancer survivors: a voxel-wise neuroimaging meta-analysis

BACKGROUND

Findings regarding chemotherapy-induced grey matter abnormalities are heterogeneous, and no meta-analysis has quantitatively assessed brain structural alterations in cancer survivors treated with chemotherapy.

PURPOSE

To investigate the grey matter abnormalities in non-CNS (central nervous system) cancer survivors treated with chemotherapy using Anisotropic Effect Size Signed Differential Mapping (AES-SDM) software.

METHOD

We identified studies published up to Sep 2018 that compared grey matter in non-CNS cancer survivors treated with chemotherapy (CT+, 10 data sets including 433 individuals) and cancer survivors not treated with chemotherapy (CT-, 7 data sets including 210 individuals) or healthy controls (HC, 3 data sets including 407 individuals) using whole-brain VBM. We used statistical maps from the studies included where available and reported peak coordinates otherwise.

RESULTS

Compared with both CT- and HC, the CT + groups exhibited a reduced grey matter volume (GMV), mainly in the prefrontal and anterior cingulate cortex (ACC) and right fusiform gyrus (FG). A smaller GMV in the FG and prefrontal cortex were found in the CT + compared with the CT-groups and in the CT + groups with impaired cognition. GMV in two areas was positively associated with the time since chemotherapy.

CONCLUSIONS

The present results suggest that non-CNS cancer survivors treated with chemotherapy exhibit grey matter abnormalities in the brain, especially in the prefrontal and ACC cortex. Grey matter volume changes after chemotherapy may contribute to cognitive impairments in cancer survivors that can be observed after chemotherapy.

Catechol-O-Methyltransferase Gene Polymorphisms and the Risk of Chemotherapy-Induced Prospective Memory Impairment in Breast Cancer Patients with Varying Tumor Hormonal Receptor Expression

Background

Existing research evidence indicates that breast cancer patients have different degrees of cognitive dysfunction after chemotherapy, and polymorphisms in 3 genes (catechol-O-methyltransferase, COMT; apolipoprotein E, APOE; and brain-derived neurotrophic factor, BDNF) have been associated with cognitive impairment. However, the role of these 3 gene polymorphisms in modulating cognitive impairment in breast cancer survivors with varying hormonal receptor expression is not clear at present.

To explore the effects of genetic polymorphisms in BDNF, APOE, and COMT on the regulation of prospective memory impairments induced by chemotherapy in breast cancer patients with various expression levels of estrogen receptor (ER) and progesterone receptor (PR).

Material/Methods

A total of 232 patients with breast cancer (113 with ER−/PR− and 119 with ER+/PR+) were evaluated before and after chemotherapy for cognitive function, including prospective memory. Following previously published sequencing procedures, we assessed 6 single-nucleotide polymorphisms (SNPs), including BDNF (rs6265), APOE (rs429358, rs7412), and COMT (rs165599, rs4680, rs737865).

Results

The patients showed poorer prospective memory scores after chemotherapy than before chemotherapy. Furthermore, the ER−/PR− group showed poorer event-based prospective memory (EBPM) scores than the ER+/PR+ group (z=−7.831, p<0.01) after chemotherapy. The patients with the COMT rs737865G/G genotype, compared with those with the A/A and A/G genotypes, showed a linear EBPM performance (β=1.499, 95% confidence interval (CI)=1.017~2.211) and were less likely to have memory impairment. In contrast, APOE and BDNF polymorphisms did not influence cognitive performance.

Conclusions

The patterns of hormonal receptor expression may be related to prospective memory impairments induced by chemotherapy in breast cancer patients. Furthermore, the COMT polymorphism (rs737865) was linearly related to the extent of deficits in EBPM and may represent a potential genetic marker of risk for cognitive deficits triggered by chemotherapy in patients with breast cancer.

Quality of Life Among Breast and Colon Cancer Patients Before and After First-Cycle Chemotherapy

PURPOSE

This study aimed to compare the functioning, symptoms, and quality of life (QoL) of patients with breast or colon cancer before and after their first-cycle (FC) chemotherapy.

DESIGN

One-group pretest/posttest design.

METHOD

The study utilized the standardized Arabic-translated Quality of Life Questionnaire Version 3 from the European Organization for Research and Treatment of Cancer in measuring the functioning, symptoms, and QoL of 120 Saudi patients diagnosed with breast or colon cancer. Dependent t test was used in analyzing the presence of significant differences in mean scores before and after chemotherapy with periods ranging from 14 days to 21 days following the treatment protocol.

RESULTS

The findings revealed significant differences in the functioning, symptoms, and QoL among patients with breast or colon cancer before and after FC chemotherapy (p < .001). Baseline scores showed higher physical, role, emotional, cognitive, and social functioning; lesser symptoms; lower financial difficulties; and better overall global health status compared to post-FC chemotherapy.

CONCLUSION

Assessing the QoL of patients with breast or colon cancer undergoing FC chemotherapy is essential to establish a holistic care plan in supporting and alleviating the unfavorable effects of chemotherapy and implement patient-centered interventions that aid in the enhancement of their overall QoL.

Study protocol of the Aerobic exercise and CogniTIVe functioning in women with breAsT cancEr (ACTIVATE) trial: a two-arm, two-centre randomized controlled trial

BACKGROUND

Up to 75% of women diagnosed with breast cancer report chemotherapy-related cognitive changes (CRCC) during treatment, including decreased memory, attention, and processing speed. Though CRCC negatively impacts everyday functioning and reduces overall quality of life in women diagnosed with breast cancer, effective interventions to prevent and/or manage CRCC are elusive. Consequently, women seldom receive advice on how to prevent or manage CRCC. Aerobic exercise is associated with improved cognitive functioning in healthy older adults and adults with cognitive impairments. Accordingly, it holds promise as an intervention to prevent and/or manage CRCC. However, evidence from randomized controlled trials (RCTs) supporting a beneficial effect of aerobic exercise on CRCC is limited. The primary aim of the ACTIVATE trial is to evaluate the impact of supervised aerobic exercise on CRCC in women receiving chemotherapy for breast cancer.

METHODS

The ACTIVATE trial is a two-arm, two-centre RCT. Women diagnosed with stage I-III breast cancer and awaiting neo-adjuvant or adjuvant chemotherapy are recruited from hospitals in Ottawa (Ontario) and Vancouver (British Columbia), Canada. Recruits are randomized to the intervention group (aerobic exercise during chemotherapy) or the wait-list control group (usual care during chemotherapy and aerobic exercise post-chemotherapy). The primary outcome is cognitive functioning as measured by a composite cognitive summary score (COGSUM) of several neuropsychological tests. Secondary outcomes are self-reported cognitive functioning, quality of life, and brain structure and functioning (measured by magnetic resonance imaging (MRI)/functional MRI and electroencephalography). Assessments take place pre-chemotherapy (pre-intervention), mid-way through chemotherapy (mid-intervention/mid-wait period), end of chemotherapy (post-intervention/post-wait period; primary endpoint), 16-weeks post-chemotherapy, and at 1-year post-baseline.

DISCUSSION

Aerobic exercise is a promising intervention for preventing and/or managing CRCC and enhancing quality of life among women diagnosed with breast cancer. The ACTIVATE trial tests several novel hypotheses, including that aerobic exercise can prevent and/or mitigate CRCC and that this effect is mediated by the timing of intervention delivery (i.e., during versus post-chemotherapy). Findings may support prescribing exercise during (or post-) chemotherapy for breast cancer and elucidate the potential role of aerobic exercise as a management strategy for CRCC in women with early-stage breast cancer.

TRIAL REGISTRATION

The trial was registered with the ClinicalTrials.gov database ( NCT03277898 ) on September 11, 2017.

Managing Cancer and Living Meaningfully (CALM) Intervention on Chemotherapy-Related Cognitive Impairment in Breast Cancer Survivors

Objective: To evaluate the effectiveness and feasibility of Managing Cancer and Living Meaningfully (CALM), which is used to reduce chemotherapy-related cognitive impairment (CRCI), relieve psychological distress, and improve quality of life (QOL) in Chinese breast cancer survivors (BCs). Methods: Seventy-four BCs were enrolled in this study. All patients were randomly assigned to either the CALM group or the care as usual (CAU) group. All patients were evaluated by the Functional Assessment of Cancer Therapy–Cognitive Function (FACT-Cog), Distress Thermometer (DT), and the Functional Assessment of Cancer Therapy–Breast (FACT-B) before and after CALM or CAU application to BCs with CRCI. We compared the differences in all these scores between the CALM group and the control group and analyzed the correlation between cognitive function and QOL. Results: Compared with the CAU group, the performance of the CALM group on the FACT-Cog, DT, and FACT-B showed significant differences before and after CALM (t = −18.909, −5.180, −32.421, P = .000, .000, .000, respectively). Finally, there was a positive correlation between cognitive function and QOL in breast cancer patients before (r = 0.579, P = .000) and after (r = 0.797, P = .000) treatment. Conclusions: The present results indicated that CALM has salutary effects on the improvement of cognitive impairment and QOL and relieves psychological distress in breast cancer patients, which may be due to a positive correlation between psychological distress and cognitive function or QOL.

Impact of transcranial direct current stimulation on sustained attention in breast cancer survivors: Evidence for feasibility, tolerability, and initial efficacy

BACKGROUND

A significant subset of breast cancer survivors experience cognitive difficulties in attention and memory, which persist for years following treatment. Transcranial direct current stimulation (tDCS) has been shown to be effective in improving working memory, attention, processing speed, and other cognitive functions in both healthy and clinical populations. To date, no studies have examined tDCS for rehabilitation of cancer-related cognitive dysfunction.

OBJECTIVE/HYPOTHESIS

We aimed to provide preliminary evidence for feasibility, tolerability, acceptability, and efficacy of tDCS in improving performance on a measure of sustained attention.

METHODS

In a within-subjects design, 16 breast cancer survivors underwent 2 consecutive days of active tDCS over the prefrontal cortex, and 2 days of sham tDCS, counterbalanced for order of stimulation condition, while performing a continuous performance test.

RESULTS

Stimulation was feasible and tolerable, with 89% of participants completing all sessions, and none reporting more than mild to moderate discomfort. Analyses of efficacy showed that during active stimulation, participants had significantly lower standard errors of reaction times overall, indicating better sustained attention ability, as compared to sham stimulation (p < 0.05). Furthermore, the effect of stimulation on standard errors of reaction times differed by inter-stimulus interval (ISI): for 1 and 2 s ISIs, there was no significant difference in performance between sham and active tDCS conditions, but for 4 s ISIs, stimulation improved variability in response times relative to sham (p < 0.05).

CONCLUSIONS

Results suggest that tDCS is feasible, tolerable, and may be an effective intervention to improve sustained attention difficulties in survivors with cancer-related cognitive dysfunction.

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.

Self-reported cognitive decline in Japanese patients with breast cancer treated with endocrine therapy

BACKGROUND

Despite contributing to the control of hormone receptor-positive breast cancer, a highly prevalent cancer type, endocrine therapy affects patients' cognitive function. We aimed to identify cognitive decline following the start of endocrine therapy using patient-reported measures and investigate factors associated with cognitive difficulties.

METHODS

This cross-sectional survey used a self-administered, anonymous questionnaire. The participants were 876 patients with breast cancer who experienced subjective cognitive difficulties after starting endocrine therapy. Our sample was recruited from 11 patient advocacy groups, 5 clinics, and 2 hospitals in Japan. The questionnaire assessed subjective cognitive difficulties (30 items), psychological well-being, demographic and clinical information, and other subjective symptoms.

RESULTS

Of 510 (58.2%) responses, we analyzed 405 (46.2%) questionnaires. Exploratory factor analysis identified three factors of cognitive difficulties: Factor 1, "difficulties in manipulating memory and language;" Factor 2, "difficulties in processing multiple pieces of information;" and Factor 3, "difficulties in maintaining attention and concentration." Factor 1 was the most common type, and it was significantly related to the treatment characteristics of endocrine therapy. Multivariate logistic regression analysis revealed that fewer household members, a history of breast surgery, more severe menopausal symptoms, and greater psychological distress were significantly associated with cognitive difficulties. As cognitive difficulties increased, the proportion of participants suspected to have psychological disorders increased significantly.

CONCLUSIONS

Patients treated with endocrine therapy for breast cancer experience intricately intertwined impairments in several domains of cognitive function. They have an increased risk of psychological disorders corresponding to the degree of subjective cognitive function.

Pilot Feasibility Study Examining Pupillary Response During Driving Simulation as a Measure of Cognitive Load in Breast Cancer Survivors

OBJECTIVES

To test the feasibility of adding driving simulation tasks to measure visuospatial ability and processing speed to an existing neurocognitive battery for breast cancer survivors (BCSs).

SAMPLE & SETTING

38 BCSs and 17 healthy controls from a cross-sectional pilot study conducted at the University of Kansas Medical Center.

METHODS & VARIABLES

Exploratory substudy measuring pupillary response, visuospatial ability, and processing speed during two 10-minute driving simulations (with or without n-back testing) in a sample of BCSs with self-reported cognitive complaints and healthy controls.

RESULTS

Feasibility of measurement of pupillary response during driving simulation was demonstrated. No between-group differences were noted for pupillary response during driving simulation. BCSs had greater visuospatial ability and processing speed performance difficulties than healthy controls during driving simulation without n-back testing and slower n-back response time.

IMPLICATIONS FOR NURSING

Preliminary evidence showed a possible link between cancer/treatment on visuospatial ability and processing speed in BCSs.

Hippocampus-Related Cognitive and Affective Impairments in Patients With Breast Cancer-A Systematic Review

Background: Although improvements in medical treatment lead to a steadily rising survival rate of breast cancer patients (BCP), it is associated with a decrease in cognitive and affective function. The hippocampus, a brain region with a high influence on both cognitive and affective function, is increasingly becoming the focus of current research because of its high vulnerability to adverse direct (chemotherapeutic agents, endocrine therapeutic agents, and radiation) or indirect (stress and other psycho-social factors) treatment-related effects.

Methods: This systematic review analyses current data from literature combining hippocampus-related brain changes due to breast cancer treatment with associated cancer-related cognitive and affective impairments (CRCI/CRAI). The seven studies that met the inclusion criteria consisted of six cross-sectional studies and one longitudinal study.

Results: The study results indicate hippocampal differences across all types of treatment. Those differences include volume loss, deformation, and changes in functional connectivity. They are associated with CRCI, revealing executive function as well as working memory, episodic memory, and prospective memory as the most affected domains. Although an interaction between hippocampus-related brain changes, CRCI, and CRAI can be hypothesized, CRAI are less reflected in current research.

Discussion: More research including longitudinal assessments with better overall methodology is needed to fully understand the interaction between hippocampal alterations and both CRCI and CRAI due to breast cancer treatment.

Reporting of paclitaxel-induced peripheral neuropathy symptoms to clinicians among women with breast cancer: a qualitative study

PURPOSE

Cases of chemotherapy-induced peripheral neuropathy (CIPN) under-reporting have been sporadically described in the literature, but no studies have focused on actively examining this behavior. Our primary aim was to identify women who purposefully under-reported CIPN, along with reasons for doing so. A secondary aim was to explore factors enabling or hindering communication of CIPN to clinicians.

METHODS

Semi-structured interviews were conducted with women with breast cancer who had received paclitaxel in a prospective observational study. The interview guide was developed based on factors hypothesized to influence side effect disclosure to clinicians. Interviews were recorded, transcribed verbatim, and thematically content analyzed.

RESULTS

Thirty-four women were interviewed. Three main themes emerged from the analysis: (1) enablers of CIPN reporting (e.g., positive relationship with the oncology team, sufficient appointment time, existence of alternative communication channels to office visits, expectation of CIPN as a side effect); (2) deterrents to CIPN reporting (e.g., perception of need to complete the full course of therapy, fear of treatment discontinuation, lack of knowledge of long-term consequences of CIPN); and (3) balancing survival versus functional impairment due to CIPN. Women prioritized efficacy over CIPN until physical functioning was meaningfully affected. No patients reported purposeful CIPN under-reporting, but three women admitted having considered doing so.

CONCLUSIONS

Despite the lack of evidence of CIPN withholding, women considered both the effectiveness and the toxicity of paclitaxel treatment, as well as beliefs about treatment and long-term consequences of CIPN and relationship with the oncology team, when deciding whether to report CIPN symptoms.

Differential DNA methylation following chemotherapy for breast cancer is associated with lack of memory improvement at one year

The biological basis underlying cognitive dysfunction in women with early-stage breast cancer (BC) remains unclear, but could reflect gene expression changes that arise from the acquisition and long-term retention of soma-wide alterations in DNA methylation in response to chemotherapy. In this longitudinal study, we identified differences in peripheral methylation patterns present in women prior to treatment (T1) and 1 year after receiving chemotherapy (T4) and evaluated relationships among the differential methylation (DM) ratios with changes in cognitive function. A total of 58 paired (T1 and T4) blood specimens were evaluated. Methylation values were determined for DNA isolated from whole blood using a genome-wide array . Cognitive function was measured using the validated, computerized CNS Vital Signs platform. Relationships between methylation patterns and cognitive domain scores were compared using a stepwise linear regression analysis, with demographic variables as covariates. The symptom comparison analysis was restricted to 2,199 CpG positions showing significant methylation ratio changes between T1 and T4. The positions with DM were enriched for genes involved in the modulation of cytokine concentrations. Significant DM ratios were associated with memory domain (56 CpGs). Eight of the ten largest DM ratio changes associated with lack of memory improvement were localized to genes involved in either neural function (ECE2, PPFIBP2) or signalling processes (USP6NL, RIPOR2, KLF5, UBE2V1, DGKA, RPS6KA1). These results suggest that epigenetic changes acquired and retained for at least one year in non-tumour cells following chemotherapy may be associated with a lack of memory improvement following treatment in BC survivors.

Long-Term Fatigue and Cognitive Disorders in Breast Cancer Survivors

Survivors of early-stage breast cancer may report treatment-related side effects that persist for several years after the end of primary treatment. Among these, fatigue and cognitive disorders are frequent complaints and can negatively impact quality of life. Cancer-related fatigue is a very prevalent and distressing long-term side effect among breast cancer survivors that typically improves after completion of treatment, although many patients report severe fatigue several years post-treatment. Cognitive disorders are also common among survivors of breast cancer, especially if treated with chemotherapy. These symptoms are usually mild-to-moderate and often transient. Cognitive recovery is frequently observed within months or a few years after completion of chemotherapy or endocrine therapy. However, some breast cancer survivors may have persistent cognitive difficulties. Several types of interventions have proved to be beneficial in reducing cancer-related fatigue and cognitive difficulties. Most of these interventions for cancer-related fatigue are thought to be effective by reducing inflammation or disrupting pro-inflammatory circuits. Further studies are needed on cognitive management that has showed promising results. This narrative review summarizes the state of the art regarding long-term fatigue and cognitive disorders in patients with early breast cancer, describing prevalence, impact, pathophysiology, and risk factors, and focusing on available interventions.

Individualized Piano Instruction for Improving Cognition in Breast Cancer Survivors

PURPOSE

To evaluate the use of individualized piano instruction (IPI) for improving cognition among breast cancer survivors.

PARTICIPANTS & SETTING

Six participants were included in an eight-week piano program with three data collection time points at baseline, midpoint, and postintervention. Participants were recruited from the breast cancer clinic of a university cancer center in South Florida.

METHODOLOGIC APPROACH

Neurocognitive, psychosocial, and self-report assessments were conducted to determine potential benefits and program feasibility, including the NIH Toolbox® Cognition Battery, the Functional Assessment of Cancer Therapy (FACT)-Cognitive Function, the FACT-Breast, the Patient Health Questionnaire-9, the Generalized Anxiety Disorder-7, and a participant questionnaire.

FINDINGS

Results related to potential benefits suggest that IPI may significantly improve overall cognition in breast cancer survivors, with fluid cognition showing improvement. In addition, IPI may improve quality of life and self-reported measures of depression and anxiety, with large to moderate effect sizes, respectively.

IMPLICATIONS FOR NURSING

Nurses should explore different treatment options for chemotherapy-related cognitive impairment and consider including IPI in survivorship care plans.

Exercise as an Intervention to Mitigate Decreased Cognitive Function From Cancer and Cancer Treatment: An Integrative Review

BACKGROUND

Decreased cognitive function associated with non-central nervous system cancers and cancer treatment significantly affects cancer survivors' quality of life. Exercise may be an effective intervention to mitigate decreased cognitive function.

OBJECTIVE

The aim of this article is to conduct an integrative review to summarize and critique the available evidence related to the use of exercise as a potential intervention for decreased cognitive function from cancer and cancer treatment.

METHODS

We conducted an integrative review through January 2016 utilizing PubMed, CINAHL, and PsycINFO. Broad inclusion criteria included any quantitative study in which cognitive outcomes were reported in relationship to any type of exercise for adult cancer survivors. Effect sizes were calculated when possible based on available data.

RESULTS

Twenty-six studies were included for review. The majority of studies (including aerobic or resistance exercise as well as mindfulness-based exercise) were associated with some improved cognitive outcomes. However, studies varied significantly in levels of evidence, cognitive domains assessed, and types of cognitive measures. Less than half of the studies included objective measures of cognitive function.

CONCLUSIONS

The evidence shows promising trends for the use of exercise as a potential intervention for improving cognitive function following cancer and cancer treatment, but questions remain concerning exercise type, timing of initiation, intensity, frequency, and duration.

IMPLICATIONS FOR PRACTICE

Additional research is warranted to understand how various types of exercise influence cognitive function in the cancer survivor population and to better understand the mechanisms driving these effects. Trial designs that include both objective and subjective measures of cognitive function are needed.

Adaptations to cognitive problems reported by breast cancer survivors seeking cognitive rehabilitation: A qualitative study

OBJECTIVE

Qualitative studies have elucidated cancer survivors' experiences of cognitive changes associated with cancer and cancer treatment. This study specifically explored experiences of women treated for breast cancer who were seeking cognitive rehabilitation. The objective was to characterise the frequency and nature of cognitive changes and adaptations to cognitive change reported by these participants to better understand treatment needs of this group.

METHOD

Australian women who had completed primary treatments for breast cancer (surgery, chemotherapy, and/or radiotherapy) and volunteered to participate in one of two cognitive rehabilitation intervention studies were interviewed via telephone. Interview responses regarding cognitive changes and adaptations to cognitive change were transcribed by the interviewers, then coded and analysed by two researchers using content analysis.

RESULTS

Among the 95 participants (age M=54.3 years, SD=9.6), the most commonly reported cognitive change was memory (79% of participants) and 61% reported more than one type of cognitive change. Adaptations to change were reported by 87% of participants, with written or electronic cues the most common (51%). Most often, participants reported using a single type of adaptation (48%) with only 39% reporting multiple types of adaptations.

CONCLUSIONS

Women treated for breast cancer, who were seeking cognitive rehabilitation, most commonly reported memory changes, which were mainly managed through a single type of adaptation. These results suggest that there is considerable scope for increasing the range of cognitive adaptations to improve the quality of life of cancer survivors who experience adverse cognitive changes.

The relationship between diet and cognitive function in adult cancer survivors: a systematic review

PURPOSE

To perform a systematic review identifying how dietary factors are related to cognitive function in cancer survivors who are not currently undergoing primary treatment.

METHODS

Using the PRISMA framework, a search was conducted for studies published before February 2019 across multiple databases, identifying 2304 unique articles. Twelve met final inclusion criteria and were evaluated through narrative synthesis. This review was registered with the International Prospective Register Of Systematic Reviews (CRD42018111941).

RESULTS

Included studies were heterogeneous in methodology and in dietary and cognitive variables investigated making direct comparisons difficult. Evidence of a relationship between diet and cognition was mixed; the most consistent evidence was identified in relation to a positive relationship between fruit and vegetable intake and cognitive function (both self-reported and objectively tested) in five out of six studies, but was not concordant across all studies.

CONCLUSION

Preliminary evidence exists that a greater fruit and vegetable intake is associated with better cognitive functioning in cancer survivors, as has been reported in healthy populations; however, these data are correlational and include relatively small samples. Most evidence related to breast cancer survivors, with individual studies extending to colorectal and stomach cancer survivors. Experimental trials are needed to identify causal attribution of dietary factors on cognitive function in cancer survivors.

IMPLICATIONS FOR CANCER SURVIVORS

At this time, there is not sufficient evidence to make dietary or nutritional recommendations specifically for improving cognitive function in cancer survivors. This should be considered in light of the general paucity of research on this subject, necessitating further investigations.

Longitudinal association of subjective prospective and retrospective memory and depression among patients with glioma

PURPOSE

This study investigated the levels of depression, subjective prospective memory (PM), and subjective retrospective memory (RM) among Chinese glioma patients and explored the bi-directional relationships between depression and memory impairment, including subjective PM and RM.

METHODS

Seventy-one participants with glioma were assessed for depression, PM, and RM at two time points (Time 1: within 48 h of being hospitalized; Time 2: two weeks after surgery). A cross-lagged path analysis was conducted to examine the bi-directional relationships between depression and memory.

MAIN RESULTS

Depression at T1 predicted memory impairment total scores (β = 0.22, P = 0.011) and RM (β = 0.29, P < 0.001) at T2. However, depression at TI could not predict PM at T2 (β = 0.15, P = 0.090). Memory, whether PM or RM, at T1 could not predict depression at T2 (β = 0.07, P = 0.497; β = 0.00, P = 0.978; β = 0.06, P = 0.321).

CONCLUSIONS

Depression can affect RM memory impairment among glioma patients. Oncology nurses should preoperatively screen for depression in glioma patients to identify high-risk groups, for whom emotional interventions and memory training should be carried out to reduce postoperative RM memory impairment.

Trajectories of Cognitive Function and Associated Phenotypic and Genotypic Factors in Breast Cancer

OBJECTIVES

This study identified women with unique trajectories of executive function, concentration, and visual working memory before and during adjuvant therapy for breast cancer, and examined phenotypic and genotypic predictors associated with subgroups.

SAMPLE & SETTING

399 postmenopausal women, of whom 288 were women with early-stage breast cancer and 111 were women without breast cancer, matched on age and years of education to the women with breast cancer, and all at an urban cancer center.

METHODS & VARIABLES

A repeated-measures design was used; assessments occurred before adjuvant therapy and every six months post-therapy initiation. Group-based trajectory modeling determined subgroups. Multinomial logistic regression identified phenotypic and genotypic characteristics.

RESULTS

Three executive function and concentration trajectory subgroups were identified.

IMPLICATIONS FOR NURSING

Advancing age, greater pretherapy fatigue, and poorer pretherapy cognitive function are associated with the low subgroups. DNA repair and oxidative stress mechanisms may be involved in the cognitive changes that women experience.

Low Sucrose, Omega-3 Enriched Diet Has Region-Specific Effects on Neuroinflammation and Synaptic Function Markers in a Mouse Model of Doxorubicin-Based Chemotherapy

Chemotherapeutic agents such as doxorubicin may negatively affect long-term brain functioning in cancer survivors; neuroinflammation may play a causal role. Dietary approaches that reduce inflammation, such as lowering sucrose and increasing eicosapentaenoic acid plus docosahexaenoic acid (EPA + DHA), may attenuate chemotherapy-induced neuroinflammation and synaptic damage, thereby improving quality of life. Ovariectomized, C57BL/6 mice were assigned to a chemotherapy (9 mg/kg doxorubicin + 90 mg/kg cyclophosphamide) or vehicle two-injection regimen, with injections two and four weeks after starting diets. In Study 1, mice received low sucrose diets with EPA + DHA or No EPA + DHA for four to six weeks; tissues were collected four, seven, or 14 days after the second injection. Compared to vehicle, chemotherapy increased pro-inflammatory cytokine IL-1β at day seven in the cortex and hippocampus, and reduced gene expression of synaptic marker Shank 3 at all timepoints in cortex, while EPA + DHA increased expression of Shank 3. In Study 2, high or low sucrose/EPA + DHA or No EPA + DHA diets were fed for five weeks; tissues were collected ten days after the second injection. Among chemotherapy-treated mice, brain DHA was higher with low sucrose feeding. Furthermore, low sucrose increased gene expression of Shank 1, while EPA + DHA increased expression of Shank 3 and reduced protein concentrations of pro-inflammatory markers IL-5, IL-6 and KC/GRO in the cortex, but not the hippocampus. Low sucrose, EPA + DHA diets may attenuate neuroinflammation and synaptic damage induced by doxorubicin-based chemotherapy in specific brain regions.

Does walking protect against decline in cognitive functioning among breast cancer patients undergoing chemotherapy? Results from a small randomised controlled trial

BACKGROUND

Cancer related cognitive impairments have been subjectively reported and objectively detected in breast cancer patients treated with chemotherapy and are known to have a profound negative impact on productivity, psychosocial well-being and overall quality of life. Moderate levels of walking are known to be of benefit to the psychosocial well-being of those affected by breast cancer and for managing cognitive impairment in healthy adults, children, and the elderly. The purpose of this study is to investigate the effects of a home-based, self-managed, moderate intensity walking intervention on subjective and objective cognitive functioning in breast cancer patients undergoing chemotherapy.

METHODS

A home-based, self-managed intervention that consisted of moderate levels of walking was compared to usual care among breast cancer patients treated with chemotherapy in a randomised controlled trial. Outcome measures included changes in subjective (CFQ) and objectively detected cognitive functioning (Stroop, SART and two subscales from the WAIS- Digit Span and Block Design). Fifty participants were randomised to either the intervention group (n = 25), who completed 12 weeks of moderate intensity walking, or to the control group (n = 25) mid-way through chemotherapy.

RESULTS

Compared with the control group, the self-managed walking intervention had positive effects on perceived cognitive function but not on sustained attention, executive function, memory or visual spatial skills when assessed objectively using neuropsychological measures.

CONCLUSION

This home-based, self-managed intervention is beneficial for protecting against perceived cognitive decline in breast cancer patients treated with chemotherapy. There is a need for further research to objectively assess cognitive decline within this population with larger sample sizes of patients.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN50709297.

Protocol for the "Chemobrain in Motion - study" (CIM - study): a randomized placebo-controlled trial of the impact of a high-intensity interval endurance training on cancer related cognitive impairments in women with breast cancer receiving first-line chemotherapy

BACKGROUND

Up to 80% of breast cancer patients suffer from Cancer Related Cognitive Impairments (CRCI). Exercise is suggested as a potential supportive care option to reduce cognitive decline in cancer patients. This study will investigate the effects of a high-intensity interval endurance training (HIIT) on CRCI in breast cancer patients. Potentially underlying immunological and neurobiological mechanisms, as well as effects on patients' self-perceived cognitive functioning and common cancer related side-effects, will be explored.

METHODS

A single-blinded randomized controlled trial will be carried out. The impact of HIIT on CRCI will be compared to that of a placebo-intervention (supervised myofascial release training). Both interventions will be conducted simultaneously with the patients' first-line chemotherapy treatment typically lasting 12-18 weeks. Fifty-nine women with breast cancer will be included in each of the two groups. The study is powered to detect (α = .05, β = .2) a medium effect size difference between the two groups (d = .5) in terms of patients' change in cognitive testing performances, from baseline until the end of the exercise-intervention. The cognitive test battery, recommended by the International Cancer and Cognition Task Force to assess CRCI, will be used as primary measure. This includes the Hopkins Verbal Learning Test (learning/verbal memory), the Controlled Oral Word Association Test (verbal fluency) and the Trail-Making-Test A/B (attention/set-switching). The following endpoints will be assessed as secondary measures: Go-/No-Go test performance (response inhibition), self-perceived cognitive functioning, serum levels of pro- and antiinflammatory markers (tumor necrosis factor alpha, Interleukin-6, Interleukin-1 alpha, Interleukin-1 beta, C-reactive protein, Interleukin-1 receptor antagonist and Interleukin-10), serum levels of neurotrophic and growth factors (brain-derived neurotrophic factor, insulin-like growth factor 1 and vascular endothelial growth factor), as well as common cancer-related side effects (decrease in physical capacity, fatigue, anxiety and depression, sleep disturbances, quality of life and chemotherapy compliance).

DISCUSSION

This study will provide data on the question whether HIIT is an effective supportive therapy that alleviates CRCI in breast cancer patients. Moreover, the present study will help shed light on the underlying mechanisms of potential CRCI improving effects of exercise in breast cancer patients.

TRIAL REGISTRATION

DRKS.de, German Clinical Trials Register (DRKS), ID: DRKS00011390 , Registered on 17 January 2018.

Pupillary response: cognitive effort for breast cancer survivors

PURPOSE

The purpose of this cross-sectional comparative pilot study was to evaluate cognitive effort, indexed by pupillary response (PR), for breast cancer survivors (BCS) with complaints of cognitive dysfunction following chemotherapy.

STUDY AIMS

Compare the cognitive effort employed by BCS to healthy controls (HC) during neuropsychological tests (NPT) for memory, sustained attention, verbal fluency, visuospatial ability, processing speed and executive function; and Investigate the relationship between PR-indexed cognitive effort and participants' self-report of cognitive function.

METHODS

Self-report of cognitive function was collected from 23 BCS and 23 HC. PR was measured during NPT. Independent two-sample t tests or Wilcoxon rank sum tests were used to compare group scores. Between-group effect size (Cohen's d) was calculated for each outcome. Correlation between mean self-report scores and PR values, as well as 95% confidence intervals, was calculated.

RESULTS

No group differences were demonstrated for NPT performance. BCS reported more issues with cognitive function than HC (p < .0001). A group effect for BCS was seen with PR-indexed cognitive effort for components of most NPT (p < .05). PR was correlated with most self-report measures of cognitive function (r = 0.33-0.45).

CONCLUSIONS

PR sensitivity to cognitive effort across a variety of NPT and correlation with self-report of cognitive function was demonstrated. The portability, affordability, and "real-time" aspects of PR are attractive for potential use in the clinic setting to assess cognitive function. A larger study is needed to confirm these results. Prospective investigation of PR in BCS is needed to demonstrate sensitivity to cognitive function changes over time.