Potential factors associated with perceived cognitive impairment in breast cancer survivors

A scoping review of studies exploring physical activity and cognition among persons with cancer

PURPOSE

This scoping review aimed to identify and synthesize published studies on physical activity (PA) and cognition among persons with cancer and elucidate knowledge gaps.

METHODS

Articles were identified through electronic and manual searches (02/21 and 03/22) using the following inclusion criteria: (1) empirical, peer-reviewed publication in English, (2) sample comprised persons with cancer, and (3) reported at least one statistical association between PA and cognition. Multiple reviewers independently performed study selection and data extraction, and results were mapped in tabular and narrative form.

RESULTS

Ninety-seven articles were eligible; these were largely published from 2017 to 2022 (54.6%), conducted in high-income countries (96.9%), and presented (quasi-)experimental studies (73.2%). Samples predominantly comprised women with breast cancer (48.5%), and recruitment often occurred post-treatment (63.9%). PA interventions included: aerobic (32.3%), resistance (4.8%), combined aerobic/resistance (38.7%), mind-body (19.4%), or other PA (4.8%). Most (66%) articles reported inconclusive findings; 32% were positive (in support of PA promoting cognition or vice versa), and 2.1% were negative. Diverse samples and studies with long-term follow-up were scarce.

CONCLUSIONS

The state of knowledge is insufficient and more rigorous, large-scale studies are required to provide definitive conclusions about the cognitive benefits of PA among persons with cancer.

IMPLICATIONS FOR CANCER SURVIVORS

Cancer-related cognitive impairment (CRCI) thwarts quality of life. This review summarizes what is known about the association between PA and cognition among persons with cancer and concludes that the evidence is currently equivocal. Hence, it remains uncertain if PA interventions can reduce CRCI, and large-scale PA intervention trials explicitly designed to promote cognition are greatly needed.

The Relationship Between Self-reported Cognitive Abilities and Psychological Symptoms in Breast Cancer Survivors

BACKGROUND

Many breast cancer survivors (BCSs) report numerous symptoms following cancer treatment, including cognitive concerns and psychological symptoms (anxiety and depression). However, the association among these symptoms is not well understood.

OBJECTIVES

The objectives were to, primarily, examine the relationship between self-reported cognitive ability and psychological symptoms (anxiety and depressive symptoms) controlling for potential confounders of age, education, and time posttreatment and, secondarily, examine the relationship between self-reported cognitive domains (attention, language, visuoperception, visual memory, and verbal memory) and psychological symptoms.

METHODS

This secondary data analysis pooled data from 2 theoretically and conceptually congruent, institutional review board-approved studies of BCSs. Breast cancer survivors completed the Multiple Ability Self-report Questionnaire (cognitive ability), Spielberger State Trait Anxiety Inventory-State (anxiety), and Center for Epidemiological Studies-Depression Scale (depressive symptoms). Data were analyzed using descriptive statistics, Pearson correlations, and separate linear regression.

RESULTS

One hundred fifty-five BCSs who were on average 54.8 (SD, 8.9) years of age, approximately 5 years (mean, 5.2 [SD, 3.8] years) posttreatment, and well-educated (mean, 15.2 [SD, 2.2] years) completed questionnaires. In bivariate correlations, higher anxiety and depressive symptoms were significantly related to cognitive abilities in all domains ( P = <.01). In the regression model, increased anxiety was associated with poorer cognitive abilities in all domains ( P < .01).

CONCLUSIONS

Anxiety and depressive symptoms were associated with decrements in self-reported cognitive abilities among BCSs.

IMPLICATIONS FOR PRACTICE

With increasing numbers of BCSs, more research is needed to address psychological symptoms, which correlate with cognitive function. Findings from this analysis can inform clinical BCS survivorship care planning and future interventional research, focused on comprehensive symptom management.

Impact of psychosocial, behavioral and lifestyle factors on subjective cognitive complaints and perceived quality of life in a large cohort of Italian breast cancer patients

The impact of psychosocial and behavioral factors on Cancer Related Cognitive Impairment manifestations is still under debate. Study’s purpose is to determine the prevalence rate of cancer related cognitive impairment in a cohort of Italian breast cancer patients and to evaluate the implication of specific behavioral factors. For these purposes, a total of 233 women (106 breast cancer patients and 127 age-matched controls without oncological diagnosis) completed a questionnaire investigating cognitive functionality (FACT-Cog v3.0), sociodemographic characteristics, clinical information, psychosocial and behavioral factors (cognitive reserve, sleep quality, dietary habits, physical activity). The results indicated a higher prevalence rate of subjective cognitive complaints in breast cancer patients (37%) compared to a representative sample of women in the same age group without an oncological diagnosis (p &lt; 0.001). Moreover, breast cancer patients showed significantly lower levels of cognitive reserve (p &lt; 0.05) and worse sleep quality (p &lt; 0.01) compared to age-matched controls. Further analysis revealed that breast cancer patients reporting subjective cognitive complaints differed significantly from breast cancer patients without subjective cognitive complaints on measures of perceived cognitive abilities (p &lt; 0.001) and on the impact of cognitive difficulties on perceived quality of life (p &lt; 0.01). Future studies are needed to examine behavioral directed interventions to prevent subjective cognitive deficits in breast cancer patients.

Sleep Disturbance and Its Association With Sluggish Cognitive Tempo and Attention in Pediatric Brain Tumor Survivors

Background

Pediatric brain tumor (PBT) survivors are at risk for developing sleep disturbances. While in other pediatric populations sleep disturbance has been associated with worse cognitive functioning, it is unclear to what extent this relationship generalizes to PBT survivors. The aim of the current study was to assess the relationship between sleep disturbance and aspects of cognition, including sluggish cognitive tempo (SCT) as well as attention and working memory.

Materials and Methods

Eighty-three PBT survivors 6–18 years of age who were at least 3 months post-treatment were included in the present cross-sectional study. Level of sleep disturbance was measured as a composite score reflecting various sleep problems as rated by caregivers. Cognitive measures included caregiver-ratings of sluggish cognitive tempo and attention problems, as well as performance-based cognitive measures assessing attention and executive functioning. Hierarchical regression analysis was used to assess associations between sleep and cognition.

Results

Of all caregivers, 32.5% reported one or more sleep disturbances as “very/often true” and over 68% of caregivers rated at least one sleep-related item as “somewhat true.” Of all cognitive variables, scores were most frequently impaired for SCT (30%). A higher level of sleep disturbance was associated with worse SCT and parent-rated attention problems. Associations between sleep and performance-based cognitive measures assessing attention and working memory were not statistically significant.

Conclusion

Findings of the current study highlight the importance of further investigation into the relationship between sleep and cognition in PBT survivors, which may assist efforts to maximize cognitive outcome and health-related quality of life in PBT survivors. The current study additionally suggests further investigation of SCT in this population is warranted, as it may be more sensitive to detecting possible associations with sleep disturbance relative to discrete measures that assess cognitive performance under ideal circumstances.

Cancer treatment regimens and their impact on the patient-reported outcome measures health-related quality of life and perceived cognitive function

Background and purpose

Breast cancer can be a significant challenge for those affected. Knowledge of physical function, social-emotional challenges, and perceived cognitive function based on the cancer treatment regimens may help to inform adequate support.

Methods

For this prospective observational pilot study, we collected data of seventy-nine women (mean age 54.6 ± 9.5 years) before (T0) and after (T1) initial breast cancer treatment. Functional Assessment of Cancer Therapy-Breast (FACT-B) and Functional Assessment of Cancer Therapy–Cognitive-Function (FACT-Cog) were used to collect data of four treatment subgroups: SCR = Surgery + Chemotherapy + Radiation Therapy; SC = Surgery + Chemotherapy; SR = Surgery + Radiation Therapy; S = Surgery. A mixed ANOVA and posthoc analysis (Tukey, Games-Howell) were used to detect interactions (group by time) and the main effect. A repeated-measures ANOVA displayed individual group differences (time).

Results

Significant interaction showed more deterioration was experienced with SC and SCR than SR and S for FACT-B (p < 0.01) and FACT-Cog (p < 0.001). The longitudinal comparison between T0 and T1 indicated a significant group main effect on all subscales (p < 0.001) except for Emotional Well-Being. Significant reductions (p < 0.05) in FACT-B, (− 19%); FACT-Cog, (− 21%) with most pronounced effect in Physical Well-Being (− 30%), Functional Well-Being (− 20%), Breast Cancer Subscale (− 20%), Perceived Cognitive Impairments (− 18%) and Impact of Cognitive Impairments on Quality of Life (− 39%) were detected for SCR.

Conclusion

Our study showed that the extent of change in health-related quality of life (HRQoL) and perceived cognitive function (PCF) depends on the treatment regimen. Multidisciplinary support initiated early in breast cancer therapy is needed, especially for women undergoing combined cancer treatment. Routine assessment of patient-reported outcomes (PROs) in oncology practice may increase the transparency of patients’ perceived circumstances, leading to personalized and optimized acute and survivorship care.

Impact of taxane-based chemotherapy among older women with breast cancer on cognition and quality of life: a longitudinal pooled analysis

PURPOSE

Older cancer patients are susceptible to long-term effects of chemotherapy, including cancer-related cognitive decline and impairments to quality of life. Taxane-based chemotherapies are associated with physical declines among older women and may negatively impact cognitive performance. We sought to examine whether changes in objective and subjective measures of cognitive performance and well-being differ among older breast cancer survivors as a function of taxane-based chemotherapy treatment regimens.

METHODS

Individual-level data were pooled and harmonized from two large prospective studies of older (greater than 60 years) breast cancer survivors. Assessments were conducted prior to systemic therapy and up to 36 months after. Cognitive performance was assessed with objective (working memory, processing speed, and executive functions) and subjective tests and physical, emotional, and functional well-being were also assessed.

RESULTS

One hundred and sixty-seven (M age = 67.3 years) women with 116 receiving chemotherapy with taxanes and 51 without taxanes contributed data. Declines in subjective cognition for both groups were significant between pre-treatment and 12-month follow-up. Significant improvements were seen on a measure of objective cognition (working memory) from 12 to 36 months. Measures of well-being improved from prior to systemic therapy to 12 months. Longitudinal changes across all measures did not vary as a function of receipt of taxane-based treatment.

CONCLUSION

Older women who received treatment with taxanes did not have greater declines in cognitive performance or well-being than women receiving other chemotherapy regimens. Despite older cancer survivors being at greater risk for negative outcomes, treatment with taxane-based chemotherapies does not appear to exacerbate these health consequences.

Exploring the Effects of Yoga Therapy on Heart Rate Variability and Patient-Reported Outcomes After Cancer Treatment: A Study Protocol

BACKGROUND

Following cancer treatment, adults commonly report worsened patient-reported outcomes (PROs) such as anxiety, stress, depression, persistent and upsetting cognitive complaints, unrelenting fatigue, and reduced quality of life. Poorer PROs are associated with disrupted autonomic nervous system functioning as measured by heart rate variability (HRV), both of which have been associated with greater morbidity and mortality. Interventions to improve HRV and PROs among adults following cancer treatment are needed. Yoga therapy holds promise as an intervention to improve HRV and PROs. Therefore, we conducted a single-subject exploratory experimental study to investigate the effects of yoga therapy on HRV and specific PROs (ie, cancer-related fatigue, anxiety, cognitive function, depression, stress, quality of life) in adults treated for cancer. To reduce publication bias, improve reproducibility, and serve as a reference for forthcoming reporting of study results, we present the study protocol for this study herein.

METHODS

Participants were adults who completed cancer treatment that were recruited from the Ottawa Integrative Cancer Centre. Consenting and eligible participants received one 1:1 yoga therapy session (ie, 1 participant, 1 Yoga Therapist) and 6 weekly group-based yoga therapy sessions (ie, 2-3 participants, 1 Yoga Therapist). Participants completed assessments 7 times: 3 times prior to the program (ie, -6 weeks, -3 weeks, immediately prior to the 1:1 yoga therapy session), immediately following the 1:1 yoga therapy session, prior to the first group-based yoga therapy session, after the last group-based yoga therapy session, and at a 6-week follow-up. Hierarchical linear modeling will be used to test the average effects of the yoga therapy program across participants.

DISCUSSION

This study will explore several novel hypotheses, including whether yoga therapy can improve HRV and/or specific PROs among adults treated for cancer acutely (ie, during a 1:1 yoga therapy session) and/or through repeated exposure (ie, after completing 6 weeks of group-based yoga therapy). Although the findings will require confirmation or refutation in future trials, they may provide initial evidence that YT may benefit adults treated for cancer.

TRIAL REGISTRATION

ISRCTN registry, ISRCTN64763228. Registered on December 12, 2021. This trial was registered retrospectively. URL of trial registry record: https://www.isrctn.com/ISRCTN64763228.

'Food for Thought'-The Relationship between Diet and Cognition in Breast and Colorectal Cancer Survivors: A Feasibility Study

Survivors of cancer frequently experience persistent and troublesome cognitive changes. Little is known about the role diet and nutrition plays in survivors' cognition. We explored the feasibility of collecting cross-sectional online data from Australian survivors of breast and colorectal cancer to enable preliminary investigations of the relationships between cognition with fruit and vegetable intake, and the Omega-3 Index (a biomarker of long chain omega 3 fatty acid intake). A total of 76 participants completed online (and postal Omega-3 Index biomarker) data collection (62 breast and 14 colorectal cancer survivors): mean age 57.5 (±10.2) years, mean time since diagnosis 32.6 (±15.6) months. Almost all of the feasibility outcomes were met; however, technical difficulties were reported for online cognitive testing. In hierarchical linear regression models, none of the dietary variables of interest were significant predictors of self-reported or objective cognition. Age, BMI, and length of treatment predicted some of the cognitive outcomes. We demonstrated a viable online/postal data collection method, with participants reporting positive levels of engagement and satisfaction. Fruit, vegetable, and omega-3 intake were not significant predictors of cognition in this sample, however the role of BMI in survivors' cognitive functioning should be further investigated. Future research could adapt this protocol to longitudinally monitor diet and cognition to assess the impact of diet on subsequent cognitive function, and whether cognitive changes impact dietary habits in survivors of cancer.

Cognitive effects of chemotherapy: An integrative review

PURPOSE

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

METHOD

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

RESULTS

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

CONCLUSIONS

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

Cancer-Related Symptoms and Cognitive Intervention Adherence Among Breast Cancer Survivors: A Mixed-Methods Study

BACKGROUND

Breast cancer survivors (BCSs) experience long-term symptoms of cancer and treatment, which may exacerbate cognitive function and ability to adhere to interventions aimed at improving cognition.

OBJECTIVE

The intent of this study was to explore the relationship between selected cancer-related symptoms and adherence to the Speed of Processing in Middle Aged and Older BreAst Cancer SuRvivors (SOAR) cognitive training (CT) intervention among BCSs residing in Alabama.

METHODS

A sequential quantitative to qualitative (Quan→Qual) mixed-methods design was used. First, the relationship between selected cancer-related symptoms and adherence to SOAR among BCSs (n = 30) was examined using self-reported questionnaire data. Follow-up semistructured interviews with 15 purposefully selected participants (adherent and nonadherent) were conducted to explore how symptoms contributed to/explained differences in adherence to SOAR. Data were analyzed using RStudio and NVivo software.

RESULTS

Spearman's ρ correlation suggested relationships between adherence and perceived cognitive impairment, depressive symptoms, and sleep quality. Inductive thematic analysis yielded 4 themes: (1) experiences of cancer-related symptoms, (2) influences of CT, (3) adherence to CT, and (4) environment for CT. Integration of quantitative and qualitative results revealed that experiences of and responses to CT and cancer-related symptoms differently shape adherence to CT among BCSs.

CONCLUSIONS

To aid in cognitive intervention adherence among BCSs, future studies may consider applying a comprehensive approach aimed at addressing concurrent cancer-related symptoms.

IMPLICATIONS FOR PRACTICE

Clinicians can routinely assess cognition and provide education and resources for management of cancer-related symptoms.

Differentiation of groups of patients with cognitive complaints at breast cancer diagnosis: Results from a sub-study of the French CANTO cohort

OBJECTIVE

Cognitive complaints are more frequent in women with breast cancer (BC) than in healthy controls and can be present before any treatment. Findings regarding contributive factors remain inconsistent. This study aimed to identify different groups of patients with cognitive complaints at BC diagnosis and to determine whether these different groups were associated with demographic, medical, or psychological characteristics.

METHODS

Cognitive complaints were assessed in a subset of 264 women from the French multicenter prospective CANTO cohort, at baseline before any treatment. Clustering analyzes were performed using the six-cognitive dimension Costa's scoring of the FACT-Cog V3. Univariable analyses were used to study how cognitive function (standardized neuropsychological tests, ICCTF), anxiety, depression, fatigue, and quality of life (HADS, FA12, QLQ-C30) were associated with specific cognitive complaints groups.

RESULTS

Results included 263 women (54±11 years), newly diagnosed with BC (69% stages I-III). Four distinct groups emerged, ranged from "no complaints" (22.8%), "low complaints" (55.1), "mixed complaints" (14.5%), to "consistent complaints" (7.6%). No significant differences were found in terms of demographic and medical factors between the four groups. However, the groups with higher proportions of patients with complaints were found to have more impairment in executive function, higher scores of anxiety, depressive symptoms, and fatigue, and lower quality of life, than the groups with lower proportions of cognitive complaints.

CONCLUSION

Using complete cognitive assessment prior to BC treatment, we identified four distinct cognitive complaints groups with specific characteristics. This work provides valuable clinical basis to further investigations for a better understanding of cognitive complaints and their associates.

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.

Non-pharmacological interventions for cognitive impairment in women with breast cancer post-chemotherapy: A systematic review

PURPOSE

Cognitive impairment is a well-reported side-effect of chemotherapy in persons with breast cancer. Whilst non-pharmacological interventions have proven efficacious in the management of cognitive impairment in high-risk groups, their efficacy in cognitive impairment post-chemotherapy in patients with breast cancer remains unclear.

METHODS

Medline, CINAHL, PsycINFO, Web of Science and Cochrane were searched for randomized controlled trials of non-pharmacological interventions for cognitive impairment post-chemotherapy in women with breast cancer.

RESULTS

Of 429 results, 83 full-texts were reviewed with ten meeting inclusion criteria. Interventions included cognitive training, exercise and complementary therapies. The non-pharmacological interventions assessed displayed variable benefits in subjective and/or objective cognitive assessments, with no strong evidence for beneficial effects across included studies. No studies assessed the efficacy of multi-domain interventions.

CONCLUSIONS

There is mixed evidence supporting non-pharmacological interventions for cognitive impairment post-chemotherapy in women with breast cancer. Moving forward, multidomain trials combining non-pharmacological interventions are imperative in this high risk cohort.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Effects of Exercise on Brain and Cognition Across Age Groups and Health States

Exercise has been shown to benefit brain structure and function, particularly in aging populations. However, the mechanisms by which exercise exerts its effects, especially in humans, are not fully understood. This review argues that one reason for this knowledge gap is that exercise likely operates through multiple levels of mechanisms. Furthermore, the mechanisms of exercise may vary depending on factors such as age and health state. We discuss the state of evidence at each of three levels of analysis (molecular/cellular, brain structure/function, and mental states and higher-order behaviors) and highlight consistencies across these levels, inconsistencies within them, and knowledge gaps. Lastly, based on these, we speculate about which mechanisms of exercise may be universal across age groups and populations versus those that might be distinct to specific age ranges or populations.

The Brief Perceived Cognitive Impairment Scale-Korean: A Validation Study

BACKGROUND

Practical brief measures are needed for clinicians and researchers to identify and effectively manage cognitive impairment in cancer patients.

OBJECTIVE

This study evaluated the reliability (ie, internal consistency reliability) and validity (ie, construct, convergent, concurrent, and known-group validity) of the Brief Perceived Cognitive Impairment Scale-Korean (BPCIS-K).

METHODS

From a university hospital, 249 cancer patients participated. The BPCIS-K was constructed with 6 items evaluating key aspects of cognitive impairment in cancer patients. For internal consistency reliability, Cronbach's α and item-total correlations were evaluated. For construct validity, confirmatory factor analysis was performed. For convergent validity, Pearson correlations were tested with the Functional Assessment of Cancer Therapy-Cognitive Function. For concurrent validity, Pearson correlations were tested with the Functional Assessment of Chronic Illness Therapy-Fatigue. For known-group validity, t tests were performed.

RESULTS

The BPCIS-K showed high internal consistency reliability (Cronbach's α = .92; item-total correlations ranged from 0.76 to 0.81). Factor analysis confirmed the scale is unidimensional. It is highly associated with another validated cognitive impairment measure (r = -0.91, P < .001) and moderately correlated with a fatigue measure (r = -0.52, P < .001). In known-group validity, female and patients undergoing treatment experienced more severe impairment than did male patients and patient awaiting treatment (P = .05, P = .08, respectively).

CONCLUSION

The BPCIS-K is valid and reliable for assessing cancer patients' perceived cognitive impairment, particularly in concentration, memory, and executive functions.

IMPLICATION FOR PRACTICE

This study introduces a practical brief measure to clinicians and researchers.

Systematic review of longitudinal studies on chemotherapy-associated subjective cognitive impairment in cancer patients

OBJECTIVES

This systematic review of longitudinal studies, assessing subjective cognitive impairment (SCI) reported by adult cancer patients, aimed to summarize evidence on the impact of chemotherapy on SCI, identify moderators of SCI, and evaluate methodological issues.

METHODS

Data accrued from Pubmed, EMBASE, CINAHL, PsychInfo, and the Cochrane library. Inclusion criteria were original studies, an exclusively adult sample, valid and reliable subjective cognitive measures, and at least one baseline data point prior to and another after the initiation of chemotherapy. Data were collected on the sample composition, data-collection time points, outcome measures, statistical analysis, and major findings (ie, longitudinal changes in prevalence, severity, and associated factors).

RESULTS

Forty articles published between 2004 and 2019 were retained: 21 examined chemotherapy-treated patients only, and 19 employed control groups. Findings were mixed, with slightly more studies supporting the impact of chemotherapy on SCI. SCI tended to be more prevalent and severe after initiating chemotherapy, compared with patients' own baseline and controls not treated with chemotherapy. Impact appeared to be acute and more likely limited to subsamples. Most studies examining non-breast-cancer samples reported the lack or limited impact of chemotherapy on SCI. The most consistent moderators were depression and fatigue. Methodological issues regarding sampling design, measurement, and statistical analysis were discussed.

CONCLUSION

More rigorously designed longitudinal studies would clarify direct and indirect effects of chemotherapy on SCI.

Cognitive Rehabilitation for Cognitive Dysfunction after Cancer and Cancer Treatment: Implications for Nursing Practice

OBJECTIVE

To provide an overview of cognitive rehabilitation approaches for cognitive dysfunction after cancer and cancer treatment.

DATA SOURCES

Review and synthesis of empirical articles.

CONCLUSION

Cognitive rehabilitation approaches, including cognitive behavioral therapy and cognitive training, for cognitive dysfunction appear feasible to deliver, satisfactory to participants, and have shown promising results in cancer survivors. Future research is needed to address optimal dose, delivery method, access, cost, and the vulnerable aging cancer survivor population.

IMPLICATIONS FOR NURSING PRACTICE

Oncology nurses must understand the available evidence and be able to provide information and options to cancer survivors to address cognitive changes after cancer.

Computerized programs for cancer survivors with cognitive problems: a systematic review

PURPOSE

This study aimed to review and identify characteristics and lessons learned from studies on computerized cognitive interventions for cancer survivors (CSs) with cognitive dysfunction, exploring the content and results of interventions.

METHODS

Studies were collected from the CINAHL, Web of Science, PubMed, and PsycINFO databases.

RESULTS

Seven articles that met the inclusion criteria were included. Reviewed studies measured objective cognitive function, subjective cognitive function, and psychological aspects. Computerized interventions for CSs with cognitive decline were effective for executive function, memory, working memory, and speed of thought in the domain of objective cognitive function. Some subjective cognitive functions also showed significant improvement.

CONCLUSIONS

Computerized cognitive interventions have a positive impact on objective, subjective, and psychological aspects of cognitive problems. Further research needs to include more men as well as different cancer types. Programs also should include more than one target domain. Future researchers need to develop mobile applications that can effectively use computerized cognitive interventions.

IMPLICATIONS FOR CANCER SURVIVORS

Results of this study should help provide optimal approaches to develop and apply effective computerized-cognitive-intervention programs. Health care providers need to be involved in these types of interventions and methods to encourage CSs to proactively practice cognitive-function training need to be developed.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

IMPLICATIONS FOR PRACTICE

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

Cognitive complaints in cancer survivors and expectations for support: Results from a web-based survey

Background

Cognitive complaints are common in cancer survivors. We aimed to assess cognitive complaints in cancer survivors and the associated factors using a large web–based survey.

Methods

This online survey was proposed to cancer survivors. Participants completed several questions on cognitive complaints experience, expectations for support of cognitive difficulties, preexisting knowledge about chemotherapy–associated cognitive problems and demographic and medical variables. We used multivariable logistic regression models to estimate Odds Ratios and 95% confidence intervals to estimate associations.

Results

Among 1610 eligible participants (median age 52 [21‐84]), >85% (n = 1393) were breast cancer survivors. Median postcancer treatment time (excluding hormone therapy) was 2.83 years [0.8‐33]. Seventy five percent of the participants (n = 1214) reported cognitive complaints related to cancer treatments. Cognitive difficulties had an impact on work resumption for 76% of the participants (n = 754/982). Most cancer survivors would like to receive support (75%, n = 909) and especially cognitive training (72%, n = 658). Chemotherapy was strongly associated with cognitive complaints (multivariable OR = 3.67, 95% CI: 2.80‐4.82). Self–reported sleep difficulties (OR_{often vs. never} = 2.84, 95% CI: 1.80‐4.47), preexisting knowledge about chemotherapy–associated cognitive problems (OR_{No vs. Yes} = 1.69, 95% CI: 1‐29‐2.22) and age (OR_{21‐64 vs. ≥65} = 0.37, 95% CI: 0.23‐0.58) were also associated with cancer–related cognitive complaints.

Conclusions

According to this large web–based survey including mainly breast cancer survivors, cognitive complaints were reported by three quarters of participants, which reinforces that cognitive difficulties are a major issue in cancer survivors. Chemotherapy, self–reported sleep difficulties and preexisting knowledge about chemotherapy–associated cognitive problems were strongly associated with cancer–related cognitive complaints. Most cancer survivors wished to receive support and especially cognitive training.

Associations Between Breast Cancer Survivorship and Adverse Mental Health Outcomes: A Systematic Review

Background

We aimed to systematically review the evidence on adverse mental health outcomes in breast cancer survivors (≥1 year) compared with women with no history of cancer.

Methods

Studies were identified by searching MEDLINE, PsycINFO, the Cumulative Index to Nursing and Allied Health Literature, and the Social Sciences Citation Index, and through backward citation tracking. Two researchers selected the studies, extracted data, and assessed the risk of bias.

Results

Sixty studies were included. Of 38 studies of depression, 33 observed more depression in breast cancer survivors; this was statistically significant in 19 studies overall, including six of seven where depression was ascertained clinically, three of four studies of antidepressants, and 13 of 31 that quantified depressive symptoms. Of 21 studies of anxiety, 17 observed more anxiety in breast cancer survivors, statistically significant in 11 studies overall, including two of four with clinical/prescription-based outcomes, and in eight of 17 of anxiety symptoms. Breast cancer survivors also had statistically significantly increased symptoms/frequency of neurocognitive dysfunction (18 of 24 studies), sexual dysfunctions (5 of 6 studies), sleep disturbance (5 of 5 studies), stress-related disorders/PTSD (2 of 3 studies), suicide (2 of 2 studies), somatisation (2 of 2 studies), and bipolar and obsessive-compulsive disorders (1 of 1 study each). Studies were heterogeneous in terms of participants' characteristics, time since diagnosis, ascertainment of outcomes, and measures reported. Approximately one-half of the studies were at high risk of selection bias and confounding by socio-economic status.

Conclusions

There is compelling evidence of an increased risk of anxiety, depression and suicide, and neurocognitive and sexual dysfunctions in breast cancer survivors compared with women with no prior cancer. This information can be used to support evidence-based prevention and management strategies. Further population-based and longitudinal research would help to better characterize these associations.

Exploratory Study of Associations Between DNA Repair and Oxidative Stress Gene Polymorphisms and Cognitive Problems Reported by Postmenopausal Women With and Without Breast Cancer

PURPOSE

Women with breast cancer report varying frequencies of cognitive problems during adjuvant systemic therapy. This variability suggests latent subgroups. Therefore, we identified latent subgroups of self-reported cognitive problems among postmenopausal women with and without breast cancer. We explored associations between membership in these subgroups and (a) demographic, clinical, and symptom characteristics and (b) variations in candidate gene polymorphisms.

METHODS

We evaluated frequency of cognitive problems using the Patient Assessment of Own Functioning Inventory. Growth mixture modeling identified latent subgroups over 18 months of adjuvant systemic therapy and at matched time points for women without cancer ( N = 331). We evaluated for differences among subgroups in demographic, clinical, and symptom characteristics and in 41 single nucleotide polymorphisms in 10 candidate genes involved in DNA repair and oxidative stress pathways ( n = 199). We modeled associations between genotypes and subgroup membership using multinomial logistic regression.

RESULTS

We identified three latent subgroups: more frequent, persistent, and almost never. Receipt of chemotherapy plus anastrozole, depressive symptoms, and baseline neuropathic symptoms increased the odds of belonging to the more frequent subgroup. Anxiety and depressive symptoms increased the odds of belonging to the persistent subgroup. With covariates controlled for, carrying the ERCC5 rs873601 G minor allele increased the odds of reporting more frequent cognitive problems.

CONCLUSIONS

Chemotherapy plus anastrozole, depressive symptoms, and presence of neuropathic symptoms may predict more frequent cognitive problems during systemic therapy that later resolve. Mood dysregulation before therapy may predict persistent cognitive problems during therapy. ERCC5 genotype may influence frequency of cognitive problems after controlling for these risk factors.

Distinct attentional function profiles in older adults receiving cancer chemotherapy

PURPOSE

While attentional function is an extremely important patient outcome for older adults, research on changes in function in this group is extremely limited. The purposes of this study were to: identify subgroups of older patients (i.e., latent growth classes) based on changes in their level of self-reported attentional function; determine which demographic and clinical characteristics were associated with subgroup membership; and determine if these subgroups differed on quality of life (QOL) outcomes.

METHODS

Older oncology outpatients (n = 365) who were assessed for changes in attention and working memory using the Attentional Function Index a total of six times over two cycles of chemotherapy (CTX). QOL was assessed using the Medical Outcomes Study-Short Form 12 and the QOL-Patient Version Scale. Latent profile analysis (LPA) was used to identify subgroups of older adults with distinct attentional function profiles.

RESULTS

Three distinct attentional functional profiles were identified (i.e., low, moderate, and high attentional function). Compared to the high class, older adults in the low and moderate attentional function classes had lower functional status scores, a worse comorbidity profile and were more likely to be diagnosed with depression. In addition, QOL scores followed an expected pattern (low class < moderate class < high attentional function class).

CONCLUSIONS

Three distinct attentional function profiles were identified among a relatively large sample of older adults undergoing CTX. The phenotypic characteristics associated with membership in the low and moderate latent classes can be used by clinicians to identify high risk patients.

Qigong intervention for breast cancer survivors with complaints of decreased cognitive function

PURPOSE

The purpose of this pilot study was to evaluate the feasibility of an 8-week Qigong intervention to improve objectively and subjectively assessed cognitive function in breast cancer survivors who were 2 months to 8 years post completion of chemotherapy and radiation therapy.

METHODS

A randomized, single-blind, three-arm intervention pilot was conducted to compare Qigong to gentle exercise and survivorship support. Feasibility was measured by recruitment, group session attendance, and adherence to home practice for the two exercise groups. Changes in self-report and objectively measured cognitive function were compared between the three groups from baseline (T1) to completion of the intervention (T2) and 4 weeks post intervention (T3).

RESULTS

Fifty participants consented (83% of desired sample) with an overall attrition rate of 28%. Attrition was highest for the gentle exercise group (50%). Group attendance adherence ranged from 44 to 67%. The a priori established rate of 75% weekly attendance was not achieved, nor was the goal of 75% adherence to home practice for the two exercise groups (7 to 41%). Self-report of cognitive function improved most for the Qigong group (p = .01). Improvement was demonstrated for the Trail Making A (gentle exercise, p = .007) and F-A-S verbal fluency (support group, p = .02) tests. Qigong participants reported the most reduction of distress (p = .02).

CONCLUSIONS

The study results suggest that mindfulness-based exercise may be superior to gentle exercise alone or survivorship support for improving self-report of cognitive function and distress after treatment for breast cancer. The mindfulness component may enhance the positive impact of exercise on cognitive function.

Pupillary response: cognitive effort for breast cancer survivors

PURPOSE

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

STUDY AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

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

Relationships between self-reported sleep quality components and cognitive functioning in breast cancer survivors up to 10 years following chemotherapy

OBJECTIVE

Links have been made between aspects of sleep quality and cognitive function in breast cancer survivors (BCS), but findings are heterogeneous. The objective of this study is to examine relationships between specific sleep quality components (latency, duration, efficiency, daytime sleepiness, sleep disturbance, use of sleep aids) and cognitive impairment (performance and perceived), and determine which sleep quality components are the most significant contributors to cognitive impairments in BCS 6 months to 10 years post chemotherapy.

METHODS

Women 21 to 65 years old with a history of non-metastatic breast cancer following chemotherapy completion were recruited. Data collection included surveys to evaluate sleep quality and perceived cognitive impairments, and neuropsychological testing to evaluate verbal fluency and memory. Descriptive statistics, bivariate correlations, and hierarchical multiple regression were calculated.

RESULTS

Ninety women (mean age 49) completed data collection. Moderate significant correlations were found between daytime dysfunction, sleep efficiency, sleep latency, and sleep disturbance and perceived cognitive impairment (Rs = -0.37 to -0.49, Ps < .00049), but not objective cognitive performance of verbal fluency, memory, or attention. After accounting for individual and clinical characteristics, the strongest predictors of perceived cognitive impairments were daytime dysfunction, sleep efficiency, and sleep disturbance.

CONCLUSIONS

Findings support links between sleep quality and perceived cognitive impairments in BCS and suggest specific components of sleep quality (daytime dysfunction, sleep efficiency, and sleep disturbance) are associated with perceived cognitive functioning in this population. Findings can assist clinicians in guiding survivors to manage sleep and cognitive problems and aid in the design of interventional research.

Efficacy of a web-based cognitive rehabilitation intervention for adult cancer survivors: A pilot study

The purpose of this study was to evaluate the efficacy of a web-based cognitive rehabilitation intervention in survivors of adult-onset cancer and a sample of non-cancer community dwelling adults. Fifty-one participants were recruited and allocated to a cancer intervention group, a non-cancer intervention group, or a non-cancer waitlist group. Intervention groups completed a 4-week online program and all participants were assessed at baseline, post-intervention and 3-month follow-up. The primary outcome measure was subjective cognitive functioning. Secondary outcome measures included objective cognitive functioning, distress, quality of life (QoL), illness perception and program satisfaction. Results from the study found significant improvements on self-report measures of cognitive functioning in both treatment groups, as well as improvements on objective measures assessing attention and executive functioning. No intervention effects were observed for distress, QoL or illness perception. High participant satisfaction was observed with 75% of participants in the cancer group reporting being either "satisfied" or "very satisfied" with the program compared to 87% in the non-cancer treatment group. Initial evaluation of the program suggests that the web-based cognitive rehabilitation intervention shows potential for improving subjective and objective cognitive functioning in cancer survivors and community dwelling adults.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

IMPLICATIONS FOR CANCER SURVIVORS

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

Cognitive functioning and quality of life following chemotherapy in pre- and peri-menopausal women with breast cancer

PURPOSE

The purpose of the study was to prospectively examine changes in subjective and objective cognitive functions and quality of life (QOL) for pre- and peri-menopausal women receiving chemotherapy for breast cancer and to explore potential predictors of cognitive changes.

METHODS

Participants were assessed as follows: prior to chemotherapy (T1), after cycle 3 (T2), within 2-3 weeks of completing adjuvant chemotherapy (T3) (N = 20), and 8+ years later (T4; n = 18). Objective cognitive function was measured with the High Sensitivity Cognitive Screen (T1, T3, T4). Subjective measures for cognitive function, depressive symptoms, fatigue, and mental and physical QOL were assessed at all time points. Estradiol levels were measured at T1, T2, and T3. The Functional Assessment of Cancer Therapy-Cognition and the MD Anderson Cancer Symptom Inventory item for neuropathy were administered at T4.

RESULTS

No significant changes in objective cognitive function were found. However, participants reported decreased cognitive function over the course of treatment accompanied by depressive symptoms and fatigue. Depression and fatigue returned to near-baseline levels at T4, but over half of the participants continued to report mild to moderate depression. Estradiol levels were not associated with cognitive function. Neuropathy and higher body mass index (BMI) were associated with persistent cognitive complaints at T4 (adjusted R ² = 0.712, p = 0.001). Higher QOL was correlated with better subjective cognitive function (r = 0.705, p = 0.002) and lower body mass index (r = - 0.502, p = 0.017) at T4.

CONCLUSIONS

Further investigation of BMI, neuropathy, and depressive symptoms as predictors of persistent cognitive dysfunction following chemotherapy for breast cancer is warranted.

Perceived cognitive function for breast cancer survivors: association of genetic and behaviorally related variables for inflammation

PURPOSE

We explored relationships between genetic variability and behaviorally related variables (body mass index and exercise frequency) for inflammation, and perceived cognitive function (PCF) for breast cancer survivors (BCS). Our primary aim was to explore relationships between select single-nucleotide polymorphisms (SNPs) for IL1R1, IL6, TNF genes, and PCF. Our secondary aim was to explore whether body mass index (BMI) and exercise frequency moderate these relationships.

METHODS

We conducted an exploratory candidate gene substudy. Saliva samples from participants (N = 101) in a larger, cross-sectional study were genotyped. Multiple linear regression analysis was used to explore relationships between SNPs and PCF, controlling for age, education level, fatigue, and distress. Hierarchical expansion of regression models included main effects for BMI and exercise frequency and interaction effects between BMI, exercise frequency, and each SNP.

RESULTS

The most parsimonious regression model included fatigue, exercise frequency, and IL1R1rs2287047 minor alleles (AA+GG) (R 2 = 0.244, adjusted R 2 = 0.220, p = 0.013). No other SNPs were significant. Higher exercise frequency (b = 7.300, p = 0.013) and IL1R1rs2287047 (AA+AG) (b = 6.512, p = 0.025) predicted better PCF. Greater fatigue predicted poorer PCF (b = -2.359, p < 0.01). No interaction was demonstrated between BMI and exercise related to PCF or between BMI, exercise, and SNPs.

CONCLUSIONS

Our results suggest a protective relationship between IL1R1rs2287047 (AA+AG) and PCF and provide further evidence supporting exercise as a potential intervention for poorer PCF. Ours is the first study to investigate genetic variability associated with inflammation, behaviorally related variables, and PCF for BCS.

Mechanisms of Neurotoxic Symptoms as a Result of Breast Cancer and Its Treatment: Considerations on the Contribution of Stress, Inflammation, and Cellular Bioenergetics

PURPOSE OF REVIEW

Breast cancer and its treatment are associated with a range of neurotoxic symptoms, such as fatigue, cognitive impairment, and pain. Although these symptoms generally subside after treatment completion, they become chronic in a significant subset of patients. We here summarize recent findings on neuroinflammation, stress, and mitochondrial dysfunction as mechanistic pathways leading to neurotoxic symptom experience in breast cancer patients and survivors.

RECENT FINDINGS

Neuroinflammation related to stress or cancer treatment and stress resulting from diagnosis, treatment, or (cancer-related) worrying are important predictors of a neurotoxic symptom experience, both during and after treatment for breast cancer. Both inflammation and stress hormones, as well as cancer treatment, can induce mitochondrial dysfunction resulting in reduced cellular energy.

SUMMARY

We propose reduced cellular energy (mitochondrial dysfunction) induced by inflammation, oxygen radical production, and stress as a result of cancer and/or cancer treatment as a final mechanism underlying neurotoxic symptoms.

Modifiable and non-modifiable characteristics associated with sleep disturbance in oncology outpatients during chemotherapy

PURPOSE

In a sample of outpatients with breast, gastrointestinal, gynecological, and lung cancer who received at least two cycles of chemotherapy (CTX), the purposes were to evaluate for inter-individual differences in the severity of sleep disturbance and determine which demographic, clinical, and symptom characteristics were associated with initial levels as well as the trajectories of sleep disturbance.

METHODS

A total of 1331 patients completed study questionnaires in their homes, at six time points over two cycles of CTX (prior to CTX administration, approximately 1 week after CTX administration, and approximately 2 weeks after CTX administration). Questionnaires included demographic, clinical, and symptom assessments (i.e., General Sleep Disturbance Scale, Lee Fatigue Scale, Center for Epidemiological Studies-Depression Scale, Spielberger State-Trait Anxiety Inventories, Attentional Function Index). Hierarchical linear modeling based on full maximum likelihood estimation was performed.

RESULTS

Characteristics associated with higher initial levels of sleep disturbance included higher body mass index, poorer functional status, higher trait anxiety, higher depressive symptoms, and higher evening fatigue. Characteristics associated with the worse trajectories of sleep disturbance were higher levels of education and higher sleep disturbance at enrollment. Characteristics associated with both higher initial levels and worse trajectories of sleep disturbance were higher morning fatigue and worse attentional function.

CONCLUSIONS

A large amount of inter-individual variability exists in sleep disturbance during CTX. The modifiable and non-modifiable characteristics found in this study can be used to identify higher risk patients and provide earlier interventions to reduce sleep disturbance.

Aging, obesity, and post-therapy cognitive recovery in breast cancer survivors

Therapy-induced cognitive impairment is prevalent and long-lasting in cancer survivors, but factors affecting post-therapy cognitive recovery are unclear. We conducted this study to evaluate the associations of age, body mass index (BMI), waist-to-hip ratio (WHR), and physical activity (PA) with post-therapy cognitive changes in a population-based breast cancer (BC) survivor cohort. We collected information on PA, weight, height, waist and hip circumferences of 1286 BC survivors aged 20-75. We assessed their cognitive functions, including immediate memory, delayed memory, verbal fluency, and attention, at 18 and 36 months after cancer diagnosis. Linear regression models were used to examine the associations of age, BMI, WHR and PA with mean changes in cognitive scores from 18- to 36-month follow-up interview. We found that the post-therapy cognitive changes differed by age and obesity status. Verbal fluency and attention improved in younger patients aged <60 and non-abdominally obese patients, but deteriorated in older patients aged ≥60 (i.e. verbal fluency and attention) and abdominally obese patients (i.e. verbal fluency). Memory improved in all patients, with a smaller improvement in obese patients compared with normal-weight patients. No significant association was found between PA and post-therapy cognitive change. Due to the novelty of our findings and the limitations of our study, further research, including intervention trials, is warranted to confirm the causal relationship between obesity and cognitive impairments.

Characteristics associated with inter-individual differences in the trajectories of self-reported attentional function in oncology outpatients receiving chemotherapy

PURPOSE

Between 14 and 85 % of patients report noticeable changes in cognitive function during chemotherapy (CTX). The purposes of this study were to determine which demographic, clinical, and symptom characteristics were associated with inter-individual variability in initial levels of attentional function as well as with changes in the trajectories of attentional function in a sample of oncology patients who received two cycles of CTX.

METHODS

Oncology outpatients (n = 1329) were recruited from two comprehensive cancer centers, one veteran's affairs hospital, and four community-based oncology programs. The Attentional Function Index (AFI) was used to assess perceived effectiveness in completing daily tasks that required working memory and attention. Hierarchical linear modeling (HLM) was used to evaluate for inter-individual variability in initial levels and in the trajectories of attentional function.

RESULTS

Demographic, clinical, and symptom characteristics associated with inter-individual differences of attentional function at enrollment (i.e., intercept) were as follows: employment status, functional status, trait anxiety, depressive symptoms, sleep disturbance, evening fatigue, and morning energy. Gender was the only characteristic associated with inter-individual differences in the trajectories of attentional function. Morning fatigue was the only characteristic associated with both initial levels and the trajectories of attentional function.

CONCLUSIONS

Prior to their next dose of CTX, patients reported moderate levels of attentional function that persisted over two cycles of CTX. Many of the clinical and symptom characteristics associated with decrements in attentional function are amenable to interventions. Clinicians need to assess patients for changes in attentional function and associated characteristics and recommend evidence-based interventions.

Correspondence between Subjective and Objective Cognitive Functioning Following Chemotherapy for Breast Cancer

This study examined subjective and objective cognitive functioning in 26 female breast cancer survivors (BCS) who received chemotherapy treatment that finished .5 to 5 years prior to testing and compared their results to 25 demographically matched women with no history of cancer. Participants were assessed on prospective memory (PM) tasks; neuropsychological tests of processing speed, attentional flexibility with greater cognitive load, executive function, and verbal memory; self-report measures of cognitive dysfunction and PM failures; and distress. The BCS group showed significantly slower speed of processing and reduced attentional flexibility, and reported significantly more cognitive complaints and PM failures than the control group on five of six self-report measures. The groups did not differ on other PM or neuropsychological measures or on a measure of distress. Subjective cognition correlated with some neuropsychological tests and with a virtual reality PM task. Objective cognitive impairments were associated with reduced quality of life in the BCS group. The results provide some evidence of both self-reported impairment and objective cognitive dysfunction following chemotherapy treatment.

Advancing breast cancer survivorship among African-American women

Advances have occurred in breast cancer survivorship but, for many African-American women, challenges and gaps in relevant information remain. This article identifies opportunities to address disparities in breast cancer survival and quality of life, and thereby to increase breast cancer survivorship among African-American women. For breast cancer survivors, common side effects, lasting for long periods after cancer treatment, include fatigue, loss of strength, difficulty sleeping, and sexual dysfunction. For addressing physical and mental health concerns, a variety of interventions have been evaluated, including exercise and weight training, dietary interventions, yoga and mindfulness-based stress reduction, and support groups or group therapy. Obesity has been associated with breast cancer recurrence and poorer survival. Relative to white survivors, African-American breast cancer survivors are more likely to be obese and less likely to engage in physical activity, although exercise improves overall quality of life and cancer-related fatigue. Considerable information exists about the effectiveness of such interventions for alleviating distress and improving quality of life among breast cancer survivors, but few studies have focused specifically on African-American women with a breast cancer diagnosis. Studies have identified a number of personal factors that are associated with resilience, increased quality of life, and positive adaptation to a breast cancer diagnosis. There is a need for a better understanding of breast cancer survivorship among African-American women. Additional evaluations of interventions for improving the quality of life and survival of African-American breast cancer survivors are desirable.