Neuropsychological performance in survivors of breast cancer more than 20 years after adjuvant chemotherapy

Association Between Cardiovascular Disease and Cognitive Dysfunction in Breast Cancer Survivors

BACKGROUND

Breast cancer survivors (BCSs) may have a greater risk for cardiovascular disease (congestive heart failure and hypertension), which in turn, can affect cognitive dysfunction, a frequent, bothersome, and potentially debilitating symptom.

OBJECTIVE

The purpose of this study was to examine the relationship of cardiovascular disease on cognitive function in BCSs.

METHODS

Baseline data from a double-blind randomized controlled trial for cognitive training of BCSs were examined. Early-stage BCS (stages I-IIIA) who were 21 years or older, completed adjuvant therapy (≥6 months), and reported cognitive concerns completed questionnaires and a brief neuropsychological assessment, including tests of memory, attention and working memory, speed of processing, and verbal fluency. Descriptive statistics, Pearson correlation coefficient, and separate linear regression models for each cognitive domain were conducted.

RESULTS

Forty-seven BCSs, who were on average 57.3 (SD, 8.1) years old, were 58% White, and had some college education (75%), completed the study. Furthermore, 44.7% of the BCS had cardiovascular disease (congestive heart failure or hypertension). In linear regression models, cardiovascular disease was significantly related to immediate and delayed memory and attention and working memory ( P < .01-.05).

CONCLUSION

Breast cancer survivors who have cardiovascular disease may also be at a greater risk for cognitive dysfunction post treatment. Results from this study inform both clinical practice and future research, specifically by examining the intersection between cancer, cardiovascular disease (cardiotoxicity), and cognition.

IMPLICATIONS FOR PRACTICE

Nurses should be aware that BCSs with co-occurring cardiovascular disease are at a higher risk for cognitive dysfunction and work within the multidisciplinary team to optimize BCS health and function.

Four-year follow-up on fatigue and sleep quality of a three-armed partly randomized controlled study in breast cancer survivors with cancer-related fatigue

Cancer-related fatigue (CRF) is a frequent long-term symptom in non-metastasized breast cancer patients (BC). This 4-year follow-up intended to compare the long-term effects of a 10-week multimodal therapy (MT: sleep education, psychoeducation, eurythmy- and painting therapy) and combination therapy [CT: MT plus aerobic training (AT)] to AT-control. BC-patients were randomized or allocated by preference to three arms in a comprehensive cohort study. Primary outcome was a composite score including Pittsburgh Sleep Quality Index (PSQI) and Cancer Fatigue Scale (CFS-D), captured at baseline, after 10 weeks of intervention (T1), 6 months later (T2), and after 4 years (T3). We exploratively tested for superiority of MT and CT versus AT after 4 years (T3) based on the statistical model of the main analysis. Of 126 (65 randomized) BC-patients included, 105 started treatments and 79 were re-assessed for long-term effects (T3). MT and CT were superior over AT after 4 years regarding PSQI/CFS-D and PSQI sum-score, respectively (all p < 0.05), but not for CFS-D. The multimodal and combination treatment for breast cancer patients with CRF indicates sustainable long-term superiority over aerobic training for the outcomes sleep quality and combined sleep quality/fatigue. A confirmative randomized controlled trial is warranted.

Experiences of cognitive training on primary breast cancer survivor's cognitive impairments at work: A longitudinal qualitative study

OBJECTIVES

Cancer-related cognitive impairment (CRCI) is associated with adverse work-related outcomes in women living with a history of primary breast cancer. We explored the perceived impact of receiving adaptive cognitive training (dual n-back training) or active control training (dual 1-back training) on CRCI. Furthermore, we explored the perceived transfer effects of cognitive training on work-related self-management methods for cognitive impairment and work-related outcomes such as career development.

DESIGN

Longitudinal qualitative study.

METHODS

A 'framework' analysis approach was used to analyse semi-structured telephone interviews completed by women with a history of primary breast cancer before training (N = 40), one month (N = 30) and six months (N = 29) post-training.

RESULTS

Four main themes were identified: (1) impact of cognitive impairment at work, (2) perceived impact of cognitive training on impaired cognitive function, (3) perceived effects of training on work-related self-management methods for cognitive impairment and (4) perceived impact on women's career development and progression. Compared to baseline, women who received adaptive dual n-back training reported sustained improvement in multiple cognitive domains including memory and attention up to six months post-training when the follow-up interviews were conducted. Perceived improvements in cognitive function were associated with greater self-confidence and better emotional well-being in work. These improvements were found to lower dependency on self-management methods for cognitive impairment and enhance effectiveness as well as prompt career development or progression for many women. Although some findings of a similar nature were reported in the active control dual 1-back training group the perceived effects were more pronounced and consistent in the dual n-back group.

CONCLUSIONS

Adaptive cognitive training (dual n-back training) improves perceived CRCI experienced by women in the workplace, enhancing their self-confidence and general emotional well-being. These perceived improvements, in turn, can decrease reliance on self-management methods for cognitive impairment and improve work efficiency and contribute to career development and progression.

Neurons as stromal drivers of nervous system cancer formation and progression

Similar to their pivotal roles in nervous system development, neurons have emerged as critical regulators of cancer initiation, maintenance, and progression. Focusing on nervous system tumors, we describe the normal relationships between neurons and other cell types relevant to normal nerve function, and discuss how disruptions of these interactions promote tumor evolution, focusing on electrical (gap junctions) and chemical (synaptic) coupling, as well as the establishment of new paracrine relationships. We also review how neuron-tumor communication contributes to some of the complications of cancer, including neuropathy, chemobrain, seizures, and pain. Finally, we consider the implications of cancer neuroscience in establishing risk for tumor penetrance and in the design of future anti-tumoral treatments.

Physical activity and cognitive function: A comparison of rural and urban breast cancer survivors

PURPOSE

Increasing evidence suggests rural breast cancer survivors (BCS) may experience greater burden in symptoms known to be associated with cancer-associated cognitive decline (CACD). Yet, little is known about CACD in rural BCS. This study (1) examined differences in cognitive function, moderate-to-vigorous physical activity (MVPA), and other CACD correlates and (2) tested the effects of MVPA on cognitive function in rural versus urban BCS.

METHODS

Rural and urban BCS (N = 80), matched on age, education, and time since diagnosis from a larger study, completed cognitive tasks assessing processing speed (Trails-B, Mazes, Task-Switch) and working memory (spatial working memory) and questionnaires assessing subjective memory impairment (SMI), MVPA, and CACD correlates (i.e., sleep quality, fatigue, anxiety/depression). Some participants (n = 62) wore an accelerometer to objectively estimate MVPA. Multiple linear regression and multivariate analysis of covariance were used to test study aims.

RESULTS

Rural BCS (n = 40, M = 61.1±8.4 years-old) performed significantly slower on Trails-B (p<0.01) compared with urban BCS (n = 40, M = 61.0±8.2 years-old) and engaged in less objectively-estimated daily MVPA (mean difference = 13.83±4.73 minutes; p = 0.01). No significant differences in SMI, self-reported MVPA, or CACD correlates were observed (all p>0.28). Regression models did not reveal a significant interaction between MVPA and cognitive performance (all p>0.1); however, estimated marginal means models indicated that the effect of MVPA on processing speed was evident only among rural BCS (Trails-B, p = 0.04; Mazes, p = 0.03).

CONCLUSIONS

Findings suggest rural BCS may suffer greater CACD and engage in less MVPA. Additional research is warranted to further examine CACD and more effectively promote MVPA in rural BCS.

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

Backgrounds

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

Methods

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

Results

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

Conclusion

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

Systematic review registration

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

Use of focused computerized cognitive training (Neuroflex) to improve symptoms in women with persistent chemotherapy-related cognitive impairment

Purpose

Chemotherapy-related cognitive impairment (CRCI) is a distressing and increasingly recognized long-term sequela reported by breast cancer patients following cancer treatment. There is an urgent but unmet clinical need for treatments that improve CRCI. In this context, we proposed the use of a novel cognitive enhancement strategy called Neuroflex to target CRCI experienced by breast cancer survivors.

Methods

The primary aim of this pilot study was to evaluate the feasibility and acceptability of Neuroflex, a novel digital cognitive enhancement strategy, in breast and gynecologic cancer survivors with CRCI. Secondary analyses focused on whether improvements in performance on Neuroflex were associated with improvement in subjective cognitive complaints and objective cognitive performance measures.

Results

Participants (N = 21) completed an average of 7.42 hours of Neuroflex training per week, an average of 44.5 (±1.01) hours total, and had a 100% completion rate. Participants exhibited significant improvement in self-reported cognitive function as well as significant improvement on tasks of verbal learning and memory and auditory working memory. Participants also exhibited improvement in mood, as well as improvement on a disability assessment.

Conclusions

Results demonstrate feasibility and that breast cancer survivors are capable of completing a lengthy and challenging cognitive training program. Secondly, Neuroflex may confer specific cognitive benefits to both self-reported and objective performance. Results strongly support further investigation of Neuroflex in a larger controlled trial to establish efficacy for CRCI symptoms. Further studies may also result in optimization of this digital intervention for women with CRCI.

Neurological Complications of Conventional and Novel Anticancer Treatments

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

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

BACKGROUND

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

OBJECTIVE

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

INTERVENTIONS/METHODS

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

RESULTS

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

CONCLUSIONS

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

IMPLICATIONS FOR PRACTICE

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

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.

Circadian disruption and cancer- and treatment-related symptoms

Cancer patients experience a number of co-occurring side- and late-effects due to cancer and its treatment including fatigue, sleep difficulties, depressive symptoms, and cognitive impairment. These symptoms can impair quality of life and may persist long after treatment completion. Furthermore, they may exacerbate each other's intensity and development over time. The co-occurrence and interdependent nature of these symptoms suggests a possible shared underlying mechanism. Thus far, hypothesized mechanisms that have been purported to underlie these symptoms include disruptions to the immune and endocrine systems. Recently circadian rhythm disruption has emerged as a related pathophysiological mechanism underlying cancer- and cancer-treatment related symptoms. Circadian rhythms are endogenous biobehavioral cycles lasting approximately 24 hours in humans and generated by the circadian master clock - the hypothalamic suprachiasmatic nucleus. The suprachiasmatic nucleus orchestrates rhythmicity in a wide range of bodily functions including hormone levels, body temperature, immune response, and rest-activity behaviors. In this review, we describe four common approaches to the measurement of circadian rhythms, highlight key research findings on the presence of circadian disruption in cancer patients, and provide a review of the literature on associations between circadian rhythm disruption and cancer- and treatment-related symptoms. Implications for future research and interventions will be discussed.

Cerebral glucose changes after chemotherapy and their relation to long-term cognitive complaints and fatigue

Purpose

To investigate the short-term cerebral metabolic effects of intravenous chemotherapy and their association with long-term fatigue/cognitive complaints.

Experimental design

Using [¹⁸F]-FDG-PET/CT whole-body scans, we retrospectively quantified relative cerebral glucose metabolism before and after neoadjuvant chemotherapy in a cohort of patients treated for non-metastatic breast cancer (2009-2019). Self-report of cognitive complaints and fatigue were prospectively assessed 7 ± 3 years after therapy. Metabolic changes were estimated with i) robust mixed-effects modelling in regions-of-interest (frontal, parietal, temporal, occipital, and insular cortex) and ii) general-linear modelling of whole-brain voxel-wise outcomes. iii) The association between metabolic changes and self-reported outcomes was evaluated using linear regression-analysis.

Results

Of the 667 screened patients, 263 underwent PET/CT before and after chemotherapy and 183 (48 ± 9 years) met the inclusion criteria. After chemotherapy, decreased frontal and increased parietal and insular metabolism were observed (|ß|>0.273, p_FDR<0.008). Separately, additional increased occipital metabolism after epiribucin+ cyclophosphamide (EC) and temporal metabolism after EC+ fluorouracil chemotherapy were observed (ß>0.244, p_FDR≤0.048). Voxel-based analysis (p_cluster-FWE<0.001) showed decreased metabolism in the paracingulate gyrus (-3.2 ± 3.9%) and putamen (3.1 ± 4.1%) and increased metabolism in the lateral cortex (L=2.9 ± 3.1%) and pericentral gyri (3.0 ± 4.4%). Except for the central sulcus, the same regions showed changes in EC, but not in FEC patients. Of the 97 self-reported responders, 23% and 27% experienced extreme fatigue and long-term cognitive complaints, respectively, which were not associated with metabolic changes.

Conclusion

Both hyper- and hypometabolism were observed after chemotherapy for breast cancer. Combined with earlier findings, this study could support inflammatory mechanisms resulting in relative hypermetabolism, mainly in the parietal/occipital cortices. As early metabolic changes did not precede long-term complaints, further research is necessary to identify vulnerable patients.

Cognitive function is well preserved in a cohort of breast cancer survivors: Roles of cognitive reserve, resilience, and general health

Many patients return to cognitively demanding work after breast cancer treatments. This makes treatment-related cognitive decline an important research topic. Psychological resilience, cognitive reserve and better perceived general health may work as protective factors against cognitive decline. The aim of this study was to analyse whether these factors are associated with cognitive function among such women.

Data from 384 breast cancer survivors who underwent neuropsychological examination at follow-up 4–9 years after surgery were used. The neurocognitive domain variable Learning and Memory was computed from Wechsler Memory Scale-III subtests Learning and Delayed Recall. Another variable, Attention, Processing speed and Executive function, was computed from semantic and verbal fluency tests, Trail Making Test A and B, and Wechsler Adult Intelligence Test-IV subtest Coding. Psychological resilience was measured with Resilience Scale-14, and perceived general health with RAND-36 subitem General Health.

Results

showed that levels of cognitive performance and general health were statistically higher than population average. Resilience and general health in separate models were associated with Attention, Processing speed and Executive function (β = 0.14, p = 0.01; β = 0.13, p = 0.03, respectively). When added simultaneously in the same model, resilience was significant (β = 0.13, p = 0.04), but general health was not. These associations were nonsignificant after controlling for confounding factors. Learning and Memory was not associated with resilience or general health.

Future research should focus on longitudinal studies identifying patients at a high risk of developing cognitive decline after breast cancer treatments and on preventive and therapeutic approaches.

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401 women were neuropsychologically examined 4–9 years after breast cancer surgery.

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Their cognitive performance was on average well preserved.

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Psychological Resilience associated with better cognitive performance in one domain.

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The association between General Health and cognition was less prominent.

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High education level might protect against cognitive decline after breast cancer.

Psychometric properties of the 37-item Functional Assessment of Cancer Therapy-Cognitive Function (FACT-Cog) scale

Aim: To validate the French version of the 37-item Functional Assessment of Cancer Therapy-Cognitive Function, including the four items related to multitasking, previously excluded from the scoring algorithm. Materials & methods: A cross-sectional study was carried out among 261 cancer patients. Validity was confirmed by factor analyses using the principal component analysis technique. Results: Construct validity was demonstrated, and items loaded on subscales with adequate sample adequacy to factor analyses outcomes. Better cognitive functioning was noted with age and in working patients, whereas lower functioning was observed in metastatic patients. Conclusion: The 37-item French tool is valid and reliable; questions related to multitasking could be included in the score.

Signal Variability and Cognitive Function in Older Long-Term Survivors of Breast Cancer with Exposure to Chemotherapy: A Prospective Longitudinal Resting-State fMRI Study

The purpose of this study was to assess the effect of chemotherapy on brain functional resting-state signal variability and cognitive function in older long-term survivors of breast cancer. This prospective longitudinal study enrolled women age ≥ 65 years of age who were breast cancer survivors after exposure to chemotherapy (CH), age-matched survivors not exposed to chemotherapy, and healthy controls. Participants completed resting-state functional brain MRI and neurocognitive testing upon enrollment (timepoint 1, TP1) and again two years later (timepoint 2, TP2). There were 20 participants in each of the three groups at TP1. The CH group showed a significant decrease in SD_BOLD (blood-oxygen-level-dependent signal variability in standard deviation) in the right middle occipital gyrus (ΔSD_BOLD = -0.0018, p = 0.0085, q (p_FDR) = 0.043 at MNI (42, -76, 17)) and right middle temporal gyrus (ΔSD_BOLD = -0.0021, p = 0.0006, q (p_FDR) = 0.001 at MNI (63, -39, -12)). There were negative correlations between the crystallized composite scores and SD_BOLD values at the right inferior occipital gyrus (correlation coefficient r = -0.84, p = 0.001, q (p_FDR) = 0.016) and right middle temporal gyrus (r = -0.88, p = 0.000, q (p_FDR) = 0.017) for the CH group at TP1. SD_BOLD could be a potentially useful neuroimaging marker for older long-term survivors of breast cancer with exposure to chemotherapy.

The effect of doxorubicin or cyclophosphamide treatment on auditory brainstem response in mice

Clinical studies suggest that chemotherapy is associated with long-term cognitive impairment in some patients. Several underlying mechanisms have been proposed; however, the etiology of chemotherapy-related cognitive dysfunction remains relatively unknown. There is evidence that oligodendrocytes and white matter tracts within the CNS may be particularly vulnerable to chemotherapy-related damage and dysfunction. Auditory brainstem responses (ABRs) have been used to detect and measure functional integrity of myelin in a variety of animal models of autoimmune disorders and demyelinating diseases. Limited evidence suggests that increases in interpeak latencies, associated with disrupted impulse conduction, can be detected in ABRs following 5-fluorouracil administration in mice. It is unknown if similar functional disruptions can be detected following treatment with other chemotherapeutic compounds and the extent to which alterations in ABR signals represent robust and long-lasting impairments associated with chemotherapy-related cognitive impairment. Thus, C57BL/6 J mice were treated every 3rd day for a total of 3 injections with low or high dose cyclophosphamide, or doxorubicin. ABRs of mice were assessed on days 1, 7, 14, 56 and 6 months following completion of chemotherapy administration. There were timing and amplitude differences in the ABRs of the doxorubicin and the high dose cyclophosphamide groups relative to the control animals. However, despite significant toxic effects as assessed by weight loss, the changes in the ABR were transient.

Prevalence of Breast Cancer Survivors Among Canadian Women

BACKGROUND

The 49% decrease in breast cancer mortality since 1986 has increased the number of breast cancer survivors requiring survivorship care. The purpose of this analysis was to estimate the 2022 prevalence of breast cancer survivors diagnosed within the past 15 years among Canadian women.

METHODS

We extracted the projected female breast cancer cases from 2007 to 2021 and rates of net survival (competing noncancer causes of death removed) from the Canadian Cancer Society's statistical reports. Overall survival was extracted from published Ontario data. Using known survival rates for 1, 5, 10, and 15 years, we interpolated remaining years and applied the corresponding net and overall survival rates to the projected cases for each year from 2007 to 2021 to determine survivors in 2022. Prevalence for predefined age groups was also calculated. As an example of excess healthcare costs attributable to breast cancer, we calculated the excess costs of heart failure hospitalizations.

RESULTS

From 2007 to 2021, there were 370,756 breast cancer cases. Using net survival, 318,429 (85.9%) of these patients were projected to survive breast cancer by 2022, a prevalence of 2.1% of Canadian women. Using overall survival, prevalence was 1.8%. Prevalence increased with age group, from 0.01% of those aged 20 to 24 years to 12.7% of those aged ≥90 years, and from 1.0% among the working and/or child-raising (age 20-64 years) to 5.4% among elderly populations (age ≥65 years). Among these survivors, 24.9% of projected heart failure hospitalizations would be in excess of those among matched control subjects, with projected excess costs of $16.5 million CAD. Given the excess healthcare costs, potential for reduced contributions to the workforce, and reduced quality of life associated with long-term impairments and risk of excess non-breast cancer death, enhanced breast cancer survivorship care is warranted.

CONCLUSIONS

With an overall prevalence of 2% among Canadian women, breast cancer survivors represent an increasing segment of the working-age and elderly populations.

Cognitive impairment and elevated peripheral cytokines in breast cancer patients receiving chemotherapy

BACKGROUND

Anthracyclines-based regimen (5-fluorouracil, doxorubicin, and cyclophosphamide (FAC); cyclophosphamide, epirubicin, and 5-fluorouracil [CEF]) and non-anthracycline based regimens (cyclophosphamide, methotrexate, and 5-fluorouracil [CMF]) are widely used as neoadjuvant chemotherapy for breast cancer patients.

OBJECTIVE

The present study was conducted to observe the effects of FAC, CEF, and CMF regimen on cognition and circulatory proinflammatory cytokines (interleukin 6 [IL-6] and interleukin 1β [IL-1β]) for the duration of three cycles of chemotherapy in breast cancer patients.

METHODS

Eighty newly diagnosed HER-2 negative breast cancer patients were enrolled and divided into 3 groups as FAC- (n = 27), CEF- (n = 26), and CMF- (n = 27) receiving patients. Serum IL-6 and IL-1β levels were measured by using enzyme-linked immunosorbent assay (ELISA), and cognition was assessed using the Mini-Mental State examination (MMSE) questionnaire.

RESULTS

Anthracycline-based regimen was found to increase the levels of IL-6, IL-1β, and decreased MMSE scores compared with CMF regimen (p < 0.05).

CONCLUSION

Anthracycline-based regimen caused comparatively higher peripheral inflammation, which could be the reason for more decline in cognition in anthracycline-receiving patients than non-anthracycline group.

Adenosine A2A receptor blockade prevents cisplatin-induced impairments in neurogenesis and cognitive function

Chemotherapy-induced cognitive impairment (CICI) has emerged as a significant medical problem without therapeutic options. Using the platinum-based chemotherapy cisplatin to model CICI, we revealed robust elevations in the adenosine A2A receptor (A2AR) and its downstream effectors, cAMP and CREB, by cisplatin in the adult mouse hippocampus, a critical brain structure for learning and memory. Notably, A2AR inhibition by the Food and Drug Administration-approved A2AR antagonist KW-6002 prevented cisplatin-induced impairments in neural progenitor proliferation and dendrite morphogenesis of adult-born neurons, while improving memory and anxiety-like behavior, without affecting tumor growth or cisplatin's antitumor activity. Collectively, our study identifies A2AR signaling as a key pathway that can be therapeutically targeted to prevent cisplatin-induced cognitive impairments.

Transdisciplinary Preliminary Evaluation of Goal Maintenance in Cancer-Related Cognitive Impairment

Women treated for breast cancer often experience decreases in executive functioning, including goal maintenance, which interferes with daily living. The objective of this study was to conduct a preliminary comparison of cognitive neuroscience assessment performance with neuropsychological, self-report, and performance-based assessments of goal maintenance in women with breast cancer. Women treated for breast cancer in the preceding 3 years completed a battery of cognitive assessments. Relationships between assessment methods were evaluated using Spearman rho correlations. Consistent with prior literature, the AY condition of the Dot Pattern Expectancy (DPX) assessment had the highest error rate. No consistent relationships between the DPX and other methods of assessment were identified; however, some moderate correlations were identified between assessments. Women treated for breast cancer present with DPX performance patterns similar to that of healthy controls in past literature. A larger study is required to confirm relationships between measures of goal maintenance across disciplines.

Alterations in degree centrality and cognitive function in breast cancer patients after chemotherapy

The goal of this study was to determine the presence or absence of persistent functional impairments in specific brain regions in breast cancer patients during the recovery period after chemotherapy. We calculated degree centrality (DC) and explored the correlation between brain changes and cognitive scores in 29 female patients with breast cancer who had completed chemotherapy within 1-6 years (C + group) and in 28 age-matched patients with breast cancer who did not receive chemotherapy (C- group). All patients underwent rs-fMRI and cognitive testing. Differences in brain functional activity were explored using DC parameters. Correlations between brain features and cognitive scores were analyzed via correlation analysis. Compared with the C- group, the C + group obtained significantly lower motor and cognitive subscores on the Fatigue Scale for Motor and Cognitive Functions and four subscale scores of the Functional Assessment of Cancer Therapy-Cognitive Function (P < 0.05). Furthermore, the C + group exhibited a significantly higher DC z-score (zDC) in the right superior temporal gyrus and left postcentral gyrus (P < 0.01, FWE-corrected), and a lower zDC in the left caudate nucleus (P < 0.01, FWE-corrected). We found a positive correlation between digit symbol test (DST) scores and zDC values in the right superior temporal gyrus (r = 0.709, P < 0.001), and a negative correlation between DST scores and zDC values in the right angular gyrus (r = -0.784, P < 0.001) and left superior parietal gyrus (r = -0.739, P < 0.001). Chemotherapy can cause abnormal brain activity and cognitive decline in patients with breast cancer, and these effects are likely to persist. DC can be used as an imaging marker for chemotherapy-related cognitive impairment after chemotherapy in breast cancer patients.

Chemobrain in Breast Cancer: Mechanisms, Clinical Manifestations, and Potential Interventions

Among the potential adverse effects of breast cancer treatment, chemotherapy-related cognitive impairment (CRCI) has gained increased attention in the past years. In this review, we provide an overview of the literature regarding CRCI in breast cancer, focusing on three main aspects. The first aspect relates to the molecular mechanisms linking individual drugs commonly used to treat breast cancer and CRCI, which include oxidative stress and inflammation, reduced neurogenesis, reduced levels of specific neurotransmitters, alterations in neuronal dendrites and spines, and impairment in myelin production. The second aspect is related to the clinical characteristics of CRCI in patients with breast cancer treated with different drug combinations. Data suggest the incidence rates of CRCI in breast cancer vary considerably, and may affect more than 50% of treated patients. Both chemotherapy regimens with or without anthracyclines have been associated with CRCI manifestations. While cross-sectional studies suggest the presence of symptoms up to 20 years after treatment, longitudinal studies confirm cognitive impairments lasting for at most 4 years after the end of chemotherapy. The third and final aspect is related to possible therapeutic interventions. Although there is still no standard of care to treat CRCI, several pharmacological and non-pharmacological approaches have shown interesting results. In summary, even if cognitive impairments derived from chemotherapy resolve with time, awareness of CRCI is crucial to provide patients with a better understanding of the syndrome and to offer them the best care directed at improving quality of life.

Lack of cognitive impairment in long-term survivors of colorectal cancer

Background

Our longitudinal study reported cognitive impairment in 43% of people following diagnosis of localised colorectal cancer (CRC) versus 15% in healthy controls (p < 0.001) and 50% versus 13% 1–2 years later (p < 0.001). Here we evaluate cognitive function and neuroimaging in a subgroup at long-term follow-up.

Patients and methods

Cancer-free Australian participants in the study, and controls, completed cognitive and functional assessments. Neuroimaging was optional. Blood tests included inflammatory markers, clotting factors, sex hormones and apolipoprotein E genotype. The primary endpoint was demographically and practice effect-corrected cognitive scores comparing CRC survivors with controls over time examined using a linear mixed model, adjusted for baseline performance. Secondary endpoints included cognitive impairment rate using the Global Deficit Score [GDS > 0.5], Functional Deficit Score, blood results and neuroimaging.

Results

The study included 25 CRC survivors (60% men, median age 72) at mean 9 years after baseline (9 received adjuvant chemotherapy) and 25 controls (44% men, median age 68) at mean 6 years after baseline. There were no significant differences in cognitive scores or proportion with cognitive impairment (16 vs. 8%) between survivors and controls and no evidence of accelerated ageing in CRC survivors. Baseline cognitive performance predicted for subsequent cognitive function. There were no differences in functional tests or blood tests between groups. In 18 participants undergoing neuroimaging, 10 CRC survivors had higher myoinositol levels than 8 controls, and lower volume in the right amygdala and caudate and left hippocampal regions.

Conclusions

There was no difference in cognitive capacity and function between CRC survivors and controls 6–12 years after diagnosis. Differences in neuroimaging require confirmation in a larger sample.

Highlights

• No evidence of long term cognitive impairment in colorectal cancer survivors compared to controls 6–12 years after diagnosis

• No evidence of accelerated cognitive ageing in colorectal cancer survivors

• No evidence of long-term functional impairment in colorectal cancer survivors

Supplementary Information

The online version contains supplementary material available at 10.1007/s00520-022-07008-3.

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

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

ADSC-Exosomes Alleviate MTX-induced Rat Neuronal Damage by Activating Nrf2-ARE Pathway

The aim of this study was to analyze the efficacy and underlying mechanism of adipose-derived mesenchymal stem cell exosome (ADSC-exosomes)-mediated protection on methotrexate (MTX)-induced neuronal damage. We established a H₂O₂-induced oxidative stress model in vitro, as well as an MTX-induced neuronal damage rat model in vivo. We analyzed the effects of ADSC-exosomes on neuronal damage and Nrf2-ARE signaling pathway in rats and related mechanisms. The morphological and functional recovery of rat hippocampal neurons by ADSC-exosomes was examined by Nissl staining and modified neurological severity score (mNSS) score. The activation of Nrf2-ARE pathway effectively inhibited H₂O₂-induced oxidative stress. ADSC-exosomes treatment restored the activity of hippocampal neuronal cells, reduced ROS production, and inhibited hippocampal neuronal cells apoptosis. In in vivo experiments, ADSC-exosomes ameliorates MTX-induced hippocampal neuron damage by triggering Nrf2-ARE pathway, decreasing IL-6, IFN-, and TNF-a levels and TUNEL positive cells in hippocampus, and repairing hippocampal neuronal cell damage. ADSC-exosomes ameliorated MTX-induced neuronal damage and suppressed oxidative stress induced by neuronal damage through the activation of Nrf2-ARE signaling pathway.

A review on the neuroprotective effect of berberine against chemotherapy-induced cognitive impairment

Chemobrain is one of the major side effects of chemotherapy, despite increased research, the mechanisms underlying chemotherapy-induced cognitive changes remain unknown. Though, several possibly important candidate mechanisms have been identified and will be studied further in the future. Chemobrain is characterized by memory loss, cognitive impairment, difficulty in language, concentration, acceleration, and learning. The major characteristic of chemobrain is oxidative stress, mitochondrial dysfunction, immune dysregulation, hormonal alteration, white matter abnormalities, and DNA damage. Berberine (BBR) is an isoquinoline alkaloid extracted from various berberine species. BBR is a small chemical that easily passes the blood-brain barrier (BBB), making it useful for treating neurodegenerative diseases. Many studies on the pharmacology of BBR have been reported in the past. Furthermore, several clinical and experimental research indicates that BBR has a variety of pharmacological effects. So, in this review, we explore the pathogenesis of chemobrain and the neuroprotective potential of BBR against chemobrain. We also introduced the therapeutic role of BBR in various neurodegenerative and neurological diseases such as Alzheimer's, Parkinson's disease, mental depression, schizophrenia, anxiety, and also some stroke.

Potential Molecular Biomarkers of Central Nervous System Damage in Breast Cancer Survivors

Damage of the central nervous system (CNS), manifested by cognitive impairment, occurs in 80% of women with breast cancer (BC) as a complication of surgical treatment and radiochemotherapy. In this study, the levels of ICAM-1, PECAM-1, NSE, and anti-NR-2 antibodies which are associated with the damage of the CNS and the endothelium were measured in the blood by ELISA as potential biomarkers that might reflect pathogenetic mechanisms in these patients. A total of 102 patients enrolled in this single-center trial were divided into four groups: (1) 26 patients after breast cancer treatment, (2) 21 patients with chronic brain ischemia (CBI) and asymptomatic carotid stenosis (ICA stenosis) (CBI + ICA stenosis), (3) 35 patients with CBI but without asymptomatic carotid stenosis, and (4) 20 healthy female volunteers (control group). Intergroup analysis demonstrated that in the group of patients following BC treatment there was a significant increase of ICAM-1 (mean difference: −368.56, 95% CI −450.30 to −286.69, p < 0.001) and PECAM-1 (mean difference: −47.75, 95% CI −68.73 to −26.77, p < 0.001) molecules, as compared to the group of healthy volunteers. Additionally, a decrease of anti-NR-2 antibodies (mean difference: 0.89, 95% CI 0.41 to 1.48, p < 0.001) was detected. The intergroup comparison revealed comparable levels of ICAM-1 (mean difference: −33.58, 95% CI −58.10 to 125.26, p = 0.76), PECAM-1 (mean difference: −5.03, 95% CI −29.93 to 19.87, p = 0.95), as well as anti-NR-2 antibodies (mean difference: −0.05, 95% CI −0.26 to 0.16, p = 0.93) in patients after BC treatment and in patients with CBI + ICA stenosis. The NSE level in the group CBI + ICA stenosis was significantly higher than in women following BC treatment (mean difference: −43.64, 95% CI 3.31 to −83.99, p = 0.03). Comparable levels of ICAM-1 were also detected in patients after BC treatment and in the group of CBI (mean difference: −21.28, 95% CI −111.03 to 68.48, p = 0.92). The level of PECAM-1 molecules in patients after BC treatment was also comparable to group of CBI (mean difference: −13.68, 95% CI −35.51 to 8.15, p = 0.35). In conclusion, among other mechanisms, endothelial dysfunction might play a role in the damage of the CNS in breast cancer survivors.

Neuroprotective effect of Mulmina Mango against chemotherapy-induced cognitive decline in mouse model of mammary carcinoma

The post-treatment status of breast cancer survivors has become a concern because of the toxicity induced by chemotherapeutic agents in the brain tissues resulting in cognitive deficits, which is generally referred as chemobrain. The aim of this study was to assess the effect of a proprietary ayurvedic formulation Mulmina Mango against chemotherapy-induced cognitive impairment (CICI). Mammary carcinoma was induced by subcutaneously inoculating 4T1 cells into the mammary fat pad of the animals. Intraperitoneal administration of Cyclophosphamide, Methotrexate, 5-Fluorouracil (CMF) regimen was carried out once a week for three weeks. Treatment of Mulmina began one week before chemotherapy and continued till the end of the chemotherapy cycle. After three cycles of chemotherapy, cognitive decline was assessed by Morris water maze task followed by assessment of locomotor activity by open-field test. Tumor progression was evaluated by measurement of tumor volume. Oxidative and neuroinflammatory markers were also evaluated from the isolated brain samples. CMF treatment resulted in a considerable reduction in tumour volume. We found chemotherapy negatively affected behavioral and biochemical parameters in animals and Mulmina treatment ameliorated these cognitive impairments by restoring antioxidant and maintaining cytokine levels. The combination of phytochemicals in Mulmina proved its possible ability to alleviate CICI without affecting chemotherapeutic efficiency and could pave the way for identifying treatment strategies to combat chemobrain.

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

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

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.

Prospective Rates, Longitudinal Associations, and Factors Associated With Comorbid Insomnia Symptoms and Perceived Cognitive Impairment

Background

Insomnia and cognitive impairment are both common conditions experienced by people diagnosed with cancer. Individually, these conditions have negative impacts on functioning, but the combined burden has yet to be evaluated. The purpose of this research was to estimate rates of comorbid insomnia and perceived cognitive impairments, examine the longitudinal associations between these two conditions, and identify demographic and clinical factors associated with reporting both insomnia and perceived cognitive impairment.

Methods

In this secondary analysis, a heterogeneous sample of 962 patients completed the Insomnia Severity Index (ISI) and the Cognitive Failures Questionnaire (CFQ) at the time of their cancer surgery (baseline; T1) and then again at 2 (T2), 6 (T3), 10 (T4), 14 (T5), and 18 (T6) months. Correlations and partial correlations, controlling for age and education level, were computed at each time point to assess the relationship between ISI and CFQ scores. Cross-lagged correlations assessed associations between ISI and CFQ scores over time. Proportions of patients with comorbid insomnia and cognitive impairments were calculated and logistic regressions investigated changes over time in these proportions. ANOVAs, logistic regressions, ordinal regressions, and multinomial regressions were used to identify risk factors of having comorbid insomnia and cognitive difficulties.

Results

Significant and bidirectional correlations between ISI and CFQ scores were observed at each time point and over time. The proportion of patients having both clinical levels of insomnia and perceived cognitive difficulties ranged from 18.73 to 25.84% across time points and this proportion was significantly greater at T1 and T2 than T4, T5, and T6. Participants who reported comorbid insomnia and cognitive impairment were more likely to be younger, female, not currently working, currently receiving chemotherapy, with clinical levels depression and anxiety, and using antidepressants or anxiolytics.

Conclusion

Comorbid insomnia and perceived cognitive impairment affects around one in five patients and is more frequent at the beginning of the cancer care trajectory. The relationship between insomnia and cognitive impairment appears to be bidirectional. Insomnia may represent an important patient level vulnerability that when identified and treated can improve perception of cognitive function.

Electroacupuncture for Cancer-Related Cognitive Impairment: A Clinical Feasibility Study

BACKGROUND

Cancer-related cognitive impairment (CRCI) is a significant problem for cancer patients, as the number of cancer survivors experiencing cognitive impairments is increasing in the absence of standard treatment. There have been attempts to improve the cognitive function of patients with cancer using acupuncture; however, no studies have been conducted using electroacupuncture. Thus, we designed a preliminary study to investigate the feasibility of a clinical trial using electroacupuncture in CRCI patients.

METHODS

We conducted a single-arm, pilot, clinical trial to investigate the feasibility of a study protocol for further large-scale clinical trials of electroacupuncture in CRCI patients. All participants were treated with electroacupuncture twice a week for 30 minutes at a time, for 8 weeks on acupoints GV20, GV24, EX-HN1, and GB20, HT7, PC6, and KI3. Both subjective and objective outcomes of cognitive function, quality of life (QoL), and psychological factors were measured in all participants at baseline, week 4, 8, and 12. For safety assessment, vital signs, laboratory examinations, and adverse events (AEs) were observed throughout the trial.

RESULTS

A total of 12 participants were enrolled at Daejeon and Dunsan Korean Medicine Hospital of Daejeon University from 21 April 2017 to 31 January 2018. After 8 weeks of treatment, electroacupuncture significantly improved both subjective and objective cognitive outcomes, including the perceived cognitive impairments scale of the Functional Assessment of Cancer Therapy-Cognitive Function, QoL scale of the European Organization for Research and Treatment of Cancer Quality of Life Core Questionnaire-C30, Korean version of Montreal Cognitive Assessment, Boston Naming Test, Seoul Verbal Learning Test, and Rey Complex Figure Test. During the entire trial period, 19 AEs were observed, with no serious AEs. Additionally, it was found that all feasibility outcomes, including recruitment, completion, and adherence rates, achieved successful results as the ratio exceeded 0.8.

CONCLUSION

Our study results revealed that electroacupuncture improved cognitive complaints in cancer patients, and we expect electroacupuncture to be a safe and effective management therapy for CRCI patients. These feasibility trial results will be used as preliminary data for future randomized controlled clinical trials.

TRIAL REGISTRATION NUMBER

Korean Clinical Trial Registry (KCT0002168).

Research advances on how metformin improves memory impairment in "chemobrain"

Cognitive impairment caused by chemotherapy, referred to as “chemobrain,” is observed in approximately 70% of cancer survivors. However, it is not completely understood how chemotherapy induces cognitive dysfunction, and clinical treatment strategies for this problem are lacking. Metformin, used as a first-line treatment for type 2 diabetes mellitus, is reported to reduce the effects of chemobrain. Recently, several studies have examined the effect of metformin in rescuing chemobrain. This review discusses recent clinical/preclinical studies that addressed some mechanisms of chemobrain and evaluates the effect of metformin in rescuing chemobrain and its potential mechanisms of action.

Long-Term Cognitive Dysfunction in Cancer Survivors

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

Crosstalk between anticancer drugs and mitochondrial functions

Chemotherapy is an important component of cancer treatment, which has side effects like vomiting, peripheral neuropathy, and numerous organ toxicity but the most significant outcomes of chemotherapy are cognitive impairment, which is mainly referred to as chemobrain or CICI (chemotherapy-induced cognitive impairment). It is characterized by difficulty with language, concentrating, processing speed, learning, and memory, as it affects the hippocampus areas of the brain. Mitochondrial dysfunction and oxidative stress are one of the major mechanisms causing chemobrain. The generation of reactive oxygen species (byproducts of oxidative phosphorylation) mainly occurs in mitochondria that play a prominent role in the induction of oxidative stress. The homeostasis of ROS in the mitochondria is maintained by mitochondrial antioxidant mechanism via enzymes like catalase, glutathione, and superoxide dismutase. Lungs and breast cancer are the two most common types of cancer, which are the most leading cancers in the world with about 4.18 million cases. In this review we exposed the current knowledge regarding chemotherapy-induced oxidative stress and mitochondrial dysfunction to cause cognitive impairment.We especially focused on the antineoplastic agent (ADRIAMYCIN, CYCLOPHOSPHAMIDE), platinum group agent CISPLATIN, antimetabolite agents (METHOTREXATE), and nitrogen mustard agent (CARMUSTINE) which increase oxidative stress and inflammatory markers in the PNS (peripheral nervous system) as well as the central nervous system. We also highlight the behavioural and functional changes in the brain.

Residual work capacity and (in)ability to work fulltime among a year cohort of cancer survivors who claim a disability benefit

PURPOSE

Residual work capacity (RWC) and inability to work fulltime (IWF) are important outcomes in disability benefit assessments for workers diagnosed with cancer. The aim of this study is to gain insight into the prevalence of both outcomes, the associations of disease-related and socio-demographic factors and if these differ across cancer diagnosis groups.

METHODS

A year cohort of anonymized register data of cancer survivors who claim a disability benefit after 2 years of sick leave (n = 3690, age 53.3 ± 8.8, 60.4% female) was used. Having no RWC was defined as having no possibilities to perform any work at all, whereas IWF was defined as being able to work less than 8 h per day.

RESULTS

The prevalence of being assessed with no RWC was 42.6%. Of the applicants with RWC (57.4%), 69.8% were assessed with IWF. Cancers of the respiratory organs showed the highest odds for having no RWC, whereas lymphoid and haematopoietic cancers showed the highest odds for IWF. Within specific cancer diagnosis groups, different associations were identified for both outcomes.

CONCLUSION

The prevalence of no RWC and IWF in applicants of work disability benefits diagnosed with cancer is high compared to the prevalence in other diagnoses. The odds for no RWC, IWF, and associated factors differ per cancer diagnosis group.

IMPLICATIONS FOR CANCER SURVIVORS

Being diagnosed with cancer has an enormous impact on work (dis)ability. Our results show that 2 years after being diagnosed with cancer, the majority of the disability benefit applicants are assessed with RWC; however, only 15% of all applicants with cancer had a normal ability to work fulltime, and therefore, it is of great importance to accompany them in their return to work.

Predictors of health-related quality of life after completion of chemotherapy among Malaysian early-stage breast cancer survivors

PURPOSE

Health-related quality of life (QoL) is an important outcome measure in breast cancer management. Evidence of QoL of breast cancer patients in lower and middle-income countries remains scarce. We examined the level of QoL, cognitive impairment, psychological distresses, and the predictors of QoL among multiethnic Malaysian early-stage breast cancer survivors 1 to 3 years following chemotherapy.

METHODS

A total of 160 breast cancer survivors from the University of Malaya Medical Centre (UMMC) participated in this cross-sectional study. Their QoL was evaluated with the Malay version of the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core 30 (QLQ-C30) version 3.0. Cognitive functioning and psychological distress were evaluated using the Malay version of the Montreal Cognitive Assessment (MoCA-BM) and Hospital Anxiety and Depression Scale (HADS), respectively. Data analysis was performed with Pearson's correlation and multiple regression analyses.

RESULTS

At 1- to 3-year post-chemotherapy, the mean EORTC QLQ-C30 global health status of the breast cancer survivors was relatively low (60.5 over 100, SD = 10.88). One-third (31.9%) of them demonstrated cognitive impairment, and another 3.2% showed moderate to severe anxiety levels. The significant predictors for global health status and functioning included age, psychological distresses, cognitive performance, fatigue, appetite loss, insomnia, pain, and constipation.

CONCLUSION

Our breast cancer survivors demonstrated poor global health status. Health care providers and policymakers must strive to provide holistic intervention strategies to improve the multiple dimensions of QoL and the cognitive and psychological functioning of this vulnerable population.

The Effects of 5-Fluorouracil/Leucovorin Chemotherapy on Cognitive Function in Male Mice

5-Fluorouracil (5-Fu) and leucovorin (LV) are often given in combination to treat colorectal cancer. 5-Fu/LV prevents cell proliferation by inhibiting thymidylate synthase, which catalyzes the conversion of deoxyuridine monophosphate to deoxythymidine monophosphate. While 5-Fu has been shown to cause cognitive impairment, the synergistic effect of 5-Fu with LV has not been fully explored. The present investigation was designed to assess how the combination of 5-Fu and LV affect cognition in a murine model. Six-month-old male mice were used in this study; 15 mice received saline injections and 15 mice received 5-Fu/LV injections. One month after treatment, the elevated plus maze, Y-maze, and Morris water maze behavioral tasks were performed. Brains were then extracted, cryosectioned, and stained for CD68 to assay microglial activation and with tomato lectin to assay the vasculature. All animals were able to locate the visible and hidden platform locations in the water maze. However, a significant impairment in spatial memory retention was observed in the probe trial after the first day of hidden-platform training (first probe trial) in animals that received 5-Fu/LV, but these animals showed spatial memory retention by day 5. There were no significant increases in inflammation as measured by CD68, but 5-Fu/LV treatment did modulate blood vessel morphology. Tandem mass tag proteomics analysis identified 6,049 proteins, 7 of which were differentially expressed with a p-value of <0.05 and a fold change of >1.5. The present data demonstrate that 5-Fu/LV increases anxiety and significantly impairs spatial memory retention.

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

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

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

PROBLEM IDENTIFICATION

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

LITERATURE SEARCH

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

DATA EVALUATION

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

SYNTHESIS

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

IMPLICATIONS FOR PRACTICE

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

Exploring primary breast cancer survivors' self-management of sustained cancer-related cognitive impairment in the workplace

OBJECTIVE

Work plays a central role in return to a more 'normal' life among women diagnosed with primary breast cancer. However, ongoing cancer-related cognitive impairment (CRCI) and cancer-related sequelae continue to detrimentally impact workability. Only a few studies have explored the long-term consequences of CRCI and self-management coping strategies applied in the workplace. This study explored women's experiences of sustained post-treatment CRCI and its impact on workability beyond the initial return-to-work (RTW), as well as experiences of self-management coping strategies.

METHOD

Forty employed women with a diagnosis of primary breast cancer who were between 6 and 60 months post-active treatment completed a semi-structured telephone interview. A 'framework' analysis approach was used.

RESULTS

Two superordinate themes were identified: 'Sustained consequences of CRCI' and 'Self-management coping strategies to support work-related performance'. We found that the impact of CRCI extends beyond the initial RTW. The adopted self-management coping strategies could provoke mixed emotions, including emotional distress. Reduced workability was experienced up to 5-years post-active-treatment.

CONCLUSION

Sustained CRCI induces negative emotions, fatigue and diminishes confidence reducing workability long into survivorship beyond RTW. The self-management coping strategies implemented to manage these sequelae generate mixed feelings, with some describing the strategies as problematic and of little benefit.

Management of Cancer-Related Cognitive Impairment: A Systematic Review of Computerized Cognitive Stimulation and Computerized Physical Activity

Cancer-related cognitive impairment (CRCI) occurs frequently in patients living with cancer, with consequences on quality of life. Recently, research on the management of these difficulties has focused on computerized cognitive stimulation and computerized physical activity programs. This systematic review presents the state of knowledge about interventions based on computerized-cognitive stimulation and/or physical activity to reduce CRCI. The review followed the PRISMA guidelines. A search was conducted in PUBMED and Web of Science databases. Risk of bias analysis was conducted using the Rob2 tool and the quality of evidence was conducted following the GRADE approach. A total of 3776 articles were initially identified and 20 of them met the inclusion criteria. Among them, sixteen investigated computerized-cognitive stimulation and four computerized-physical activity. Most of the studies were randomized controlled trials and assessed the efficacy of a home-based intervention on objective cognition in adults with cancer. Overall, cognitive improvement was found in 11/16 computerized-cognitive stimulation studies and 2/4 computerized-physical activity studies. Cognitive stimulation or physical activity improved especially cognitive complaints, memory, and attention. These results suggest the efficacy of both computerized-cognitive stimulation and physical activity. However, we report a high risk of bias for the majority of studies and a low level of quality of evidence. Therefore, further investigations are needed to confirm the efficacy of these interventions and to investigate the possible added benefit on cognition of a combined computerized-cognitive/physical intervention.

Routine Cancer Treatment Regimens and Its Impact on Fine Motor Dexterity in Breast Cancer

INTRODUCTION

Breast cancer can be a major challenge for those affected. Knowledge of changes in fine motor dexterity in affected women due to routine cancer therapies can help guide effective support.

METHODS

For this prospective observational study, we collected data of 79 women with a mean age 54.6 ± 9.5 years prior to, after breast cancer therapy (T1), and at 3-month follow-up. The fine motor dexterity was assessed for 4 treatment subgroups: SC = Surgery + Chemotherapy, SCR = Surgery + Chemotherapy + Radiotherapy Therapy, SR = Surgery + Radiotherapy, and S = Surgery.

RESULTS

Over time, women with breast cancer showed significant decreases in fine motor dexterity across all treatment groups (p < 0.001). The strongest negative effect was seen in the treatment groups receiving additional chemotherapy. SCR group showed pronounced limitations for dominant hand (DH) -12%; non-dominant hand (NDH) -15%; both hands (BH) -17%; assembly (ASSY) -11% at T1. Significant interaction was noticeable in DH (F = 5.59, p < 0.001), NDH (F = 6.61, p < 0.001), BH (F = 13.11 p < 0.001), and ASSY (F = 5.84 p < 0.001).

DISCUSSION/CONCLUSION

Our study showed that the extent of change in fine motor dexterity depends on the treatment regimen. The detection of unmet care needs could help to personalize and optimize clinical and survivorship care. Based on our findings, multidisciplinary support initiated early in breast cancer therapy is required.

Focal white matter microstructural alteration after anthracycline-based systemic treatment in long-term breast cancer survivors: a structural magnetic resonance imaging study

Understanding the neural correlates of cognitive problems in patients with breast cancer (BC) after systemic treatment have been a topic of increasing investigation. The heterogeneity of the systemic treatment regimens may undermine our ability to identify brain microstructural alterations resulting from any given regimen. We investigated the detrimental effects of the anthracycline-based systemic treatment (AST) regimen (epirubicin and cyclophosphamide + docetaxel + tamoxifen) on brain gray matter (GM) and white matter (WM) microstructural alteration in long-term BC survivors. We performed a battery of neuropsychological tests and structural magnetic resonance imaging (MRI) to 31 long-term BC survivors who had received the AST regimen (AST group) and 43 healthy controls (HC group). Voxel-based morphometry evaluated the whole-brain voxel-wise GM volume, while diffusion tensor imaging technique with tract-based spatial statistics analysis evaluated whole-brain WM microstructural alteration. Partial least squares regression (PLSR) was used to evaluate the relationship between cognitive impairment and brain microstructural alteration in BC survivors. Compared with the HC group, the AST group exhibited a significantly poorer performance in attention, as well as a marginal significantly poorer performance in verbal working memory and executive function. Significantly lower fractional anisotropy (FA), higher radial diffusivity (RD), and lower axial diffusivity (AD) in multiple brain WM regions were showed in AST group compared with the HC group. Overlap of lower FA and higher RD was found in the body of corpus callosum (CC) and bilateral superior corona radiata (SCR), whereas overlap of lower FA and AD was found in the body of CC and right SCR. The PLSR results showed that the WM regions with overlap of lower FA and AD were significantly associated with executive and verbal working memory decline. No significant difference was observed in the GM volume between groups. Our results suggest that microstructural abnormalities of certain vulnerable WM regions in the AST regimen-exposed brain may provide neuroimaging evidence for the identification of brain injury and cognitive impairment induced by specific chemotherapy regimens.