The circadian timing system in clinical oncology

One Health: Circadian Medicine Benefits Both Non-human Animals and Humans Alike

Circadian biology's impact on human physical health and its role in disease development and progression is widely recognized. The forefront of circadian rhythm research now focuses on translational applications to clinical medicine, aiming to enhance disease diagnosis, prognosis, and treatment responses. However, the field of circadian medicine has predominantly concentrated on human healthcare, neglecting its potential for transformative applications in veterinary medicine, thereby overlooking opportunities to improve non-human animal health and welfare. This review consists of three main sections. The first section focuses on the translational potential of circadian medicine into current industry practices of agricultural animals, with a particular emphasis on horses, broiler chickens, and laying hens. The second section delves into the potential applications of circadian medicine in small animal veterinary care, primarily focusing on our companion animals, namely dogs and cats. The final section explores emerging frontiers in circadian medicine, encompassing aquaculture, veterinary hospital care, and non-human animal welfare and concludes with the integration of One Health principles. In summary, circadian medicine represents a highly promising field of medicine that holds the potential to significantly enhance the clinical care and overall health of all animals, extending its impact beyond human healthcare.

The Relationship between Circadian Rhythm and Cancer Disease

The circadian clock regulates biological cycles across species and is crucial for physiological activities and biochemical reactions, including cancer onset and development. The interplay between the circadian rhythm and cancer involves regulating cell division, DNA repair, immune function, hormonal balance, and the potential for chronotherapy. This highlights the importance of maintaining a healthy circadian rhythm for cancer prevention and treatment. This article investigates the complex relationship between the circadian rhythm and cancer, exploring how disruptions to the internal clock may contribute to tumorigenesis and influence cancer progression. Numerous databases are utilized to conduct searches for articles, such as NCBI, MEDLINE, and Scopus. The keywords used throughout the academic archives are "circadian rhythm", "cancer", and "circadian clock". Maintaining a healthy circadian cycle involves prioritizing healthy sleep habits and minimizing disruptions, such as consistent sleep schedules, reduced artificial light exposure, and meal timing adjustments. Dysregulation of the circadian clock gene and cell cycle can cause tumor growth, leading to the need to regulate the circadian cycle for better treatment outcomes. The circadian clock components significantly impact cellular responses to DNA damage, influencing cancer development. Understanding the circadian rhythm's role in tumor diseases and their therapeutic targets is essential for treating and preventing cancer. Disruptions to the circadian rhythm can promote abnormal cell development and tumor metastasis, potentially due to immune system imbalances and hormonal fluctuations.

Longitudinal associations of diurnal rest-activity rhythms with fatigue, insomnia, and health-related quality of life in survivors of colorectal cancer up to 5 years post-treatment

BACKGROUND

There is a growing population of survivors of colorectal cancer (CRC). Fatigue and insomnia are common symptoms after CRC, negatively influencing health-related quality of life (HRQoL). Besides increasing physical activity and decreasing sedentary behavior, the timing and patterns of physical activity and rest over the 24-h day (i.e. diurnal rest-activity rhythms) could also play a role in alleviating these symptoms and improving HRQoL. We investigated longitudinal associations of the diurnal rest-activity rhythm (RAR) with fatigue, insomnia, and HRQoL in survivors of CRC.

METHODS

In a prospective cohort study among survivors of stage I-III CRC, 5 repeated measurements were performed from 6 weeks up to 5 years post-treatment. Parameters of RAR, including mesor, amplitude, acrophase, circadian quotient, dichotomy index, and 24-h autocorrelation coefficient, were assessed by a custom MATLAB program using data from tri-axial accelerometers worn on the upper thigh for 7 consecutive days. Fatigue, insomnia, and HRQoL were measured by validated questionnaires. Confounder-adjusted linear mixed models were applied to analyze longitudinal associations of RAR with fatigue, insomnia, and HRQoL from 6 weeks until 5 years post-treatment. Additionally, intra-individual and inter-individual associations over time were separated.

RESULTS

Data were available from 289 survivors of CRC. All RAR parameters except for 24-h autocorrelation increased from 6 weeks to 6 months post-treatment, after which they remained relatively stable. A higher mesor, amplitude, circadian quotient, dichotomy index, and 24-h autocorrelation were statistically significantly associated with less fatigue and better HRQoL over time. A higher amplitude and circadian quotient were associated with lower insomnia. Most of these associations appeared driven by both within-person changes over time and between-person differences in RAR parameters. No significant associations were observed for acrophase.

CONCLUSIONS

In the first five years after CRC treatment, adhering to a generally more active (mesor) and consistent (24-h autocorrelation) RAR, with a pronounced peak activity (amplitude) and a marked difference between daytime and nighttime activity (dichotomy index) was found to be associated with lower fatigue, lower insomnia, and a better HRQoL. Future intervention studies are needed to investigate if restoring RAR among survivors of CRC could help to alleviate symptoms of fatigue and insomnia while enhancing their HRQoL.

TRIAL REGISTRATION

EnCoRe study NL6904 ( https://www.onderzoekmetmensen.nl/ ).

Temporal Considerations in Brain Metastases Radiation Therapy: The Intersection of Chronobiology and Patient Profiles

The circadian system, a vital temporal regulator influencing physiological processes, has implications for cancer development and treatment response. Our study assessed circadian timing's impact on whole-brain radiotherapy outcomes in brain metastases for personalized cancer therapy insights. The aim of the study was to evaluate circadian influence on radiation treatment timing and its correlation with clinical outcomes and to identify patient populations benefiting from interventions synchronizing circadian rhythms, considering subgroup differences and potential disparities. An IRB-approved retrospective analysis of 237 patients undergoing whole-brain radiotherapy for brain metastases (2017-2021), receiving over 80% of treatments in the morning or afternoon, was performed. Survival analyses utilized Kaplan-Meier curves. This was a single-institution study involving patients receiving whole-brain radiotherapy. Demographic, disease, and socioeconomic parameters from electronic medical records were collected. Morning treatment (n = 158) showed a trend toward improved overall survival vs. afternoon (n = 79); the median survival was 158 vs. 79 days (p = 0.20, HR = 0.84, CI95% 0.84-0.91). Subgroup benefits for morning treatment in females (p = 0.04) and trends in controlled primary disease (p = 0.11) and breast cancer metastases (p = 0.08) were observed. Black patients exhibited diminished circadian influence. The present study emphasized chronobiological factors' relevance in brain metastases radiation therapy. Morning treatment correlated with improved survival, particularly in specific subgroups. Potential circadian influence disparities were identified, laying a foundation for personalized cancer therapy and interventions synchronizing circadian rhythms for enhanced treatment efficacy.

Mechanisms of sleep disturbances in long-term cancer survivors: a childhood cancer survivor study report

BACKGROUND

Sleep problems following childhood cancer treatment may persist into adulthood, exacerbating cancer-related late effects and putting survivors at risk for poor physical and psychosocial functioning. This study examines sleep in long-term survivors and their siblings to identify risk factors and disease correlates.

METHODS

Childhood cancer survivors (≥5 years from diagnosis; n = 12 340; 51.5% female; mean [SD] age = 39.4 [9.6] years) and siblings (n = 2395; 57.1% female; age = 44.6 [10.5] years) participating in the Childhood Cancer Survivor Study completed the Pittsburgh Sleep Quality Index (PSQI). Multivariable Poisson-error generalized estimating equation compared prevalence of binary sleep outcomes between survivors and siblings and evaluated cancer history and chronic health conditions (CHC) for associations with sleep outcomes, adjusting for age (at diagnosis and current), sex, race/ethnicity, and body mass index.

RESULTS

Survivors were more likely to report clinically elevated composite PSQI scores (>5; 45.1% vs 40.0%, adjusted prevalence ratio [PR] = 1.20, 95% CI = 1.13 to 1.27), symptoms of insomnia (38.8% vs 32.0%, PR = 1.26, 95% CI = 1.18 to 1.35), snoring (18.0% vs 17.4%, PR = 1.11, 95% CI = 1.01 to 1.23), and sleep medication use (13.2% vs 11.5%, PR = 1.28, 95% CI = 1.12 to 1.45) compared with siblings. Within cancer survivors, PSQI scores were similar across diagnoses. Anthracycline exposure (PR = 1.13, 95% CI = 1.03 to 1.25), abdominal radiation (PR = 1.16, 95% CI = 1.04 to 1.29), and increasing CHC burden were associated with elevated PSQI scores (PRs = 1.21-1.48).

CONCLUSIONS

Among survivors, sleep problems were more closely related to CHC than diagnosis or treatment history, although longitudinal research is needed to determine the direction of this association. Frequent sleep-promoting medication use suggests interest in managing sleep problems; behavioral sleep intervention is advised for long-term management.

Circadian Regulation of Drug Responses: Toward Sex-Specific and Personalized Chronotherapy

Today's challenge for precision medicine involves the integration of the impact of molecular clocks on drug pharmacokinetics, toxicity, and efficacy toward personalized chronotherapy. Meaningful improvements of tolerability and/or efficacy of medications through proper administration timing have been confirmed over the past decade for immunotherapy and chemotherapy against cancer, as well as for commonly used pharmacological agents in cardiovascular, metabolic, inflammatory, and neurological conditions. Experimental and human studies have recently revealed sexually dimorphic circadian drug responses. Dedicated randomized clinical trials should now aim to issue personalized circadian timing recommendations for daily medical practice, integrating innovative technologies for remote longitudinal monitoring of circadian metrics, statistical prediction of molecular clock function from single-timepoint biopsies, and multiscale biorhythmic mathematical modelling. Importantly, chronofit patients with a robust circadian function, who would benefit most from personalized chronotherapy, need to be identified. Conversely, nonchronofit patients could benefit from the emerging pharmacological class of chronobiotics targeting the circadian clock.

Internal circadian misallignment in a mouse model of chemotherapy induced fatigue

BACKGROUND

Cancer survivors can experience long lasting fatigue resulting in a lower quality of life. How chemotherapy treatment contributes to this fatigue is poorly understood. Previously we have shown in a mouse model of cancer related fatigue that doxorubicin treatment induces fatigue-like symptoms related to disturbed circadian rhythms. However, the specific components of the circadian regulatory circuitry affected by doxorubicin treatment remained unclear. Therefore we investigated the role of the central circadian clock, the suprachiasmatic nucleus (SCN), in chemotherapy-induced fatigue.

METHODS

We measured circadian controlled behavior and multiunit neuronal activity in the SCN in freely moving mice exhibiting fatigue-like behavior after doxorubicin treatment under both light-dark (LD) and constant dark (DD) conditions. Additionally, we assessed the expression of inflammation related genes in spleen and kidney as potential inducers of CRF.

RESULTS

Doxorubicin treatment significantly reduced both the running wheel activity and time spent using the running wheel for over five weeks after treatment. In contrast to the pronounced effects on behavior and neuronal activity of doxorubicin on circadian rhythms, peripheral inflammation markers only showed minor differences, five weeks after the last treatment. Surprisingly, the circadian SCN neuronal activity under both LD and DD conditions was not affected. However, the circadian timing of neuronal activity in peri-SCN areas (the brain areas surrounding SCN) and circadian rest-activity behavior was strongly affected by doxorubicin, suggesting that the output of the SCN was altered. The reduced correlation between the SCN neuronal activity and behavioral activity after doxorubicin treatment, suggests that the information flow from the SCN to the periphery was disturbed.

CONCLUSION

Our preclinical study suggests that chemotherapy-induced fatigue disrupts the circadian rhythms in peripheral brain areas and behavior downstream from the SCN, potentially leading to fatigue like symptoms. Our data suggest that peripheral inflammation responses are less important for the maintenance of fatigue. Chronotherapy that realigns circadian rhythms could represent a non-invasive way to improve patient outcomes following chemotherapy.

A proposed multi-domain, digital model for capturing functional status and health-related quality of life in oncology

Whereas traditional oncology clinical trial endpoints remain key for assessing novel treatments, capturing patients' functional status is increasingly recognized as an important aspect for supporting clinical decisions and assessing outcomes in clinical trials. Existing functional status assessments suffer from various limitations, some of which may be addressed by adopting digital health technologies (DHTs) as a means of collecting both objective and self-reported outcomes. In this mini-review, we propose a device-agnostic multi-domain model for oncology capturing functional status, which includes physical activity data, vital signs, sleep variables, and measures related to health-related quality of life enabled by connected digital tools. By using DHTs for all aspects of data collection, our proposed model allows for high-resolution measurement of objective data as patients navigate their daily lives outside of the hospital setting. This is complemented by electronic questionnaires administered at intervals appropriate for each instrument. Preliminary testing and practical considerations to address before adoption are also discussed. Finally, we highlight multi-institutional pre-competitive collaborations as a means of successfully transitioning the proposed digitally enabled data collection model from feasibility studies to interventional trials and care management.

Circadian clock and lipid metabolism disorders: a potential therapeutic strategy for cancer

Recent research has emphasized the interaction between the circadian clock and lipid metabolism, particularly in relation to tumors. This review aims to explore how the circadian clock regulates lipid metabolism and its impact on carcinogenesis. Specifically, targeting key enzymes involved in fatty acid synthesis (SREBP, ACLY, ACC, FASN, and SCD) has been identified as a potential strategy for cancer therapy. By disrupting these enzymes, it may be possible to inhibit tumor growth by interfering with lipid metabolism. Transcription factors, like SREBP play a significant role in regulating fatty acid synthesis which is influenced by circadian clock genes such as BMAL1, REV-ERB and DEC. This suggests a strong connection between fatty acid synthesis and the circadian clock. Therefore, successful combination therapy should target fatty acid synthesis in addition to considering the timing and duration of drug use. Ultimately, personalized chronotherapy can enhance drug efficacy in cancer treatment and achieve treatment goals.

Cancer related fatigue-light therapy: updated meta-analysis of randomised controlled trials

BACKGROUND

Moderate-to-severe cancer related fatigue occurs in 45% of patients with cancer and interferes with many aspects of quality of life. Although physical exercise has level 1 evidence for improvement of cancer related fatigue, it has a relatively high behavioural demand compared with other non-pharmacological interventions. The aim of this updated meta-analysis was to address the efficacy of light therapy in improving cancer related fatigue in patients with cancer.

METHODS

We included randomised controlled trials investigating the efficacy of bright white light (BWL) therapy in ameliorating cancer related fatigue in patients with cancer. This meta-analysis was conducted using a random-effects model. The target outcomes were changes in cancer related fatigue associated with BWL or dim red light (DRL).

RESULTS

There were 9 articles with 231 participants included. The main results revealed that daily morning BWL for 30 min was associated with significantly better improvement in fatigue severity compared with DRL (k=5, Hedges' g=-0.414, 95% CI -0.740 to -0.087, p=0.013). The subgroup without psychiatric comorbidities (k=4, Hedges' g=-0.479, 95% CI -0.801 to -0.156, p=0.004) was associated with significantly better improvement in fatigue severity with BWL than with DRL. In contrary, BWL was not associated with significantly different changes in depression severity or quality of life compared with DRL. Finally, BWL was associated with similar acceptability (ie, dropout rate) and safety profile (ie, any discomfort) as those of DRL.

CONCLUSIONS

This meta-analysis provides an updated evidence on the rationale for application of BWL in ameliorating cancer related fatigue in patients with different types of cancer.

TRIAL REGISTRATION NUMBER

INPLASY202140090.

The Impact of Immunotherapy on Sleep and Circadian Rhythms in Patients with Cancer

Immunotherapy has revolutionized treatments for both early and advanced cancers, and as their role evolves, their impact on sleep and circadian rhythms continues to unfold. The recognition, evaluation, and treatment of sleep and circadian rhythm disturbance leads to improved symptom management, quality of life and treatment outcomes. An intricate complex relationship exists in the microenvironment with immunity, sleep and the tumor, and these may further vary based on the cancer, addition of standard chemotherapy, and pre-existing patient factors. Sleep and circadian rhythms may offer tools to better utilize immunotherapy in the care of cancer patients, leading to better treatment outcome, reduced symptom burden, and increased quality of life.

Mediation and Dose-Response Relationship Among Physical Activity, Daylight Exposure, and Rest-Activity Circadian Rhythm in Patients With Esophageal and Gastric Cancer

BACKGROUND

Physical activity and daylight exposure predict rest-activity circadian rhythm (RACR) in patients with cancer. However, whether daylight exposure mediates the relationship between physical activity and RACR and the optimal amounts of physical activity and daylight that benefit RACR remain unclear.

OBJECTIVES

This study investigated the mediating role of daylight exposure and determined the dose-response relationship among daylight exposure, physical activity, and RACR in patients with cancer.

METHODS

This cross-sectional exploratory study recruited 319 patients with esophageal and gastric cancer from 2 surgery outpatient departments in Taiwan. Daylight exposure (>500 lux), physical activity (up activity mean), and RACR (midline estimating statistic of rhythm) were measured through actigraphy. Regression was performed, and the receiver operating characteristic curve was plotted.

RESULTS

Daylight exposure (>500 lux) partially mediated the relationship between physical activity (up activity mean) and RACR (midline estimating statistic of rhythm). The optimal cutoffs for discriminating between satisfactory and poor RACR were 187.43 counts/min for physical activity (sensitivity, 90.3%; specificity, 84.4%) and 35.71 min/d for daylight exposure (sensitivity, 55.9%; specificity, 78.2%).

CONCLUSIONS

Participants who engaged in physical activity were more likely to receive daylight exposure and experience improved RACR. The optimal level of daylight exposure and frequency of physical activity that can improve RACR in patients with esophageal and gastric cancer are 36 min/d and 187 counts/min, respectively.

IMPLICATIONS FOR PRACTICE

Healthcare professionals should encourage patients to engage in exercise or physical activity during the daytime to improve their circadian rhythm.

Circadian, hormonal, and sleep rhythms: effects on cancer progression implications for treatment

Circadian, hormonal, and sleep rhythm disruptions are commonly experienced concerns among cancer patients throughout the cancer care continuum. This review aims to summarize the existing literature on circadian, hormonal, and sleep rhythms in the oncological population, focusing on circadian disruption and physiological and psychological abnormalities, disease progression, and chronomodulated treatment approaches. The findings demonstrate that subjectively and objectively measured circadian rhythm disruption is associated with adverse mental health and disease outcomes in patients with cancer. Chronomodulated chemotherapy, light therapy, cognitive behavioral therapy for insomnia, and physical activity have shown evidence of effectiveness in improving sleep, and occasionally, disease outcomes.

An integrative mathematical model for timing treatment toxicity and Zeitgeber impact in colorectal cancer cells

Increasing evidence points to a role of the circadian clock in the regulation of cancer hallmarks with a strong impact on the understanding and treatment of this disease. Anti-cancer treatment can be personalized considering treatment timing. Here we present a new mathematical model based on data from three colorectal cancer cell lines and core-clock knock-outs, which couples the circadian and drug metabolism network, and that allows to determine toxicity profiles for a given drug and cell type. Moreover, this model integrates external Zeitgebers and thus may be used to fine-tune toxicity by using external factors, such as light, and therefore, to a certain extent, help fitting the endogenous rhythms of the patients to a defined clinic routine facilitating the implementation of time-dependent treatment in clinical practice.

The Role of REV-ERB Receptors in Cancer Pathogenesis

REV-ERB receptors are members of the nuclear receptor superfamily of proteins, which act as both intracellular receptors and transcription factors, therefore modulating the expression of target genes. REV-ERBs act as transcription repressors because of their unique structure. Their predominant role involves the control of peripheral circadian rhythmicity by participating in a transcription-translation feedback loop with other major clock genes. Regarding their role in cancer pathogenesis, recent studies in various cancerous tissues have revealed that their expression was downregulated in the majority of the cases. Dysregulation of their expression was also implicated in cancer-associated cachexia. The pharmacological restoration of their effects is feasible with synthetic agonists, which have been explored in preclinical studies but with scarce data. There is a need for further investigation, primarily with mechanistic studies, on the effect of the REV-ERB-induced circadian rhythm deregulation in carcinogenesis and cancer-related systemic effects, such as cachexia, in order to address the potential of relevant therapeutic implications.

Spatiotemporal Metabolic Liver Zonation and Consequences on Pathophysiology

Hepatocytes are the main workers in the hepatic factory, managing metabolism of nutrients and xenobiotics, production and recycling of proteins, and glucose and lipid homeostasis. Division of labor between hepatocytes is critical to coordinate complex complementary or opposing multistep processes, similar to distributed tasks at an assembly line. This so-called metabolic zonation has both spatial and temporal components. Spatial distribution of metabolic function in hepatocytes of different lobular zones is necessary to perform complex sequential multistep metabolic processes and to assign metabolic tasks to the right environment. Moreover, temporal control of metabolic processes is critical to align required metabolic processes to the feeding and fasting cycles. Disruption of this complex spatiotemporal hepatic organization impairs key metabolic processes with both local and systemic consequences. Many metabolic diseases, such as nonalcoholic steatohepatitis and diabetes, are associated with impaired metabolic liver zonation. Recent technological advances shed new light on the spatiotemporal gene expression networks controlling liver function and how their deregulation may be involved in a large variety of diseases. We summarize the current knowledge about spatiotemporal metabolic liver zonation and consequences on liver pathobiology.

Prognostication in Advanced Cancer by Combining Actigraphy-Derived Rest-Activity and Sleep Parameters with Routine Clinical Data: An Exploratory Machine Learning Study

Survival prediction is integral to oncology and palliative care, yet robust prognostic models remain elusive. We assessed the feasibility of combining actigraphy, sleep diary data, and routine clinical parameters to prognosticate. Fifty adult outpatients with advanced cancer and estimated prognosis of <1 year were recruited. Patients were required to wear an Actiwatch® (wrist actigraph) for 8 days, and complete a sleep diary. Univariate and regularised multivariate regression methods were used to identify predictors from 66 variables and construct predictive models of survival. A total of 49 patients completed the study, and 34 patients died within 1 year. Forty-two patients had disrupted rest-activity rhythms (dichotomy index (I < O ≤ 97.5%) but I < O did not have prognostic value in univariate analyses. The Lasso regularised derived algorithm was optimal and able to differentiate participants with shorter/longer survival (log rank p < 0.0001). Predictors associated with increased survival time were: time of awakening sleep efficiency, subjective sleep quality, clinician’s estimate of survival and global health status score, and haemoglobin. A shorter survival time was associated with self-reported sleep disturbance, neutrophil count, serum urea, creatinine, and C-reactive protein. Applying machine learning to actigraphy and sleep data combined with routine clinical data is a promising approach for the development of prognostic tools.

Circadian disruption and cancer- and treatment-related symptoms

Cancer patients experience a number of co-occurring side- and late-effects due to cancer and its treatment including fatigue, sleep difficulties, depressive symptoms, and cognitive impairment. These symptoms can impair quality of life and may persist long after treatment completion. Furthermore, they may exacerbate each other's intensity and development over time. The co-occurrence and interdependent nature of these symptoms suggests a possible shared underlying mechanism. Thus far, hypothesized mechanisms that have been purported to underlie these symptoms include disruptions to the immune and endocrine systems. Recently circadian rhythm disruption has emerged as a related pathophysiological mechanism underlying cancer- and cancer-treatment related symptoms. Circadian rhythms are endogenous biobehavioral cycles lasting approximately 24 hours in humans and generated by the circadian master clock - the hypothalamic suprachiasmatic nucleus. The suprachiasmatic nucleus orchestrates rhythmicity in a wide range of bodily functions including hormone levels, body temperature, immune response, and rest-activity behaviors. In this review, we describe four common approaches to the measurement of circadian rhythms, highlight key research findings on the presence of circadian disruption in cancer patients, and provide a review of the literature on associations between circadian rhythm disruption and cancer- and treatment-related symptoms. Implications for future research and interventions will be discussed.

An Update on Prevalence, Assessment, and Risk Factors for Sleep Disturbances in Patients with Advanced Cancer—Implications for Health Care Providers and Clinical Research

Simple Summary

This review focuses on sleep in patients with advanced cancer. Cancer patients experience multiple symptoms and they receive concomitant medications. These are all factors that may affect sleep. In this paper, we present recommendations on sleep assessment in patients with advanced cancer and highlight cancer-related factors that may contribute to insomnia. Sleep is an essential aspect of health-related quality of life; therefore, it is important for health care providers to focus on sleep to improve patient care.

Abstract

Patients with advanced cancer experience multiple symptoms, with fluctuating intensity and severity during the disease. They use several medications, including opioids, which may affect sleep. Sleep disturbance is common in cancer patients, decreases the tolerability of other symptoms, and impairs quality of life. Despite its high prevalence and negative impact, poor sleep quality often remains unrecognized and undertreated. Given that sleep is an essential aspect of health-related quality of life, it is important to extend both the knowledge base and awareness among health care providers in this field to improve patient care. In this narrative review, we provide recommendations on sleep assessment in patients with advanced cancer and highlight cancer-related factors that contribute to insomnia. We also present direct implications for health care providers working in palliative care and for future research.

[Chronopharmacology : The right timing can be crucial]

BACKGROUND

Chronopharmacology takes into account, among other things, the circadian rhythm, a recurring, daily rhythm of biological functions that is significantly influenced by the day-night rhythm. Daily rhythm, diseases, and therapies influence each other: the circadian rhythm, among other factors, could influence the effect of pharmacological and nonpharmacological therapies, especially in urological oncology.

AIM

This article focuses on the question of the optimal time for therapeutic interventions and considers relevant basics of chronobiological principles depending on possible biomarkers that could be targets of a future therapeutic approach.

RESULTS

With chronomodulated chemotherapy, cancer therapies are not only more tolerable, but also more effective. Effects and side effects of an active substance can change according to the circadian rhythm. Due to the introduction of particularly targeted, oral tumor therapies, a daily application would be organizationally possible, but further clinical studies are necessary for this. The internal clock could play an unexpected role, especially in hormone-dependent prostate cancer: the amount of the circadian factor Cry1 not only seems to increase in the advanced stage, but is also closely associated with a poorer prognosis. Epidemiological studies also show a connection between hormone-dependent tumors and the disruption of the rhythmic release of melatonin. Melatonin appears to be able to improve therapy as an adjunct to cancer therapy in some urological tumor entities.

Digital circadian and sleep health in individual hospital shift workers: A cross sectional telemonitoring study

BACKGROUND

Telemonitoring of circadian and sleep cycles could identify shift workers at increased risk of poor health, including cancer and cardiovascular diseases, thus supporting personalized prevention.

METHODS

The Circadiem cross-sectional study aimed at determining early warning signals of risk of health alteration in hospital nightshifters (NS) versus dayshifters (DS, alternating morning and afternoon shifts). Circadian rhythmicity in activity, sleep, and temperature was telemonitored on work and free days for one week. Participants wore a bluetooth low energy thoracic accelerometry and temperature sensor that was wirelessly connected to a GPRS gateway and a health data hub server. Hidden Markov modelling of activity quantified Rhythm Index, rest quality (probability, p1-1, of remaining at rest), and rest duration. Spectral analyses determined periods in body surface temperature and accelerometry. Parameters were compared and predictors of circadian and sleep disruption were identified by multivariate analyses using information criteria-based model selection. Clusters of individual shift work response profiles were recognized.

FINDINGS

Of 140 per-protocol participants (133 females), there were 63 NS and 77 DS. Both groups had similar median rest amount, yet NS had significantly worse median rest-activity Rhythm Index (0·38 [IQR, 0·29-0·47] vs. 0·69 [0·60-0·77], p<0·0001) and rest quality p1-1 (0·94 [0·94-0·95] vs 0·96 [0·94-0·97], p<0·0001) over the whole study week. Only 48% of the NS displayed a circadian period in temperature, as compared to 70% of the DS (p=0·026). Poor p1-1 was associated with nightshift work on both work (p<0·0001) and free days (p=0·0098). The number of years of past night work exposure predicted poor rest-activity Rhythm Index jointly with shift type, age and chronotype on workdays (p= 0·0074), and singly on free days (p=0·0005).

INTERPRETATION

A dedicated analysis toolbox of streamed data from a wearable device identified circadian and sleep rhythm markers, that constitute surrogate candidate endpoints of poor health risk in shift-workers.

FUNDING

French Agency for Food, Environmental and Occupational Health & Safety (EST-2014/1/064), University of Warwick, Medical Research Council (United Kingdom, MR/M013170), Cancer Research UK(C53561/A19933).

Advanced cancer patients in a randomized clinical trial of night-simulating eyeglasses observed to have a normal 24-h circadian rhythm during chemotherapy

Objectives:

Cancer patients routinely exhibit dysfunctional circadian organization. Indeed, a dysfunctional circadian organization is a hallmark of advanced cancer. A cohort of advanced cancer patients undergoing chemotherapy was recruited to investigate whether manipulating exposure to blue light could restore or ameliorate their circadian organization.

Methods:

Thirty advanced metastatic cancer patients participated in a randomized crossover trial to evaluate whether blue light-blocking night-simulating eyeglasses could ameliorate a disrupted circadian organization better than sham eyeglasses. Circadian organization was evaluated by actigraphy and patients’ self-reports of sleep, fatigue, and quality of life. Kruskal–Wallis tests compared patients’ outcomes in circadian organization with a cohort of non-cancer, disease-free individuals with normal sleep as a negative control, and with advanced cancer patients with disrupted circadian organization as a positive control. Quality-of-life outcomes of the patients were compared with population-based controls (negative controls) and with cohorts of advanced cancer patients (positive controls).

Results:

Actigraphy measurements, self-reported sleep, fatigue levels, and quality-of-life outcomes of trial participants were similar to those of negative controls with a normal circadian organization, in spite of the trial patients’ concurrent chemotherapy. Night-simulating glasses did not improve circadian organization. The 24-h correlation of day-to-day rhythms of rest and activity was 0.455 for the experimental eyeglasses and 0.476 for the sham eyeglasses (p = 0.258). Actigraphic and patient-reported outcomes compared favorably to outcomes of positive controls.

Conclusion:

The circadian organization of patients in this study unexpectedly resembled that of healthy controls and was better than comparison populations with disrupted circadian organization. The study clinic implements chronomodulated chemotherapy and a systematic, supportive integrative treatment protocol. Results suggest a need for further research on interventions for circadian rhythm. Although the study intervention did not benefit the participants, this work highlights the value of supporting circadian time structure in advanced cancer patients.

Circadian rhythms and cancers: the intrinsic links and therapeutic potentials

The circadian rhythm is an evolutionarily conserved time-keeping system that comprises a wide variety of processes including sleep-wake cycles, eating-fasting cycles, and activity-rest cycles, coordinating the behavior and physiology of all organs for whole-body homeostasis. Acute disruption of circadian rhythm may lead to transient discomfort, whereas long-term irregular circadian rhythm will result in the dysfunction of the organism, therefore increasing the risks of numerous diseases especially cancers. Indeed, both epidemiological and experimental evidence has demonstrated the intrinsic link between dysregulated circadian rhythm and cancer. Accordingly, a rapidly increasing understanding of the molecular mechanisms of circadian rhythms is opening new options for cancer therapy, possibly by modulating the circadian clock. In this review, we first describe the general regulators of circadian rhythms and their functions on cancer. In addition, we provide insights into the mechanisms underlying how several types of disruption of the circadian rhythm (including sleep-wake, eating-fasting, and activity-rest) can drive cancer progression, which may expand our understanding of cancer development from the clock perspective. Moreover, we also summarize the potential applications of modulating circadian rhythms for cancer treatment, which may provide an optional therapeutic strategy for cancer patients.

Single-item chronotype is associated with dim light melatonin onset in lymphoma survivors with fatigue

Chronotype is frequently assessed in human observational studies using various morningness-eveningness questionnaires. An alternative single-item chronotype question has been proposed for its reduced administration time and its accessibility to all types of populations. We investigated whether this single-item chronotype is associated with dim light melatonin onset, the "gold standard" for estimating the endogenous circadian phase. We used data from a randomised trial in 166 (non-)Hodgkin lymphoma survivors with cancer-related fatigue. All participants completed a questionnaire, including a single-item chronotype question. A subsample of 47 participants also provided saliva samples before sleep onset for melatonin measurement. Using multiple linear regression, we examined whether chronotype based on a single question was associated with dim light melatonin onset. The subsample of 47 participants had a mean age of 44.6 years. The mean (SD) dim light melatonin onset was at 8:42 (1:19) p.m. and the most common chronotype was more evening than morning person (29.2%). A gradual increase in dim light melatonin onset with later chronotype (i.e. evening preference) was observed, with a mean ranging from 7:45 p.m. in definite morning persons to 9:16 p.m. in definite evening persons. Our study shows that single-item chronotype is associated with dim light melatonin onset as a marker of the endogenous circadian phase of fatigued lymphoma survivors. This type of chronotype assessment can therefore be a useful alternative for more extensive morningness-eveningness questionnaires.

Circadian timing of eating and BMI among adults in the American Time Use Survey

BACKGROUND/OBJECTIVES

Experimental studies of time-restricted eating suggest that limiting the daily eating window, shifting intake to the biological morning, and avoiding eating close to the biological night may promote metabolic health and prevent weight gain.

SUBJECTS/METHODS

We used the Eating & Health Module of the 2006-2008 and 2014-2016 American Time Use Survey to examine cross-sectional associations of timing of eating in relation to sleep/wake times as a proxy for circadian timing with body mass index (BMI). The analytical sample included 38 302 respondents (18-64 years; BMI 18.5-50.0 kg/m²). A single 24-hour time use diary was used to calculate circadian timing of eating variables: eating window (time between first and last eating activity); morning fast (time between end of sleep and start of eating window); and evening fast (time between end of eating window and start of sleep). Multinomial logistic regression and predictive margins were used to estimate adjusted population prevalences (AP) by BMI categories and changes in prevalences associated with a one-hour change in circadian timing of eating, controlling for sociodemographic and temporal characteristics.

RESULTS

A one-hour increase in eating window was associated with lower adjusted prevalence of obesity (AP = 27.1%, SE = 0.1%). Conversely, a one-hour increase in morning fast (AP = 28.7%, SE = 0.1%) and evening fast (AP = 28.5%, SE = 0.1%) were each associated with higher prevalence of obesity; interactions revealed differing patterns of association by combination of eating window with morning/evening fast (p < 0.0001).

CONCLUSIONS

Contrary to hypotheses, longer eating windows were associated with a lower adjusted prevalence of obesity and longer evening fasts were associated with a higher prevalence of obesity. However, as expected, longer morning fast was associated with a higher adjusted prevalence of obesity. Studies are needed to disentangle the contributions of diet quality/quantity and social desirability bias in the relationship between circadian timing of eating and BMI.

Chronotherapy of Early Colon Cancer: Advantage of Morning Dose Schedules

Colon adenomas with proliferating mutant cells may progress to invasive carcinomas. Proliferation of cells in human colorectal tissue is circadian, greater in the interval 4 to 12 hours after midnight than 16 to 24 hours after midnight. We have tested the hypothesis that chemotherapy administered during the time of greater cell proliferation will be more effective than chemotherapy administered during the time of lesser proliferation. An agent-based computer model of cell proliferation in colon crypts was calibrated with measurements of cell numbers in human biopsy specimens. It was used to simulate cytotoxic chemotherapy of an early stage of colon cancer, adenomas with about 20% of mutant cells. Chemotherapy doses were scheduled at different 4-hour intervals during the 24-hour day, and repeated at weekly intervals. Chemotherapy administered at 4 to 8 hours after midnight cured mutant cells in 100% of 50 trials with an average time to cure of 7.82 days (s.e.m. = 0.99). In contrast, chemotherapy administered at 20 to 24 hours after midnight cured only 18% of 50 trials, with the average time to cure of 23.51 days (s.e.m. = 2.42). These simulation results suggest that clinical chemotherapy of early colon cancer may be more effective when given in the morning than later in the day.

Chronodisruption and Ambulatory Circadian Monitoring in Cancer Patients: Beyond the Body Clock

Purpose of Review

Circadian rhythms impose daily rhythms a remarkable variety of metabolic and physiological functions, such as cell proliferation, inflammation, and DNA damage response. Accumulating epidemiological and genetic evidence indicates that circadian rhythms’ disruption may be linked to cancer. The integration of circadian biology into cancer research may offer new options for increasing cancer treatment effectiveness and would encompass the prevention, diagnosis, and treatment of this disease.

Recent Findings

In recent years, there has been a significant development and use of multi-modal sensors to monitor physical activity, sleep, and circadian rhythms, allowing, for the very first time, scaling accurate sleep monitoring to epidemiological research linking sleep patterns to disease, and wellness applications providing new potential applications.

Summary

This review highlights the role of circadian clock in tumorigenesis, cancer hallmarks and introduces the state-of-the-art in sleep-monitoring technologies, discussing the eventual application of insights in clinical settings and cancer research.

Synergies of Multiple Zeitgebers Tune Entrainment

Circadian rhythms are biological rhythms with a period close to 24 h. They become entrained to the Earth's solar day via different periodic cues, so-called zeitgebers. The entrainment of circadian rhythms to a single zeitgeber was investigated in many mathematical clock models of different levels of complexity, ranging from the Poincaré oscillator and the Goodwin model to biologically more detailed models of multiple transcriptional translational feedback loops. However, circadian rhythms are exposed to multiple coexisting zeitgebers in nature. Therefore, we study synergistic effects of two coexisting zeitgebers on different components of the circadian clock. We investigate the induction of period genes by light together with modulations of nuclear receptor activities by drugs and metabolism. Our results show that the entrainment of a circadian rhythm to two coexisting zeitgebers depends strongly on the phase difference between the two zeitgebers. Synergistic interactions of zeitgebers can strengthen diurnal rhythms to reduce detrimental effects of shift-work and jet lag. Medical treatment strategies which aim for stable circadian rhythms should consider interactions of multiple zeitgebers.

Holistic Needs Assessment of Cancer Survivors-Supporting the Process Through Digital Monitoring of Circadian Physiology

The year 2022 could represent a significant juncture in the incorporation of mHealth solutions in routine cancer care. With the recent global COVID-19 pandemic leading a surge in both observation- and intervention-based studies predominantly aimed at remote monitoring there has been huge intellectual investment in developing platforms able to provide real time analytics that are readily usable. Another fallout from the pandemic has seen record waiting times and delayed access to cancer therapies leading to exhausting pressures on global healthcare providers. It seems an opportune time to utilize this boom in platforms to offer more efficient “at home” clinical assessments and less “in department” time for patients. Here, we will focus specifically on the role of digital tools around cancer survivorship, a relevant aspect of the cancer journey, particularly benefiting from integrative approaches. Within that context a further concept will be introduced and that is of the likely upsurge in circadian-based interpretation of continuous monitoring and the engendered therapeutic modifications. Chronobiology across the 24-hour span has long been understood to control key bodily aspects and circadian dysregulation plays a significant role in the risk of cancer and also the response to therapy and therefore progressive outcome. The rapid improvement in minimally invasive monitoring devices is, in the opinion of the authors, likely to advance introducing chronobiological amendments to routine clinical practices with positive impact on cancer survivors.

Circadian and chemotherapy-related changes in urinary modified nucleosides excretion in patients with metastatic colorectal cancer

Urinary levels of modified nucleosides reflect nucleic acids turnover and can serve as non-invasive biomarkers for monitoring tumour circadian dynamics, and treatment responses in patients with metastatic colorectal cancer. In 39 patients, median overnight urinary excretion of LC-HRMS determinations of pseudouridine, was ~ tenfold as large as those of 1-methylguanosine, 1-methyladenosine, or 4-acetylcytidine, and ~ 100-fold as large as those of adenosine and cytidine. An increase in any nucleoside excretion after chemotherapy anticipated plasma carcinoembryonic antigen progression 1–2 months later and was associated with poor survival. Ten fractionated urines were collected over 2-days in 29 patients. The median value of the rhythm-adjusted mean of urinary nucleoside excretion varied from 64.3 for pseudouridine down to 0.61 for cytidine. The rhythm amplitudes relative to the 24-h mean of 6 nucleoside excretions were associated with rest duration, supporting a tight link between nucleosides turnover and the rest-activity rhythm. Moreover, the amplitude of the 1-methylguanosine rhythm was correlated with the rest-activity dichotomy index, a significant predictor of survival outcome in prior studies. In conclusion, urinary excretion dynamics of modified nucleosides appeared useful for the characterization of the circadian control of cellular proliferation and for tracking early responses to treatments in colorectal cancer patients.

Differential phase register of Hes1 oscillations with mitoses underlies cell-cycle heterogeneity in ER+ breast cancer cells

Tumors exhibit heterogeneities that are not due to mutations, including cancer stem cells with different potencies. We show that the cancer stem-cell state predisposed to dormancy in vivo has a highly variable and long cell cycle. Using single-cell live imaging for the transcriptional repressor Hes1 (a key molecule in cancer), we show a type of circadian-like oscillatory expression of Hes1 in all cells in the population. The most potent cancer stem cells tend to divide around the trough of the Hes1 oscillatory wave, a feature predictive of a long cell cycle. A concept proposed here is that the position of cell division with respect to the Hes1 wave is predictive of its prospective cell-cycle length and cancer cellular substate.

Here, we study the dynamical expression of endogenously labeled Hes1, a transcriptional repressor implicated in controlling cell proliferation, to understand how cell-cycle length heterogeneity is generated in estrogen receptor (ER)⁺ breast cancer cells. We find that Hes1 shows oscillatory expression with ∼25 h periodicity and during each cell cycle has a variable peak in G1, a trough around G1–S transition, and a less variable second peak in G2/M. Compared to other subpopulations, the cell cycle in CD44^HighCD24^Low cancer stem cells is longest and most variable. Most cells divide around the peak of the Hes1 expression wave, but preceding mitoses in slow dividing CD44^HighCD24^Low cells appear phase-shifted, resulting in a late-onset Hes1 peak in G1. The position, duration, and shape of this peak, rather than the Hes1 expression levels, are good predictors of cell-cycle length. Diminishing Hes1 oscillations by enforcing sustained expression slows down the cell cycle, impairs proliferation, abolishes the dynamic expression of p21, and increases the percentage of CD44^HighCD24^Low cells. Reciprocally, blocking the cell cycle causes an elongation of Hes1 periodicity, suggesting a bidirectional interaction of the Hes1 oscillator and the cell cycle. We propose that Hes1 oscillations are functionally important for the efficient progression of the cell cycle and that the position of mitosis in relation to the Hes1 wave underlies cell-cycle length heterogeneity in cancer cell subpopulations.

Cancer-Related Fatigue-Is There a Role for Complementary and Integrative Medicine?

PURPOSE OF REVIEW

This review aims to assess recent data on possible effective and safe complementary and integrative medicine (CIM) modalities that can be of help to patients affected by cancer that suffer from cancer-related fatigue (CRF).

RECENT FINDINGS

Cancer-related fatigue (CRF) is one of the most common, persistent, and challenging symptoms among cancer patients and survivors. Many world-leading cancer centers incorporate CIM into routine cancer care including integrating multiple approaches to address CRF. Approaches that are supported by clinical evidence on the use of CIM during and following conventional oncology treatments are being discussed in this review. The review suggests that some CIM modalities might have a potential role in alleviating cancer-related fatigue. These modalities include acupuncture, touch therapies, nutrition, nutritional supplements, stress reduction, homeopathy, and circadian rhythm management. Additional research is still needed to better support the process of integrating CIM into a routine approach to cancer-related fatigue.

The promoter hypermethylation of SULT2B1 accelerates esophagus tumorigenesis via downregulated PER1

Background

Esophageal cancer is currently the eighth most common tumor in the world and a leading cause of cancer death. SULT2B1 plays crucial roles in tumorigenesis. The purpose of this study is to explore the role of SULT2B1 in esophageal squamous cell carcinoma (ESCC).

Methods

The expression of SULT2B1 and its clinicopathological characteristics were evaluated in ESCC cohorts. Bisulfite genomic sequencing and methylation specific PCR were used to detect the promoter hypermethylation of the SULT2B1 gene. The effects of SULT2B1 on the biological characters of ESCC cells were identified on functional assays. Subcutaneous xenograft models revealed the role of SULT2B1 in vivo with tumor growth. RNA‐Seq analysis and qRT‐PCR were performed to recognize the targeted effect of SULT2B1 on PER1.

Results

SULT2B1 was not expressed or at a low level in most patients with ESCC or in ESCC cell lines, and this was accompanied by poor clinical prognosis. Furthermore, the downregulation of SULT2B1 occurred in promoter hypermethylation. According to the functional results, overexpression of SULT2B1 could inhibit tumoral proliferation in vitro and retard tumor growth in vivo, whereas SULT2B1 knockdown could accelerate ESCC progression. Mechanistically, SULT2B1 targeted PER1 at the mRNA level during post‐transcriptional regulation. Finally, PER1 was verified as a suppressor and poor‐prognosis factor in ESCC.

Conclusions

SULT2B1 loss is a consequence owing to its ability to promote hypermethylation. In addition, it serves as a suppressor and poor‐prognosis factor because of the post‐transcriptional regulation of PER1 in ESCC.

Sedation-Led chEmotherapy Evades Pain (S.L.E.E.P.)

Chemotherapy and other invasive therapies are often limited by side effects, pain and negative experiences that can limit adherence to the therapy itself. Such negative components add to the patient's depressive state due to the disease. This research project proposes the use of deep sedation during chemotherapy sessions or other disabling therapies in the treatment of tumors or other severe diseases. The proposed protocol provides for an ad hoc hospitalization which could be during the night, during the day or limited to a few hours. Administration during sleep eliminates the memory and the negative impact the treatment has on the rest of the patient's daily life. This approach also agrees with the evidence of the circadian rhythm of cellular repair processes, which is greater at sunrise and sunset and linked to a good quantity and quality of sleep. In conclusion, this project aims to reduce the negative impact and increase the adherence to and efficacy of the therapy itself.

A mathematical model of the circadian clock and drug pharmacology to optimize irinotecan administration timing in colorectal cancer

Scheduling anticancer drug administration over 24 h may critically impact treatment success in a patient-specific manner. Here, we address personalization of treatment timing using a novel mathematical model of irinotecan cellular pharmacokinetics and -dynamics linked to a representation of the core clock and predict treatment toxicity in a colorectal cancer (CRC) cellular model. The mathematical model is fitted to three different scenarios: mouse liver, where the drug metabolism mainly occurs, and two human colorectal cancer cell lines representing an in vitro experimental system for human colorectal cancer progression. Our model successfully recapitulates quantitative circadian datasets of mRNA and protein expression together with timing-dependent irinotecan cytotoxicity data. The model also discriminates time-dependent toxicity between the different cells, suggesting that treatment can be optimized according to their cellular clock. Our results show that the time-dependent degradation of the protein mediating irinotecan activation, as well as an oscillation in the death rate may play an important role in the circadian variations of drug toxicity. In the future, this model can be used to support personalized treatment scheduling by predicting optimal drug timing based on the patient's gene expression profile.

Roles of circadian clocks in cancer pathogenesis and treatment

Circadian clocks are ubiquitous timing mechanisms that generate approximately 24-h rhythms in cellular and bodily functions across nearly all living species. These internal clock systems enable living organisms to anticipate and respond to daily changes in their environment in a timely manner, optimizing temporal physiology and behaviors. Dysregulation of circadian rhythms by genetic and environmental risk factors increases susceptibility to multiple diseases, particularly cancers. A growing number of studies have revealed dynamic crosstalk between circadian clocks and cancer pathways, providing mechanistic insights into the therapeutic utility of circadian rhythms in cancer treatment. This review will discuss the roles of circadian rhythms in cancer pathogenesis, highlighting the recent advances in chronotherapeutic approaches for improved cancer treatment.

Light Therapy for Cancer-Related Fatigue in (Non-)Hodgkin Lymphoma Survivors: Results of a Randomized Controlled Trial

Simple Summary

Cancer-related fatigue (CRF) is one of the most frequently reported symptoms with prevalence rates of 25 to 60 percent in (non-)Hodgkin lymphoma survivors. Several (pilot) studies showed promising effects of light therapy to reduce CRF. The aim of the current study is to evaluate the short- and long-term efficacy of light therapy on CRF and associated symptoms in chronically fatigued (non-)Hodgkin lymphoma survivors. Eighty-three survivors were exposed to bright white light (intervention) and another 83 survivors were exposed to dim white light (comparison). Results showed that all participants, irrespective of light condition, reported reduced levels of fatigue after the completion of light therapy. Similar results were found for depression, sleep quality, and some aspects of quality of life. No effect was found on circadian rhythms or objectively assessed sleep. Therefore, it is important to further investigate which aspects of intervention are associated with the improvements observed after light therapy.

Abstract

Purpose: To evaluate the short- and long-term effects of light therapy on fatigue (primary outcome) and sleep quality, depression, anxiety, quality of life, and circadian rhythms (secondary outcomes) in survivors of (non-)Hodgkin lymphoma presenting with chronic cancer-related fatigue. Methods: We randomly assigned 166 survivors (mean survival 13 years) to a bright white light intervention (BWL) or dim white light comparison (DWL) group. Measurements were completed at baseline (T0), post-intervention (T1), at three (T2), and nine (T3) months follow-up. A mixed-effect modeling approach was used to compare linear and non-linear effects of time between groups. Results: There were no significant differences between BWL and DWL in the reduction in fatigue over time. Both BWL and DWL significantly (p < 0.001) improved fatigue levels during the intervention followed by a slight reduction in this effect during follow-up (ES_T0-T1 = −0.71; ES_T1-T3 = 0.15). Similar results were found for depression, sleep quality, and some aspects of quality of life. Light therapy had no effect on circadian rhythms. Conclusions: BWL was not superior in reducing fatigue compared to DWL in HL and DLBCL survivors. Remarkably, the total sample showed clinically relevant and persistent improvements on fatigue not commonly seen in longitudinal observational studies in these survivors.

Circadian Rhythms, Disease and Chronotherapy

Circadian clocks are biological timing mechanisms that generate 24-h rhythms of physiology and behavior, exemplified by cycles of sleep/wake, hormone release, and metabolism. The adaptive value of clocks is evident when internal body clocks and daily environmental cycles are mismatched, such as in the case of shift work and jet lag or even mistimed eating, all of which are associated with physiological disruption and disease. Studies with animal and human models have also unraveled an important role of functional circadian clocks in modulating cellular and organismal responses to physiological cues (ex., food intake, exercise), pathological insults (e.g. virus and parasite infections), and medical interventions (e.g. medication). With growing knowledge of the molecular and cellular mechanisms underlying circadian physiology and pathophysiology, it is becoming possible to target circadian rhythms for disease prevention and treatment. In this review, we discuss recent advances in circadian research and the potential for therapeutic applications that take patient circadian rhythms into account in treating disease.

Circadian disruption in lung cancer

Despite major developments in lung cancer investigations and the progress of innovative oncology treatments in recent decades, lung cancer continues to be the predominant cause of cancer-related mortality globally, with over a million deaths each year. This highlights the urgent need to develop a deeper understanding of the current state of cancer care. At the environmental and cellular levels, circadian rhythms are closely associated with living organisms. In humans, the suprachiasmatic nucleus is the principal circadian pacemaker. Circadian gene feedback loops regulate the clock, connecting peripheral tissue metabolism, cell proliferation, DNA repair, and cell death to energy homeostasis, physical activity, and neurohormonal regulation at the organismal level. Endogenous circadian homeostasis has been frequently disturbed in modern civilizations, resulting in a higher risk of many disorders, including lung cancer. Despite major developments in lung cancer investigations and the progress of innovative oncology treatments in recent decades, lung cancer continues to be the predominant cause of cancer-related mortality globally, with over a million deaths each year. This highlights the urgent need to develop a deeper understanding of the current state of cancer care. At the environmental and cellular levels, circadian rhythms are closely associated with living organisms. In humans, the suprachiasmatic nucleus is the principal circadian pacemaker. Circadian gene feedback loops regulate the clock, connecting peripheral tissue metabolism, cell proliferation, DNA repair, and cell death to energy homeostasis, physical activity, and neurohormonal regulation at the organismal level. Endogenous circadian homeostasis has been frequently disturbed in modern civilizations, resulting in a higher risk of many disorders, including lung cancer. The mammalian circadian clock controls metabolism and cell division, and disruption of these processes may lead to cancer pathogenesis. Furthermore, circadian disturbance has recently been identified as a self-regulating cancer risk factor and is listed as a carcinogen. The theory that both somatic and systemic disturbances of circadian rhythms are related to a higher risk of lung cancer development and poor prognosis is addressed in this study. The chronotherapy principles hold much more promise for enhancing the lung cancer care options currently available. Developing a better understanding of the molecular interactions that control the physiological equilibrium between both the circadian rhythm and the cycle of cell division could significantly influence the development of novel treatments for lung cancer and other diseases.

Evaluation and Management of Sleep and Circadian Rhythm Disturbance in Cancer

OPINION STATEMENT

Sleep and circadian rhythm disturbance are among the most commonly experienced symptoms in patients with cancer. These disturbances occur throughout the spectrum of cancer care from diagnosis, treatment, and long into survivorship. The pathogenesis of these symptoms and disturbances is based on common inflammatory pathways related to cancer and its' treatments. The evaluation of sleep and circadian disorders requires an understanding of how these symptoms cluster with other cancer-related symptoms and potentiate each other. A thorough evaluation of these symptoms and disorders utilizing validated diagnostic tools, directed review of clinical information, and diagnostic testing is recommended. Treatment of sleep and circadian disturbance in cancer patients should be based on the findings of a detailed evaluation, including specific treatment of primary sleep and circadian disorders, and utilize integrative and personalised management of cancer-related symptoms through multiple pharmacologic and non-pharmacologic modalities. Recognition, evaluation, and treatment of sleep and circadian rhythm disturbance in cancer may lead to improved symptom management, quality of life, and outcomes.

Efficacy and safety of chronomodulated irinotecan, oxaliplatin, 5-fluorouracil and leucovorin combination as first- or second-line treatment against metastatic colorectal cancer: Results from the International EORTC 05011 Trial

The triplet combination of irinotecan, oxaliplatin and fluorouracil is an active frontline regimen in metastatic colorectal cancer, but scarce data exist on its use as salvage treatment. We aimed at assessing its safety and efficacy profiles with its circadian-based administration (chronoIFLO5) as either first- or second-line treatment, within the time-finding EORTC 05011 trial. Five-day chronoIFLO5 was administered every 3 weeks in patients with PS 0, 1 or 2. It consisted of chronomodulated irinotecan (180 mg/sqm), oxaliplatin (80 mg/sqm) and fluorouracil-leucovorin (2800 and 1200 mg/sqm, respectively). For our study, toxicity and antitumour activity were evaluated separately in first- and second-line settings. Primary endpoints included Grade 3-4 toxicity rates, best objective response rate (ORR), progression-free survival (PFS) and overall survival (OS). One-hundred forty-nine and 44 patients were treated in first-line and second-line settings, respectively, with a total of 1138 cycles with median relative dose intensities of about 90%. Demographics were comparable in the two groups. Thirty-six (24.7%) and 10 (22.2%) patients experienced at least one episode of severe toxicity in first line and second line, respectively. Frontline chronoIFLO5 yielded an ORR of 62.3% [95% CI: 54.2-70.4] and resulted in median PFS and OS of 8.7 months [7.5-9.9] and 19.9 months [15.4-24.5]. Corresponding figures in second line were 37.5% [22.5-52.5], 6.7 months [4.8-8.9] and 16.3 months [11.8-20.8]. International and prospective evaluation revealed the favourable safety and efficacy profiles of chronoIFLO5, both as frontline and as salvage treatment against metastatic colorectal cancer. In particular, encouraging activity in second line was observed, with limited haematological toxicity.

A novel approach to management of sleep-associated problems in patients with breast cancer (MOSAIC) during chemotherapy : A pilot study

STUDY OBJECTIVES

This pilot randomized controlled trial (RCT) was conducted to assess the preliminary effects of Brief Behavioral Therapy for Cancer-Related Insomnia (BBT-CI) delivered by trained research staff in comparison to a sleep hygiene pamphlet control and to assess moderators of treatment effect in patients with breast cancer undergoing chemotherapy.

METHODS

Of 74 participants recruited, 37 were randomized to BBT-CI and 37 were randomized to the control condition. Trained staff members delivered the intervention during chemotherapy treatments to reduce patients' burden. Insomnia was assessed with the Insomnia Severity Index (ISI), anxiety was assessed with the Spielberger State-Trait Anxiety Inventory, symptom burden was assessed with the Symptom Inventory (SI), and study staff recorded previous treatments and surgeries received by patients.

RESULTS

Patients randomized to BBT-CI showed significantly greater improvements in their ISI scores compared to the sleep hygiene group. Additionally, several treatment moderators were identified. The effect of BBT-CI was greater among individuals with lower baseline state-trait anxiety, with previous surgery for cancer, and with higher baseline somatic symptom severity.

CONCLUSIONS

BBT-CI shows preliminary efficacy compared to the sleep hygiene handout on insomnia in cancer patients undergoing chemotherapy. A large-phase III RCT needs to be conducted to replicate the preliminary findings.

The role of the circadian clock in cancer hallmark acquisition and immune-based cancer therapeutics

The circadian system temporally regulates physiology to maintain homeostasis. Co-opting and disrupting circadian signals appear to be distinct attributes that are functionally important for the development of a tumor and can enable or give rise to the hallmarks that tumors use to facilitate their initiation, growth and progression. Because circadian signals are also strong regulators of immune cell proliferation, trafficking and exhaustion states, they play a role in how tumors respond to immune-based cancer therapeutics. While immuno-oncology has heralded a paradigm shift in cancer therapeutics, greater accuracy is needed to increase our capability of predicting who will respond favorably to, or who is likely to experience the troubling adverse effects of, immunotherapy. Insights into circadian signals may further refine our understanding of biological determinants of response and help answer the fundamental question of whether certain perturbations in circadian signals interfere with the activity of immune checkpoint inhibitors. Here we review the body of literature highlighting circadian disruption as a cancer promoter and synthesize the burgeoning evidence suggesting circadian signals play a role in how tumors respond to immune-based anti-cancer therapeutics. The goal is to develop a framework to advance our understanding of the relationships between circadian markers, cancer biology, and immunotherapeutics. Bolstered by this new understanding, these relationships may then be pursued in future clinical studies to improve our ability to predict which patients will respond favorably to, and avoid the adverse effects of, traditional and immune-based cancer therapeutics.

Cancer-related Fatigue in Relation to Chronotype and Sleep Quality in (Non-)Hodgkin Lymphoma Survivors

Cancer-related fatigue has been related to circadian disruptions and lower levels of sleep quality. However, it is unknown whether the circadian phase, which is associated with chronotype and timing of sleep, is related to fatigue after cancer. The aims of this study were to investigate the associations between (1) chronotype and cancer-related fatigue and (2) sleep quality and cancer-related fatigue. In this cross-sectional questionnaire study, 458 (non-)Hodgkin lymphoma survivors (n = 231 female, mean age 49.7 years) completed a Visual Analogue Scale for fatigue (VAS-fatigue) from 0 (no fatigue) to 10 (worst imaginable fatigue), the Munich Chronotype Questionnaire (MCTQ), and the Pittsburgh Sleep Quality Index (PSQI) between October 2018 and July 2019. A hierarchical linear regression analysis was used to evaluate the associations between the dependent variable fatigue and chronotype (based on early, intermediate, or late average midsleep) in Model 1, and fatigue and sleep quality in Model 2. The results showed no indications for an association between chronotype and fatigue (all p values ≥ 0.50). There were associations between two (out of seven) aspects of sleep quality and fatigue: subjective sleep quality (p < 0.001) and daily dysfunctioning (p < 0.001). Therefore, it is more likely that fatigue is associated with self-reported sleep quality rather than with chronotype. However, experimental studies with objective, physiological data on circadian phase and sleep quality are necessary to confirm the conclusions of this cross-sectional study.

Therapeutic targets of cancer drugs: Modulation by melatonin

The biological functions of melatonin range beyond the regulation of the circadian rhythm. With regard to cancer, melatonin's potential to suppress cancer initiation, progression, angiogenesis and metastasis as well as sensitizing malignant cells to conventional chemo- and radiotherapy are among its most interesting effects. The targets at which melatonin initiates its anti-cancer effects are in common with those of a majority of existing anti-cancer agents, giving rise to the notion that this molecule is a pleiotropic agent sharing many features with other antineoplastic drugs in terms of their mechanisms of action. Among these common mechanisms of action are the regulation of several major intracellular pathways including mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinase (ERK) and protein kinase B (AKT/PKB) signaling. The important mediators affected by melatonin include cyclins, nuclear factor-κB (NF-κB), heat shock proteins (HSPs) and c-Myc, all of which can serve as potential targets for cancer drugs. Melatonin also exerts some of its anti-cancer effects via inducing epigenetic modifications, DNA damage and mitochondrial disruption in malignant cells. The regulation of these mediators by melatonin mitigates tumor growth and invasiveness via modulating their downstream responsive genes, housekeeping enzymes, telomerase reverse transcriptase, apoptotic gene expression, angiogenic factors and structural proteins involved in metastasis. Increasing our knowledge on how melatonin affects its target sites will help find ways of exploiting the beneficial effects of this ubiquitously-acting molecule in cancer therapy. Acknowledging this, here we reviewed the most studied target pathways attributed to the anti-cancer effects of melatonin, highlighting their therapeutic potential.

Do malignant cells sleep at night?

Biological rhythms regulate the biology of most, if not all living creatures, from whole organisms to their constitutive cells, their microbiota, and also parasites. Here, we present the hypothesis that internal and external ecological variations induced by biological cycles also influence or are exploited by cancer cells, especially by circulating tumor cells, the key players in the metastatic cascade. We then discuss the possible clinical implications of the effect of biological cycles on cancer progression, and how they could be exploited to improve and standardize methods used in the liquid biopsy field.

Comparing Conventional Chemotherapy to Chronomodulated Chemotherapy for Cancer Treatment: Protocol for a Systematic Review

BACKGROUND

Chronomodulated chemotherapy aims to achieve maximum drug safety and efficacy by adjusting the time of treatment to an optimal biological time as determined by the circadian clock. Although it is a promising alternative to conventional (non-time-stipulated) chemotherapy in several instances, the lack of scientific consensus and the increased logistical burden of timed administration limit the use of a chronomodulated administration protocol.

OBJECTIVE

With the goal to increase scientific consensus on this subject, we plan to conduct a systematic review of the current literature to compare the drug safety and efficacy of chronomodulated chemotherapy with those of conventional chemotherapy.

METHODS

This systematic review will comply with the PRISMA (Preferred Reporting Items for the Systematic Reviews and Meta-Analysis) guidelines. In order to identify relevant studies, we conducted a comprehensive search in PubMed and Embase on May 18, 2020. We included clinical studies that compare either the safety or efficacy of chronomodulated chemotherapy with that of conventional chemotherapy. Potential studies will be reviewed and screened by 2 independent reviewers. Quality assessment will be performed using the National Institutes of Health's Study Quality Assessment Tool (Quality Assessment of Controlled Intervention Studies). Disagreements will be resolved by consulting a third independent reviewer.

RESULTS

This protocol has received funding, and the search for studies from databases commenced on May 18, 2020. The systematic review is planned to be completed by October 31, 2020.

CONCLUSIONS

In this systematic review, we will compare drug safety and drug efficacy for cancer patients who were administered either chronomodulated chemotherapy or conventional chemotherapy. Moreover, we will highlight the outcomes and quality of the selected trials for this review.

TRIAL REGISTRATION

PROSPERO International Prospective Register of Systematic Reviews CRD42020177878; https://tinyurl.com/y53w9nq6.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/18023.