Dynamin-1 is a potential mediator in Cancer-Related Cognitive Impairment

Dynamin-1 (DNM1) consolidates memory through synaptic transmission and modulation and has been explored as a therapeutic target in Alzheimer's disease. Through a two-prong approach, this study examined its role in cancer-related cognitive impairment (CRCI) pathogenesis using human and animal models. The human study recruited newly diagnosed, chemotherapy-naïve adolescent and young adult cancer and non-cancer controls to complete a cognitive instrument (FACT-Cog) and blood draws for up to three time points. Concurrently, a syngeneic young-adult WT (C57BL/6 female) mouse model of breast cancer was developed to study DNM1 expression in the brain. Samples from eighty-six participants with 30 adolescent and young adult (AYA) cancer and 56 non-cancer participants were analyzed. DNM1 levels were significantly lower among cancer participants compared to non-cancer prior to treatment. While receiving cancer treatment, cognitively impaired patients were found with a significant downregulation of DNM1, but not among those without impairment. In murine breast cancer-bearing mice receiving chemotherapy, we consistently found a significant decline in DNM1 immunoreactivity in the hippocampal CA1 and CA3 subregions. Observed in both human and animal studies, the downregulation of DNM1 is linked with the onset of CRCI. Future research should explore the potential of DNM1 in CRCI pathogenesis and therapeutics development.

Can more be done? - A qualitative study of breast cancer survivors' perspectives on regular walking exercise to improve post-chemotherapy neurotoxicity impairments

PURPOSE

Chemotherapy-induced neurotoxicity in breast cancer survivors requires attention as their population are increasing. Limited qualitative study is known about breast cancer survivors' perspectives on regular walking exercise to improve post-chemotherapy neurotoxicity impairments in their free-living setting. This study explored regular walking exercise to improve post-chemotherapy neurotoxicity impairments from breast cancer survivors' perspectives.

METHODS

A qualitative descriptive study was conducted. A purposive sample of 15 participants experiencing neurotoxicity impairments was invited to semi-structured interviews. Textual interview data were managed in NVivo. Content analysis was performed.

RESULTS

Participants were aged 39-68 and had received 4-8 cycles of chemotherapy. Most (86.7%, n = 13) reported engaging in regular walking exercise. Four main categories emerged from the data: (1) perceived effects of regular exercise on neurotoxicity impairments, (2) unmet information needs, (3) regular walking habit being self-sustained, and (4) enablers and constraints of regular walking exercise.

CONCLUSIONS

Walking exercise, as commonly employed by participants in their free-living setting, was the essence in the management of chemotherapy-induced neurotoxic conditions during survivorship. Participants undertaking walking exercise lacked informed and individualized information about the regular walking exercise regime, and vigilance to evaluate post-exercise neurotoxic conditions. These might be the unmet needs of this research area and in clinical practice. Assessing and addressing individualized endeavors in a walking exercise regime will continue to be a vital component of cancer supportive care to fill the unmet information needs in survivorship.

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 (Mage = 30.8 ± 6.0 years; 87.5% female; Myears 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.

BDNF Augmentation Using Riluzole Reverses Doxorubicin-Induced Decline in Cognitive Function and Neurogenesis

Cancer-related cognitive impairment (CRCI) considerably affects the quality of life of millions of cancer survivors. Brain-derived neurotrophic factor (BDNF) has been shown to promote survival, differentiation, and maintenance of in vivo dentate neurogenesis, and chemotherapy induces a plethora of physiological and cellular alterations, including a decline in neurogenesis and increased neuroinflammation linked with cognitive impairments. In our clinical studies, breast cancer patients treated with doxorubicin (Adriamycin®, ADR) experienced a significant reduction in the blood levels of BDNF that was associated with a higher risk of CRCI. Our past rodent studies in CRCI have also shown a significant reduction in dentate neurogenesis accompanied by cognitive impairment. In this study, using a female mouse model of ADR-induced cognitive decline, we tested the impact of riluzole (RZ), an orally active BDNF-enhancing medication that is FDA-approved for amyotrophic lateral sclerosis. ADR-treated mice receiving RZ in the drinking water for 1 month showed significant improvements in hippocampal-dependent learning and memory function (spatial recognition), fear extinction memory consolidation, and reduced anxiety-like behavior. RZ prevented chemotherapy-induced reductions of BDNF levels in the hippocampus. Importantly, RZ mitigated chemotherapy-induced loss of newly born, immature neurons, dentate neurogenesis, and neuroinflammation. In conclusion, this data provides pre-clinical evidence for a translationally feasible approach to enhance the neuroprotective effects of RZ treatment to prevent CRCI.

Cognitive impairment in adolescent and young adult cancer patients: Pre-treatment findings of a longitudinal study

BACKGROUND

There is little information about cancer-related cognitive impairment (CRCI) in adolescent and young adults (AYA, 15-39 years old) due to its rare incidence. Here, we present the pre-treatment (before chemotherapy or radiotherapy) evaluation of cognitive function and ability of AYA with cancer (AYAC) in a multicentered cohort study.

METHODS

Newly diagnosed AYAC and age-matched healthy controls (HC) were recruited between 2018 and 2021. The primary outcome was the comparison of pre-treatment cognitive impairment defined as 2 standard deviations (SDs) below the HC on ≥1 cognitive test, or >1.5 SDs below on ≥2 tests using CANTAB® between AYAC and HC. Secondary outcomes included self-perceived cognitive ability assessed by FACT-Cog v3 and biomarkers (inflammatory cytokines and brain-derived neurotrophic factor [BDNF]).

RESULTS

We recruited 74 AYAC (median age = 34) and 118 HC (median age = 32). On objective cognitive testing, we observed three times more AYAC patients performed poorly on at least 2 cognitive tests compared to HC (40.5% vs. 13.6%, p < 0.001). AYAC self-perceived less degree of cognitive impairment than HC (p < 0.001). However, AYAC perceived a greater impact of cognitive changes on their quality of life compared to HC (p = 0.039). Elevated baseline inflammatory markers (IL-2, IL-4, IL-6, IL-8, IL-10 and IFN-γ) were observed among AYAC compared to HC, and baseline BDNF was lower in AYAC compared to HC. Interaction effects between cancer diagnosis and biomarkers were observed in predicting cognitive function.

CONCLUSION

With the pre-existence of CRCI and risk factors of neuroinflammation even prior to systemic therapy, AYAC should receive early rehabilitation to prevent further deterioration of cognitive function after initiation of systemic therapies. (ClinicalTrials.gov Identifier: NCT03476070).

BDNF and its signaling in cancer

PURPOSE

Brain-derived neurotrophic factor (BDNF) belongs to the family of neurotrophic factors that can potentially increase cancer cell growth, survival, proliferation, anoikis, and migration by tyrosine kinase receptors TrkB and the p75NTR death receptor. The activation of BDNF/TrkB pathways leads to several downstream signaling pathways, including PI3K/Akt, Jak/STAT, PLCγ, Ras-Raf-MEK-ERK, NF-kB, and transactivation of EGFR. The current review aimed to provide an overview of the role of BDNF and its signaling in cancer.

METHODS

We searched a major medical database, PubMed, to identify eligible studies for a narrative synthesis.

RESULTS

Pathological examinations demonstrate BDNF overexpression in human cancer, notably involving the prostate, lung, breast, and underlying tissues, associated with a higher death rate and poor prognosis. Therefore, measurement of BDNF, either for identifying the disease or predicting response to therapy, can be helpful in cancer patients. Expression profiling studies have recognized the role of microRNAs (miR) in modulating BDNF/TrkB pathways, such as miR-101, miR-107, miR-134, miR-147, miR-191, miR-200a/c, miR-204, miR-206, miR-210, miR-214, miR-382, miR-496, miR-497, miR-744, and miR-10a-5p, providing a potential biological mechanism by which targeted therapies may correlate with decreased BDNF expression in cancers. Clinical studies investigating the use of agents targeting BDNF receptors and related signaling pathways and interfering with the related oncogenic effect, including Entrectinib, Larotrectinib, Cabozantinib, Repotrectinib, Lestaurtinib, and Selitrectinib, are in progress.

CONCLUSION

The aberrant signaling of BDNF is implicated in various cancers. Well-designed clinical trials are needed to clarify the BDNF role in cancer progression and target it as a therapeutic method.

Effect of Light Therapy on Cancer-Related Fatigue: A Systematic Review and Meta-Analysis

CONTEXT

Light therapy is a non-pharmacological therapy that is currently being studied in cancer-related symptoms and is certificated as a low-risk intervention by FDA. Cancer-related fatigue (CRF) is the most common symptom reported by cancer patients.

OBJECTIVE

To examine the effectiveness of light therapy for CRF in cancer patients through a systematic review and meta-analysis.

METHODS

We conducted a systematic review of four electronic databases targeted randomized clinical trials evaluating light therapy for CRF (CRD42020215446), from inception to May 2021. The primary outcome was changes of CRF scores; secondary outcomes included depression, sleep, and quality of life (QoL). We quantitatively pooled outcomes using meta-analysis with random-effects models and assessed methodological bias.

RESULTS

We identified thirteen RCTs representing 551 cancer patients, encompassing breast (n = 5), ovarian or endometrial (n = 1), multiple myeloma (n = 1), lung (n = 1), or combined (n = 5) cancers. The comparison groups included dim light (n = 12) and waiting list (n = 1). Duration of intervention ranged from 1 to 12 weeks. Light intensities ranged from 417.9 to 12,000 lux. Light therapy was associated with a significant improvement in CRF (SMD = 0.45, P = 0.007), depression (SMD = -0.26, P = 0.03) and sleep difficulty (SMD = -2.46, P = 0.0006); a statistically non-significant trend was observed for QoL (SMD = 0.33, P = 0.09). Funnel plots for CRF suggest not significant publication bias.

CONCLUSION

Light therapy could be a feasible and effective option for improving CRF in cancer patients. Larger sample, rigor trials design and a standard protocol of intervention are needed to draw more conclusive conclusions.

Chemotherapy-related cognitive impairment (CRCI) among early-stage breast cancer survivors in Malaysia

Introduction: Breast cancer survivors frequently develop cognitive impairment following chemotherapy which can significantly hamper their well-being, ability to function independently, and overall quality of life. Evidence of cognitive functioning in breast cancer survivors from lower and middle-income countries remains scarce. We examined the prevalence of cognitive impairment among Malaysian multiethnic early-stage breast cancer survivors one to three years post-chemotherapy.Methods: This cross-sectional study included 160 breast cancer survivors from the University Malaya Medical Center (UMMC). The cognitive assessments used included the Montreal Cognitive Assessment (MoCA-BM), the Rey Auditory and Verbal Learning Test (RAVLT-BM), and the digit span and arithmetic of the Working Memory Index (WMI) of Wechsler Adult Intelligence Scale-IV (WAIS-IV). Data were analyzed using independent sample t-tests and Pearson's correlation.Results: Our breast cancer survivors demonstrated poor performances in MoCA-BM (31.9%) RAVLT-BM, recall (53.8%), and WMI of WAIS-IV (51.3%) with 30.6% of them performed poorly in all three cognitive tests administered. There were no significant mean group differences in cognitive performances between <24 months after chemotherapy and ≥24 months after chemotherapy.Conclusions: A high proportion of breast cancer survivors exhibited poor performances in the cognitive assessments. Cognitive rehabilitation programmes tailored to the needs of these survivors should be incorporated into cancer care management.

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

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

Cognitive Perception among Post-Chemotherapy, Non-Chemotherapy Breast Cancer Survivors and Non-Cancer

Objective:

This study aims to compare the cognitive function perceived by post-chemotherapy breast cancer survivors, breast cancer survivors without chemotherapy, and non-cancer woman patients.

Methods:

This study was conducted by a descriptive comparative method. The respondents consisted of 82 survivors of post-chemotherapy breast cancer, 81 non-chemotherapy breast cancer survivors, and 80 non-cancer woman patients who were recruited using consecutive sampling. The data were collected from October until December 2017 by using a FACT-Cog version 3 questionnaire. Data analysis was performed by using a comparative test of Kruskal-Wallis followed by a Mann-Whitney posthoc analysis.

Results:

The results showed that the median of cognitive function perception in breast cancer survivors post-chemotherapy, non-chemotherapy, and non-cancerous women are 94 (52-122), 113 (53-130), and 121 (69-132), respectively. Mann-Whitney’s post-hoc analysis showed a significantly different perception of cognitive function between post-chemotherapy survivors and non-chemotherapy survivors; also between post-chemotherapy survivors and non-cancer women, and between non-chemotherapy survivors with non-cancer women.

Conclusion:

Perceived cognitive impairment, comments from others, perceived cognitive abilities, and effects on quality of life in breast cancer survivors who received chemotherapy are significantly different as compared to the survivor group without chemotherapy and non-cancerous healthy women.

Extracellular Vesicle Proteome of Breast Cancer Patients with and Without Cognitive Impairment Following Anthracycline-based Chemotherapy: An Exploratory Study

Cognitive impairment due to cancer and its therapy is a major concern among cancer patients and survivors. Extracellular vesicle (EVs) composition altered by cancer and chemotherapy may affect neurological processes such as neuroplasticity, potentially impacting the cognitive abilities of cancer patients and survivors. We investigated the EV proteome of breast cancer patients with and without cognitive impairment following anthracycline-based chemotherapy from longitudinally collected plasma. EVs were cup-shaped and positive for Flotillin-1 and TSG-101. We identified 517 differentially expressed EV proteins between the cognitive impaired and non-impaired groups during and post-chemotherapy. The observed decreased expression of p2X purinoceptor, cofilin-1, ADAM 10, and dynamin-1 in the plasma EVs of the cognitive impaired group may suggest alterations in the mechanisms underlying synaptic plasticity. The reduced expression of tight junction proteins among cognitive-impaired patients may imply weakening of the blood-brain barrier. These EV protein signatures may serve as a fingerprint that underscores the mechanisms underlying cognitive impairment in cancer patients and survivors.

Attention Dysregulation in Breast Cancer Patients Following a Complementary Alternative Treatment Routine: A Double-Blind Randomized Trial

Introduction:

Breast cancer patients and survivors frequently report fatigue, emotional, and cognitive disturbances, which reduce performance at all levels of occupation and make life quality issues a considerable clinical concern. The aim of this study is to evaluate attention and emotion regulation across radiotherapy period and the possible effects of complementary alternative medicine (CAM).

Methods:

Fifty-seven patients with unilateral breast cancer underwent surgery and systemic chemotherapy before participating in this double-blind randomized study. Two thirds were given CAM (n = 38) while the rest received placebo (carrier only, n = 19). Patients’ attention and anxiety were physiologically tested at baseline, 2 and 4 weeks during the radiation period as well as 1-month after the end of radiation session.

Results:

Both groups showed similar levels of anxiety with no significant differences at baseline nor post-radiotherapy. Long-term significant recovery of attention performance was observed in the CAM patients, accompanied by a similar tendency in anxiety level, measured by the eye-blink probability.

Conclusions:

This study physiologically validates the attention impairment reported among breast cancer survivors; also, it depicted a beneficial late-effect of a routine CAM on attention dysregulation. The suggested non-invasive physiological measures can physiologically monitor patients’ psychological and cognitive well-being as well as evaluate the beneficial effect of CAM in breast cancer patients by assessing their coping ability to support the treatment plan. Thus, the results have potential clinical implications on patients’ and survivors’ quality of life.

Trial Registration:

NIH, NCT02890316. Registered July 2016, http://www.ClinicalTrials.gov

Suffering experiences of people with cancer undergoing chemotherapy: A meta-ethnographic study

This meta-ethnography had the objectives of identifying, evaluating, and summarizing the findings of qualitative studies regarding the suffering experiences of people undergoing chemotherapy, as well as developing an explanatory conceptual structure regarding what affects these experiences. A systematic literature review was carried out, covering the past 10 years, in the following databases: CINAHL, Embase, Medline, LILACS and Scopus. By using meta-ethnographic synthesis methods, the following themes were found: the pain of loss; evaluating, measuring, and neutralizing the threat; and social contours of suffering. The experience of living with cancer and undergoing chemotherapy was synthesized into a theoretical-explanatory model with a structure that resembles barbed-wire loops. The model expresses people's suffering experiences as marked by the feeling of loss, restraint of emotions, and resilience. While transcendent movements broke the cycle of suffering, resilience emerged as a learning experience that made patients more resistant to the pain of loss. The results indicated a complex and diverse set of factors that influence suffering, which confirmed that experiences are individual, comprehensive, and continuously reinterpreted.

Effects of brief acceptance and commitment therapy (ACT) on subjective cognitive impairment in breast cancer patients undergoing chemotherapy

PURPOSE

This study examined the efficacy of a brief acceptance and commitment therapy (ACT) on subjective cognitive impairment in breast cancer patients undergoing chemotherapy.

METHODS

Data collection was carried out in 3-time points: baseline (T1), screening (T2), and post-treatment (T3). Respondents who had significant subjective cognitive impairment were randomly divided into two groups: intervention (n = 30) and waitlist (n = 30). Respondents in the intervention group received 4 sessions of 1 hour of ACT therapy.

FINDINGS

Respondents in the intervention group showed significant improvement in subjective cognitive impairment, depression, anxiety, and psychological inflexibility after the ACT intervention (p < 0.05). After controlling the covariates, group differences in all variables were significant except for fatigue and psychological inflexibility has the highest effect size (d = 4.69).

CONCLUSION

ACT could be considered as an effective intervention to ameliorate subjective cognitive impairment, anxiety, depression, and psychological inflexibility in breast cancer patients undergoing chemotherapy.

IMPLICATIONS FOR PSYCHOSOCIAL PROVIDERS

This study highlights the importance of screening for subjective cognitive impairment in breast cancer patients undergoing chemotherapy and heightens their opportunity to receive proper management as earlier as possible.

A Cross-Sectional Exploration of Cytokine-Symptom Networks in Breast Cancer Survivors Using Network Analysis

PURPOSE

The purpose of this study is to (a) visualize the symptom-cytokine networks (perceived stress, fatigue, loneliness, perceived cognitive impairment, daytime sleepiness, sleep quality, and 13 cytokines) and (b) explore centrality metrics of symptom-cytokine networks in breast cancer survivors who completed chemotherapy treatment.

METHODS

Cross-sectional analysis of data collected from 66 breast cancer survivors who were on average three years post chemotherapy completion. Perceived stress, fatigue, loneliness, perceived cognitive impairment, daytime sleepiness, and sleep quality were measured with self-report instruments, and a panel of 13 cytokines was measured from serum using multiplex assays. Symptoms and cytokines were simultaneously evaluated with correlations, network analysis, and community analysis.

RESULTS

Network analysis revealed the nodes with the greatest degree and closeness were interleukin-2, granulocyte-macrophage colony-stimulating factor, interleukin-13, and perceived cognitive impairment. Node betweenness was highest for perceived cognitive impairment and interleukin-2. Community analysis revealed two separate communities of nodes within the network (symptoms and the cytokines). Several edges connected the two communities including perceived cognitive impairment, stress, fatigue, depression, interleukin-2, granulocyte-macrophage colony-stimulating factor, interleukin-8, interleukin-13, and interleukin-10. Partial correlation analyses revealed significant negative relationships between interleukin-2 and fatigue, loneliness, stress, and perceived cognitive impairment (rs = -.27 to -.37, ps < .05) and a significant negative relationship between perceived cognitive impairment and granulocyte-macrophage colony-stimulating factor (r = -.34, p < .01).

CONCLUSIONS

Our analyses support that perceived cognitive impairment, stress, loneliness, depressive symptoms, and fatigue co-occur and extend the literature by suggesting that interleukin-2 may contribute to the underlying mechanistic pathway of these co-occurring symptoms. Our findings add to a growing body of literature that is shifting to study symptoms as they co-occur, or cluster, rather than individual symptoms.

Meta-Analysis of the Efficacy of Virtual Reality-Based Interventions in Cancer-Related Symptom Management

Background. This meta-analysis summarizes the results from recent studies that examined the use of virtual reality (VR)–based interventions on health-related outcomes in patients with cancer, and quantitatively evaluates the efficacy of VR-based interventions. Findings of this meta-analysis can provide direction for future symptom management research. Methods. The search terms included a combination of “virtual reality” OR “virtual environment” OR “head-mounted display” with “oncology” OR “cancer.” Three databases (Medline, PubMed, and CAJ Full-text Database), one search engine (Google Scholar), and the website of ResearchGate, covering the period from December 2013 to May 15, 2019, and including articles published in both English and Chinese, were searched. Data synthesis used the RevMan 5.3 to generate pooled estimates of effect size. Results. A total of 6 empirical studies met the eligibility criteria. VR-based interventions had statistically significant effects on reducing symptoms of anxiety, depression, pain, and cognitive function, whereas statistically significant benefit was observed for fatigue (Z = 2.76, P = .006). Conclusion. Most recent studies have primarily examined VR-based interventions for symptom management in the acute stages of cancer care. However, the management of late and long-term side effects is central to cancer survivorship care. There is burgeoning empirical support for further research to evaluate the efficacy of VR-based interventions in cancer rehabilitation.

Role of Exosomes in Cancer-Related Cognitive Impairment

A decline in cognitive function following cancer treatment is one of the most commonly reported post-treatment symptoms among patients with cancer and those in remission, and include memory, processing speed, and executive function. A clear understanding of cognitive impairment as a result of cancer and its therapy can be obtained by delineating structural and functional changes using brain imaging studies and neurocognitive assessments. There is also a need to determine the underlying mechanisms and pathways that impact the brain and affect cognitive functioning in cancer survivors. Exosomes are small cell-derived vesicles formed by the inward budding of multivesicular bodies, and are released into the extracellular environment via an exocytic pathway. Growing evidence suggests that exosomes contribute to various physiological and pathological conditions, including neurological processes such as synaptic plasticity, neuronal stress response, cell-to-cell communication, and neurogenesis. In this review, we summarize the relationship between exosomes and cancer-related cognitive impairment. Unraveling exosomes’ actions and effects on the microenvironment of the brain, which impacts cognitive functioning, is critical for the development of exosome-based therapeutics for cancer-related cognitive impairment.

Understanding on the association between informal caregiver characteristics and cognitive function of adults with cancer: a scoping review protocol

INTRODUCTION

Adults with cancer frequently report symptoms such as decline in cognitive function throughout the trajectory of illness. Patients with cognitive deficits need support and assistance from their informal caregivers and often rely on them to manage their symptoms based on their degree of deficits. Patients spend a significant amount of time with their informal caregivers and become interdependent with each other. In spite of their interdependence, it is unclear whether patients' cognitive outcomes (ie, cognitive function) are associated with their informal caregivers. Therefore, the body of literature related to the association between caregiver characteristics and cognitive function of adults with cancer needs to be fully mapped with assessment for knowledge gaps.

METHODS AND ANALYSIS

Methods for this scoping review was informed by the framework proposed by Arksey and O'Malley. Seven electronic databases will be searched: (1) PubMed (MEDLINE), (2) CINAHL, (3) Embase, (4) PsycINFO, (5) Scopus, (6) Sociological Abstracts and (7) ProQuest dissertation abstracts. In addition, the search for grey literature will include the conference abstracts available through Embase, Scopus and Sociological abstracts as well as dissertations available in ProQuest dissertations. All retrieved citations will be independently screened by two authors and eligibility will be determined based on inclusion and exclusion criteria at title and abstract level. Studies meeting inclusion criteria, will be screened at full text level by two reviewers followed by abstraction of included studies. Eligible studies will be collated, summarised and reported using the data charting form that research team developed.

ETHICS AND DISSEMINATION

This scoping review does not require ethics approval. Results of this scoping review will be disseminated via conference presentation and/or publication in a scientific journal.

Verbal Learning and Memory Function and the Influencing Factors on Breast Cancer Survivors: A Cross-Sectional Study

Impairment of cognitive function is a common complaint by post-chemotherapy breast cancer survivors, specifically impairment of verbal learning and memory. The objective of this study was to identify the association between age, duration of education, chemotherapy type, hormone therapy usage, menopausal status, sleep quality, fatigue, stress, and hemoglobin (Hb) levels to memory and verbal learning function. This cross-sectional study consisted of 82 post-chemotherapy breast cancer survivors, 81 non-chemotherapy survivors, and 80 non-cancer female patients in two hospitals. The data were collected using the Hopkins Verbal Learning Test in Indonesian, Pittsburgh Sleep Quality Index, 10-item Perceived Stress Scale, and the Piper Fatigue Scale-12. All instruments were already adopted into Indonesian. Characteristic data were obtained from hospital reports. The mean age of the respondents was 43.06 (8.18) years, 197 (81.1%) had been educated for ≤12 years, 82 (33.7%) were post-chemotherapy survivors, 46 (18.9%) were using hormonal therapy, and 125 (51.4%) had gone through menopause. Among the remaining respondents, 91 (37.4%) were anemic, 124 (51.0%) had poor sleep quality, and 115 (47.3%) experienced moderate fatigue. Twenty-one (25.6%) of post-chemotherapy survivors had a high possibility of having dementia. The significant variables associated with memory and verbal learning function included age, stress, survivor type, chemotherapy category, sleep quality, and fatigue. The insignificant variables included the length of education, hormone therapy usage, menopausal status, and hemoglobin levels. A logistic regression analysis showed that stress was the most influential variable with an odds ratio of 1.159. It is recommended that nurses consider the significant variables when providing services to post-chemotherapy breast cancer survivors.

Replication and Meta-analysis of the Association between BDNF Val66Met Polymorphism and Cognitive Impairment in Patients Receiving Chemotherapy

Cancer-related cognitive impairment (CRCI) adversely affects cancer patients. We had previously demonstrated that the BDNF Val66Met genetic polymorphism is associated with lower odds of subjective CRCI in the multitasking and verbal ability domains among breast cancer patients receiving chemotherapy. To further assess our previous findings, we evaluated the association of BDNF Val66Met polymorphism with subjective and objective CRCI in a temporally separate cohort of patients and pooled findings from both the original (n = 145) and current (n = 193) cohorts in a meta-analysis. Subjective CRCI was assessed using FACT-Cog. Objective CRCI was evaluated using computerized neuropsychological tests. Genotyping was carried out using Sanger sequencing. The association of BDNF Val66Met genotypes and CRCI was examined with logistic regression. A fixed-effect meta-analysis was conducted using the inverse variance method. In the meta-analysis (n = 338), significantly lower odds of CRCI were associated with Met allele carriers based on the global FACT-Cog score (OR = 0.52, 95% CI 0.29–0.94). Furthermore, Met allele carriers were at lower odds of developing impairment in the domains of memory (OR = 0.34, 95% CI: 0.17–0.70), multitasking (OR = 0.33, 95% CI: 0.18–0.59), and verbal ability (OR = 0.46, 95% CI: 0.24–0.88). Consistent with the previous study, lower odds of subjective CRCI among patients with the BDNF Met allele was observed after adjusting for potential confounders in the multitasking (OR = 0.30, 95% CI: 0.14–0.67) domain. In conclusion, carriers of the BDNF Met allele were protected against global subjective CRCI, particularly in the domains of memory, multitasking, and verbal ability. Our findings further contribute to the understanding of CRCI pathophysiology.

How to Identify and Manage Cognitive Dysfunction After Breast Cancer Treatment

Attention and memory dysfunction is a common complaint among patients with breast cancer that can be reported during and up to several years after treatment. It can negatively affect patients' quality of life and their ability to work. This phenomenon has mainly been studied in patients with breast cancer who are treated with adjuvant chemotherapy. Women describe concentration problems and difficulties with word finding, multitasking, or remembering new information, as well as more effort and time needed to accomplish these tasks. Such cognitive dysfunction is subtle or moderate and occurs in 15% to 25% of patients. Older patients seem more likely to experience cognitive decline with chemotherapy than do young women with breast cancer. Patients who report that cognitive dysfunction has affected their daily lives for 6 to 12 months after the end of chemotherapy or during hormone therapy may need referral to a neuropsychologist. During the cognitive assessment, the etiology of their cognitive complaints is sought and neuropsychological tests are administered to assess objective cognitive functioning. Psychological factors-fatigue and pain-should be assessed systematically with cognitive complaints to identify precisely the cause of the problems. A nonpharmacologic approach-mainly cognitive rehabilitation-seems to be the most promising for the management of these difficulties, but these preliminary results require confirmation. In the future, early detection of cognitive impairment and cognitive rehabilitation should be included in the portfolio of oncology supportive care to facilitate the return to work of young women and to avoid potential repercussions on adherence to oral treatments and on autonomy in older patients.

A train the trainer program for healthcare professionals tasked with providing psychosocial support to breast cancer survivors

BACKGROUND

The objective of this study is to develop, implement, and evaluate a training program for healthcare providers to improve ability to provide psychosocial support to breast cancer survivors in Korea.

METHODS

Based on a needs assessment survey and in-depth interviews with breast cancer survivors, a multidisciplinary team developed two-day intensive training program as well as education materials and counseling notes. Participants' overall satisfaction was evaluated after the training.

RESULTS

The training program included a total of 16 lectures held over the course of seven sessions. Forty-one nurses and 3 social workers participated in the training program. Mean age was 37.5(± 6.4) years, and on average, they had 11.1 (± 5.6) years of experience. Participants' overall satisfaction was good as following: program contents (4.04), trainee guidebook (3.82), location and environment (4.10), and program organization (4.19). Among the participants, 31 (70.4%) received certification after submitting real consultation cases after the training.

CONCLUSION

Two day intensive training can provide a comprehensive and coordinated education to healthcare professionals for implementing survivorship care with an emphasis on psychosocial support. Furthermore, the program should resume as a periodic continuing education course for healthcare providers. Similar education for graduate students in oncology nursing would be beneficial.

Evaluation of plasma brain-derived neurotrophic factor levels and self-perceived cognitive impairment post-chemotherapy: a longitudinal study

Background

Preliminary evidence suggests that changes in plasma brain-derived neurotrophic factor (BDNF) levels may contribute to the occurrence of chemotherapy-associated cognitive impairment (CACI), and a previous study suggested that carriers of the BDNF Met homozygous genotype are protected from CACI.

Methods

This multicenter, prospective cohort study involved chemotherapy-receiving early-stage breast cancer (ESBC) patients. Self-perceived cognitive function was longitudinally assessed using the validated FACT-Cog (ver. 3) across three time points: Prior to chemotherapy (T1), during chemotherapy (T2), and at the end of chemotherapy (T3). Plasma BDNF levels were quantified using enzyme-linked immunosorbent assay. Genotyping was performed using Sanger Sequencing.

Results

A total of 51 chemotherapy-receiving ESBC patients (mean age: 52.6 ± 9.5 years) were recruited, and 11 patients (21.6%) reported subjective cognitive impairment post-chemotherapy. Overall, there was a reduction in median plasma BDNF levels over time (T1: 5423.0 pg/ml; T2: 5313.6 pg/ml; T3: 4050.3 pg/ml; p < 0.01). After adjusting for confounding factors, longitudinal analysis revealed that BDNF levels were associated with self-reported concentration deficit (p = 0.032). Carriers of Val/Val (p = 0.011) and Val/Met (p = 0.003) BDNF genotypes demonstrated a significant reduction in plasma BDNF levels over time; however, plasma BDNF levels were similar across all time points among Met homozygous carriers (p = 0.107).

Conclusion

There was a statistically significant change in BDNF levels post-chemotherapy in ESBC patients, and plasma BDNF levels were associated with self-perceived concentration deficit in patients receiving chemotherapy.

Modifiable correlates of perceived cognitive function in breast cancer survivors up to 10 years after chemotherapy completion

BACKGROUND

Cognitive changes following breast cancer treatment are likely multifactorial and have been linked to emotional factors, biophysiological factors, and fatigue, among others. Little is known about the contributions of modifiable factors such as stress, loneliness, and sleep quality. The purpose of this study was to explore the direct and indirect effects of perceived stress, loneliness, and sleep quality on perceived cognitive function (PCF) in breast cancer survivors (BCS) after chemotherapy completion.

METHODS

In this observational study, BCS 6 months to 10 years post chemotherapy were recruited from the community. We measured perceived stress, loneliness, sleep quality, anxiety, depression, fatigue, and PCF. Data analyses included descriptive statistics, correlations, and mediation analyses utilizing ordinary least square regression.

RESULTS

Ninety women who were on average 3 years post chemotherapy completion participated in the study. Moderate to largely negative correlations were found between PCF and the psychosocial and sleep variables (r values ranged from - 0.31 to - 0.70, p values < .0009). Mediation analyses revealed that stress and daytime sleepiness both directly and indirectly impact PCF and that loneliness and sleep quality only have indirect effects (through anxiety and fatigue).

CONCLUSION

Our findings suggest that perceived cognitive changes following breast cancer treatment are multifactorial and that higher stress levels, loneliness, daytime sleepiness, and poorer sleep quality are linked to worse perceived cognitive functioning. Also, stress, loneliness, and sleep quality may affect cognitive functioning through a shared psychobiological pathway.

IMPLICATIONS FOR CANCER SURVIVORS

Interventions targeting stress, loneliness, and sleep quality may improve perceived cognitive functioning in breast cancer survivors.

Title: Cervical cancer survivors' perceived cognitive complaints and supportive care needs in mainland China: a qualitative study

OBJECTIVES

This study explores Chinese cervical cancer survivors' perceived cognitive complaints and relevant supportive care needs after primary cancer treatment.

DESIGN

This study utilised a qualitative research design. A semi-structured interview was used to probe cervical cancer patients' perceived cognitive complaints and supportive care needs.

SETTING

This study was conducted at a secondary cancer care centre located in South China.

PARTICIPANTS

31 women with cervical cancer after primary cancer treatment, aged 18-60 years, were purposively selected using non-random sampling procedures.

RESULTS

31 cervical cancer survivors joined this study. Of these, 20 women (64.5%) reported cognitive complaints after cancer treatment. The most common complaint was loss of concentration (n=17, 85.0%). Perceived contributing factors to these cognitive complaints included chemotherapy (n=15, 75.0%) and ageing (n=8, 40.0%). These cognitive problems most commonly impacted daily living (n=20, 100%). Common supportive care needs included symptom management strategies (n=11, 55.0%) and counselling services (n=8, 40.0%).

CONCLUSION

This study adds new insight into the growing body of research on cognitive complaints by cancer survivors, in particular Chinese cervical cancer survivors. Improved understanding of cognitive complaints could subsequently facilitate the development of relevant therapeutic interventions for prevention as well as the provision of supportive care services, such as educational and counselling services, to reduce cognitive impairment in women with cervical cancer.

Perceptions and Barriers of Survivorship Care in Asia: Perceptions From Asian Breast Cancer Survivors

Purpose

With the long-term goal to optimize post-treatment cancer care in Asia, we conducted a qualitative study to gather in-depth descriptions from multiethnic Asian breast cancer survivors on their perceptions and experiences of cancer survivorship and their perceived barriers to post-treatment follow-up.

Methods

Twenty-four breast cancer survivors in Singapore participated in six structured focus group discussions. The focus group discussions were voice recorded, transcribed verbatim, and analyzed by thematic analysis.

Results

Breast cancer survivors were unfamiliar with and disliked the term “survivorship,” because it implies that survivors had undergone hardship during their treatment. Cognitive impairment and peripheral neuropathy were physical symptoms that bothered survivors the most, and many indicated that they experienced emotional distress during survivorship, for which they turned to religion and peers as coping strategies. Survivors indicated lack of consultation time and fear of unplanned hospitalization as main barriers to optimal survivorship care. Furthermore, survivors indicated that they preferred receipt of survivorship care at the specialty cancer center.

Conclusion

Budding survivorship programs in Asia must take survivor perspectives into consideration to ensure that survivorship care is fully optimized within the community.

Assessment of mental health literacy in patients with breast cancer

INTRODUCTION

Psychosocial distress is often underdiagnosed and undertreated among breast cancer patients due to the poor recognition of the associated symptoms and inadequate knowledge of the treatments available.

OBJECTIVE

To evaluate the mental health literacy of breast cancer patients by assessing (1) their ability to recognize the symptoms of anxiety, fatigue, depression, and cognitive disturbances, and (2) their knowledge of help-seeking options and professional treatments.

METHODS

In this multi-center, cross-sectional study, early-stage breast cancer patients receiving chemotherapy underwent four assessments to measure their levels of anxiety, depression, fatigue, and cognitive disturbances. With the aid of cancer-specific vignettes, a questionnaire was administered to evaluate their mental health literacy.

RESULTS

Fifty-four patients were recruited (77.7% Chinese, aged 52.7 ± 8.5 years). Clinically significant anxiety (15.1%), fatigue (27.8%), and cognitive disturbances (25.9%) were more prevalent than depression (5.6%). Although the majority of the patients could recognize the symptoms of fatigue accurately (75.9%), less than half could identify those of anxiety (35.2%), depression (48.1%), and cognitive disturbances (48.1%). Patients were more receptive to help from their family members (score: 3.39 out of 4.00) and oncologists (score: 3.13) than from other mental health specialists, such as psychiatrists (score: 2.26) and psychologists (score: 2.19) in the management of their psychosocial distress. Approximately half of the patients indicated that embarrassment and fear were their main barriers to seeking professional treatment (55.6%).

CONCLUSIONS

Our results suggest that the mental health literacy of breast cancer patients was inadequate. Intervention and management strategies could be implemented to teach these patients about evidence-based treatments and professional help that are specific to mental disorders.

Systematic review of pharmacologic and non-pharmacologic interventions to manage cognitive alterations after chemotherapy for breast cancer

PURPOSE

Cognitive alterations are reported in breast cancer patients receiving chemotherapy. This has adverse effects on patients' quality of life and function. This systematic review investigates the effectiveness of pharmacologic and non-pharmacologic interventions to manage cognitive alterations associated with breast cancer treatment.

METHODS

Medline via EBSCO host, CINAHL and Cochrane CENTRAL were searched for the period January 1999-May 2014 for prospective randomised controlled trials related to the management of chemotherapy-associated cognitive alterations. Included studies investigated the management of chemotherapy-associated cognitive alterations and used subjective or objective measures in patients with breast cancer during or after chemotherapy. Two authors independently extracted data and assessed the risk of bias.

RESULTS

Thirteen studies involving 1138 participants were included. Overall, the risk of bias for the 13 studies was either high (n=11) or unclear (n=2). Pharmacologic interventions included psychostimulants (n=4), epoetin alfa (n=1) and Ginkgo biloba (n=1). Non-pharmacologic interventions were cognitive training (n=5) and physical activity (n=2). Pharmacologic agents were ineffective except for self-reported cognitive function in an epoetin alfa study. Cognitive training interventions demonstrated benefits in self-reported cognitive function, memory, verbal function and language and orientation/attention. Physical activity interventions were effective in improving executive function and self-reported concentration.

CONCLUSION

Current evidence does not favour the pharmacologic management of cognitive alterations associated with breast cancer treatment. Cognitive training and physical activity interventions appear promising, but additional studies are required to establish their efficacy. Further research is needed to overcome methodological shortfalls such as heterogeneity in participant characteristics and non-standardised neuropsychological outcome measures.

Chemobrain experienced by breast cancer survivors: a meta-ethnography study investigating research and care implications

BACKGROUND

Cognitive impairment, colloquially termed "chemobrain", occurs in 10-40% of all cancer patients, and is an emerging target of cancer survivorship research.

AIM

This study reviews published qualitative studies to explore cognitive impairments or chemobrain among breast cancer survivors, with particular attention given to the impact on quality of life.

METHOD

Using keywords, we searched ten electronic databases (CINAHL, EMBASE, Proquest, OVID SP, MEDLINE, Oxford Journal, Science Direct, PubMED).

FINDINGS

Of 457 papers, seven relevant papers were included. Data was extracted and concepts were analysed using a meta ethnography approach. Four second order intepretations were identified, on the basis of which, four third order intrepretations were constructed. Linked together in a line of argument, was a consistent account on their struggles to self-manage the chemobrain impairments that impact their daily lives. Five concepts emerged from the analysis of the primary findings: i) real experiences of cognitive changes, ii) calls for help, iii) impact of cognitive impairments, iv) coping and v) survivorship and meaning. Further synthesis resulted in four new order intepretations: i) The chemobrain struggle, ii) The substantial impact of chemobrain on life domains, iii) The struggle to readjust and to self manage, and iv) 'thankful yet fearful' representation.

DISCUSSION

Awareness of cognitive changes were context-dependent on healthcare settings and cultural contexts as strong determinants. Subjects verified the existence of chemobrain but healthcare providers mis-recognised, under-recognised, and sometimes negated it perhaps due to its unknown aetiology. Asian breast cancer survivors appear less vocal than their western counterparts.

CONCLUSION

The current literature on the lived experiences of how women experienced chemobrain provides a consistent report that chemobrain is real, persistent and with detrimental impacts on quality of life - manifested as a constant struggles. A greater awareness of the effects of chemobrain with improved functional assessment and interventions is warranted.

Cytokines as mediators of chemotherapy-associated cognitive changes: current evidence, limitations and directions for future research

Objectives

While various clinical and pharmacological determinants for chemotherapy-associated cognitive impairment have been identified, conflicting evidence suggests that cytokines might play an intermediary role. The objective of this systematic review was to evaluate the current evidence pertaining to the associations among chemotherapy, cytokines induction and cognitive impairment in cancer patients.

Methods

A literature search with PubMed and SciVerse Scopus was conducted in March 2013 to gather relevant articles and abstracts that fulfilled the inclusion and exclusion criteria. This review included studies that had performed objective and/or subjective cognitive assessments and cytokine measurements on defined populations of cancer patients who received chemotherapy.

Results

High methodological heterogeneity existed among the selected studies which differed in cancer populations, subject characteristics, cognitive endpoints, types of cytokines tested and their measurement methods. Weak to moderate correlations were observed between IL-1β, IL-6, TNF-α levels, and different degrees of cognitive impairment. Different types of chemotherapy treatments might lead to varying presentations and severities of cytokine-induced cognitive impairment. Notably, the time concordance between the onset of cytokine induction and occurrence of cognitive impairment was not well elucidated. A number of confounding factors was identified to interfere with the expression levels of cytokines; these confounders included subjects' cancer types, ages, genders, genetics and psychosocial characteristics such as anxiety, depression and fatigue.

Conclusion

Although existing studies observed cognitive impairment and cytokine dysregulation in patients who receive chemotherapy, our results suggest that the intermediary role of cytokines in post-chemotherapy cognitive impairment is still controversial and requires further evaluation. A list of methodological recommendations is proposed to harmonize future studies of this subject matter.

Impact of cancer-related fatigue on chemotherapy-induced nausea and vomiting in Asian cancer patients

INTRODUCTION

Cancer-related fatigue (CRF) has been suggested to be associated with the occurrence of chemotherapy-induced nausea and vomiting (CINV). This study aims to evaluate the potential of CRF in predicting the occurrence of CINV.

METHOD

This is a prospective, observational study. Recruited patients received moderately to highly emetogenic single-day chemotherapy regimens. On the day of chemotherapy, patients were instructed to provide a score (Likert scale of 0-10) to describe how CRF interfered with his or her ability to engage in daily activities and a score for how severe it was. Patients were then given a standardized 5-day diary to document their CINV events.

RESULTS

A total of 473 eligible patients (median age: 55 years, interquartile range (IQR): 48-61 years) were recruited, with most of the patients diagnosed with gastrointestinal (45%) and breast (37%) cancers. The median score of fatigue interference was 3 (IQR: 0-5). After confounders were adjusted for, patients with low fatigue interference scores (≤3) were more likely to achieve complete protection (no nausea, no vomiting, and no breakthrough antiemetics) of CINV (adjusted odds ratio = 1.57, 95%CI [1.05, 2.35], p = 0.027).

CONCLUSION

This is the largest study to date to evaluate the association between CRF and CINV. Patients experiencing CRF possessed a higher risk of poor control for CINV.

Psychometric properties and measurement equivalence of the English and Chinese versions of the functional assessment of cancer therapy-cognitive in Asian patients with breast cancer

OBJECTIVE

This study was designed to examine the psychometric properties and measurement equivalence of the English and Chinese versions of the Functional Assessment of Cancer Therapy-Cognitive Function (Version 3) (FACT-Cog) in multiethnic Asian patients with breast cancer.

METHODS

This prospective study involved patients with breast cancer from the National Cancer Centre Singapore. The concurrent validity of the FACT-Cog was assessed according to its strength of correlation with the validated European Organization for Research and Treatment of Cancer Quality of Life Core Questionnaire 30 cognitive functioning scale, and its association with fatigue, global health status, and anxiety. The known-group validity was assessed on the basis of receipt of chemotherapy. Factor analysis was conducted to ascertain the one-factor structure of each cognitive domain. The reliability was evaluated by using Cronbach's alpha and intraclass correlation coefficient within the cognitive domains. Multiple regression analyses were performed to compare the total scores between the two language versions, adjusting for covariates.

RESULTS

A total of 185 English-speaking and 143 Chinese-speaking patients were recruited. Both the English and Chinese FACT-Cog total scores correlated strongly with the European Organization for Research and Treatment of Cancer Quality of Life Core Questionnaire 30 cognitive functioning scale scores (r = 0.725 and 0.646), whereas correlations with fatigue, anxiety, and global health status were weak to moderate (|r| = 0.376-0.589). Regarding the known-group validity, more severe perceived cognitive disturbance was observed among patients receiving chemotherapy than among those who were not for both versions (P = .010 and .008, respectively). Internal consistencies within the cognitive domains were high (Cronbach's α 0.707-0.929), and test-retest reliability was satisfactory for both versions (intraclass correlation coefficient 0.762 and 0.697). The measurement equivalence between the English and Chinese versions was established for all domains except the multitasking domain.

CONCLUSION

The English and Chinese versions of the FACT-Cog are valid, reliable, and equivalent for clinical and research use.

Vascular endothelial growth factor inhibitors and cognitive impairment: evidence and controversies

INTRODUCTION

Chemotherapy-induced cognitive impairment, or 'chemobrain,' has been well established in the literature. However, neurocognitive toxic effect induced by targeted therapies such as anti-angiogenic agents is poorly investigated. Recently, emerging evidence suggests vascular endothelial growth factor (VEGF) to have a possible role in brain cognition giving rise to concerns whether VEGF inhibitors (VEGFIs) may induce neurotoxic effect on cancer patients' cognitive function.

AREAS COVERED

The aim of this review was to evaluate the plausible mechanisms underlying VEGF and cognition, and to highlight the evidence and controversies surrounding the cognitive issues associated with the use of VEGFIs.

EXPERT OPINION

This review paper has brought attention to the potential cognitive issues associated with the use of VEGFIs and has added a new, unexplored dimension to the problem of cancer treatment-related cognitive changes. However, the lack of evidence warrants the need for more well-designed studies to quantify the prevalence and severity of VEGFI-induced cognitive impairment in the cancer population, and to establish the role of VEGF in human cognitive function.

Acknowledging the relevance of cognitive changes in cancer patients: perspectives of oncology practitioners in Asia

PURPOSE

Previous studies have suggested that cognitive impairment can affect cancer patients' health-related quality of life (HRQoL) and daily functioning. This study investigated oncology practitioners' perceptions of the relevance, effects, and causes of such cognitive changes in cancer patients, and their awareness of coping strategies.

METHODS

Oncology practitioners completed a self-administered cross-sectional survey. Practitioners were recruited from four major cancer centers in Singapore and Thailand, and through a regional cancer meeting that took place in Singapore in September 2011.

RESULTS

The sample (n = 193) consisted of nurses (51.3 %), oncologists (35.2 %), and pharmacists (13.5 %). Cognitive changes were frequently observed among cancer patients, particularly in the domains of memory (77.1 %) and concentration (74.6 %). The majority (86.5 %) of respondents agreed that cognitive changes adversely effected patients' HRQoL. The majority (65.3 %) of the respondents also recognized the need to implement routine neuropsychological assessments in clinical settings. The following factors were perceived as contributing to cognitive changes: aging (77.6 %), cancer-related fatigue (65.2 %), and anxiety (61.2 %). Compared with other healthcare professionals, oncologists were less likely to agree that chemotherapy was a major contributing factor to cognitive changes (25.0 % vs. 9.8 %, p = 0.038). Psychosocial support and the use of complementary alternative medicines (CAM) were identified as coping strategies for cognitive changes.

CONCLUSIONS

Healthcare professionals do not perceive a uniform set of contributing factors to cognitive impairment among cancer patients, although they all acknowledge that cancer patients' experience of cognitive impairment is a relevant issue.

IMPLICATIONS FOR CANCER SURVIVORS

It is important to equip clinicians with the knowledge necessary for monitoring and managing the cognitive disturbances and psychological distress experienced by at risk patients in a clinical setting.

Effects of chemotherapy and psychosocial distress on perceived cognitive disturbances in Asian breast cancer patients

BACKGROUND

There is conflicting evidence on the effect of chemotherapy and psychosocial distress on perceived cognitive changes in cancer patients.

OBJECTIVE

To compare the severity of perceived cognitive disturbance in Asian breast cancer patients receiving chemotherapy and those not receiving chemotherapy, and identify clinical characteristics associated with perceived cognitive disturbances.

METHODS

A cross-sectional, observational study was conducted at the largest cancer center in Singapore. Breast cancer patients receiving chemotherapy and not receiving chemotherapy completed the Functional Assessment of Cancer Therapy-Cognitive Function (FACT-Cog), European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (QLQ-C30), and Beck Anxiety Inventory to assess their perceived cognitive functioning, health-related quality of life, and anxiety, respectively. Multiple regression was conducted to delineate the factors associated with perceived cognitive disturbances.

RESULTS

A total of 85 breast cancer patients receiving chemotherapy and 81 not receiving chemotherapy were recruited. Chemotherapy patients experienced more fatigue (QLQ-C30 fatigue scores: 33.3 vs 22.2 points; p = 0.005) and moderate-to-severe anxiety (21.9% vs 8.6%; p = 0.002) compared to non-chemotherapy patients. Non-chemotherapy patients reported better perceived cognitive functioning than those who received chemotherapy (FACT-Cog scores: 124 vs 110 points, respectively; p < 0.001). Chemotherapy and endocrine therapy were strongly associated with perceived cognitive disturbances (p < 0.001 and 0.021, respectively). The interacting effect between anxiety and fatigue was moderately associated with perceived cognitive disturbances (β = -0.29; p = 0.037).

CONCLUSIONS

Chemotherapy and endocrine treatment were associated with significant cognitive disturbances among Asian breast cancer patients. Psychosocial factors could be used to identify cancer patients who are more susceptible to cognitive disturbances in the clinical setting.

An evaluation on the neuropsychological tests used in the assessment of postchemotherapy cognitive changes in breast cancer survivors

OBJECTIVES

The choice of appropriate neuropsychological tests is important in evaluating the onset, severity, duration, and site of cognitive changes in postchemotherapy breast cancer survivors. This literature review is designed to evaluate and provide a summary of suitable neuropsychological tests to determine cognitive changes in breast cancer survivors.

METHOD

A literature search restricted to publications in English before June 2011 was performed using the following combination of keywords: "neuropsychological assessments," "breast cancer," "chemotherapy," and "cognitive impairment." Only observational studies that performed cognitive assessments on breast cancer survivors were included. The neuropsychological assessments were grouped as "objective" (traditional batteries and screening tests), "subjective," or "computerized."

RESULTS

Of the 43 studies extracted, memory (88 %) and attention/concentration (88 %) are the two most commonly assessed domains. A majority (63 %) employed the use of Wechsler Adult Intelligent Scale (an objective test), while only 49 % incorporated subjective assessments to assess perceived cognitive impairment. Computerized tests received low popularity (28 %) despite their numerous advantages, which include overcoming the language- and cultural-dependent limitations of traditional objective tests.

CONCLUSIONS

In the selection of a suitable neuropsychological tool to determine the onset, severity, site, and duration of cognitive changes in breast cancer survivors, incorporation of both subjective and objective tests is essential to facilitate a comprehensive assessment. With more validation work performed in future studies, it may be feasible to employ computerized neuropsychological assessments in both clinical and research settings.