Metamemory function in chemotherapy-treated patients with breast cancer: an explanation for the dissociation between subjective and objective memory measures?

Quantifying chemotherapy-induced cognitive impairment in gastrointestinal cancer patients: A scoping review of methodological concerns in the literature

PURPOSE

Chemotherapy is one of the common treatments in cancer management. However, chemotherapy-induced cognitive impairment (CICI) is one notable side effect that can greatly impact a patient's quality of life. Literature on CICI in gastrointestinal (GI) cancers are few and inconsistent. This review aims to identify the methodological differences in such studies.

METHODS

A systematic search was performed in four electronic databases. All peer-reviewed primary literature published in English that evaluated cognitive-related functioning scores related to chemotherapy in GI cancer patients were included. Information about each study such as CICI findings, study limitations, methodology, and sample characteristics was extracted and synthesized.

RESULTS

A total of 19 studies were included. Evidence of CICI was found in 50.0% (8 of 16) and 62.5% (5 of 8) studies that used objective and subjective measures, respectively. Methodological differences such as groups used for comparison, instruments used, and assessment from the length of time since chemotherapy were highlighted between studies that did and did not find evidence of CICI.

CONCLUSIONS

This review suggests that the mixed findings can be attributed to the heterogeneous methodologies adopted in the evaluation of CICI in this field.

IMPLICATIONS FOR CANCER SURVIVORS

Further studies are necessary to establish the presence and chronicity of CICI, and in which groups of patients to facilitate targeted interventions and treatments.

Tamoxifen Effects on Cognition and Language in Women with Breast Cancer

Cognitive changes following adjuvant treatment for breast cancer (BC) are well documented following chemotherapy. However, limited studies have examined cognitive and/or language functions in chemotherapy-naive women with BC taking tamoxifen (TAM). Using ambulatory cognitive assessment, we investigated the trajectory of cognitive and language changes during early period of adjuvant endocrine treatment (TAM) in women with BC at two time periods (pretreatment and 2 months after treatment began). Four women with BC and 18 cognitively healthy age-matched controls completed three cognitive tasks using smartphones, during a short time period (5 days) and repeated them at two time periods. To determine language ability, language samples were collected at two time periods, where the participants described two stories from two wordless picture books and samples were assessed using core lexicon analyses. Wilcoxon-signed rank tests were computed to identify differences in linguistic and cognitive performances of both the groups at two time periods. No significant within-group or between-group differences were seen on the cognitive and language tasks at the two time periods; however, women with BC performed more poorly compared to the control group. We did see decline in some women with BC and not in others, in cognition and language during initial course of TAM treatment. However, the approach we used to assess these changes is valuable and innovative. This approach will help refine current research paradigms for determining cognitive and linguistic changes and will help determine if women with BC might require language intervention in the future.

Interventions promoting cognitive function in patients experiencing cancer related cognitive impairment: A systematic review

OBJECTIVE

To examine the effect of interventions used to enhance cognitive function in patients experiencing cancer-related cognitive impairment.

METHODS

Studies including adults with a non-metastatic cancer who have received chemotherapy as part of their treatment and who have undergone interventions targeting cancer-related cognitive impairment were included. Studies involving patients with metastatic cancer and pre-existing cognitive deficits were excluded. Academic Search Complete, CINAHL Plus with full text, MEDLINE, Education Full Text, PsycARTICLES, PsycINFO, and ERIC were searched for studies published between January 2011 and September 2022. Data extraction and quality appraisal were conducted by two authors and cross-checked by the review team. Quality appraisal was conducted using 12 items from the Mixed Methods Appraisal Tool. Findings were presented narratively without meta-analysis.

RESULTS

Thirty-one studies were included. Interventions were categorised as integrative/complementary, cognitive behavioural therapy and compensatory strategies, exercise, psychoeducational/psychosocial, brain-training, and pharmacological. Over 100 instruments were identified, including the Functional Assessment of Cancer Therapy-Cognitive, Trail Making Tests-A and B, and instruments measuring secondary outcomes, including depression. Instruments often measured attention and concentration, language, memory, executive function, and/or patient-reported outcomes. Improvements were reported, with most studies measuring some or various aspects of cognitive functioning and very few studies measuring all domains of cognitive functioning, making it difficult to draw definitive conclusions about effectiveness.

CONCLUSIONS

Various interventions are available to treat cancer-related cognitive impairment. Outcome measurement was inconsistent and future research should prioritise using standardised measures. Current evidence, whilst not being definitive, suggests that certain interventions show greater promise than others, including cognitive behavioural therapy and brain training.

Effect of physical exercise on cognitive function after chemotherapy in patients with breast cancer: a randomized controlled trial (PAM study)

BACKGROUND

Up to 60% of breast cancer patients treated with chemotherapy is confronted with cognitive problems, which can have a significant impact on daily activities and quality of life (QoL). We investigated whether exercise training improves cognition in chemotherapy-exposed breast cancer patients 2-4 years after diagnosis.

METHODS

Chemotherapy-exposed breast cancer patients, with both self-reported cognitive problems and lower than expected performance on neuropsychological tests, were randomized to an exercise or control group. The 6-month exercise intervention consisted of supervised aerobic and strength training (2 h/week), and Nordic/power walking (2 h/week). Our primary outcome was memory functioning (Hopkins Verbal Learning Test-Revised; HVLT-R). Secondary outcomes included online neuropsychological tests (Amsterdam Cognition Scan; ACS), self-reported cognition (MD Anderson Symptom Inventory for multiple myeloma; MDASI-MM), physical fitness (relative maximum oxygen uptake; VO_2peak), fatigue (Multidimensional Fatigue Inventory), QoL (European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire; EORTC QLQ C-30), depression (Patient Health Questionnaire-9, Hospital Anxiety and Depression Scale; HADS), and anxiety (HADS). HVLT-R total recall was analyzed with a Fisher exact test for clinically relevant improvement (≥ 5 words). Other outcomes were analyzed using multiple regression analyses adjusted for baseline and stratification factors.

RESULTS

We randomized 181 patients to the exercise (n = 91) or control group (n = 90). Two-third of the patients attended ≥ 80% of the exercise sessions, and physical fitness significantly improved compared to control patients (B VO_2peak 1.4 ml/min/kg, 95%CI:0.6;2.2). No difference in favor of the intervention group was seen on the primary outcome. Significant beneficial intervention effects were found for self-reported cognitive functioning [MDASI-MM severity (B-0.7, 95% CI - 1.2; - 0.1)], fatigue, QoL, and depression. A hypothesis-driven analysis in highly fatigued patients showed positive exercise effects on tested cognitive functioning [ACS Reaction Time (B-26.8, 95% CI - 52.9; - 0.6) and ACS Wordlist Learning (B4.4, 95% CI 0.5; 8.3)].

CONCLUSIONS

A 6-month exercise intervention improved self-reported cognitive functioning, physical fitness, fatigue, QoL, and depression in chemotherapy-exposed breast cancer patients with cognitive problems. Tested cognitive functioning was not affected. However, subgroup analysis indicated a positive effect of exercise on tested cognitive functioning in highly fatigued patients. Trial Registration Netherlands Trial Registry: Trial NL5924 (NTR6104). Registered 24 October 2016, https://www.trialregister.nl/trial/5924 .

Factors associated with cognitive impairment and cognitive concerns in patients with metastatic non-small cell lung cancer

Background

Knowledge regarding cognitive problems in metastatic non-small cell lung cancer (mNSCLC) is limited. Such problems may include both patient-reported cognitive concerns and demonstrable cognitive impairment. Greater understanding of these outcomes is needed to inform rehabilitation strategies for these difficulties. We aimed to identify the frequency of cognitive problems and associated factors in patients with mNSCLC.

Methods

In this cross-sectional study, adults with mNSCLC completed validated neuropsychological tests and self-report questionnaires measuring cognitive concerns, neurobehavioral concerns, depression, demoralization, illness intrusiveness, self-esteem, and physical symptoms. Cognitive impairment (performance based) was defined according to International Cancer and Cognition Task Force criteria. Clinically significant cognitive concerns were defined by a score ≥1.5 SD below the normative mean on the Functional Assessment of Cancer Therapy-Cognitive Function Perceived Cognitive Impairment (FACT-Cog PCI). Univariate and multivariate logistic regression analyses were performed to identify associated factors.

Results

Of 238 patients approached, 77 participated (median age: 62 years; range: 37-82). Brain metastases were present in 41 patients (53%), and 23 (29%) received cranial irradiation. Cognitive impairment and cognitive concerns were present in 31 (40%) and 20 patients (26%), respectively. Cognitive impairment and cognitive concerns co-occurred in 10 patients (13%), but their severity was unrelated. Cognitive impairment was associated with cranial irradiation (odds ratio [OR] = 2.89; P = .04), whereas cognitive concerns were associated with greater illness intrusiveness (OR = 1.04; P = .03) and lower self-esteem (OR = 0.86; P = .03).

Conclusions

Cognitive impairment and cognitive concerns are both common in patients with mNSCLC but are not necessarily related, and their risk factors differ. The association of illness intrusiveness and self-esteem with cognitive concerns can inform therapeutic interventions in this population.

Are Sleep Complaints Related to Cognitive Functioning in Non-Central Nervous System Cancer? A Systematic Review

Patients with non-central nervous system (CNS) cancer frequently report cognitive complaints, that are recurrent and affect their quality of life. In order to improve supportive care of these cognitive difficulties, it is important to identify associated factors. Sleep disturbance is a good candidate to study, as patients with non-CNS cancer frequently report sleep disorders, and sleep plays a key role in cognitive functioning. The objective of the present systematic review was to summarize the results of studies evaluating the relationship between cognition and sleep in non-CNS cancer, and to highlight the need for further studies. PubMed [Medline] and Scopus databases were screened from April to November 2020 for studies published in English evaluating the association between cognition and sleep in adults with non-CNS cancer. The characteristics and risk of bias for each of the 30 included studies have been reported. Greater cognitive complaints in patients with non-CNS cancer were related to poorer self-reported sleep quality in almost all studies (n = 22/24). By contrast, around half of the studies reported a significant association between poorer neuropsychological performances and sleep complaints (n = 5/11). The studies were found to have several limitations, such as the lack of a control group, which would have shed the light on the period of occurrence of this association (e.g. after cancer diagnosis or after cancer treatments). Our review also identified factors that may influence the relationship between cognition and sleep. Recommendations are given for improving the methodology of future studies and extending the impact of their results.

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

BACKGROUND

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

METHODS

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

DISCUSSION

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

TRIAL REGISTRATION

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

Cognitive complaints by hematopoietic cell transplantation recipients and change in neuropsychological performance over time

PURPOSE

Hematopoietic stem cell transplant (HSCT) recipients are at risk for cognitive decline. Cross-sectional studies show patients' complaints of cognitive decline do not correlate well with concurrently measured objective neuropsychological performance, but rather with emotional variables and health-related quality of life. This longitudinal study investigated whether patient self-report of cognitive status would be concordant with objectively measured neuropsychological performance after accounting for change from their own pre-transplant objective baseline.

METHODS

Pre-HSCT and at 30 and 100 days post-HSCT, 46 patients underwent computerized neuropsychological testing (CogState) and completed surveys assessing patient-reported cognitive complaints, emotional symptoms (depression, anxiety), sleep quality, daytime sleepiness, and physical and functional well-being. Correlations were calculated between cognitive complaints and neuropsychological performance (at each time-point and across time-points), as well as all other patient-reported variables.

RESULTS

Patient-reported cognitive complaints were largely independent of concurrently assessed objective neuropsychological performance. Uniquely, our longitudinal data demonstrated significant medium to large effect size associations between subjective cognitive complaints post-HSCT with objectively measured change from pre-HSCT in attention, visual learning, and working memory (p < .05-.01). Subjective cognitive complaints post-HSCT were also associated with depression, anxiety, daytime sleepiness and physical well-being (p < .05-.001).

CONCLUSIONS

Patients appear better able to assess their cognitive functioning relative to their own baseline and changes across time rather than relative to community norms. Thus, patient complaints of cognitive compromise justify further in-depth neuropsychological, emotional, and functional assessment. Future research into relationships between cognitive complaints and neuropsychological performance should account for changes in performance over time.

The role of metamemory on cognitive complaints in cancer patients

OBJECTIVE

Although cancer patients frequently report cognitive disturbances, it is commonly asserted a lack of association between cognitive complaints and neuropsychological test performances. Our goal was to better understand the relationships between subjective and objective cognitive scores through a metamemory monitoring assessment.

METHODS

Sixty cancer patients currently treated by chemotherapy and/or targeted therapy, and 30 healthy controls (HC) were included. Cognitive complaint was assessed by FACT-cog, QAM and DEX questionnaires. One or more z-scores ≤-1.65 among these three questionnaires defined the presence of cognitive complaints. Objective cognitive performances assessed episodic memory, processing speed and executive functions/working memory (ESR paradigm, TMT, Stroop, n-back). Metamemory was assessed with a Judgment of Learning (JOL) task.

RESULTS

Patients with cognitive complaints had significantly more depressive and anxiety symptoms (ps < .004), and lower performances on several cognitive tests (ps < .05) than both patients without complaints and HC. More specifically, analyses of the metamemory scores revealed that HC gave significantly more overestimations ("Yes" judgment and incorrect recall) than patients with cognitive complaints (p = .036). For these patients, JOL scores correlated positively with executive functioning (ps < .01).

CONCLUSION

Metamemory monitoring seems to be well-preserved during cancer. What is more, patients make less overestimation than HC, and they do not underestimate their memory. An accurate self-estimation of memory abilities in cancer patients, particularly those with mild cognitive deficits, may play an adaptive function. Our results suggest that the discrepancy frequently reported between cognitive complaints and objective cognitive scores may not be related to metamemory monitoring dysfunction.

Psychostimulants for cancer-related cognitive impairment in adult cancer survivors: a systematic review and meta-analysis

BACKGROUND

Cognitive impairment is recognized as a common symptom experienced by cancer survivors which impacts on quality of life (QoL) and day-to-day activities. One of the treatment options is the use of psychostimulants but the evidence supporting its use remains unclear.

OBJECTIVES

To identify the level of evidence of psychostimulants' effect on the management of cognitive impairment in adult cancer survivors.

METHODS

Electronic databases (MEDLINE, EMBASE, CENTRAL, CINAHL) and reference lists of relevant reviews were searched from inception to December 2017, with no language restrictions applied. Randomized controlled trials (RCTs), evaluating the effect of psychostimulants on cognitive impairment among cancer patients with no primary or secondary brain tumor or brain radiation, were included. The primary outcome was cognitive function changes, whereas secondary outcomes were adverse events (AEs) and QoL.

RESULTS

Six RCTs were included: three studies investigating methylphenidate and three modafinil, with a total of 244 and 146 patients, respectively. Due to important differences in methodologies between studies, a meta-analysis was assumed inappropriate for the primary outcome. A narrative synthesis was performed. One study using methylphenidate and two using modafinil demonstrated improvements in some cognitive functions as measured by objective cognitive assessment tests. Psychostimulants did not improve QoL and were not associated with more AEs.

CONCLUSION

To date, limited evidence is available to estimate the usefulness (or lack) of psychostimulants on cognitive function in this population.

Preventing adverse information effects on health outcomes: A self-affirmation intervention reduced information-induced cognitive decline in gastrointestinal cancer patients

RATIONALE

Nocebo studies show that informing patients about treatment side effects can adversely impact expectancies and symptom reporting.

OBJECTIVE

The current study examined how to inform patients fully about treatment side effects without increasing their occurrence. Extending theoretical assumptions about self-affirmation from the social-psychological to the medical domain, we tested whether allowing cancer patients to self-affirm prior to informing them about potential cognitive decline reduced the occurrence of Adverse Information Effects (AIE) on cognitive problem reporting (CPR) and verbal memory performance.

METHOD

Participants were 90 Dutch and Belgian gastrointestinal cancer patients with and without chemotherapy experience. Patients were randomized across three experimental conditions (information about chemotherapy-related cognitive problems with or without self-affirmation; no-information control) before completing an online questionnaire. Data were collected from May until August 2015. Main dependent variables were CPR and verbal memory performance. Stigma consciousness was included as a moderator.

RESULTS

Informing patients about chemotherapy-related cognitive problems increased CPR and decreased scores on two out of three memory measures. Self-affirmation reduced these AIE. Stigma conscious patients reported more problems in the information than the self-affirmation group.

CONCLUSIONS

Nocebo effects may be reduced by allowing patients the opportunity to restore their self-integrity at the implicit level. Self-affirmation has the potential to reduce AIE in patient populations without withholding relevant information about potential treatment side effects.

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.

Relationship of systemic cytokine concentrations to cognitive function over two years in women with early stage breast cancer

Cancer and its treatment are frequently associated with cancer-related cognitive impairment (CRCI). While CRCI has been associated with linked to chemotherapy, there is increasing evidence that the condition may start prior to treatment and for some, remain unresolved after active treatment and into survivorship. Although the pathophysiology of the condition is complex, alterations in systemic cytokines, signaling molecules activated in response to infection or injury that trigger inflammation, are a possible mechanism linked to cognitive dysfunction in breast cancer and other conditions. Given the conflicting results in the literature, the lack of focus on domain specific cognitive testing, and the need for a longer time period given the multiple modalities of standard treatments for early-stage breast cancer, this longitudinal study was conducted to address these gaps.

METHODS

We assessed 75 women with early-stage breast cancer at five points over two years, starting prior to the initial chemotherapy through 24months after chemotherapy initiation. Measures included a validated computerized evaluation of domain-specific cognitive functioning and a 17-plex panel of plasma cytokines. Linear mixed-effects models were applied to test the relationships of clinical variables and cytokine concentrations to each cognitive domain.

RESULTS

Levels and patterns of cytokine concentrations varied over time: six of the 17 cytokines (IL-6, IL-12, IL-17, G-CSF, MIPS-1β, and MCP-1) had the most variability. Some cytokine levels (e.g., IL-6) increased during chemotherapy but then decreased subsequently, while others (e.g., IL-17) consistently declined from baseline over time. There were multiple relationships among cytokines and cognition, which varied over time. At baseline, elevated concentrations of G-CSF and reduced concentrations of IL-17 were associated with faster psychomotor speed. At the second time-point (prior to the mid-chemotherapy), multiple cytokines had significant associations with psychomotor speed, complex attention, executive function, verbal memory, cognitive flexibility, composite memory and visual memory. Six months after chemotherapy initiation and at the one-year point, there were multiple, significant relationships among cytokines and multiple cognitive. At two years, fewer significant relationships were noted; however, lower concentrations of IL-7, a hematopoietic cytokine, were associated with better psychomotor speed, complex attention, and memory (composite, verbal and visual). MCP-1 was inversely associated with psychomotor speed and complex attention and higher levels of MIP-1β were related to better complex attention.

CONCLUSION

Levels and patterns of cytokines changed over time and demonstrated associations with domain-specific cognitive functioning that varied over time. The observed associations between cytokines and cognitive performance provides evidence that not only prototypical cytokines (i.e., IL-6, TNF-α, and IL1-β) but also cytokines from multiple classes may contribute to the inflammatory environment that is associated with cognitive dysfunction. Future studies to better delineate the cytokine changes, both individually and in networks, are needed to precisely assess a mechanistic link between cytokines and cognitive function in women receiving treatments for breast cancer.