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.

Immunotherapy and Chemotherapy Versus Sleep Disturbances for NSCLC Patients

INTRODUCTION

Cancer patients are known to experience sleep disturbances that differ between disease stages and treatments. Regarding lung cancer patients and immunotherapy, information on their sleep disturbances has been recently acquired, but no comparison has been made between different treatment modalities.

PATIENTS AND METHODS

We recruited 98 non-small cell lung cancer patients; 49 had programmed death-ligand 1 expression of ≥50% and received immunotherapy as first-line treatment and 49 had programmed death-ligand 1 expression in the range from 0-49 and received chemotherapy as first-line treatment. All patients were stage IV, but with no bone metastasis. Sleep disturbances were recorded through polysomnography and sleep questionnaires.

RESULTS

For immunotherapy patients with PD-L1 expression ≥ 50%, the disease response was rapid and the sleep disturbances decreased rapidly. On the other hand, for chemotherapy patients, the sleep disturbances remained for all those patients that had partial response and stable disease. It was noticed that chemotherapy drugs induce severe adverse effects.

DISCUSSION

In our study, it was observed that patients with complete response had reduced sleep disturbances in the case of immunotherapy patients. However, sleep disturbances continued for several patients in the chemotherapy group due to the adverse effects of chemotherapy drugs.

IN CONCLUSION

Immunotherapy drugs on their own do not induce sleep disturbances and, through treatment response, alleviate sleep disturbances in lung cancer patients.

Non-Small-Cell Lung Cancer Immunotherapy and Sleep Characteristics: The Crossroad for Optimal Survival

INTRODUCTION

Non-small-cell lung cancer is still diagnosed at an inoperable stage and systematic treatment is the only option. Immunotherapy is currently considered to be the tip of the arrow as the first-line treatment for patients with a programmed death-ligand 1 ≥ 50. Sleep is known to be an essential part of our everyday life.

PATIENTS AND METHODS

We investigated, upon diagnosis and after nine months, 49 non-small-cell lung cancer patients undergoing immunotherapy treatment with nivolumab and pemprolisumab. A polysomnographic examination was conducted. Moreover, the patients completed the Epworth Sleepiness Scale (ESS), the Pittsburgh Sleep Quality Index (PSQI), the Fatigue Severity Scale (FSS) and the Medical Research Council (MRC) dyspnea scale.

RESULTS

Tukey mean-difference plots, summary statistics, and the results of paired t-test of five questionnaire responses in accordance with the PD-L1 test across groups were examined. The results indicated that, upon diagnosis, patients had sleep disturbances which were not associated with brain metastases or their PD-L1 expression status. However, the PD-L1 status and disease control were strongly associated, since a PD-L1 ≥80 improved the disease status within the first 4 months. All data from the sleep questionnaires and polysomnography reports indicated that the majority of patients with a partial response and complete response had their initial sleep disturbances improved. There was no connection between nivolumab or pembrolisumab and sleep disturbances.

CONCLUSION

Upon diagnosis, lung cancer patients have sleep disorders such as anxiety, early morning wakening, late sleep onset, prolonged nocturnal waking periods, daytime sleepiness, and unrefreshing sleep. However, these symptoms tend to improve very quickly for patients with a PD-L1 expression ≥80, because disease status improves also very quickly within the first 4 months of treatment.

Effects of sleep interventions on cancer-related fatigue and quality of life in cancer patients: a systematic review and meta-analysis

BACKGROUND

Nondrug treatments are potentially beneficial for cancer patients. However, the effect of sleep on cancer-related fatigue (CRF) and quality of life (QOL) in cancer patients remains unclear. We conducted a meta-analysis of randomized controlled trials to examine the efficacy of sleep in cancer patients undergoing treatment.

METHODS

The PubMed, Ovid, Embase, Cochrane Central Register of Controlled Trials, and China National Knowledge Infrastructure databases were searched to identify suitable studies. Stata 15.0 software was used for statistical analyses. Sensitivity analyses were conducted. Fourteen studies (6 in English and 8 in Chinese) involving 1151 patients were included in the meta-analysis. Ten, five, and six studies that assessed the effects of sleep on CRF, QOL, and quality of sleep, respectively, in cancer patients undergoing treatment were identified.

RESULTS

Sleep interventions significantly affected overall CRF (standardized mean difference (SMD) = -1.52, P < 0.01), overall QOL (SMD = 1.20, P < 0.01), physical fatigue (SMD = -0.66, P < 0.01), cognitive fatigue (SMD = -0.38, P = 0.015), and physical function (SMD = 0.64, P < 0.01). Comprehensive intervention measures focusing on sleep, sleep nondrug interventions, and interventions for ≥3 or <3 months affect CRF. However, no significant effects on emotional fatigue, emotional function, perpetual fatigue, depression, or quality of sleep were observed.

CONCLUSIONS

Comprehensive interventions focusing on sleep are helpful for CRF. Sleep interventions may only affect physiological function and have no effect on emotional function, perpetual function, or sleep quality. Future research should focus on how to combine sleep interventions with psychological, social, cognitive, and emotional interventions and provide targeted comprehensive nursing measures to better improve CRF, sleep quality, and QOL.

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.

The day after: correlates of patient-reported outcomes with actigraphy-assessed sleep in cancer patients at home (inCASA project)

Subjective sleep assessment in cancer patients poorly correlates with actigraphy parameters that usually encompass multiple nights. We aimed to determine the objective actigraphy measures that best correlated with subjective sleep ratings on a night-by-night basis in cancer patients. Thirty-one cancer patients daily self-rated sleep disturbances using the single dedicated item of the MD Anderson Symptom Inventory (0-10 scale) with 18 other items, and continuously wore a wrist actigraph for 30 days. Objective sleep parameters were computed from the actigraphy nighttime series, and correlated with subjective sleep disturbances reported on the following day, using repeated measures correlations. Multilevel Poisson regression analysis was performed to identify the objective and subjective parameters that affected subjective sleep rating. Poor subjective sleep score was correlated with poor sleep efficiency (rrm = -0.13, p = 0.002) and large number of wake episodes (rrm = 0.12, p = 0.005) on the rated night. Multilevel analysis demonstrated that the expected sleep disturbance score was affected by the joint contribution of the wake episodes (exp(β) = 1.01, 95% confidence interval = 1.00 to 1.02, p = 0.016), fatigue (exp(β) = 1.35, 95% confidence interval = 1.15 to 1.55, p < 0.001) and drowsiness (exp(β) = 1.70, 95% confidence interval = 1.19 to 2.62, p = 0.018), self-rated the following evening, and sleep disturbance experienced one night before (exp(β) = 1.77, 95% confidence interval = 1.41 to 2.22, p < 0.001). The night-by-night approach within a multidimensional home tele-monitoring framework mainly identified the objective number of wake episodes computed from actigraphy records as the main determinant of the severity of sleep complaint in cancer patients on chemotherapy. This quantitative information remotely obtained in real time from cancer patients provides a novel framework for streamlining and evaluating interventions toward sleep improvement in cancer patients.

Circadian rest-activity rhythm as an objective biomarker of patient-reported outcomes in patients with advanced cancer

BACKGROUND

Psychosocial symptoms often cluster together, are refractory to treatment, and impair health-related quality of life (HR-QoL) in cancer patients. The contribution of circadian rhythm alterations to systemic symptoms has been overlooked in cancer, despite a causal link shown under jet lag and shift work conditions. We investigated whether the circadian rest-activity rhythm provides a reliable and objective estimate of the most frequent patient-reported outcome measures (PROMs).

METHODS

Two datasets were used, each involving concomitant 3-day time series of wrist actigraphy and HR-QoL questionnaires: EORTC QLQ-C30 was completed once by 237 patients with metastatic colorectal cancer; MD Anderson Symptom Inventory (MDASI) was completed daily by 31 patients with advanced cancer on continuous actigraphy monitoring, providing 1015 paired data points. Circadian function was assessed using the clinically validated dichotomy index I < O. Nonparametric tests compared PROMs and I < O. Effect sizes were computed. Sensitivity subgroup and temporal dynamics analyses were also performed.

RESULTS

I < O values were significantly lower with increasing symptom severity and worsening HR-QoL domains. Fatigue and anorexia were worse in patients with circadian disruption. The differences were both statistically and clinically significant (P < 0.001; d ≥ 0.33). Physical and social functioning, and global quality/enjoyment of life were significantly better in patients with robust circadian rhythm (P < 0.001; d ≥ 0.26). Sensitivity analyses validated these findings.

CONCLUSION

Objectively determined circadian disruption was consistently and robustly associated with clinically meaningfully severe fatigue, anorexia, and interference with physical and social functioning. This supports an important role of the circadian system in the determination of cancer patients' HR-QoL and symptoms that deserves therapeutic exploitation.

Systems Chronotherapeutics

Chronotherapeutics aim at treating illnesses according to the endogenous biologic rhythms, which moderate xenobiotic metabolism and cellular drug response. The molecular clocks present in individual cells involve approximately fifteen clock genes interconnected in regulatory feedback loops. They are coordinated by the suprachiasmatic nuclei, a hypothalamic pacemaker, which also adjusts the circadian rhythms to environmental cycles. As a result, many mechanisms of diseases and drug effects are controlled by the circadian timing system. Thus, the tolerability of nearly 500 medications varies by up to fivefold according to circadian scheduling, both in experimental models and/or patients. Moreover, treatment itself disrupted, maintained, or improved the circadian timing system as a function of drug timing. Improved patient outcomes on circadian-based treatments (chronotherapy) have been demonstrated in randomized clinical trials, especially for cancer and inflammatory diseases. However, recent technological advances have highlighted large interpatient differences in circadian functions resulting in significant variability in chronotherapy response. Such findings advocate for the advancement of personalized chronotherapeutics through interdisciplinary systems approaches. Thus, the combination of mathematical, statistical, technological, experimental, and clinical expertise is now shaping the development of dedicated devices and diagnostic and delivery algorithms enabling treatment individualization. In particular, multiscale systems chronopharmacology approaches currently combine mathematical modeling based on cellular and whole-body physiology to preclinical and clinical investigations toward the design of patient-tailored chronotherapies. We review recent systems research works aiming to the individualization of disease treatment, with emphasis on both cancer management and circadian timing system–resetting strategies for improving chronic disease control and patient outcomes.

Polysomnographic Study of Sleep in Survivors of Breast Cancer

STUDY OBJECTIVE

Insomnia is a frequent complaint in breast cancer patients during and after treatment. Breast cancer survivors, 1-10 years posttreatment, underwent in-lab polysomnography (PSG) to objectively define the insomnia in those patients with such a complaint.

METHODS

Twenty-six breast cancer survivors (aged 39-80, mean 54.0 months posttreatment) spent 2 nights in the sleep laboratory. Sleep on Night 2 was scored for sleep stages, sleep onset latency, REM sleep onset latency, wake time, apneas and hypopneas, periodic limb movements and arousals. Subjects were allocated into 2 groups by their scores on the Pittsburgh Sleep Quality Index (PSQI): no/ mild sleep disturbance (PSQI score ≤ 9, n = 15) or moderate/ severe sleep disturbance (PSQI ≥ 10, n = 11).

RESULTS

Standard PSG/EEG parameters failed to differentiate insomniacs from non-insomniacs. The single variable that distinguished the insomnia group was periodic limb movements in sleep (PLMS). PLMS were significantly correlated (r ≅ 0.7, p < 0.02) with subjective report of insomnia on PSQI and insomnia severity index. Log[Number of PLMS] was higher in the moderate/severe insomnia group (p = 0.008). Five of 11 patients in the moderate/severe insomnia group had a PLMS index ≥ 15, compared to only one of 15 patients in the none/mild insomnia group (p = 0.02). Menopausal symptoms and use of caffeine, hypnotics, and antidepressants were unrelated to insomnia severity or PLMS.

CONCLUSIONS

PLMS was the sole PSG variable that separated breast cancer survivors with moderate/severe insomnia from those with no/mild sleep disturbance. Further study of the incidence and significance of PLMS in breast cancer survivors with the complaint of insomnia is merited.

Effects of melatonin on physical fatigue and other symptoms in patients with advanced cancer receiving palliative care: A double-blind placebo-controlled crossover trial

BACKGROUND

Patients with advanced cancer often experience fatigue and other symptoms that negatively impact their quality of life. The current trial investigated the effect of melatonin on fatigue and other symptoms in patients with advanced cancer.

METHODS

Patients who were aged ≥18 years, had a histologically confirmed stage IV cancer (TNM Classification), and who reported feeling significantly tired were recruited from the palliative care unit at the study institution. The study was a double-blind, randomized, placebo-controlled crossover trial. Patients received 1 week of melatonin at a dose of 20 mg or a placebo orally each night, before crossing over and receiving the opposite treatment for 1 week. Between the 2 periods, a washout period of 2 days was implemented. Outcomes were measured using the Multidimensional Fatigue Inventory (MFI-20) and The European Organization for Research and Treatment of Cancer Quality of Life Questionnaire. Physical fatigue from the MFI-20 was the primary outcome. The primary analysis was a complete complier analysis (ie, it included only those patients who had consumed at least 5 capsules per week and who had answered the MFI-20 on days 1, 7, 10, and 17). Sensitivity analysis using multiple imputations including all randomized patients and all patients completing the intervention were conducted.

RESULTS

A total of 72 patients were randomized. Fifty patients completed the intervention and 44 patients were complete compliers. No significant differences between the placebo and melatonin periods were found for physical fatigue, secondary outcomes, or explorative outcomes.

CONCLUSIONS

In the current study, oral melatonin at a dose of 20 mg was not found to improve fatigue or other symptoms in patients with advanced cancer.

Use of opioid analgesics or sleeping medication and survival of cancer patients

PURPOSE OF THE RESEARCH

Pain and sleep disturbance have been shown to have a profound influence on the outcomes of cancer treatment. This study sought to determine whether administering opioid analgesics or sleeping medication to cancer patients during their first admission to a hospital is associated with poor prognoses.

METHODS AND SAMPLE

We conducted a population-based retrospective cohort study by analyzing data obtained from the National Health Insurance Research Database in Taiwan. The study population comprised cancer patients whose first admission to a hospital for initial cancer treatment was in 2004.

KEY RESULTS

We collected data on 2302 cancer patients. To analyze the effect of opioid analgesic and sleeping medication usage on cancer patient survival, we compared the 3-year survival rates among 4 groups of patients (no use, sleeping medications-only, opioid analgesics-only, both used). The 3-year Kaplan-Meier plots for these 4 groups show that the difference was statistically significant (log rank 48.244, p < 0.001). The longevity of cancer patients was the greatest among the no-use group, followed by the sleeping medications-only group, then the opioid analgesics-only group, and finally, the group in which both sleeping medications and opioid analgesics were used.

CONCLUSIONS

The use of opioid analgesics or sleeping medication was shown to be negatively correlated with the survival rate of cancer patients.

Wrist actimetry circadian rhythm as a robust predictor of colorectal cancer patients survival

The disruption of the circadian timing system (CTS), which rhythmically controls cellular metabolism and proliferation, accelerated experimental cancer progression. A measure of CTS function in cancer patients could thus provide novel prediction information for outcomes, and help to identify novel specific therapies. The rest-activity circadian rhythm is a reliable and non-invasive CTS biomarker, which was monitored using a wrist watch accelerometer for 2 days in 436 patients with metastatic colorectal cancer. The relative percentage of activity in-bed versus out-of-bed (I < O) constituted the tested CTS measure, whose prognostic value for overall survival (OS) and progression-free survival (PFS) was determined in a pooled analysis of three patient cohorts with different treatment exposures. Median OS was 21.6 months [17.8-25.5] for patients with I < O above the median value of 97.5% as compared to 11.9 months [10.4-13.3] for those with a lower I < O (Log-rank p < 0.001). Multivariate analyses retained continuous I < O as a joint predictor of both OS and PFS, with respective hazard ratios (HR) of 0.954 (p < 0.001) and 0.970 (p < 0.001) for each 1% increase in I < O. HRs had similar values in all the patient subgroups tested. The circadian physiology biomarker I < O constitutes a robust and independent quantitative predictor of cancer patient outcomes, that can be easily and cost-effectively measured during daily living. Interventional studies involving 24-h schedules of clock-targeted drugs, light intensity, exercise and/or meals are needed for testing the relevance of circadian synchronization for the survival of patients with disrupted rhythms.

The circadian timing system in clinical oncology

The circadian timing system (CTS) controls several critical molecular pathways for cancer processes and treatment effects over the 24 hours, including drug metabolism, cell cycle, apoptosis, and DNA damage repair mechanisms. This results in the circadian time dependency of whole-body and cellular pharmacokinetics and pharmacodynamics of anticancer agents. However, CTS robustness and phase varies among cancer patients, based on circadian monitoring of rest- activity, body temperature, sleep, and/or hormonal secretion rhythms. Circadian disruption has been further found in up to 50% of patients with metastatic cancer. Such disruption was associated with poor outcomes, including fatigue, anorexia, sleep disorders, and short progression-free and overall survival. Novel, minimally invasive devices have enabled continuous CTS assessment in non-hospitalized cancer patients. They revealed up to 12-hour differences in individual circadian phase. Taken together, the data support the personalization of chronotherapy. This treatment method aims at the adjustment of cancer treatment delivery according to circadian rhythms, using programmable-in-time pumps or novel release formulations, in order to increase both efficacy and tolerability. A fixed oxaliplatin, 5-fluorouracil and leucovorin chronotherapy protocol prolonged median overall survival in men with metastatic colorectal cancer by 3.3 months as compared to conventional delivery, according to a meta-analysis (P=0.009). Further analyses revealed the need for the prevention of circadian disruption or the restoration of robust circadian function in patients on chronotherapy, in order to further optimize treatment effects. The strengthening of external synchronizers could meet such a goal, through programmed exercise, meal timing, light exposure, improved social support, sleep scheduling, and the properly timed administration of drugs that target circadian clocks. Chrono-rehabilitation warrants clinical testing for improving quality of life and survival in cancer patients.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Bedtime misalignment and progression of breast cancer

Disruption of circadian rhythms, which frequently occurs during night shift work, may be associated with cancer progression. The effect of chronotype (preference for behaviors such as sleep, work, or exercise to occur at particular times of day, with an associated difference in circadian physiology) and alignment of bedtime (preferred vs. habitual), however, have not yet been studied in the context of cancer progression in women with breast cancer. Chronotype and alignment of actual bedtime with preferred chronotype were examined using the Morningness-Eveningness Scale (MEQ) and sleep-wake log among 85 women with metastatic breast cancer. Their association with disease-free interval (DFI) was retrospectively examined using the Cox proportional hazards model. Median DFI was 81.9 months for women with aligned bedtimes ("going to bed at preferred bedtime") (n = 72), and 46.9 months for women with misaligned bedtimes ("going to bed later or earlier than the preferred bedtime") (n = 13) (log rank p = 0.001). In a multivariate Cox proportional hazard model, after controlling for other significant predictors of DFI, including chronotype (morning type/longer DFI; HR = 0.539, 95% CI = 0.320-0.906, p = 0.021), estrogen receptor (ER) status at initial diagnosis (negative/shorter DFI; HR = 2.169, 95% CI = 1.124-4.187, p = 0.028) and level of natural-killer cell count (lower levels/shorter DFI; HR = 1.641, 95% CI = 1.000-2.695, p = 0.050), misaligned bedtimes was associated with shorter DFI, compared to aligned bedtimes (HR = 3.180, 95% CI = 1.327-7.616, p = 0.018). Our data indicate that a misalignment of bedtime on a daily basis, an indication of circadian disruption, is associated with more rapid breast cancer progression as measured by DFI. Considering the limitations of small sample size and study design, a prospective study with a larger sample is necessary to explore their causal relationship and underlying mechanisms.

Circadian Disruption, Fatigue, and Anorexia Clustering in Advanced Cancer Patients: Implications for Innovative Therapeutic Approaches

A disruption of the circadian timing system, as identified by monitoring of marker biorhythms, is common in cancer patients. The recording of the rest—activity rhythm with a wrist actigraph has been commonly used. This noninvasive monitoring allows a robust estimation of circadian disruption. The authors have previously found that altered patterns of circadian rest—activity rhythms are significantly and independently associated with the severity of fatigue and anorexia in patients with metastatic colorectal cancer. Elevated proinflammatory cytokines could partly account for this circadian disruption and its associated constitutional symptoms. Here, the authors present and discuss the data supporting the hypothesis that circadian disruption is often associated with fatigue and anorexia, which in turn further alter and dampen circadian synchronization, thus, creating a vicious cycle. This body of evidence paves the path for innovative therapeutic approaches targeting the circadian timing system in an effort to diminish constitutional symptoms induced by cancer and some anticancer treatments.

Breast cancer patients have progressively impaired sleep-wake activity rhythms during chemotherapy

PURPOSE

Prior cross-sectional studies have shown that cancer patients have sleep-wake activity cycles that show little distinction between daytime and nighttime, a pattern indicative of circadian disruption. This pattern is seen both before and during cancer treatment. Long-term data are needed, however, to assess to what extent circadian rhythm impairments evolve over the course of chemotherapy. The goal of this study was to assess the longitudinal course of sleep-wake activity rhythms before and during chemotherapy for breast cancer.

PATIENTS AND METHODS

Ninety-five women scheduled to receive neoadjuvant or adjuvant anthracycline based chemotherapy for a stage I-III breast cancer participated. The participants wore a wrist actigraph for 72 consecutive hours at baseline (pre-chemotherapy), as well as during the weeks 1, 2 and 3 (W1, W2, W3) of cycle 1 and cycle 4 of chemotherapy. Sleep-wake circadian activity variables were computed based on actigraphic data.

RESULTS

Compared to baseline, with the exception of acrophase, all circadian rhythm variables examined, including amplitude, mesor, up-mesor, down-mesor, and rhythmicity were significantly impaired during the first week of both chemotherapy cycles. Although the circadian variables approached baseline values during W2 and W3 of cycle 1, most remained significantly more impaired during W2 and W3 of cycle 4.

CONCLUSION

These data suggest that the first administration of chemotherapy is associated with transient disruption of sleep-wake rhythm, while repeated administration of chemotherapy results in progressively worse and more enduring impairments in sleep-wake activity rhythms.

Circadian rhythm in rest and activity: a biological correlate of quality of life and a predictor of survival in patients with metastatic colorectal cancer

The rest-activity circadian rhythm (CircAct) reflects the function of the circadian timing system. In a prior single-institution study, the extent of CircAct perturbation independently predicted for survival and tumor response in 192 patients receiving chemotherapy for metastatic colorectal cancer. Moreover, the main CircAct parameters correlated with several health-related quality of life (HRQoL) scales. In this prospective study, we attempted to extend these results to an independent cohort of chemotherapy-naive metastatic colorectal cancer patients participating in an international randomized phase III trial (European Organisation for Research and Treatment of Cancer 05963). Patients were randomized to receive chronomodulated or conventional infusion of 5-fluorouracil, leucovorin, and oxaliplatin as first-line treatment for metastatic colorectal cancer. Patients from nine institutions completed the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-C30 and wore a wrist accelerometer (actigraph) for 3 days before chemotherapy delivery. Two validated parameters (I<O and r24) were used to estimate CircAct. Of 130 patients with baseline CircAct assessments, 96 had baseline HRQoL data. I<O was confirmed to correlate with global quality of life, physical functioning, social functioning, fatigue, and appetite loss (r > |0.25|; P < 0.01). I<O further independently predicted for overall survival with a hazard ratio of 0.94 (P < 0.0001). The associations between CircAct parameters, HRQoL, and survival, which were shown in this international study involving previously untreated metastatic colorectal cancer patients, confirm prior single-institution findings in mostly pretreated metastatic colorectal cancer patients. The circadian timing system constitutes a novel therapeutic target. Interventions that normalize circadian timing system dysfunction may affect quality of life and survival in cancer patients.