Cognitive effects of chemotherapy in post-menopausal breast cancer patients 1 year after treatment

Letrozole delays acquisition of water maze task in female BALB/c mice: Possible involvement of anxiety

Letrozole, an aromatase inhibitor preventing estrogen synthesis from testosterone, is used as an adjuvant therapy in estrogen receptor-positive breast cancer patients. However, like other aromatase inhibitors, it induces many side effects, including impaired cognition. Despite its negative effect in humans, results from animal models are inconsistent and suggest that letrozole can either impair or improve cognition. Here, we studied the effects of chronic letrozole treatment on cognitive behavior of adult female BALB/c mice, a relevant animal model for breast cancer studies, to develop an appropriate animal model aimed at testing therapies to mitigate side effects of letrozole. In Morris water maze, letrozole 0.1 mg/kg impaired reference learning and memory. Interestingly, most of the letrozole 0.1 mg/kg-treated mice were able to learn the new platform position in reversal training and performed similar to control mice in a reversal probe test. Results of the reversal test suggest that letrozole did not completely disrupt spatial navigation, but rather delayed acquisition of spatial information. The delay might be related to increased anxiety as suggested by increased thigmotactic behavior during the reference memory training. The learning impairment was water maze-specific since we did not observe impairment in other spatial tasks such as in Y-maze or object location test. In contrast, the dose of 0.3 mg/kg did not have effect on water maze learning and facilitated locomotor habituation and recognition in novel object recognition test. The current study shows that letrozole dose-dependently modulates behavioral response and that its effects are task-dependent.

Chemotherapy-induced cognitive impairment in breast cancer survivors: A systematic review of studies from 2000 to 2021

BACKGROUND

Studies have indicated that apart from enhancing patient survival, chemotherapy has adverse side effects on the psychological, social, and cognitive functions of breast cancer survivors.

AIMS

This study was conducted to understand chemotherapy's impact on breast cancer survivors' cognitive functions.

METHODS AND RESULTS

Our study is a systematic review based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. We searched English databases, including PubMed/MEDLINE, PsycINFO, and Web of Science, and Persian databases, such as Irandoc and Elmnet, using Persian keywords of cancer, breast cancer, chemotherapy, cognitive functions, executive functions, and neuropsychological functions. Two reviewers independently evaluated the full text of the articles according to predefined criteria. Among the 937 available studies, 26 were selected based on the inclusion and exclusion criteria, of which 17 (65%) were longitudinal and 9 (35%) were cross-sectional. The findings indicated a significant relationship between the use of chemotherapy and cognitive impairments, most notably attention, working and short-term memory, and executive functions. However, the studies differed in their findings regarding the long-term persistence of cancer-related cognitive impairment (CRCI), which could be due to the wide range of tools used, different methods to measure cognitive functions, and the difference in the sample size of the studies.

CONCLUSION

Chemotherapy, affecting cortical and subcortical brain structures, causes a set of cognitive impairments that can lead to impairments in social responsibility acceptance, daily functioning, and quality of life of women. Therefore, rigorous and extensive research design is required to understand the causes and consequences of CRCI using standardized and sensitive measures of cognitive functions. Specifically, studies comparing the effects of different chemotherapy regimens on cognition and potential mechanisms and/or moderators of CRCI would be instrumental in designing more effective therapy regimens and evaluating the efficacy and cost-effectiveness of cognitive rehabilitation and supportive care programs.

Peripubertal Nutritional Prevention of Cancer-Associated Gene Expression and Phenotypes

Breast cancer (BC) is a nearly ubiquitous malignancy that effects the lives of millions worldwide. Recently, nutritional prevention of BC has received increased attention due to its efficacy and ease of application. Chief among chemopreventive compounds are plant-based substances known as dietary phytochemicals. Sulforaphane (SFN), an epigenetically active phytochemical found in cruciferous vegetables, has shown promise in BC prevention. In addition, observational studies suggest that the life stage of phytochemical consumption may influence its anticancer properties. These life stages, called critical periods (CPs), are associated with rapid development and increased susceptibility to cellular damage. Puberty, a CP in which female breast tissue undergoes proliferation and differentiation, is of particular interest for later-life BC development. However, little is known about the importance of nutritional chemoprevention to CPs. We sought to address this by utilizing two estrogen receptor-negative [ER(-)] transgenic mouse models fed SFN-containing broccoli sprout extract during the critical period of puberty. We found that this treatment resulted in a significant decrease in tumor incidence and weight, as well as an increase in tumor latency. Further, we found significant alterations in the long-term expression of cancer-associated genes, including p21, p53, and BRCA2. Additionally, our transcriptomic analyses identified expressional changes in many cancer-associated genes, and bisulfite sequencing revealed that the antiproliferation-associated gene Erich4 was both hypomethylated and overexpressed in our experimental group. Our study indicates that dietary interventions during the CP of puberty may be important for later-life ER(-) BC prevention and highlights potential important genetic and epigenetic targets for treatment and study of the more deadly variants of BC.

A Delphi technique toward the development of a cognitive intervention framework module for breast cancer survivors with cognitive impairment following chemotherapy

Objective

Chemotherapy-related cognitive impairment (CRCI) is a well-known phenomenon among breast cancer survivors. Cognitive impairment among breast cancer survivors can significantly affect their quality of life and ability to function independently. However, there is a lack of specific and focused cognitive intervention to improve their cognitive performances. This study aimed to develop a tailored cognitive intervention framework module by adapting the attention and memory interventions from the Cognitive Rehabilitation Manual of the Brain Injury Interdisciplinary Special Interest Group (BI-SIG) of the American Congress of Rehabilitation Medicine (ACRM) and incorporating them with the relevant exercises for cognitive rehabilitation for Malaysian breast cancer survivors with CRCI based on the consensus agreement of the expert panel.

Methods and analysis

The Delphi consensus technique was conducted online to review and evaluate the framework module. A panel of experts, including rehabilitation medicine physicians, occupational therapists, and clinical psychologists in Malaysia, was invited to participate in this study. For each round, the expert consensus was defined as more than 90% of the expert panel agreeing or strongly agreeing with the proposed items.

Results

A total of 33 practitioners completed the three Delphi rounds. 72.7% of the expert panel have been practising in their relevant clinical fields for more than six years (M = 10.67, SD = 5.68). In Round 1, 23% of the experts suggested that the framework module for attention training required further improvements, specifically in the language (M = 1.97, SD = 0.75) and instructions (M = 2.03, SD = 0.71) provided. In Round 2, 15% of the experts recommended additional changes in the instruction (M = 2.15, SD = 0.67) for attention training. Amendments made to the framework module in line with the recommendations provided by the experts resulted in a higher level of consensus, as 94% to 100% of the experts in Round 3 concluded the framework module was suitable and comprehensive for our breast cancer survivors. Following the key results, the objectives were practical, and the proposed approaches, strategies, and techniques for attention and memory training were feasible. The clarity of the instructions, procedures, verbatim transcripts, and timeframe further enhanced the efficacy and utility of the framework module.

Conclusions

This study found out that the cognitive intervention framework module for breast cancer survivors with cognitive impairment following chemotherapy can be successfully developed and feasible to be implemented using Delphi technique.

Prevalence of cognitive impairment following chemotherapy treatment for breast cancer: a systematic review and meta-analysis

Breast cancer survival rates have markedly improved. Consequently, survivorship issues have received increased attention. One common sequel of treatment is chemotherapy-induced cognitive impairment (CICI). CICI causes a range of impairments that can have a significant negative impact on quality of life. Knowledge of the prevalence of this condition is required to inform survivorship plans, and ensure adequate resource allocation and support is available for sufferers, hence a systematic review of prevalence data was performed. Medline, Scopus, CINAHL and PSYCHInfo were searched for eligible studies which included prevalence data on CICI, as ascertained though the use of self-report, or neuropsychological tests. Methodological quality of included studies was assessed. Findings were synthesised narratively, with meta-analyses being used to calculate pooled prevalence when impairment was assessed by neuropsychological tests. The review included 52 studies. Time-points considered ranged from the chemotherapy treatment period to greater than 10 years after treatment cessation. Summary prevalence figures (across time-points) using self-report, short cognitive screening tools and neuropsychological test batteries were 44%, 16% and 21–34% respectively (very low GRADE evidence). Synthesised findings demonstrate that 1 in 3 breast cancer survivors may have clinically significant cognitive impairment. Prevalence is higher when self-report based on patient experience is considered. This review highlights a number of study design issues that may have contributed to the low certainty rating of the evidence. Future studies should take a more consistent approach to the criteria used to assess impairment. Larger studies are urgently needed.

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.

Longitudinal Changes in Cognitive Function in a Nationwide Cohort Study of Patients With Lymphoma Treated With Chemotherapy

BACKGROUND

Cancer-related cognitive decline (CRCD) is an important clinical problem, but limited research exists on assessment of cognitive function in patients with lymphoma.

METHODS

The overall objective of this nationwide, prospective, observational study conducted in the National Cancer Institute Community Clinical Oncology Research Program (NCORP) was to assess changes in memory, attention, and executive function in patients with lymphoma from pre- (A1) to postchemotherapy (A2) and to 6 months postchemotherapy (A3). Individuals without cancer served as noncancer controls, paired to patients by age and sex, and assessed at the same time-equivalent points. Longitudinal linear mixed models (LMM) including A1, A2, and A3 and adjusting for age, education, race, sex, cognitive reserve score, baseline anxiety, and depressive symptoms were fit. We assessed changes in patients compared with control participants without cancer and assessed differences in cognitive function in those patients with Hodgkin vs non-Hodgkin disease and by disease subtype. All statistical tests were 2-sided.

RESULTS

Patients with lymphoma (n = 248) and participants without cancer serving as controls (n = 212) were recruited from 19 NCORP sites. From pre- to postchemotherapy and from prechemotherapy to 6 months follow-up, patients reported more cognitive problems over time compared with controls (Functional Assessment of Cancer-Therapy-Cognitive Function [FACT-Cog] perceived cognitive impairment effect size (ES) = 0.83 and 0.84 for A1 to A2 and A1 to A3, respectively; P < .001; single-item cognitive symptoms ES range = 0.55 to 0.70 inclusive of A1 to A2 and A1 to A3; P < .001); the complaints were more pronounced in women with lymphoma compared with men with lymphoma (FACT-Cog Perceived Cognitive Impairment (PCI) score group-by-time-by-sex interaction, P = .007). Patients with lymphoma also performed statistically significantly less well on tests of verbal memory and delayed recall, attention and executive function, and telephone-based category fluency.

CONCLUSION

Patients with lymphoma experience worse patient-reported and objectively assessed cognitive function from prechemotherapy to 6-month follow-up compared with age- and sex-paired controls without cancer assessed at similar time intervals.

Prevalence of cognitive impairment and change in patients with breast cancer: A systematic review of longitudinal studies

OBJECTIVE

Patients with breast cancer face cognitive impairment that affects their quality of life; partially attributable to treatment. Our aim was to detail the prevalence and change of cognitive impairment during the course of treatment. We also investigated the effect of therapy (chemotherapy [CT]) vs. radiotherapy and/or endocrine therapy vs. healthy controls).

METHODS

This article reviews longitudinal cohort studies published to date in Medline and Embase that (i) assess cognition before and after therapy, (ii) report prevalence cognitive impairment or change, and (iii) use standardized and valid neuropsychological tests. We used the original authors' criteria for cognitive impairment.

RESULTS

The title and abstract of 891 articles were screened, resulting in the identification of 90 potentially relevant articles while applying the eligibility criteria. After full-text examination, 17 studies were included. Prevalence of cognitive impairment range from 25% before therapy, through 24% after therapy to 21% at maximal 1-year follow-up (FU). Compared to their pretreatment cognitive functioning, 24% of patients decline after treatment and 24% at 1-year FU. Some studies also reported cognitive improvement showing that 15% and 31% of patients improve, respectively. In general, patients undergoing CT have a higher chance of cognitive impairment and decline than no-CT patients and healthy controls.

CONCLUSIONS

This study shows that one out of four breast cancer patients shows cognitive impairment prior to treatment administration CT and a significant number of patients decline during the course of disease, suggesting that cognitive impairment is not exclusively related to CT and/or no-CT therapies. This study shows that assessment of cognitive functioning, ideally over time, is crucial and may help the implementation of personalized rehabilitation pathways.

Perceived Cognitive Impairment in Breast Cancer Survivors and Its Relationships with Psychological Factors

Simple Summary

Cognitive complaints are common adverse effects for breast cancer survivors, with potential negative impacts on quality of life or return to work. Identifying subjects at risk could allow to reduce cognitive disorders or to set up appropriate care. In this study we explored current cognitive complaints reported by breast cancer survivors, using the Functional Assessment of Cancer Therapy-Cognition (FACT-Cog) questionnaire and examined the relationships between current cognitive complaints and current psychological symptoms (especially post-traumatic stress symptoms). This large survey showed that about half of breast cancer survivors reported cognitive complaints after cancer treatments. These complaints were mainly associated with chemotherapy, age, self-reported sleep difficulties, the frequency of psychotropic treatments and psychological factors including post-traumatic stress symptoms or. Some modifiable risk factors should be detected early to reduce persistent cognitive complaints after cancer, including sleep difficulties and post-traumatic stress symptoms.

Abstract

Cognitive complaints are common adverse effects in cancer patients. Identifying subjects at risk could make it possible to limit their impact. We aimed to explore the relationship between current cognitive complaints and demographic and psychological factors in a group of breast cancer survivors. Through an online survey, cancer survivors reported current cognitive complaints using the FACT-Cog questionnaire (Perceived Cognitive Impairment) and answered questions about their demographics, lifestyle and cancer-related characteristics. Anxiety, depression, fatigue and post-traumatic stress symptoms were also assessed. We used multivariable logistic regression models to explore the relationships between current cognitive complaints and social and psychological factors. Among the 1393 breast cancer survivors, 47.2% (n = 657) reported current cognitive complaints. Chemotherapy (OR = 2.26, 95%CI = 1.67–3.05), age (OR_{21-44 vs. >65} = 0.14, 95%CI = 0.07–0.27), sleep difficulties (OR_{never vs. often} = 2.41, 95%CI = 1.47–3.95), frequency of psychotropic treatments (OR_{never vs. >1/week} = 1.70, 95%CI = 1.23–2.36), post-traumatic stress symptoms (OR = 2.05, 95%CI = 1.57–2.69) and employment status (OR_{full-time or part-time vs. sick leave} = 1.64, 95%CI = 1.08–2.49) were strongly associated with current cognitive complaints. In this large study, about half of breast cancer survivors reported cognitive complaints, particularly after chemotherapy. Some risk factors should be detected early to reduce persistent cognitive complaints after cancer: mainly sleep difficulties, post-traumatic stress symptoms and psychotropic medications.

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.

Connectome analysis of brain functional network alterations in breast cancer survivors with and without chemotherapy

Purpose

Treatment modalities for breast cancer, the leading cause of cancer-related deaths in women worldwide, include surgery, radiotherapy, adjuvant chemotherapy, targeted therapy, and hormonal therapy. The advancement in medical technology has facilitated substantial reduction in breast cancer mortality. However, patients may experience cognitive impairment after chemotherapy. This phenomenon called chemotherapy-induced cognitive impairment (i.e., “chemobrain”) is common among breast cancer survivors. However, cognitive function deficits may exist before chemotherapy initiation. This study examined the functional network alterations in breast survivors by using resting-state functional magnetic resonance imaging (fMRI).

Methods

We recruited 172 female participants and separated them into three groups: C+ (57 breast cancer survivors who had finished 3–12-month-long chemotherapy), C- (45 breast cancer survivors who had not undergone chemotherapy), and HC (70 participants with no breast cancer history). We analyzed mean fractional amplitudes of low-frequency fluctuation and graph theoretical topologies from resting-state fMRI and applied network-based analysis to portray functional changes among the three groups.

Results

Among the three groups, the C- group demonstrated hyperactivity in the prefrontal cortex, bilateral middle temporal gyrus, right inferior temporal gyrus and right angular gyrus. Only the left caudate demonstrated significantly more hypoactivity in the C- group than in the C+ group. Graph theoretical analysis demonstrated that the brains of the C+ group became inclined toward regular networks and the brains of the C- group became inclined toward random networks.

Conclusion

Subtle alterations were noted in the brain activity and networks of our cancer survivors. Moreover, functional network disruptions occurred regardless of chemotherapeutic agent administration.

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.

Cognitive impairment after cytotoxic chemotherapy

Background

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

Methods

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

Results

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

Conclusions

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

[A Structural Model for Chemotherapy Related Cognitive Impairment and Quality of Life in Breast Cancer Patients]

PURPOSE

This study aimed to develop and test a structural model for chemotherapy-related cognitive impairment of breast cancer patients based on a literature review and Hess and Insel's chemotherapy-related cognitive change model.

METHODS

The Participants consisted of 250 patients who were ≥19 years of age. The assessment tools included the Menopause Rating Scale, Symptom Experience Scale, Hospital Anxiety and Depression Scale, Everyday Cognition, and Functional Assessment of Cancer Therapy-Breast Cancer. Data were analyzed using the SPSS 21.0 and AMOS 21.0 programs.

RESULTS

The modified model was a good fit for the data. The model fit indices were χ²=423.18 (p<.001), χ²/df=3.38, CFI=.91, NFI=.91, TLI=.89, SRMR=.05, RMSEA=.09, and AIC=515.18. Chemotherapy-related cognitive impairment was directly influenced by menopausal symptoms (β=.38, p=.002), depression and anxiety (β=.25, p=.002), and symptom experiences (β=.19, p=.012). These predictors explained 47.7% of the variance in chemotherapy-related cognitive impairment. Depression and anxiety mediated the relations among menopausal symptoms, symptom experiences, and with chemotherapy related cognitive impairment. Depression and anxiety (β=-.51, p=.001), symptom experiences (β=-.27, p=.001), menopausal symptoms (β=-.22, p=.008), and chemotherapy-related cognitive impairment (β=-.15, p=.024) had direct effects on the quality of life and these variables explained 91.3%.

CONCLUSION

These results suggest that chemotherapy-related toxicity is highly associated with cognitive decline and quality of life in women with breast cancer. Depression and anxiety increased vulnerability to cognitive impairment after chemotherapy. Nursing intervention is needed to relieve chemotherapy-related toxicity and psychological factor as well as cognitive decline for quality of life in patients undergoing chemotherapy.

Neuroimmunology of the female brain across the lifespan: Plasticity to psychopathology

The female brain is highly dynamic and can fundamentally remodel throughout the normal ovarian cycle as well as in critical life stages including perinatal development, pregnancy and old-age. As such, females are particularly vulnerable to infections, psychological disorders, certain cancers, and cognitive impairments. We will present the latest evidence on the female brain; how it develops through the neonatal period; how it changes through the ovarian cycle in normal individuals; how it adapts to pregnancy and postpartum; how it responds to illness and disease, particularly cancer; and, finally, how it is shaped by old age. Throughout, we will highlight female vulnerability to and resilience against disease and dysfunction in the face of environmental challenges.

International Cognition and Cancer Task Force Recommendations for Neuroimaging Methods in the Study of Cognitive Impairment in Non-CNS Cancer Patients

Cancer- and treatment-related cognitive changes have been a focus of increasing research since the early 1980s, with meta-analyses demonstrating poorer performance in cancer patients in cognitive domains including executive functions, processing speed, and memory. To facilitate collaborative efforts, in 2011 the International Cognition and Cancer Task Force (ICCTF) published consensus recommendations for core neuropsychological tests for studies of cancer populations. Over the past decade, studies have used neuroimaging techniques, including structural and functional magnetic resonance imaging (fMRI) and positron emission tomography, to examine the underlying brain basis for cancer- and treatment-related cognitive declines. As yet, however, there have been no consensus recommendations to guide researchers new to this field or to promote the ability to combine data sets. We first discuss important methodological issues with regard to neuroimaging study design, scanner considerations, and sequence selection, focusing on concerns relevant to cancer populations. We propose a minimum recommended set of sequences, including a high-resolution T1-weighted volume and a resting state fMRI scan. Additional advanced imaging sequences are discussed for consideration when feasible, including task-based fMRI and diffusion tensor imaging. Important image data processing and analytic considerations are also reviewed. These recommendations are offered to facilitate increased use of neuroimaging in studies of cancer- and treatment-related cognitive dysfunction. They are not intended to discourage investigator-initiated efforts to develop cutting-edge techniques, which will be helpful in advancing the state of the knowledge. Use of common imaging protocols will facilitate multicenter and data-pooling initiatives, which are needed to address critical mechanistic research questions.

Fluorodeoxyglucose Detected Changes in Brain Metabolism After Chemotherapy in Pediatric Non-Hodgkin Lymphoma

BACKGROUND

Potential neurocognitive dysfunction after chemotherapy is a worrisome long-term outcome. Our objective was to evaluate the effect on brain metabolism in pediatric patients with non-central nervous system cancer treated with chemotherapy by analyzing brain data from serial whole-body fluorodeoxyglucose positron emission tomography/computed-tomography (FDG-PET/CT) scans taken before and sequentially after therapy.

METHODS

Fourteen pediatric patients diagnosed with lymphoma and treated with systemic and prophylactic intrathecal chemotherapy were included. All patients had baseline pretreatment whole-body FDG-PET/CT and at least one post-therapy study preformed as part of standard surveillance. Brain positron emission tomography data were quantitatively analyzed for normalized fluorodeoxyglucose uptake in various brain regions. A generalized estimating equation approach was used to evaluate temporal changes after chemotherapy.

RESULTS

Median time of follow-up surveillance positron emission tomography-computed-tomography was 456 days after chemotherapy course. Various brain regions demonstrated significant changes in fluorodeoxyglucose uptake as a function of time passed since chemotherapy. Increased fluorodeoxyglucose uptake was noted in the parietal and cingulate cortexes. Decreased fluorodeoxyglucose uptake was demonstrated in deep gray matter nuclei and in the brainstem.

CONCLUSIONS

Our study provides novel insights into long-standing and progressive changes in regional glucose metabolism after chemotherapy in pediatric cancer population, lasting long after the end of therapy and reaching clinical remission. Expanding the utility of regular surveillance fluorodeoxyglucose positron emission tomography to a detailed quantitative assessment of regional brain metabolism after chemotherapy can provide valuable information on individual chemotherapy-related neuromodulation and facilitate the development of strategies to minimize neurocognitive side effects.

Longitudinal Trajectory and Characterization of Cancer-Related Cognitive Impairment in a Nationwide Cohort Study

PURPOSE

Cancer-related cognitive impairment (CRCI) is an important clinical problem in patients with breast cancer receiving chemotherapy. Nationwide longitudinal studies are needed to understand the trajectory and severity of CRCI in specific cognitive domains.

PATIENTS AND METHODS

The overall objective of this nationwide, prospective, observational study conducted within the National Cancer Institute Community Clinical Oncology Research Program was to assess trajectories in specific cognitive domains in patients with breast cancer (stage I-IIIC) receiving chemotherapy, from pre- (A1) to postchemotherapy (A2) and from prechemotherapy to 6 months postchemotherapy (A3); controls were assessed at the same time-equivalent points. The primary aim assessed visual memory using the Cambridge Neuropsychological Test Automated Battery Delayed Match to Sample test by longitudinal mixed models including A1, A2, and A3 and adjusting for age, education, race, cognitive reserve score, and baseline anxiety and depressive symptoms. We also assessed trajectories of CRCI in other aspects of memory as well as in attention and executive function with computerized, paper-based, and telephone-based cognitive tests.

RESULTS

In total, 580 patients with breast cancer (mean age, 53.4 years) and 363 controls (mean age, 52.6 years) were assessed. On the Delayed Match to Sample test, the longitudinal mixed model results revealed a significant group-by-time effect ( P < .005); patients declined over time from prechemotherapy (A1) to 6 months postchemotherapy (A3; P = .005), but controls did not change ( P = .426). The group difference between patients and controls was also significant, revealing declines in patients but not controls ( P = .017). Several other models of computerized, standard, and telephone tests indicated significantly worse performance by patients compared with controls from pre- to postchemotherapy and from prechemotherapy to 6 months postchemotherapy.

CONCLUSION

This nationwide study showed CRCI in patients with breast cancer affects multiple cognitive domains for at least 6 months postchemotherapy.

Rationale and design of a cohort study on primary ovarian insufficiency in female survivors of Hodgkin's lymphoma: influence on long-term adverse effects (SOPHIA)

INTRODUCTION

Hodgkin's lymphoma (HL) has become the prototype of a curable disease. However, many young survivors suffer from late adverse effects of treatment. Both chemotherapy (CT) and radiotherapy (RT) may induce primary ovarian insufficiency (POI), which has been associated with reduced bone mineral density (BMD), neurocognitive dysfunction and possibly cardiovascular disease (CVD). While the general assumption is that POI increases CVD risk, other hypotheses postulate reverse causality, suggesting that cardiovascular risk factors determine menopausal age or that biological ageing underlies both POI and CVD risk. None of these hypotheses are supported by convincing evidence. Furthermore, most studies on POI-associated conditions have been conducted in women with early natural or surgery-induced menopause with short follow-up times. In this study, we will examine the long-term effects of CT-induced and/or RT-induced POI on BMD, cardiovascular status, neurocognitive function and quality of life in female HL survivors.

METHODS AND ANALYSIS

This study will be performed within an existing Dutch cohort of HL survivors. Eligible women were treated for HL at ages 15-39 years in three large hospitals since 1965 and survived for ≥8 years after their diagnosis. Women visiting a survivorship care outpatient clinic will be invited for a neurocognitive, cardiovascular and BMD assessment, and asked to complete several questionnaires and to provide a blood sample. Using multivariable regression analyses, we will compare the outcomes of HL survivors who developed POI with those who did not. Cardiovascular status will also be compared with women with natural POI.

ETHICS AND DISSEMINATION

This study has been approved by the Institutional Review Board of the Netherlands Cancer Institute and has been registered at 'Toetsingonline' from the Dutch Central Committee on Research involving Human Subjects (file no. NL44714.031.13). Results will be disseminated through peer-reviewed publications and will be incorporated in follow-up guidelines for HL survivors.

Breast cancer treatment and its effects on aging

Breast cancer is the most common cancer of women in the United States. It is also proving to be one of the most treatable. Early detection, surgical intervention, therapeutic radiation, cytotoxic chemotherapies and molecularly targeted agents are transforming the lives of patients with breast cancer, markedly improving their survival. Although current breast cancer treatments are largely successful in producing cancer remission and extending lifespan, there is concern that these treatments may have long lasting detrimental effects on cancer survivors, in part, through their impact on non-tumor cells. Presently, the impact of breast cancer treatment on normal cells, its impact on cellular function and its effect on the overall function of the individual are incompletely understood. In particular, it is unclear whether breast cancer and/or its treatments are associated with an accelerated aging phenotype. In this review, we consider breast cancer survivorship from the perspective of accelerated aging, and discuss the evidence suggesting that women treated for breast cancer may suffer from an increased rate of physical and cognitive decline that likely corresponds with underlying vulnerabilities of genome instability, epigenetic changes, and cellular senescence.

Cancer-related cognitive impairment in breast cancer survivors: An examination of conceptual and statistical cognitive domains using principal component analysis

There is a great deal of variability in the composition of neuropsychological test batteries used in the assessment of cancerrelated cognitive impairment (CRCI). Not only the development of a gold standard approach for CRCI assessment would allow for easier identification of women suffering from CRCI but it would also promote optimal care for survivors. As a first step towards the development of a valid and reliable unified test battery, the objective of this study was to verify whether the theoretical domains commonly used in CRCI assessment are statistically supported, before and after breast cancer treatment. Principal component analyses (PCA) were performed on the results from 23 neuropsychological tests grouped into eight conceptual domains. For baseline data, the Kaiser-Meyer-Olkin was .82 and Bartlett's X2(253, N=95) = 949.48, P<0.001. A five-component solution explained 60.94% of the common variance. For the post-treatment data, the Kaiser-Meyer-Olkin was .83 and Bartlett's X2(253, N=95) = 1007.21, P<0.001 and a five component solution explained 62.03% of the common variance. Although a visual comparison of the theoretical model with those determined via PCA indicated important overlap between conceptual domains and statistical components, significant dissimilarities were also observed.

Cognitive Changes in Cancer Survivors

Advances in cancer treatments have led to substantially improved survival for patients with cancer. However, many patients experience changes in cognition as a side effect of both cancer and cancer treatment. This occurs with both central nervous system (CNS) tumors and non-CNS tumors and in both children and adults. Studies of patients with non-CNS cancer have shown that cancer-related cognitive impairment (CRCI), which can include changes in memory, executive function, attention, and processing speed, occurs in up to 30% of patients prior to any treatment and in up to 75% of patients during treatment. A subset of patients with non-CNS and CNS cancer appear to be at higher risk for CRCI, so much research has gone into identifying who is vulnerable. Risk factors for CRCI in adults include cognitive reserve, age, genetic factors, and ethnicity; risk factors for children include genetic factors, female sex, younger age at diagnosis, chemotherapy dose, and both dose and field size for radiation. Although the field has made substantial strides in understanding and treating CRCI, more research is still needed to improve outcomes for both pediatric and adult cancer survivors.

From the Bottom-Up: Chemotherapy and Gut-Brain Axis Dysregulation

The central nervous system and gastrointestinal tract form the primary targets of chemotherapy-induced toxicities. Symptoms associated with damage to these regions have been clinically termed chemotherapy-induced cognitive impairment and mucositis. Whilst extensive literature outlines the complex etiology of each pathology, to date neither chemotherapy-induced side-effect has considered the potential impact of one on the pathogenesis of the other disorder. This is surprising considering the close bidirectional relationship shared between each organ; the gut-brain axis. There are complex multiple pathways linking the gut to the brain and vice versa in both normal physiological function and disease. For instance, psychological and social factors influence motility and digestive function, symptom perception, and behaviors associated with illness and pathological outcomes. On the other hand, visceral pain affects central nociception pathways, mood and behavior. Recent interest highlights the influence of functional gut disorders, such as inflammatory bowel diseases and irritable bowel syndrome in the development of central comorbidities. Gut-brain axis dysfunction and microbiota dysbiosis have served as key portals in understanding the potential mechanisms associated with these functional gut disorders and their effects on cognition. In this review we will present the role gut-brain axis dysregulation plays in the chemotherapy setting, highlighting peripheral-to-central immune signaling mechanisms and their contribution to neuroimmunological changes associated with chemotherapy exposure. Here, we hypothesize that dysregulation of the gut-brain axis plays a major role in the intestinal, psychological and neurological complications following chemotherapy. We pay particular attention to evidence surrounding microbiota dysbiosis, the role of intestinal permeability, damage to nerves of the enteric and peripheral nervous systems and vagal and humoral mediated changes.

Cognitive Effects of Cancer and Cancer Treatments

As the population of cancer survivors has grown into the millions, there has been increasing emphasis on understanding how the late effects of treatment affect survivors' ability to return to work/school, their capacity to function and live independently, and their overall quality of life. This review focuses on cognitive change associated with cancer and cancer treatments. Research in this area has progressed from a pharmacotoxicology perspective to a view of the cognitive change as a complex interaction of aspects of the treatment, vulnerability factors that increase risk for posttreatment cognitive decline, cancer biology, and the biology of aging. Methodological advances include the development of (a) measurement approaches that assess more fine-grained subcomponents of cognition based on cognitive neuroscience and (b) advanced statistical approaches. Conceptual issues that arise from this multidimensional perspective are described in relation to future directions, understanding of mechanisms, and development of innovative interventions.

Assay of Calcium Transients and Synapses in Rat Hippocampal Neurons by Kinetic Image Cytometry and High-Content Analysis: An In Vitro Model System for Postchemotherapy Cognitive Impairment

Postchemotherapy cognitive impairment (PCCI) is commonly exhibited by cancer patients treated with a variety of chemotherapeutic agents, including the endocrine disruptor tamoxifen (TAM). The etiology of PCCI is poorly understood. Our goal was to develop high-throughput assay methods to test the effects of chemicals on neuronal function applicable to PCCI. Rat hippocampal neurons (RHNs) were plated in 96- or 384-well dishes and exposed to test compounds (forskolin [FSK], 17β-estradiol [ES]), TAM or fulvestrant [FUL], aka ICI 182,780) for 6-14 days. Kinetic Image Cytometry™ (KIC™) methods were developed to quantify spontaneously occurring intracellular calcium transients representing the activity of the neurons, and high-content analysis (HCA) methods were developed to quantify the expression, colocalization, and puncta formed by synaptic proteins (postsynaptic density protein-95 [PSD-95] and presynaptic protein Synapsin-1 [Syn-1]). As quantified by KIC, FSK increased the occurrence and synchronization of the calcium transients indicating stimulatory effects on RHN activity, whereas TAM had inhibitory effects. As quantified by HCA, FSK also increased PSD-95 puncta and PSD-95:Syn-1 colocalization, whereas ES increased the puncta of both PSD-95 and Syn-1 with little effect on colocalization. The estrogen receptor antagonist FUL also increased PSD-95 puncta. In contrast, TAM reduced Syn-1 and PSD-95:Syn-1 colocalization, consistent with its inhibitory effects on the calcium transients. Thus TAM reduced activity and synapse formation by the RHNs, which may relate to the ability of this agent to cause PCCI. The results illustrate that KIC and HCA can be used to quantify neurotoxic and neuroprotective effects of chemicals in RHNs to investigate mechanisms and potential therapeutics for PCCI.

Effects on 18F-FDG PET/CT Brain Glucose Metabolism in Rectal Cancer Patients Undergoing Neoadjuvant Chemotherapy

PURPOSE

Retrospective study of the effects of anticancer treatment on the brain metabolism of patients diagnosed with rectal cancer based on a large and homogeneous sample of 40 paired F-FDG PET/CT volumes taken from 20 patients. The results are compared to the ones presented by related works to help elucidating the mechanisms of neurotoxicity associated to a decrease in memory, learning and motor skills.

PATIENTS AND METHODS

Twenty patients with rectal adenocarcinoma were scanned before and after neoadjuvant chemoradiation based exclusively on 5-fluorouracil and leucovorin. The sample was non-rigidly registered to a common template to allow for the comparison of regional metabolism. Statistical analysis was based on adjusted paired t-tests.

RESULTS

The analysis primarily revealed a statistically significant decrease in the metabolism after neoadjuvant chemotherapy at the hypothalamus, putamen, head of the caudate, globus pallidus, red nucleus, substantia nigra, amygdala, cerebellum and the parahippocampal gyrus. The analysis also revealed smaller regions of increased metabolic activity at the middle temporal gyrus, precuneus of the parietal lobe and cuneus of the occipital lobe.

CONCLUSIONS

The regions of decreased metabolism detected in the study are related to memory, learning and voluntary movement which is consistent with previous findings based on clinical studies and neuropsychological tests that report impairments on neurocognitive and motor skills associated to these therapies.

Executive functioning impairment in women treated with chemotherapy for breast cancer: a systematic review

PURPOSE

Women with breast cancer have reported adverse cognitive effects following chemotherapy. Evidence is mixed on whether executive functioning is particularly impaired in women treated with chemotherapy, in part due to the wide range of tasks used to measure executive processes. We performed a systematic review of the published literature to evaluate whether some subcomponents of executive functioning are more vulnerable to impairment than others among breast cancer survivors who had been treated with chemotherapy.

METHODS

Studies published as of April 2017 were identified using three electronic databases (MEDLINE, PsycINFO, and Web of Science) and a manual search of relevant reference lists. The methodological quality of included studies was assessed using a checklist of predefined criteria.

RESULTS

Of 1280 identified articles, a total of 41 were included for review. Study findings were categorized into three primary subdomains of executive functioning: inhibition, shifting, and updating. Although there was heterogeneity in the neuropsychological measures used to assess executive functioning, tests could be grouped into the subcomponents they assessed. Inhibition appears relatively spared from the effects of chemotherapy, whereas impairments in shifting and updating are more commonly found following chemotherapy.

CONCLUSIONS

Examination of subcomponents of executive functioning is recommended to better characterize the nature of executive dysfunction in women treated with chemotherapy. Future studies should include executive functioning tasks of varying complexity, use of multiple tasks to increase reliability, and alternative indices to capture performance, such as within-person variability.

Topological Organization of Metabolic Brain Networks in Pre-Chemotherapy Cancer with Depression: A Resting-State PET Study

This study aimed to investigate the metabolic brain network and its relationship with depression symptoms using 18F-fluorodeoxyglucose positron emission tomography data in 78 pre-chemotherapy cancer patients with depression and 80 matched healthy subjects. Functional and structural imbalance or disruption of brain networks frequently occur following chemotherapy in cancer patients. However, few studies have focused on the topological organization of the metabolic brain network in cancer with depression, especially those without chemotherapy. The nodal and global parameters of the metabolic brain network were computed for cancer patients and healthy subjects. Significant decreases in metabolism were found in the frontal and temporal gyri in cancer patients compared with healthy subjects. Negative correlations between depression and metabolism were found predominantly in the inferior frontal and cuneus regions, whereas positive correlations were observed in several regions, primarily including the insula, hippocampus, amygdala, and middle temporal gyri. Furthermore, a higher clustering efficiency, longer path length, and fewer hubs were found in cancer patients compared with healthy subjects. The topological organization of the whole-brain metabolic networks may be disrupted in cancer. Finally, the present findings may provide a new avenue for exploring the neurobiological mechanism, which plays a key role in lessening the depression effects in pre-chemotherapy cancer patients.

Cognitive Impairment in a Subset of Breast Cancer Patients After Systemic Therapy-Results From a Longitudinal Study

CONTEXT

Studies indicate adverse effects of breast cancer (BC) and cancer treatment on cognitive function.

OBJECTIVES

To investigate the effects of systemic treatment on cognitive performance in BC patients.

METHODS

Participants were BC patients scheduled to receive systemic treatment (BC + SYST; n = 31), or no systemic treatment (BC; n = 24) and no-cancer (NC) controls (n = 33). Neuropsychological examinations were used to study cognitive performance on 18 tests grouped into eight cognitive domains, before adjuvant treatment (T1) and six months after chemotherapy (T2), or at similar intervals. We also assessed health-related quality of life, anxiety and depression, mood, stress, and cognitive problems. Analysis of variance was used to assess group differences of cognitive performance and multivariate normative comparison to classify impairment, comparing scores of each participant against the distribution of the scores of NC controls.

RESULTS

Of BC + SYST, 16% were cognitively impaired at T2, compared to 4% in BC and 6% in NC. Although not significant, we observed moderate effect sizes for worse performance in the BC + SYST group compared to NC (Flanker congruent [effect size {ES} = 0.44] and stimulus incongruent [ES = 0.44]) and compared to BC (Controlled Oral Word Association Test [ES = 0.47], digit span [ES = 0.41], and Hopkins Verbal Learning Test immediate [ES = 0.71] and delayed recall [ES = 0.65]). Cognitively impaired patients had a significantly lower estimated premorbid intelligence, worse physical and social functioning, and more distress at T2 compared to unimpaired patients.

CONCLUSION

Our findings indicate that cognitive impairment after systemic treatment occurs in a subset of BC patients. The predictive value of demographic and psychosocial factors in cognitive impairment should be further investigated in a larger sample of impaired patients.

Use of complementary therapies for side effect management in breast cancer: evidence and rationale

Women diagnosed with breast cancer can experience chronic side effects after curative treatment concludes, negatively impacting survivorship. The most prevalent side effects addressed in the medical and nursing literature include symptoms such as hot flashes, fatigue, myalgias/arthralgias and cognitive impairment. Complementary therapies, particularly natural products including herbs, dietary supplements, vitamins, minerals, and probiotics, and mind–body techniques that include such modalities as yoga, meditation, massage, acupuncture, relaxation, tai chi and hypnosis show promise for treatment of some of these symptoms associated with cancer care. However, the research in this area is nascent and much more work is needed to understand symptom physiology and mechanisms of action of complementary therapies. The purpose of this paper was to summarize key evidence from Phase II and III randomized clinical trials in order to provide guidance to distinguish promising versus nonpromising interventions for symptom management.

Decline in Cognitive Function in Older Adults With Early-Stage Breast Cancer After Adjuvant Treatment

BACKGROUND

The impact of chemotherapy on cognition among elderly patients has received little attention, although such patients are more prone to presenting with age-related cognitive deficits and/or cognitive decline during chemotherapy. The present study assessed the cognitive function in older adults treated for early-stage breast cancer (EBC).

PATIENTS AND METHODS

The participants were newly diagnosed EBC patients aged ≥65 years without previous systemic treatment or neurological or psychiatric disease and matched healthy controls. They underwent two assessments: before starting adjuvant therapy and after the end of chemotherapy (including doxorubicin ± docetaxel [CT+ group], n = 58) or radiotherapy for patients who did not receive chemotherapy (CT- group, n = 61), and at the same interval for the healthy controls (n = 62). Neuropsychological and geriatric assessments were performed. Neuropsychological data were analyzed using the Reliable Change Index.

RESULTS

Forty-nine percent of the patients (mean age, 70 ± 4 years) had objective cognitive decline after adjuvant treatment that mainly concerned working memory. Among these patients, 64% developed a cognitive impairment after adjuvant treatment. Comorbidity was not associated with cognitive decline. No significant difference in objective cognitive decline was found between the two groups of patients; however, the CT+ group had more subjective cognitive complaints after treatment (p = .008). The oldest patients (aged 70-81 years) tended to have more objective decline with docetaxel (p = .05).

CONCLUSION

This is the largest published study assessing cognitive function in older adults with EBC that included a group of patients treated with modern chemotherapy regimens. Approximately half the patients had objective cognitive decline after adjuvant treatment. The oldest patients were more likely to have cognitive decline with chemotherapy, particularly with docetaxel.

IMPLICATIONS FOR PRACTICE

This is the largest published study assessing cognitive function in older adults with early-stage breast cancer that included a group of patients treated with modern chemotherapy regimens. Approximately half the patients had objective cognitive decline after adjuvant treatment. The oldest patients were more likely to have cognitive decline with chemotherapy, particularly with docetaxel. Cognitive deficits could affect patients' quality of life and their compliance to treatment. Assessing cognitive dysfunctions in the elderly cancer population is a challenge in clinical practice, but it could influence the choice of the most appropriate therapy, including the use of oral drugs.

Long-lasting impairments in adult neurogenesis, spatial learning and memory from a standard chemotherapy regimen used to treat breast cancer

The negative impact of chemotherapy on cognitive function in cancer patients has gained increasing attention in the last decade. Whilst the short-term acute effects on cognition are expected following chemotherapy, the persistence of such impairments in the long-term is still in question. This is despite clinical evidence indicating cognitive difficulties may persist well beyond treatment and affect quality of life. In the present study, we assessed the long-term (3 months) cognitive impact of chemotherapy in a mouse model intended to mimic the human female post-menopausal population receiving chemotherapy for breast cancer. Ovariectomized, female, C57BL/6J mice received two doses of Doxorubicin, Cyclophosphamide, and 5-Fluorouracil or saline vehicle (control), separated by one week. During this interval, mice received BrdU injections to label dividing cells. Results indicate a persistent impairment in learning and recall (1h, 24h and 48h) on the Morris water maze, reduced survival and differentiation of new neurons (BrdU+/NeuN+), and a persistent decline in proliferation of new cells (Ki67(+)) in the dentate gyrus. Locomotor activity, motor performance, and anxiety-like behavior were unaffected. We further evaluated the efficacy of a diet enriched in omega-3-fatty acids (DHA+EPA+DPA), in reversing long-term chemotherapy deficits but no rescue was observed. The model described produces long-term cognitive and cellular impairments from chemotherapy that mimic those observed in humans. It could be useful for identifying mechanisms of action and to test further the ability of lifestyle interventions (e.g., diet) for ameliorating chemotherapy-induced cognitive impairments.

Assessing cognitive function in adults during or following chemotherapy: a scoping review

PURPOSE

The purpose of this scoping review was to determine the feasibility of conducting a systematic review of approaches for screening or assessing cognitive function that were comprehensive and that could be incorporated into clinical settings.

METHODS

Using the scoping review approach developed by Arksey and O'Malley, we searched Ovid Embase 1980-, Ovid PsycINFO 1806-, Ovid Health and Psychosocial Instruments 1985-, EBSCOhost CINAHL, ISI Web of Science (Science Citation Index 1900-), Social Sciences Citation Index 1900-, Conference Proceedings Citation Index -Science 1990-, Conference Proceedings Citation Index -Social Science & Humanities 1990-, Scopus 1960-, with no language restrictions. Searches were conducted in April 2009 and updated in February 2013. Studies of adults treated with chemotherapy that included at least seven of the eight domains of cognition were included.

RESULTS

Eleven studies met inclusion criteria. No screening tools suitable for inclusion in a clinic were identified. The studies reviewed varied by inclusion/exclusion criteria, design, and instruments for assessing cognitive function, and thus, there are not yet enough studies to warrant a systematic review on this topic.

Prevalence of perceived cognitive dysfunction in survivors of a wide range of cancers: results from the 2010 LIVESTRONG survey

PURPOSE

With cancer survivors now numbering over 13 million in the United States, and expected to continue to increase, it is important to consider the needs of this growing population. In the literature, one of the most common complaints by cancer survivors is perceived cognitive dysfunction. Since the preponderance of the research has focused on breast cancer survivors, the purpose of the present study was to explore the prevalence and correlates of perceived cognitive dysfunction in a large sample of cancer survivors with representation across a wide range of different types of cancer.

METHODS

A sample of 3108 post-treatment cancer survivors completed the 2010 LIVESTRONG survey as part of a larger study of cancer survivorship. Respondents completed standardized questions regarding current and past perceived cognitive dysfunction, as well as depressive symptoms, and demographic and medical variables.

RESULTS

Current perceived cognitive dysfunction was reported by nearly half of respondents (45.7%), across a wide range of cancer types, with the highest prevalence among survivors of central nervous system cancers. Receiving chemotherapy and current report of depressive symptoms were both strongly associated with current perceived cognitive dysfunction.

CONCLUSION

These findings contribute to a growing appreciation of the high prevalence of perceived cognitive dysfunction in survivors of a wide range of cancer types and the potential interactive effect of concurrent symptoms of depression. These findings highlight a need to develop more effective means of preventing or reducing cognitive dysfunction in cancer survivors.

IMPLICATIONS FOR CANCER SURVIVORS

Perceived cognitive dysfunction was reported in a wide range of cancer survivors. The potential interactive effect of symptoms of depression suggests the need to develop interventions targeting both cognitive dysfunction and depression to achieve improvements in cognitive functioning.

Structure-function-behavior relationship in estrogen-induced synaptic plasticity

This article is part of a Special Issue "Estradiol and Cognition". In estrogen-induced synaptic plasticity, a correlation of structure, function and behavior in the hippocampus has been widely established. 17ß-estradiol has been shown to increase dendritic spine density on hippocampal neurons and is accompanied by enhanced long-term potentiation and improved performance of animals in hippocampus-dependent memory tests. After inhibition of aromatase, the final enzyme of estradiol synthesis, with letrozole we consistently found a strong and significant impairment of long-term potentiation (LTP) in female mice as early as after six hours of treatment. LTP impairment was followed by loss of hippocampal spine synapses in the hippocampal CA1 area. Interestingly, these effects were not found in male animals. In the Morris water maze test, chronic administration of letrozole did not alter spatial learning and memory in either female or male mice. In humans, analogous effects of estradiol on hippocampal morphology and physiology were observed using neuroimaging techniques. However, similar to our findings in mice, an effect of estradiol on memory performance has not been consistently observed.

Is Cancer a Risk Factor for Cognitive Decline in Late Life?

With advances in screening and early detection, coupled with improved treatment and care, the number of cancer survivors has risen exponentially over the past several decades. Moreover, because age is the most significant risk factor for cancer, the majority of cancer survivors are over 65 years of age. Finally, cancer survivors often experience significant health issues for many years after the treatment has subsided. In the current article, we describe select research that has focused on changes to cognitive performance associated with cancer and its treatment, i.e., alterations that have been colloquially referred to as chemobrain. Although understanding changes in cognitive performance following cancer treatment is an active area of inquiry, the experience of older adult cancer survivors has been somewhat neglected. For example, evidence is mixed as to whether changes in cognitive performance associated with normal aging are exacerbated by cancer survivorship status. It is also unclear whether a history of cancer makes it more or less likely that a person will be diagnosed with dementia or Alzheimer's disease in the future. Finally, we identify a number of areas where existing cognitive aging research can inform studies on cognitive performance following cancer treatment. Future efforts should be directed towards designing studies that focus on the experience of older adult cancer survivors and are informed by the clinical oncology and cognitive aging literature.

A meta-analysis of cognitive impairment and decline associated with adjuvant chemotherapy in women with breast cancer

A meta-analysis was performed to quantify the magnitude and nature of the association between adjuvant chemotherapy and performance on a range of cognitive domains among breast cancer patients. A total of 27 studies (14 cross-sectional, 8 both cross-sectional and prospective, and 5 prospective) were included in the analyses, involving 1562 breast cancer patients who had undergone adjuvant chemotherapy and 2799 controls that included breast cancer patients who did not receive adjuvant chemotherapy. A total of 737 effect sizes (Cohen's d) were calculated for cross-sectional and prospective longitudinal studies separately and classified into eight cognitive domains. The mean effect sizes varied across cross-sectional and prospective longitudinal studies (ranging from -1.12 to 0.62 and -0.29 to 1.12, respectively). Each cognitive domain produced small effect sizes for cross-sectional and prospective longitudinal studies (ranging from -0.25 to 0.41). Results from cross-sectional studies indicated a significant association between adjuvant chemotherapy and cognitive impairment that held across studies with varied methodological approaches. For prospective studies, results generally indicated that cognitive functioning improved over time after receiving adjuvant chemotherapy. Greater cognitive impairment was reported in cross-sectional studies comparing chemotherapy groups with healthy control groups. Results suggested that cognitive impairment is present among breast cancer patients irrespective of a history of chemotherapy. Prospective longitudinal research is warranted to examine the degree and persisting nature of cognitive impairment present both before and after chemotherapy, with comparisons made to participants' cognitive function prior to diagnosis. Accurate understanding of the effects of chemotherapy is essential to enable informed decisions regarding treatment and to improve quality of life among breast cancer patients.

Late effects of adjuvant chemotherapy for breast cancer on fine motor function

BACKGROUND

Adjuvant chemotherapy for breast cancer has been associated with deterioration of fine motor skill. Which aspects of motor performance are underlying this problem is unclear but important because manual motor deterioration could affect quality of life. The current study aims to investigate late effects of adjuvant chemotherapy for breast cancer on fine motor function, using both speed and accuracy measures.

METHOD

We compared fine motor function of 174 women who had received adjuvant Cyclophosphamide Methotrexate 5-Fluorouracil chemotherapy for breast cancer on average 20 years ago with that of a population sample of 195 women without a history of cancer. Fine motor function was measured with the Purdue Pegboard Test and the Archimedes spiral test.

RESULTS

The group of chemotherapy-exposed breast cancer survivors was slower in drawing an Archimedes spiral than the reference group. Furthermore, in the chemotherapy-exposed subjects, we found that older age is related to more crossings of the spiral template, more return movements, and more deviations from the template. Such relationships were not observed within the reference group. No significant between-group differences were found for any of the Purdue Pegboard measures.

CONCLUSIONS

Compared with a population-based reference group, Cyclophosphamide Methotrexate 5-Fluorouracil chemotherapy-exposed breast cancer survivors demonstrated motor slowing while drawing an Archimedes spiral, on average 20 years after completion of primary treatment. Furthermore, the Archimedes spiral test is a more sensitive measure than the Purdue Pegboard Test to assess fine manual motor performance in long-term breast cancer survivors following chemotherapy.