Circadian rhythm disrupting behaviours and cancer outcomes in breast cancer survivors: a systematic review

The impact of sleep on breast cancer-specific mortality: a Mendelian randomisation study

BACKGROUND

The relationship between sleep traits and survival in breast cancer is uncertain and complex. There are multiple biological, psychological and treatment-related factors that could link sleep and cancer outcomes. Previous studies could be biased due to methodological limitations such as reverse causation and confounding. Here, we used two-sample mendelian randomisation (MR) to investigate the causal relationship between sleep and breast cancer mortality.

METHODS

Publicly available genetic summary data from females of European ancestry from UK Biobank and 23andme and the Breast Cancer Association Consortium were used to generate instrumental variables for sleep traits (chronotype, insomnia symptoms, sleep duration, napping, daytime-sleepiness, and ease of getting up (N = 446,118-1,409,137)) and breast cancer outcomes (15 years post-diagnosis, stratified by tumour subtype and treatment (N = 91,686 and Ndeaths = 7,531 over a median follow-up of 8.1 years)). Sensitivity analyses were used to assess the robustness of analyses to MR assumptions.

RESULTS

Initial results found some evidence for a per category increase in daytime-sleepiness reducing overall breast cancer mortality (HR = 0.34, 95% CI = 0.14, 0.80), and for insomnia symptoms reducing odds of mortality in oestrogen receptor positive breast cancers not receiving chemotherapy (HR = 0.18, 95% CI = 0.05, 0.68) and in patients receiving aromatase inhibitors (HR = 0.23, 95% CI = 0.07, 0.78). Importantly, these relationships were not robust following sensitivity analyses meaning we could not demonstrate any causal relationships.

CONCLUSIONS

This study did not provide evidence that sleep traits have a causal role in breast cancer mortality. Further work characterising disruption to normal sleep behaviours and its effects on tumour biology, treatment compliance and quality of life are needed.

Rhythm is essential: Unraveling the relation between the circadian clock and cancer

Physiological processes such as the sleep-wake cycle, metabolism, hormone secretion, neurotransmitter release, sensory capabilities, and a variety of behaviors, including sleep, are controlled by a circadian rhythm adapted to 24-hour day-night periodicity. Disruption of circadian rhythm may lead to the risks of numerous diseases, including cancers. Several epidemiological and clinical data reveal a connection between the disruption of circadian rhythms and cancer. On the contrary, oncogenic processes may suppress the homeostatic balance imposed by the circadian clock. The integration of circadian biology into cancer research offers new options for making cancer treatment more effective, and the pharmacological modulation of core clock genes is a new approach in cancer therapy. This review highlights the role of the circadian clock in tumorigenesis, how clock disruption alters the tumor microenvironment, and discusses how pharmacological modulation of circadian clock genes can lead to new therapeutic options.

Interaction between sleep duration and physical activity on mortality among cancer survivors: findings from National Health and Nutrition Examination Surveys 2007-2018

Background

Sleep duration and physical activity (PA) are critical factors influencing mortality risk. However, the interaction between sleep duration and PA with mortality risk among cancer survivors has not been well explored.

Methods

This cross-sectional study utilized data from the National Health and Nutrition Examination Survey (NHANES) spanning 2007-2018. Multivariable Cox regression analysis and restricted cubic splines were employed to evaluate the hazard ratios (HRs) and 95% confidence intervals (CIs) of the association of sleep duration and PA with mortality risk in cancer survivors. Multiplicative and additive interaction terms were constructed to assess interaction effects.

Results

The study included a total of 2,528 adult cancer survivors (aged≥20 years). Sleep duration exhibited a U-shaped association with all-cause and cancer-specific mortality, while demonstrating an inverted L-shaped association with cardiovascular disease (CVD) mortality. Compared to physically inactive participants, those with adequate PA had lower risks of all-cause mortality (HR = 0.542, 95% CI: 0.540-0.543), cancer mortality (HR = 0.486, 95% CI: 0.484-0.488), and CVD mortality (HR = 0.759, 95% CI: 0.755-0.763) among cancer survivors. A significant additive interaction was found between extreme sleep duration and PA on all-cause mortality risk among cancer survivors (long sleep duration: relative excess risk due to interaction (RERI) = 1.514, 95% CI: 1.504-1.525; short sleep duration: RERI = 0.725, 95% CI: 0.713-0.737).

Conclusion

Extreme sleep duration and lack of PA were associated with mortality risk in cancer survivors independently and jointly. Maintain appropriate sleep duration and doing regular PA may synergistically improve cancer survival among cancer survivors.

Sleep disturbances based on patient reported outcomes in patients with breast cancer

PURPOSE

Sleep disturbances are common in patients with breast cancer, but comprehensive evaluations with patient-reported outcomes (PRO) and sleep evaluation with polysomnography (PSG) are lacking. This study describes sleep disruption using PROs and PSG to identify underlying sleep disorders.

METHODS

A retrospective review of patients with breast cancer undergoing formal sleep evaluation from 4/1/2009 to 7/31/2014 was performed. Clinical characteristics, PROs using Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS), and PSG data were reviewed.

RESULTS

404 patients were identified with 43% early, 30% locally advanced and 17% metastatic disease. PSQI revealed poor sleep in 75%, and ESS demonstrated daytime sleepiness in 55%. Sleep aid use was reported by 39%, and pain medication use in 22%. Most patients (50.2%) had multiple sleep disorders. Insomnia (54.5%) was the most frequent sleep disorder, followed closely by obstructive sleep apnea (OSA) (53.7%). PSG was performed in 74%. Multivariate analysis linked poor sleep to use of sleep aids [OR 7.7, 95% CI 3.9 to 15.2], anxiety disorder [OR 4.8, 95% CI 1.7 to 14.0], and metastatic disease [OR 2.8, 95% CI 1.1 to 6.6]. Daytime sleepiness correlated with known diagnosis of OSA [OR 1.9, 95% CI 1.0 to 3.3] and sleep aid use [OR 0.6, 95% CI 0.4 to 0.9].

CONCLUSIONS

Poor sleep was associated with sleep aid use, anxiety disorder and metastatic disease. Insomnia was the most common sleep disorder, followed by OSA (mostly mild). Education about sleep health and proactive screening for sleep symptoms would be beneficial in patients with breast cancer.

Sleep characteristics and recurrence in platinum-sensitive ovarian cancer survivors: A prospective cohort study

Objective

To describe characteristics of sleep (quality, duration, efficiency, and insomnia) in a cohort of high-grade epithelial ovarian cancer (EOC) survivors who have completed and responded to first-line chemotherapy, and to explore their relationships with disease recurrence.

Methods

In this cohort of 97 women, sleep and other factors were assessed at baseline and 4 months later. The distribution of participants by categories of sleep characteristics were calculated. Hazard ratios (HRs) and 95 % confidence intervals (95 % CI) for the association between each sleep characteristic and recurrence were estimated using the Cox proportional hazards model, and adjusted for confounding using propensity scores. Associations were estimated for all women and among those defined as fully platinum-sensitive.

Results

At baseline, just over half of participants (52.6 % to 56.7 %) had poor sleep quality, efficiency and duration, while most (62.9 %) did not experience insomnia. Distributions remained similar 4 months later. During follow-up, 47 recurrences occurred. Among all participants, HRs (95 % CIs) of recurrence were close to the value of 1, indicating no association, for sleep quality and efficiency, 1.22 (0.66-2.23) for not meeting vs. meeting sleep duration guidelines and 0.68 (0.34-1.39) for the presence vs. absence of insomnia. In fully platinum-sensitive women, the HRs (95 % CIs) were 1.50 (0.64-3.53) for not meeting duration guidelines, 1.25 (0.56-2.79) for poor sleep efficiency, 1.44 (0.55-3.72) for the presence of insomnia, and remained null for sleep quality.

Conclusion

Most EOC survivors have poor sleep quality, duration, and efficiency. Research with larger sample sizes is required to better understand the relationship between these sleep characteristics and the risk of recurrence.

Eating frequency, timing of meals, and sleep duration before and after a randomized controlled weight loss trial for breast cancer survivors

PURPOSE

To examine eating frequency, timing of meals, and sleep duration before and after a weight loss intervention for breast cancer survivors.

METHODS

Female breast cancer survivors (n = 159; 55 ± 9 years; 31.4 ± 5.0 kg/m2; stage I-III, median [IQR] 9.5 [5.5] months post-diagnosis) participated in a randomized controlled trial of a 12-month weight loss intervention versus usual care. Eating frequency, proportion of daily calories consumed after 5 PM, eating after 8 PM, nightly fasting duration, and sleep duration were estimated and categorized based on existing associations with factors influencing breast cancer prognosis and breast cancer outcomes. These behaviors at baseline were compared to women from an Australian national survey with similar age and BMI range. Mixed-effects linear regression models were used to examine the changes in health behaviors from baseline to 18 months between intervention and usual care groups.

RESULTS

Before the trial, eating after 8 PM (67%) was higher, and short nightly fasting duration (< 13 h, 83%) and long sleep duration (> 9 h/day, 26%) were marginally higher, in breast cancer survivors than women in the national survey (52%, 75%, and 17%, respectively). "Less optimal" eating behaviors and sleep duration tended to co-occur. Behaviors remained unchanged over the 18-month follow-up, irrespective of the study group (p > 0.05; Cohen's effect sizes < 0.3).

CONCLUSIONS

Later timing of eating and long sleep duration were prevalent in breast cancer survivors and continued following a weight loss intervention.

IMPLICATIONS FOR CANCER SURVIVORS

Future multi-behavior interventions in breast cancer survivors should consider specific messages to target eating timing behaviors and sleep.

Circadian rhythms and breast cancer: from molecular level to therapeutic advancements

BACKGROUND AND OBJECTIVES

Circadian rhythms, the endogenous biological clocks that govern physiological processes, have emerged as pivotal regulators in the development and progression of breast cancer. This comprehensive review delves into the intricate interplay between circadian disruption and breast tumorigenesis from multifaceted perspectives, encompassing biological rhythms, circadian gene regulation, tumor microenvironment dynamics, and genetic polymorphisms.

METHODS AND RESULTS

Epidemiological evidence underscores the profound impact of external factors, such as night shift work, jet lag, dietary patterns, and exercise routines, on breast cancer risk and progression through the perturbation of circadian homeostasis. The review elucidates the distinct roles of key circadian genes, including CLOCK, BMAL1, PER, and CRY, in breast cancer biology, highlighting their therapeutic potential as molecular targets. Additionally, it investigates how circadian rhythm dysregulation shapes the tumor microenvironment, fostering epithelial-mesenchymal transition, chronic inflammation, and immunosuppression, thereby promoting tumor progression and metastasis. Furthermore, the review sheds light on the association between circadian gene polymorphisms and breast cancer susceptibility, paving the way for personalized risk assessment and tailored treatment strategies.

CONCLUSIONS

Importantly, it explores innovative therapeutic modalities that harness circadian rhythms, including chronotherapy, melatonin administration, and traditional Chinese medicine interventions. Overall, this comprehensive review emphasizes the critical role of circadian rhythms in the pathogenesis of breast cancer and highlights the promising prospects for the development of circadian rhythm-based interventions to enhance treatment efficacy and improve patient outcomes.

Natural Compounds for Preventing Age-Related Diseases and Cancers

Aging is a multifaceted process influenced by hereditary factors, lifestyle, and environmental elements. As time progresses, the human body experiences degenerative changes in major functions. The external and internal signs of aging manifest in various ways, including skin dryness, wrinkles, musculoskeletal disorders, cardiovascular diseases, diabetes, neurodegenerative disorders, and cancer. Additionally, cancer, like aging, is a complex disease that arises from the accumulation of various genetic and epigenetic alterations. Circadian clock dysregulation has recently been identified as an important risk factor for aging and cancer development. Natural compounds and herbal medicines have gained significant attention for their potential in preventing age-related diseases and inhibiting cancer progression. These compounds demonstrate antioxidant, anti-inflammatory, anti-proliferative, pro-apoptotic, anti-metastatic, and anti-angiogenic effects as well as circadian clock regulation. This review explores age-related diseases, cancers, and the potential of specific natural compounds in targeting the key features of these conditions.

Potential mechanisms underlying the effect of walking exercise on cancer-related fatigue in cancer survivors

PURPOSE

Cancer-related fatigue (CRF) is a common and debilitating long-term side effect of cancer and its treatment. While exercise has been shown to effectively reduce CRF, the underlying mechanisms are not fully clear. Therefore, the aim of this study was to explore the effects of a 4-month walking exercise program on fatigue severity and to explore potential underlying physiological, behavioral, and psychological mechanisms of action.

METHODS

We included 27 cancer survivors (59 ± 15 years, 37% female) with variable cancer diagnoses who were at least moderately fatigued and finished treatment between 6 and 36 months ago. This study with a quasi-experimental interrupted time-series design compared a 4-month walking intervention period with a 4-month control period. Measurements of fatigue and physiological, behavioral, and psychological factors were performed, supplemented with participants' perceptions on how exercise influenced their fatigue.

RESULTS

A significant and clinically relevant decrease in fatigue severity was found over time (β =  - 8.1, 95% CI =  - 12.1; - 4.2), but could not be attributed directly to the walking exercise intervention. Increases in muscle strength (β =  - 0.07, 95% CI =  - 0.12; - 0.02), physical activity (β =  - 0.1, 95% CI =  - 0.2; - 0.04), and sleep quality (β = 1.1, 95% CI = 0.3; 1.9), as well as decreases in muscle relaxation times (β = 0.09, 95% CI = 0.02; 0.16) and psychological distress (β = 1.1, 95% CI = 0.8; 1.3) were associated with reductions in fatigue severity. Resilience and physical well-being were perceived as most important constructs explaining the walking exercise effects on fatigue.

CONCLUSION

Our findings reveal potential physiological, behavioral, and psychological mechanisms underlying the multidimensional effects of exercise on fatigue severity.

IMPLICATIONS FOR CANCER SURVIVORS

Incorporating resistance exercise and addressing resilience and physical well-being might improve the efficacy of exercise interventions for cancer survivors.

Network dynamics investigation of omics-data-driven circadian-hypoxia crosstalk logical model in gallbladder cancer reveals key therapeutic target combinations

Recent findings in cancer research have pointed towards the bidirectional interaction between circadian and hypoxia pathways. However, little is known about their crosstalk mechanism. In this work, we aimed to investigate this crosstalk at a network level utilizing the omics information of gallbladder cancer. Differential gene expression and pathway enrichment analysis were used for selecting the crucial genes from both the pathways, followed by the construction of a logical crosstalk model using GINsim. Functional circuit identification and node perturbations were then performed. Significant node combinations were used to investigate the temporal behavior of the network through MaBoSS. Lastly, the model was validated using published in vitro experimentations. Four new positive circuits and a new axis viz. BMAL1/ HIF1αβ/ NANOG, responsible for stemness were identified. Through triple node perturbations viz.a. BMAL:CLOCK (KO or E1) + P53 (E1) + HIF1α (KO); b. P53 (E1) + HIF1α (KO) + MYC (E1); and c. HIF1α (KO) + MYC (E1) + EGFR (KO), the model was able to inhibit cancer growth and maintain a homeostatic condition. This work provides an architecture for drug simulation analysis to entrainment circadian rhythm and in vitro experiments for chronotherapy-related studies. Insight Box. Circadian rhythm and hypoxia are the key dysregulated processes which fuels-up the cancer growth. In the present work we have developed a gallbladder cancer (GBC) specific Boolean model, utilizing the RNASeq data from GBC dataset and tissue specific interactions. This work adequately models the bidirectional nature of interactions previously illustrated in experimental papers showing the effect of hypoxia on dysregulation of circadian rhythm and the influence of this disruption on progression towards metastasis. Through the dynamical study of the model and its response to different perturbations, we report novel triple node combinations that can be targeted to efficiently reduce GBC growth. This network can be used as a generalized framework to investigate different crosstalk pathways linked with cancer progression.

Trends and cancer-specific patterns of physical activity, sleep duration, and daily sitting time among US cancer survivors, 1997-2018

BACKGROUND

Physical activity, sufficient sleep, and limiting sedentary time may improve cancer survivorship.

METHODS

Utilizing US nationally representative samples from the National Health Interview Survey 1997-2018 and the National Health and Nutrition Examination Survey 2007-2018, this study investigated the trends of meeting physical activity guidelines, insufficient sleep duration, and sitting time in US cancer survivors (n = 58 527) and noncancer adults (n = 640 109).

RESULTS

From 1997 to 2018, the prevalence of meeting physical activity guidelines was consistently lower in cancer survivors than in noncancer adults. Among cancer survivors, the prevalence of meeting physical activity guidelines increased from 34.9% (95% confidence interval [CI] = 33.1% to 36.8%) to 46.5% (95% CI = 45.0% to 48.1%) for aerobic (≥150 minutes per week at moderate intensity or 75 minutes per week at vigorous intensity), from 13.9% (95% CI = 12.8% to 15.1%) to 23.1% (95% CI = 21.8% to 24.4%) for muscle strengthening (≥2 days per week) activities, and from 9.5% (95% CI = 8.4% to 10.7%) to 17.9% (95% CI = 16.7% to 19.1%) for both combined (all Ptrend < .001). From 2004 to 2018, the prevalence of insufficient sleep duration (<7 hours per day) increased from 28.4% (95% CI = 26.3% to 30.5%) to 30.8% (95% CI = 29.3% to 32.2%) (Ptrend = .004). Daily sitting time increased from 6.09 hours per day (95% CI = 5.71 to 6.46 hours per day) in 2007-2008 to 7.36 hours per day (95% CI = 7.05 to 7.68 hours per day) in 2013-2014 and attenuated to 6.20 hours per day (95% CI = 5.74 to 6.65 hours per day) in 2017-2018. The pattern of physical activity, sleep, and sitting time varied by sex, race and ethnicity, body mass index, cancer type, and time since cancer diagnosis.

CONCLUSIONS

More than half of US cancer survivors did not meet physical activity guidelines, and a large proportion had insufficient sleep duration and prolonged sitting time.