The impact of mindfulness on working memory-related brain activation in breast cancer survivors with cognitive complaints.

PURPOSE: Cancer-related cognitive impairment (CRCI) has been associated with altered brain activation after chemotherapy in areas related to working memory. Hence, improving working memory capacity and associated brain activation might aid in the recovery of CRCI. In this study, we investigated the potential of a mindfulness-based intervention (MBI) to impact working memory-related brain activation. METHODS: Female breast cancer survivors reporting cognitive complaints (N=117) were randomized into a mindfulness (n=43; MBI), physical training (n=36; PT), or waitlist control condition (n=38; WL). Participants completed MRI scans before the intervention, immediately after, and three months post-intervention. Task-based functional MRI was used to measure differences between groups over time in working memory-related brain activation while performing a visual-verbal n-back task. RESULTS: Data of 83 participants (32/26/25 MBI/PT/WL) was included. Compared to the waitlist group, MBI participants showed reduced task-related activation in the right middle frontal and angular gyrus and increased activation in the right dorsal posterior cingulate cortex over time. Compared to the physical training group, MBI participants showed reduced brain activation in the bilateral superior parietal lobule and right dorsal anterior cingulate cortex over time. No differences between physical training and no intervention were identified. CONCLUSION: This study showed that an 8-week mindfulness-based intervention can significantly alter brain activation across brain regions involved in working memory, attentional control, and emotion processing during performance of a working memory task. This might aid in the recovery of CRCI. IMPLICATIONS FOR CANCER SURVIVORS: Mindfulness might alter brain activation patterns while performing a working memory task, which might ultimately aid in restoring higher order cognitive functions.

Changes in leukoencephalopathy and serum neurofilament after (neo)adjuvant chemotherapy for breast cancer.

BACKGROUND: Previous case studies have provided evidence for chemotherapy-induced leukoencephalopathy in patients with breast cancer. However, prospective research is lacking. Hence, we investigated leukoencephalopathy before and after chemotherapy and its association with a serum neuroaxonal damage marker. METHODS: This prospective cohort study included 40 patients receiving chemotherapy for breast cancer, and two age- and education-matched control groups, recruited between 2018 and 2021 (31-64 years of age). The latter control groups consisted of 39 chemotherapy-naïve patients and 40 healthy women. Fluid-attenuated inversion-recovery magnetic resonance imaging was used for lesion volumetry (total, juxtacortical, periventricular, infratentorial, and deep white matter) and blood serum to measure neurofilament light chain (NfL) levels. Acquisition took place pre-chemotherapy and three months and one-year post-chemotherapy, or at corresponding intervals. Within/between group differences were compared using robust mixed-effects modeling, and associations between total lesion volume and serum-NfL with linear regression. RESULTS: Stronger increases in deep white matter lesion volumes were observed shortly post-chemotherapy, compared with healthy women (ßstandardized=0.09, pFDR<0.001). Increases in total lesion volume could mainly be attributed to enlargement of existing lesions (mean±SD, 0.12±0.16 mL), rather than development of new lesions (0.02±0.02 mL). A stronger increase in serum-NfL concentration was observed shortly post-chemotherapy compared with both control groups (ß>0.70, p<0.004), neither of which showed any changes over time, whereas a decrease was observed compared with healthy women one-year post-chemotherapy (ß=-0.54, p = 0.002). Serum-NfL concentrations were associated with lesion volume one-year post-chemotherapy (or at matched timepoint; ß=0.36, p = 0.010), whereas baseline or short-term post-therapy levels or changes were not. CONCLUSION: These results underscore the possibility of chemotherapy-induced leukoencephalopathy months post-treatment, as well as the added value of serum-NfL as a prognostic marker for peripheral/central neurotoxicity. TRANSLATIONAL RELEVANCE: Previous case studies have provided evidence of chemotherapy-induced leukoencephalopathy in patients with breast cancer. However, prospective studies to estimate longitudinal changes are currently missing. In this study, we used longitudinal fluid-attenuated inversion-recovery magnetic resonance imaging to assess white matter lesion volumes in patients treated for non-metastatic breast cancer and healthy women. Our findings demonstrate that chemotherapy-treated patients exhibit stronger increases in lesion volumes compared with healthy women, specifically in deep white matter, at three months post-chemotherapy. Increases could mainly be attributed to enlargement of existing lesions, rather than development of new lesions. Last, serum concentrations of neurofilament light chain, a neuroaxonal damage marker, increased shortly after chemotherapy and long-term post-chemotherapy levels were associated with lesion volumes. These findings highlight the potential of this non-invasive serum marker as a prognostic marker for peripheral and/or central neurotoxicity. Implementation in clinical practice could aid in therapeutic decisions, assessing disease activity, or monitoring treatment response.

The Impact of Mindfulness on Functional Brain Connectivity and Peripheral Inflammation in Breast Cancer Survivors with Cognitive Complaints.

BACKGROUND: Cancer-related cognitive impairment (CRCI) has been linked to functional brain changes and inflammatory processes. Hence, interventions targeting these underlying mechanisms are needed. In this study, we investigated the effects of a mindfulness-based intervention on brain function and inflammatory profiles in breast cancer survivors with CRCI. METHODS: Female breast cancer survivors reporting cognitive complaints (n = 117) were randomly assigned to a mindfulness-based intervention (n = 43), physical training (n = 36), or waitlist control condition (n = 38). Region-of-interest (ROI) and graph theory analyses of resting state functional MRI data were performed to study longitudinal group differences in functional connectivity and organization in the default mode, dorsal attention, salience, and frontoparietal network. Additionally, bead-based immunoassays were used to investigate the differences in inflammatory profiles on serum samples. Measures were collected before, immediately after and three months post-intervention. RESULTS: No ROI-to-ROI functional connectivity changes were identified. Compared to no intervention, graph analysis showed a larger decrease in clustering coefficient after mindfulness and physical training. Additionally, a larger increase in global efficiency after physical training was identified. Furthermore, the physical training group showed a larger decrease in an inflammatory profile compared to no intervention (IL-12p70, IFN-γ, IL-1ß, and IL-8). CONCLUSION: Both mindfulness and physical training induced changes in the functional organization of networks related to attention, emotion processing, and executive functioning. While both interventions reduced functional segregation, only physical training increased functional integration of the neural network. In conclusion, physical training had the most pronounced effects on functional network organization and biomarkers of inflammation, two mechanisms that might be involved in CRCI.

The impact of mindfulness on cancer-related cognitive impairment in breast cancer survivors with cognitive complaints.

BACKGROUND: Interventions that target cancer-related cognitive impairment (CRCI) to improve the quality of life of cancer survivors are needed. In this study, the potential of a mindfulness-based intervention to reduce CRCI in breast cancer survivors, compared with physical training and a wait list control group, was investigated. METHODS: Breast cancer survivors with cognitive complaints (N = 117) were randomly allocated to a mindfulness (n = 43), physical training (n = 36), or wait list control condition (n = 38). Participants completed neuropsychological tests and questionnaires before the intervention, immediately after, and 3 months after intervention. The primary outcome measure was the change in cognitive complaints over time. Secondary outcomes were objective cognitive impairment and psychological well-being. All outcomes were compared between groups over time using linear mixed models, including participants with missing values. RESULTS: Of the 117 included participants, 96 completed the three assessments. Participants in the three groups reported decreased cognitive complaints after intervention, without group differences. There were no between-group differences in objective cognitive impairment after intervention compared with baseline. Compared with the wait list control group, participants reported increased mindfulness skills and reduced emotional distress after mindfulness and reduced emotional distress and fatigue after physical training. CONCLUSION: Contrary to the hypothesis, all groups reported an improvement in cognitive complaints over time. It is suggested that priming and acknowledgment of CRCI might alter the experience of cognitive impairment. Additionally, both mindfulness-based intervention and physical training can improve psychological well-being of breast cancer survivors with cognitive complaints.

Effects of a mindfulness-based intervention on cancer-related cognitive impairment: Results of a randomized controlled functional magnetic resonance imaging pilot study.

BACKGROUND: Many breast cancer survivors suffer from cognitive complaints after cancer treatment, affecting their quality of life. The objective of this pilot study was to investigate the effect of a blended-care mindfulness-based intervention (MBI) on chemotherapy-related cognitive impairment and functional brain changes. Furthermore, correlations between changes in cognitive functioning and self-reported behavioral factors were investigated. METHODS: Breast cancer survivors (n = 33) who reported cognitive impairment were randomly allocated to a mindfulness condition (n = 18) or a waitlist control condition (n = 15). Patients completed questionnaires on cognitive impairment, emotional distress, and fatigue; neuropsychological tests; and resting-state functional magnetic resonance imaging before the start of MBI (time 1 [T1]), immediately after the completion of an 8-week MBI program (T2), and 3 months postintervention (T3). Resting-state functional connectivity was estimated in the default mode network, the dorsal and salience attention networks, and the frontoparietal network. Mixed model repeated-measures analysis was performed to test the intervention effect. RESULTS: Patients in the mindfulness condition exhibited significantly higher connectivity between the dorsal and salience attention networks after the mindfulness intervention compared with those in the control condition. MBI participants also had reduced subjective cognitive impairment, emotional distress, and fatigue. No intervention effect was observed on neurocognitive tests. CONCLUSIONS: MBI may induce functional brain changes in networks related to attention and may have a positive effect on subjective measures of cognitive impairment in breast cancer survivors. Therefore, MBI could be a suitable intervention to improve quality of life in this population and deserves further study in this context.

A mindfulness-based intervention for breast cancer patients with cognitive impairment after chemotherapy: study protocol of a three-group randomized controlled trial.

BACKGROUND: Mindfulness has been applied to improve cancer care by enhancing psychological well-being. However, little is known about its impact on cognitive impairment experienced by cancer patients after chemotherapy. Mindfulness may be relevant in tackling cognitive impairment by decreasing emotional distress and fatigue, by decreasing inflammation, and by strengthening functional brain connectivity. The aim of the present study protocol is to evaluate the efficacy and mechanisms of a mindfulness-based intervention to reduce cognitive impairment in breast cancer patients after chemotherapy. METHODS/DESIGN: The present study is a three-arm, parallel-group, randomized controlled trial with assessments at baseline, 1 to 3 weeks after the intervention and at 3 months' follow-up. One hundred and twenty breast cancer patients who ended treatment a minimum of 6 months and a maximum of 5 years before, and who have cognitive complaints, will be enrolled. They will be randomized into one of the following three study arms: (1) a mindfulness-based intervention group (n = 40), (2) an active control condition based on physical training (n = 40), or (3) a treatment as usual (TAU) control group (n = 40). Both the mindfulness-based intervention and the active control condition consist of four group sessions (3 h for the mindfulness condition and 2 h for the physical training) spread over 8 weeks. The primary outcomes will be cognitive symptoms as measured by the Cognitive Failure Questionnaire and changes in functional brain connectivity in the attention network. Secondary outcomes will be (1) levels of emotional distress, fatigue, mindfulness, quality of life; (2) neurocognitive tests; (3) structural and functional brain changes using MR imaging and (4) measures of inflammation. DISCUSSION: The study will examine the impact of a mindfulness-based intervention on cognitive impairment in breast cancer patients. If the findings of this study confirm the effectiveness of a mindfulness-based program to reduce cognitive impairment, it will be possible to improve quality of life for ex-cancer patients. We will inform health care providers about the potential use of a mindfulness-based intervention as a non-pharmaceutical, low-threshold mental health intervention to improve cognitive impairment after cancer. TRIAL REGISTRATION: ClinicalTrials.gov, ID: NCT03736460. Retrospectively registered on 8 November 2018.