Few changes observed in polysomnographic-assessed sleep before and after completion of chemotherapy

Effects of sleep disturbances and circadian rhythms modifications on cognition in breast cancer women before and after adjuvant chemotherapy: the ICANSLEEP-1 protocol

BACKGROUND

Many patients treated for breast cancer (BC) complain about cognitive difficulties affecting their daily lives. Recently, sleep disturbances and circadian rhythm disruptions have been brought to the fore as potential contributors to cognitive difficulties in patients with BC. Yet, studies on these factors as well as their neural correlates are scarce. The purpose of the ICANSLEEP-1 (Impact of SLEEP disturbances in CANcer) study is to characterize sleep using polysomnography and its relationship with the evolution of cognitive functioning at both the behavioral and the neuroanatomical levels across treatment in BC patients treated or not with adjuvant chemotherapy.

METHODS

ICANSLEEP-1 is a longitudinal study including BC patients treated with adjuvant chemotherapy (n = 25) or not treated with adjuvant chemotherapy (n = 25) and healthy controls with no history of BC (n = 25) matched for age (45-65 years old) and education level. The evaluations will take place within 6 weeks after inclusion, before the initiation of chemotherapy (for BC patients who are candidates for chemotherapy) or before the first fraction of radiotherapy (for BC patients with no indication for chemotherapy) and 6 months later (corresponding to 2 weeks after the end of chemotherapy). Episodic memory, executive functions, psychological factors, and quality of life will be assessed with validated neuropsychological tests and self-questionnaires. Sleep quantity and quality will be assessed with polysomnography and circadian rhythms with both actigraphy and saliva cortisol. Grey and white matter volumes, as well as white matter microstructural integrity, will be compared across time between patients and controls and will serve to further investigate the relationship between sleep disturbances and cognitive decline.

DISCUSSION

Our results will help patients and clinicians to better understand sleep disturbances in BC and their relationship with cognitive functioning across treatment. This will aid the identification of more appropriate sleep therapeutic approaches adapted to BC patients. Improving sleep in BC would eventually help limit cognitive deficits and thus improve quality of life during and after treatments.

TRIAL REGISTRATION

NCT05414357, registered June 10, 2022.

PROTOCOL VERSION

Version 1.2 dated March 23, 2022.

Tackling Insomnia Symptoms through Vestibular Stimulation in Patients with Breast Cancer: A Perspective Paper

Insomnia symptoms are common among patients with breast cancer (BC; 20-70%) and are predictors of cancer progression and quality of life. Studies have highlighted sleep structure modifications, including increased awakenings and reduced sleep efficiency and total sleep time. Such modifications may result from circadian rhythm alterations consistently reported in this pathology and known as carcinogenic factors, including lower melatonin levels, a flattened diurnal cortisol pattern, and lower rest-activity rhythm amplitude and robustness. Cognitive behavioral therapy and physical activity are the most commonly used non-pharmacological interventions to counter insomnia difficulties in patients with BC. However, their effects on sleep structure remain unclear. Moreover, such approaches may be difficult to implement shortly after chemotherapy. Innovatively, vestibular stimulation would be particularly suited to tackling insomnia symptoms. Indeed, recent reports have shown that vestibular stimulation could resynchronize circadian rhythms and improve deep sleep in healthy volunteers. Moreover, vestibular dysfunction has been reported following chemotherapy. This perspective paper aims to support the evidence of using galvanic vestibular stimulation to resynchronize circadian rhythms and reduce insomnia symptoms in patients with BC, with beneficial effects on quality of life and, potentially, survival.

Sleep-dependent memory consolidation in breast cancer: Use of a virtual reality prospective memory task

Background

Previous studies have revealed both sleep alterations and prospective memory (PM) impairments in breast cancer (BC) patients. PM refers to memory of intended actions and is crucial for daily living tasks and treatment compliance. As sleep is known to favor memory consolidation, one may expect that changes in sleep quality related to BC would have an impact on PM performance. This study aimed at assessing sleep-dependent consolidation of intentions using an ecological, virtual reality-based PM task in BC patients not treated with chemotherapy.

Materials and methods

Thirty-seven early stages BC patients and 21 healthy controls (HC) participated in this study. PM was assessed using a virtual reality task, during which participants learnt a list of intentions and recalled them after a retention interval filled with a day awake or a night of sleep monitored by polysomnography. Sleep spindles and slow waves, brain oscillations involved in sleep-dependent memory consolidation, were quantified automatically using the Aseega software (Physip). Subjective sleep disturbances and markers of quality of life (psychological distress, fatigue, and well-being) were assessed by questionnaires.

Results

Greater PM performance was observed after sleep than after an equivalent period of daytime wakefulness for both groups (HC and BC). PM performance after sleep did not differ significantly between groups. Yet, BC patients reported greater sleep disturbances than HC which were related with poorer intentions retrieval, greater psychological distress, fatigue and poorer well-being. The frequency of spindles was higher and the amplitude of slow waves lower in BC patients compared to HC. However, no significant association was observed between polysomnography parameters and PM scores in the whole sample of participants.

Conclusion

Although subtle changes in brain oscillations involved in sleep-dependent memory consolidation were observed, these changes did not significantly impair overnight PM consolidation in BC patients. Nevertheless, poorer PM performance was associated with greater sleep complaints which in turn were related to poorer quality of life. Overall, these data suggest that sleep-dependent PM consolidation mechanisms are not altered in early stages BC patients not treated with chemotherapy. Further investigations are needed to understand the association between markers of quality of life and sleep-dependent memory consolidation.

Sleep macro- and microstructure in breast cancer survivors

Complaints of sleep disturbance are prevalent among breast cancer (BC) patients and are predictors of quality of life. Still, electrophysiological measures of sleep are missing in patients, which prevents from understanding the pathophysiological consequences of cancer and its past treatments. Using polysomnography, sleep can be investigated in terms of macro- (e.g. awakenings, sleep stages) and micro- (i.e. cortical activity) structure. We aimed to characterize sleep complaints, and macro- and microstructure in 33 BC survivors untreated by chemotherapy and that had finished radiotherapy since at least 6 months (i.e. out of the acute effects of radiotherapy) compared to 21 healthy controls (HC). Compared to HC, BC patients had a larger number of awakenings (p = 0.008); and lower Delta power (p < 0.001), related to sleep deepening and homeostasis; greater both Alpha (p = 0.002) and Beta power (p < 0.001), related to arousal during deep sleep; and lower Theta power (p = 0.004), related to emotion regulation during dream sleep. Here we show that patients have increased cortical activity related to arousal and lower activity related to sleep homeostasis compared to controls. These results give additional insights in sleep pathophysiology of BC survivors and suggest sleep homeostasis disruption in non-advanced stages of BC.

A multidisciplinary perspective on the complex interactions between sleep, circadian, and metabolic disruption in cancer patients

Sleep is a basic need that is frequently set aside in modern societies. This leads to profound but complex physiological maladaptations in the body commonly referred to as circadian disruption, which recently has been characterized as a carcinogenic factor and reason for poor treatment outcomes, shortened survival, and reduced quality of life in cancer patients. As sleep and circadian physiology in cancer patients spans several disciplines including nursing science, neurology, oncology, molecular biology and medical technology, there is a lack of comprehensive and integrated approaches to deal with this serious and growing issue and at best a fractionated understanding of only part of the problem among researchers within each of these segments. Here, we take a multidisciplinary approach to comprehensively review the diagnosis and impact of sleep and circadian disruption in cancer patients. We discuss recent discoveries on molecular regulation of the circadian clock in healthy and malignant cells, the neurological and endocrine pathways controlling sleep and circadian rhythmicity, and their inputs to and outputs from the organism. The benefits and drawbacks of the various technologies, devices, and instruments used to assess sleep and circadian function, as well as the known consequences of sleep disruption and how sleep can be corrected in cancer patients, will be analyzed. We will throughout the review highlight the extensive crosstalk between sleep, circadian rhythms, and metabolic pathways involved in malignancy and identify current knowledge gaps and barriers for addressing the issue of sleep and circadian disruption in cancer patients. By addressing these issues, we hope to provide a foundation for further research as well as better and more effective care for the patients in the future.

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.

Impact of breast cancer on prospective memory functioning assessed by virtual reality and influence of sleep quality and hormonal therapy: PROSOM-K study

BACKGROUND

Breast cancer (BC) is the most frequent cancer in women with more than 70% of BC patients being treated with hormonal therapy (HT). Among these patients, some report difficulties in remembering what they are supposed to do at the right moment, referring to prospective memory (PM). PM is essential for autonomy and medical adherence of patients, and requires an ecological assessment. Virtual reality, that recreates naturalistic environment, seems to be a promising method to evaluate PM. Several BC patients also report sleep disturbances. Given the role of sleep on memory consolidation, it is imperative to explore the influence of sleep quality on PM in BC patients treated with HT. The purpose of PROSOM-K study is to assess PM functioning using virtual reality and sleep quality in BC treated or not with HT.

METHODS

PROSOM-K is a prospective study including post-menopausal BC patients ≤70 years old treated with radiotherapy (n = 25) or with radiotherapy and HT (n = 25), and healthy post-menopausal women (n = 25) matched for age and education. PM will be assessed using a virtual reality based task. Other cognitive functions and psychosocial factors will be assessed with validated questionnaires and neuropsychological tests. The study is divided in 3 sessions: a session of familiarisation with the virtual environment and the PM task: a day-time session during which participants learn intentions during the morning and recall them in the evening; and a night-time session during which participants learn intentions in the evening and recall them the following morning. Women will be monitored by wrist actigraphy; during the night-time session, objective sleep quality and quantity will be measured by polysomnography.

DISCUSSION

This is a novel study aiming to assess PM using virtual reality, coupled with the evaluation of other cognitive functions. Polysomnographic study of sleep will provide further information about architectural sleep disturbances in BC. Association between sleep architecture parameters and PM mechanism in BC women treated with HT will be described in detail. We expect our results will provide knowledge for patients and clinicians and further help to improve patient care and cognitive therapy.

TRIAL REGISTRATION

NCT03420105 , registered: January 10, 2018.

Impact of a combined multimodal-aerobic and multimodal intervention compared to standard aerobic treatment in breast cancer survivors with chronic cancer-related fatigue - results of a three-armed pragmatic trial in a comprehensive cohort design

BACKGROUND

Cancer-related fatigue (CRF) and insomnia are major complaints in breast cancer survivors (BC). Aerobic training (AT), the standard therapy for CRF in BC, shows only minor to moderate treatment effects. Other evidence-based treatments include cognitive behavioral therapy, e.g., sleep education/restriction (SE) and mindfulness-based therapies. We investigated the effectiveness of a 10-week multimodal program (MT) consisting of SE, psycho-education, eurythmy- and painting-therapy, administered separately or in combination with AT (CT) and compared both arms to AT alone.

METHODS

In a pragmatic comprehensive cohort study BC with chronic CRF were allocated randomly or by patient preference to (a) MT, (b) CT (MT + AT) or (c) AT alone. Primary endpoint was a composite score of the Pittsburgh Sleep Quality Index and the Cancer Fatigue Scale after 10 weeks of intervention (T1); a second endpoint was a follow-up assessment 6 months later (T2). The primary hypothesis stated superiority of CT and non-inferiority of MT vs. AT at T1. A closed testing procedure preserved the global α-level. The intention-to-treat analysis included propensity scores for the mode of allocation and for the preferred treatment, respectively.

RESULTS

Altogether 126 BC were recruited: 65 were randomized and 61 allocated by preference; 105 started the intervention. Socio-demographic parameters were generally balanced at baseline. Non-inferiority of MT to AT at T1 was confirmed (p < 0.05), yet the confirmative analysis stopped as it was not possible to confirm superiority of CT vs. AT (p = 0.119). In consecutive exploratory analyses MT and CT were superior to AT at T1 and T2 (MT) or T2 alone (CT), respectively.

CONCLUSIONS

The multimodal CRF-therapy was found to be confirmatively non-inferior to standard therapy and even yielded exploratively sustained superiority. A randomized controlled trial including a larger sample size and a longer follow-up to evaluate multimodal CRF-therapy is highly warranted.

TRIAL REGISTER

DRKS-ID: DRKS00003736 . Recruitment period June 2011 to March 2013. Date of registering 19 June 2012.

Systematic review of sleep disorders in cancer patients: can the prevalence of sleep disorders be ascertained?

Although sleep is vital to all human functioning and poor sleep is a known problem in cancer, it is unclear whether the overall prevalence of the various types of sleep disorders in cancer is known. The purpose of this systematic literature review was to evaluate if the prevalence of sleep disorders could be ascertained from the current body of literature regarding sleep in cancer. This was a critical and systematic review of peer-reviewed, English-language, original articles published from 1980 through 15 October 2013, identified using electronic search engines, a set of key words, and prespecified inclusion and exclusion criteria. Information from 254 full-text, English-language articles was abstracted onto a paper checklist by one reviewer, with a second reviewer randomly verifying 50% (k = 99%). All abstracted data were entered into an electronic database, verified for accuracy, and analyzed using descriptive statistics and frequencies in SPSS (v.20) (North Castle, NY). Studies of sleep and cancer focus on specific types of symptoms of poor sleep, and there are no published prevalence studies that focus on underlying sleep disorders. Challenging the current paradigm of the way sleep is studied in cancer could produce better clinical screening tools for use in oncology clinics leading to better triaging of patients with sleep complaints to sleep specialists, and overall improvement in sleep quality.

Psychosocial correlates of sleep quality and architecture in women with metastatic breast cancer

BACKGROUND

Sleep disturbance is prevalent among women with metastatic breast cancer (MBC). Our study examined the relationship of depression and marital status to sleep assessed over three nights of polysomnography (PSG).

METHODS

Women with MBC (N=103) were recruited; they were predominately white (88.2%) and 57.8±7.7 years of age. Linear regression analyses assessed relationships among depression, marital status, and sleep parameters.

RESULTS

Women with MBC who reported more depressive symptoms had lighter sleep (e.g., stage 1 sleep; P<.05), less slow-wave sleep (SWS) (P<.05), and less rapid eye movement (REM) sleep (P<.05). Single women had less total sleep time (TST) (P<.01), more wake after sleep onset (WASO) (P<.05), worse sleep efficiency (SE) (P<.05), lighter sleep (e.g., stage 1; P<.05), and less REM sleep (P<.05) than married women. Significant interactions indicated that depressed and single women had worse sleep quality than partnered women or those who were not depressed.

CONCLUSION

Women with MBC and greater symptoms of depression had increased light sleep and reduced SWS and REM sleep, and single women had worse sleep quality and greater light sleep than married counterparts. Marriage was related to improved sleep for women with more depressive symptoms.

Prevalence, putative mechanisms, and current management of sleep problems during chemotherapy for cancer

Sleep problems are highly prevalent in cancer patients undergoing chemotherapy. This article reviews existing evidence on etiology, associated symptoms, and management of sleep problems associated with chemotherapy treatment during cancer. It also discusses limitations and methodological issues of current research. The existing literature suggests that subjectively and objectively measured sleep problems are the highest during the chemotherapy phase of cancer treatments. A possibly involved mechanism reviewed here includes the rise in the circulating proinflammatory cytokines and the associated disruption in circadian rhythm in the development and maintenance of sleep dysregulation in cancer patients during chemotherapy. Various approaches to the management of sleep problems during chemotherapy are discussed with behavioral intervention showing promise. Exercise, including yoga, also appear to be effective and safe at least for subclinical levels of sleep problems in cancer patients. Numerous challenges are associated with conducting research on sleep in cancer patients during chemotherapy treatments and they are discussed in this review. Dedicated intervention trials, methodologically sound and sufficiently powered, are needed to test current and novel treatments of sleep problems in cancer patients receiving chemotherapy. Optimal management of sleep problems in patients with cancer receiving treatment may improve not only the well-being of patients, but also their prognosis given the emerging experimental and clinical evidence suggesting that sleep disruption might adversely impact treatment and recovery from cancer.