Sleep duration and breast cancer prognosis: perspectives from the Women's Healthy Eating and Living Study

Eyes Wide Open: Sleep as a Potential Contributor to Racial and Ethnic Disparities in Cancer

U.S. racial and ethnic minoritized groups face disproportionate cancer burdens compared to White Americans. Investigating modifiable factors, such as sleep, that are socially patterned and inequitably distributed by race and ethnicity may advance understanding of cancer disparities and provide intervention opportunities. Emerging data suggest poor sleep health is associated with cancer. Yet, its contribution to racial and ethnic cancer disparities is understudied. In this narrative review, we explored the sleep-cancer relation through a disparities lens. We (i) summarized literature reporting on associations between sleep and cancer among racial and ethnic minority populations; (ii) examined potential sleep-cancer mechanisms; and (iii) discussed future directions. We identified five studies reporting on sleep-cancer associations among minoritized groups. Poor sleep health was associated with aggressive breast cancer among Black women, increased breast cancer risk among Asian women, and increased risk of breast and total cancer among Hispanic/Latinx Americans. Sleep and cancer disparities have similar socioeconomic and behavioral determinants, suggesting racial and ethnic minoritized groups may be vulnerable to poor sleep health and its adverse health impacts. Evidence indicates that the sleep-cancer disparities relation is an emerging, but important area of research that warrants further investigation, as sleep may be an avenue for reducing cancer disparities.

Global prevalence of poor sleep quality in cancer patients: A systematic review and meta-analysis

OBJECTIVE

Poor sleep quality is common in patients with cancer, but the prevalence rates varied widely across studies. This systematic review and meta-analysis examined the pooled prevalence of poor sleep quality among patients with cancer.

METHODS

Systematic literature searches were independently conducted in the major databases (Web of Science, PubMed, EMBASE and PsycINFO). Studies that reported the prevalence of poor sleep quality in patients with cancer were analyzed using a random effects model. Funnel plots and Egger's tests were used to assess publication bias. Statistical analyses were performed using R software.

RESULTS

A total of 59 epidemiological studies involving 16,223 patients were included. The pooled prevalence of poor sleep quality in patients with cancer was 57.4% [95% confidence interval (CI): 53.3% - 61.6%]. Additionally, three comparative studies with 372 patients and 412 healthy controls were included. Compared to healthy controls, patients with cancer had a significantly higher risk for poor sleep quality [odd ratio (OR) = 3.0; 95%CI: 1.2-7.2; P < 0.05]. Subgroup analyses of the studies revealed that studies from Middle East & North Africa region and low income countries, and on gynecological cancer as well as those with a lower cut-off value of sleep quality (all P < 0.01) reported a higher prevalence of poor sleep quality. Meta-regression analyses showed that higher prevalence of poor sleep quality was associated with higher prevalence of comorbid depression (P < 0.05) and anxiety (P < 0.01), but was associated with a lower education level (P < 0.05) and alcohol use ratio (P < 0.05).

CONCLUSION

Poor sleep quality is common among patients with cancer. Considering the overall high prevalence rate and negative impact of poor sleep quality, appropriate measures to identify and improve poor sleep quality are needed to enhance the clinical outcomes in this group.

Sleep duration and mortality among breast cancer survivors in the Western New York Exposures and Breast Cancer (WEB) Study

PURPOSE

There is increasing evidence that sleep duration may affect breast cancer survival through effects on circadian function, influencing disease progression. However, further investigation of this association is needed.

METHODS

In a population-based, prospective cohort study of women from the Western New York Exposures and Breast Cancer Study, we examined mortality outcomes with invasive breast cancer identified using the National Death Index. Cox proportion hazards ratios with 95% confidence intervals were used to estimate risk of all-cause (AC) and breast cancer-specific (BC) mortality associated with self-reported usual sleep duration with adjustment for age, race/ethnicity, years of education, body mass index (BMI), menopausal status, pack-years of smoking, tumor stage, and estrogen-receptor (ER) status. We further examined associations within strata of BMI, tumor stage, menopausal status, and ER status.

RESULTS

A sample of 817 patients with breast cancer were followed for a median of 18.7 years, during which 339 deaths were reported, including 132 breast cancer-specific deaths. Those who reported shorter or longer sleep tended to have a slightly higher BMI, to be less proportionately non-Hispanic White, to report a previous history of benign breast disease, and to have consumed more alcohol during their lifetime. We found no significant associations between sleep duration and AC or BC mortality, including within stratified analyses.

CONCLUSION

Sleep duration was not associated with either AC or BC mortality including within strata of BMI, tumor stage, menopausal status, or ER status.

Clinical guidelines for managing menopausal symptoms in women with (a history of) breast cancer

Background

One in eight women will be diagnosed with breast cancer. At the time of diagnosis, 75% of patients are postmenopausal. Many will receive anti-hormone therapy, which often induces menopausal symptoms. Premenopausal breast cancer patients frequently become postmenopausal as a result of the treatment and often experience menopausal symptoms. The increased incidence of breast cancer, combined with longer survival, has led to an increase in the number of women experiencing menopausal symptoms. Therefore, the management of menopausal symptoms in women with a history or current breast cancer is a relevant and common clinical problem.

Objectives

To provide a clinically useful overview of the steps in the management of menopausal symptoms in women with (a history of) breast cancer.

Materials and Methods

A comprehensive literature review was conducted by authors JS and WT using the PubMed and Medline databases. Abstracts were critically appraised and, where appropriate, the full text was analysed.

Main Outcome Measures

Not applicable.

Results

Depending on the condition, either meta-analyses, randomised controlled trials or retrospective cohorts were identified. No evidence was found for some proposed treatments.

Conclusions

Menopausal symptoms in women with (a history of) breast cancer require a patient-tailored approach. Shared decision making is paramount and adequate up-to-date knowledge can help the breast cancer specialist to advise and guide patients accordingly.

What is new?

A comprehensive, clinically-based overview of evidence-based treatment options for menopausal symptoms in women with (a history of) breast cancer.

Dietary Composition, Meal Timing, and Cancer-Related Fatigue: Insights From the Women's Healthy Eating and Living Study

BACKGROUND

Cancer-related fatigue is difficult to treat, and dietary interventions are promising yet underused.

OBJECTIVE

We explored associations between dietary patterns and fatigue, and the effect of a dietary intervention versus control on fatigue using Women's Healthy Eating and Living study data, plus mediators and moderators of the intervention effect.

METHODS

The Women's Healthy Eating and Living study was a randomized controlled trial among early-stage breast cancer survivors. The 4-year intervention encouraged fruits, vegetables, fiber, and 15% to 20% calories from fat. Fatigue outcomes included a 9-item energy scale and a single-item tiredness question. Dietary quality was estimated using a modified Healthy Eating Index (24-hour dietary recall) and serum carotenoid concentrations. Nutrient timing was obtained from 4-day food logs.

RESULTS

Among 2914 total participants, lower body mass index was associated with less tiredness and more energy at baseline (P < .001 for both). Earlier start and end times for daily eating windows were associated with less tiredness (P = .014 and P = .027, respectively) and greater energy (P = .006 and P = .102, respectively). The intervention did not lead to improvements in fatigue on average (P > .125). However, the intervention was more effective for participants who were younger, had fewer comorbidities, and did not have radiation treatment. Mediators included increases in serum carotenoids, increases in the modified Healthy Eating Index, and weight loss/maintenance.

CONCLUSION

Diet quality and earlier eating windows were associated with less fatigue.

IMPLICATIONS FOR PRACTICE

Programs that encourage high diet quality and a morning meal and discourage nighttime eating should be tested for efficacy in reducing cancer-related fatigue in survivorship.

Association Between Physical Activity, Sedentary Behaviors, and Sleep-Related Outcomes Among Cancer Survivors: a Cross-Sectional Study

BACKGROUND

Limited research has examined the association between moderate to vigorous physical activity (MVPA), sedentary behavior (SB), and sleep-related outcomes in cancer survivors. Therefore, this study aimed to examine these associations using a nationally representative sample of US adults.

METHODS

Data from the 2005-2018 National Health and Nutrition Examination Survey (NHANES) were analyzed. A total of 3229 adults with cancer histories were included. Physical activity was measured through accelerometry, and questions on daily activities, sedentary time, and sleep were collected during the household interview. Weighted multivariable analyses were conducted after accounting for the complex sampling design of the NHANES dataset.

RESULTS

After adjustments, physical activity and SB outcomes were associated with several self-reported sleep-related parameters. Increases in minutes of self-reported MVPA and SB were associated with a decreased likelihood of reporting ≥ 8 h of sleep (OR = 0.92, 95% CI = 0.86, 0.99 and OR = 0.88, 95% CI = 0.82, 0.95). Converse associations were found between device-measured MVPA and SB with the likelihood of reporting often/always feeling overly sleepy during the day (OR = 0.86, 95% CI = 0.75 and OR = 1.13, 95% CI = 1.05, respectively). However, an increased likelihood of waking up too early in the morning (OR = 1.22, 95% CI = 1.04) was observed with increases in minutes of device-measured MVPA.

CONCLUSIONS

A sensible strategy to decrease the frequency of sedentary breaks and increase minutes of physical activity throughout the day may reduce sleep complaints reported in cancer survivors.

Stress, Isolation, and Sleep Quality among Breast Cancer Survivors throughout the COVID-19 Pandemic: A Longitudinal Study in a Multi-Ethnic Cohort

Purpose

This study examined how stress, isolation, and sleep quality were impacted throughout the COVID-19 pandemic among breast cancer survivors (BCS).

Methods

BCS enrolled in the Chicago Multiethnic Epidemiologic Breast Cancer Cohort were surveyed in 2020, 2021, and 2022. An 11-item isolation/stress score was repeatedly measured in each survey and its changes were examined through mixed-effects models. Sleep quality was assessed in 2022 by the Insomnia Severity Index (ISI).

Results

In total, 1899 BCS responded (response rate: 62.8%), of whom 69% were White and 24% Black (median time since diagnosis: 5.1 years, IQR: 2.3-9.2). The isolation/stress score decreased significantly from 2020 to 2022 for White BCS, but only started declining for Black BCS in 2022. Consequently, although there were no significant racial difference in 2020, Black BCS had significantly higher isolation/stress scores in 2021 and 2022 (P < .01), while it became nonsignificant after adjusting for socioeconomic factors. BCS who were single, on Medicaid, without a high school degree, or with annual household income <$35,000 had significantly higher isolation/stress scores. Regarding sleep quality, 48% of BCS reported clinically-significant insomnia (ISI ≥ 8), and insomnia was strongly associated with higher isolation/stress scores (P-trend < .001).

Conclusions

Our findings suggested that the isolation/stress level improved among BCS as the pandemic subsided, but this positive trend was not observed equally across racial/ethnic groups potentially due to lack of resources.

Implications for Cancer Survivors

Additional resources, such as access to counseling services and sleep assistance programs, might support the post-pandemic recovery of undersevered BCS.

Intermittent fasting interventions to leverage metabolic and circadian mechanisms for cancer treatment and supportive care outcomes

Intermittent fasting entails restricting food intake during specific times of day, days of the week, religious practice, or surrounding clinically important events. Herein, the metabolic and circadian rhythm mechanisms underlying the proposed benefits of intermittent fasting for the cancer population are described. We summarize epidemiological, preclinical, and clinical studies in cancer published between January 2020 and August 2022 and propose avenues for future research. An outstanding concern regarding the use of intermittent fasting among cancer patients is that fasting often results in caloric restriction, which can put patients already prone to malnutrition, cachexia, or sarcopenia at risk. Although clinical trials do not yet provide sufficient data to support the general use of intermittent fasting in clinical practice, this summary may be useful for patients, caregivers, and clinicians who are exploring intermittent fasting as part of their cancer journey for clinical outcomes and symptom management.

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

PURPOSE

Circadian rhythm disruptors (e.g., night-shift work) are risk factors for breast cancer, however studies on their association with prognosis is limited. A small but growing body of research suggests that altered sleep patterns and eating behaviours are potential mechanistic links between circadian rhythm disruptors and breast cancer. We therefore systematically summarised literature examining the influence of circadian rhythm disrupting behaviours on cancer outcomes in women with breast cancer.

METHODS

A systematic search of five databases from inception to January 2021 was conducted. Original research published in English, assessing the relationship between post-diagnosis sleep patters and eating behaviours, and breast cancer outcomes were considered. Risk of bias was assessed using the Newcastle-Ottawa Assessment Scale for Cohort Studies.

RESULTS

Eight studies published original evidence addressing sleep duration and/or quality (k = 7) and, eating time and frequency (k = 1). Longer sleep duration (≥ 9 h versus [referent range] 6-8 h) was consistently associated with increased risk of all outcomes of interest (HR range: 1.37-2.33). There was limited evidence to suggest that measures of better sleep quality are associated with lower risk of all-cause mortality (HR range: 0.29-0.97). Shorter nightly fasting duration (< 13 h versus ≥ 13 h) was associated with higher risk of all breast cancer outcomes (HR range: 1.21-1.36).

CONCLUSION

Our review suggests that circadian rhythm disrupting behaviours may influence cancer outcomes in women with breast cancer. While causality remains unclear, to further understand these associations future research directions have been identified. Additional well-designed studies, examining other exposures (e.g., light exposure, temporal eating patterns), biomarkers, and patient-reported outcomes, in diverse populations (e.g., breast cancer subtype-specific, socio-demographic diversity) are warranted.

Course of objectively measured physical activity and sleep in postmenopausal breast cancer survivors during the COVID-19 pandemic: A 1-year follow-up

BACKGROUND

As physical inactivity and poor sleep quality may impose additional risk for cancer recurrence and overall mortality in postmenopausal breast cancer (PMBC) survivors, it is important to gain insight into the effect of the COVID-19 pandemic on their physical activity (PA) and sleep level.

OBJECTIVE

This study aimed to assess the course of their physical activity (PA) and sleep throughout governmental measures against COVID-19 during 12 months of the COVID-19 pandemic.

METHODS

PMBC survivors (n = 96) wore an ActiGraph wGT3X-BT for seven consecutive days at 12 and 18 months after diagnosis and additional measurements were taken after onset of the second (partial) COVID-19 lockdown. Longitudinal data was categorized into four timepoints: before onset of COVID-19 (T1), during the initial lockdown (T2), in between initial and second lockdown (T3), and during the second lockdown (T4). General linear mixed effects models assessed differences in moderate-to-vigorous physical activity (MVPA) per day, total minutes of PA per day, average acceleration, intensity gradient, sleep efficiency, and sleep duration over time.

RESULTS

Levels of MVPA per day before COVID-19 were low (Median = 20.9 min/day (IQR = 10.8;36.2)), and time spent physically active was most often in light intensity, which remained stable throughout the pandemic. Sleep duration (Median = 442.8 min/night (IQR = 418.3;478.0)) and efficiency (85.9% (IQR = 79.6;88.4)) was sufficient before COVID-19 and showed stability over time.

CONCLUSIONS

Low levels of PA with mostly light intensity, and adequate sleep efficiency and duration were observed before COVID in PMBC survivors. This was not further affected by COVID-19 governmental measures.

Pre-Diagnosis Sleep Status and Survival after a Diagnosis of Ovarian Cancer: A Prospective Cohort Study

Objective: To explore if pre-diagnosis sleep status is associated with overall survival (OS) of ovarian cancer (OC). Methods: This is a prospective cohort study of 853 OC patients newly diagnosed between 2015 and 2020. Sleep status was measured by the Pittsburgh Sleep Quality Index (PSQI). Vital status of patients was obtained through active follow-up and linkage to medical records and cancer registry. The Cox proportional hazards regression model was utilized to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for aforementioned associations. Results: During the follow-up period (median: 37.57 months, interquartile: 25.00 to 50.17 months), 123 (18.39%) OC patients died. The HR (95%CI) for OS of OC was 2.13 (1.42−3.18) for sleeping after 22:00, compared with sleeping before 22:00; 2.43 (1.64−3.62) for poor sleep quality, compared to good sleep quality; 2.26 (1.37−3.72) for late bed-early rise and 1.93 (1.09−3.42) for late bed-late rise, compared with early bed-early rise; 0.40 (0.24−0.67) for night sleep duration of ≥7.5 h/day, compared with 7−7.5 h/day; 0.53 (0.29−0.98) for total sleep duration of ≥8 h/day, compared with 7.5−8 h/day. Further, the interaction effects were significant between residual lesions and wake-up time, night bedtime, sleep pattern, and between total sleep duration and menopausal status, parity. Additionally, there was a significant curvilinear association between PSQI score and OS (p nonlinear <0.05). Conclusions: Pre-diagnosis longer total and night sleep duration were associated with better OS, whereas later sleeping time, poor sleep quality, and bad sleep patterns were associated with poor OS among OC survivors.

Sleep During Oncological Treatment – A Systematic Review and Meta-Analysis of Associations With Treatment Response, Time to Progression and Survival

Introduction

Disrupted sleep and sleep-wake activity are frequently observed in cancer patients undergoing oncological treatment. These disruptions are often associated with aggravated symptom burden and diminished health-related quality of life that in turn may compromise treatment adherence and, thus, effectiveness. In addition, disrupted sleep has been linked to carcinogenic processes, which ultimately could result in worse prognostic outcomes.

Aims

Our aim was to systematically review and conduct a meta-analysis of studies examining the associations between sleep and sleep-wake activity and prognostic outcomes in cancer patients undergoing oncological treatment.

Methods

A comprehensive systematic search of English language papers was undertaken in June 2020 using PubMed, The Cochrane Library, and CINAHL. Two reviewers independently screened 4,879 abstracts. A total of 26 papers were included in the narrative review. Thirteen papers reporting hazard ratios reflecting associations between a dichotomized predictor variable (sleep) and prognostic outcomes were subjected to meta-analysis.

Results

Nineteen of the 26 eligible studies on a total of 7,092 cancer patients reported associations between poorer sleep and poorer response to treatment, shorter time to progression, and/or reduced overall survival, but were highly heterogeneous with respect to the sleep and outcome parameters investigated. Meta-analysis revealed statistically significant associations between poor self-reported sleep and reduced overall survival (HR = 1.33 [95% CI 1.09–1.62], k = 11), and shorter time to progression (HR = 1.40 [95% CI 1.23–1.59], k = 3) and between poor objectively assessed sleep and reduced overall survival (HR = 1.74 [95% CI 1.05–2.88], k = 4).

Conclusion

The current findings indicate that disturbed sleep during treatment may be a relevant behavioral marker of poor cancer prognosis. The limited number of studies, the common use of single item sleep measures, and potential publication bias highlight the need for further high quality and longitudinal studies.

Association between Pre-Existing Sleep Disorders and Survival Rates of Patients with Breast Cancer

PURPOSE: To investigate the effects of pre-existing sleep disorders on the survival outcomes of women receiving standard treatments for breast invasive ductal carcinoma (IDC). METHODS: We recruited patients from the Taiwan Cancer Registry Database who had received surgery for clinical stage I–III breast IDC. The Cox proportional hazards model was used to analyze all-cause mortality. We categorized the patients into those with and without sleep disorders (Groups 1 and 2, respectively) through propensity score matching. RESULTS: In the multivariate Cox regression analysis, the adjusted hazard ratio for all-cause mortality for Group 1 compared with Group 2 was 1.51 (95% confidence interval: 1.19, 1.91; p < 0.001). CONCLUSION: Our study demonstrated that the sleep disorder group had poorer survival rates than the non-sleep disorder group in breast cancer. Therefore, patients should be screened and evaluated for pre-existing sleep disorders prior to breast surgery, with such disorders serving as a predictor of survival in patients with breast cancer. Future studies may investigate the survival benefits of pharmacological and behavioral treatments for sleep problems in patients with breast cancer.

Sleep Quality and Related Factors in Patients with Breast Cancer: A Cross-Sectional Study in Taiwan

Background

Sleep disturbances are common and symptomatic burden in patients with breast cancer, but they are poorly documented and managed in routine clinical practice. This descriptive and cross-sectional study evaluated factors associated with post-treatment sleep disturbances in patients with breast cancer.

Patients and Methods

Patients with breast cancer who underwent standard treatment were enrolled and surveyed for their basic demographic data and precancerous and cancer treatment-related factors; they were also administered self-report questionnaires including the Family Adaptation, Partnership, Growth, Affection, Resolve questionnaire; Impact of Event Scale; Center for Epidemiologic Studies Depression Scale; and Maudsley Personality Inventory. Their sleep disturbances were evaluated using the Pittsburgh sleep quality index (PSQI). Independent sample t test and chi-square tests were used to compare the variables between patients with or without sleep disturbance, and multivariate logistic regression analyses were conducted to detect the independent factors.

Results

In total, 448 patients, including 145 with PSQI ≤ 5 and 303 with PSQI > 5, completed the investigation. Multiple logistic regression analysis revealed that significantly more patients with sleep disturbances demonstrated psychological distress, severe pain, depression, and impact of stress events than patients without sleep disturbances (adjusted odds ratios [95% confidence intervals]: 2.83 [1.135–7.067], P = 0.026; 1.14 [1.023–1.280], P = 0.018; 1.08 [1.036–1.133], P < 0.001; and 1.03 [1.002–1.051], P = 0.037, respectively).

Conclusion

Patients with breast cancer showed 67.6% prevalence of sleep disturbances after treatment. The patients with sleep disturbances were more likely to have previously experienced psychological disturbances, severe pain, depression within 5 years after diagnosis. After diagnosis for more than 5 years, higher distress caused by traumatic events still associated with sleep disturbances.

Comparisons of MicroRNA Set Enrichment Analysis Tools on Cancer De-regulated miRNAs from TCGA Expression Datasets

Background:

De-regulation of microRNAs (miRNAs) is closely related to many complex diseases, including cancers. In The Cancer Genome Atlas (TCGA), hundreds of differentially expressed miRNAs are stored for each type of cancer, which are hard to be intuitively interpreted. To date, several miRNA set enrichment tools have been tailored to predict the potential disease associations and functions of de-regulated miRNAs, including the miRNA Enrichment Analysis and Annotation tool (miEAA) and Tool for Annotations of human MiRNAs (TAM1.0 &TAM 2.0). However, independent benchmarking of these tools is warranted to assess their effectiveness and robustness, and the relationship between enrichment analysis results and the prognosis significance of cancers.

Methods:

Based on differentially expressed miRNAs from expression profiles in TCGA, we performed a series of tests and a comprehensive comparison of the enrichment analysis results of miEAA, TAM 1.0 and TAM 2.0. The work focused on the performance of the three tools, disease similarity based on miRNA-disease associations from the enrichment analysis results, the relationship between the overrepresented miRNAs from enrichment analysis results and the prognosis significance of cancers.

Results:

The main results show that TAM 2.0 is more likely to identify the regulatory disease’s functions of de-regulated miRNA; it is feasible to calculate disease similarity based on enrichment analysis results of TAM 2.0; and there is weak positive correlation between the occurrence frequency of miRNAs in the TAM 2.0 enrichment analysis results and the prognosis significance of the cancer miRNAs.

Conclusion:

Our comparison results not only provide a reference for biomedical researchers to choose appropriate miRNA set enrichment analysis tools to achieve their purpose but also demonstrate that the degree of overrepresentation of miRNAs could be a supplementary indicator of the disease similarity and the prognostic effect of cancer miRNAs.

Accelerated aging in breast cancer survivors and its association with mortality and cancer recurrence

PURPOSE

To prospectively investigate accelerated aging and its association with total mortality and breast cancer-specific mortality/recurrence among breast cancer survivors.

METHODS

This study included 4218 female breast cancer patients enrolled into a population-based cohort study approximately 6-month post-diagnosis. Information on aging-related symptoms (i.e., self-rated overall health condition, energy level, depression, sleep difficulty, and quality) was collected at 18- and 36-month post-diagnosis surveys. Information on overall health, daily function impairments, survival status, and recurrence was collected at 10-year post-diagnosis survey. Record linkages with vital statistics were conducted to collect mortality information. Cox proportional hazards model was applied.

RESULTS

Among 3041 10-year survivors with a mean age of 63.7 ± 9.7 years, respectively, 52.3%, 19.0%, and 27.6% reported poor health, limitation in daily activity, and climbing floors. Age-specific prevalence revealed that breast cancer survivors reached similar prevalence of the functional limitations 5-10 years earlier than cancer-free women. At the 18-month post-diagnosis survey, respectively, 47.0%, 72.5%, and 25.1% of survivors reported unsatisfied overall health condition, reduced energy level, and depression symptoms. After a median follow-up of 10.9 years, low self-rated overall health, low energy level, and depression were significantly associated with increased total mortality, with hazard ratios (HRs; 95% confidence intervals [CI]) of 3.14 (2.43, 4.06), 1.49 (1.20, 1.84), and 1.59 (1.21, 2.09), respectively. Low self-rated health was associated with breast cancer-specific mortality/recurrence (HR  1.85, 95% CI 1.30, 2.65). No significant association was found for sleep difficulty and quality.

CONCLUSION

Aging-related physical changes/symptoms are commonly presented at 18 months after breast cancer diagnosis and are associated with worse prognosis.

IMPACT

Our findings highlight the concern of accelerated aging among breast cancer survivors.

Epidemiological characteristics of and risk factors for breast cancer in the world

AIM

Breast cancer is the most common cancer among women and one of the most important causes of death among them. This review aimed to investigate the incidence and mortality rates of breast cancer and to identify the risk factors for breast cancer in the world.

MATERIALS AND METHODS

A search was performed in PubMed, Web of Science, and Scopus databases without any time restrictions. The search keywords included the following terms: breast cancer, risk factors, incidence, and mortality and a combination of these terms. Studies published in English that referred to various aspects of breast cancer including epidemiology and risk factors were included in the study. Overall, 142 articles published in English were included in the study.

RESULTS

Based on the published studies, the incidence rate of breast cancer varies greatly with race and ethnicity and is higher in developed countries. Results of this study show that mortality rate of breast cancer is higher in less developed regions. The findings of this study demonstrated that various risk factors including demographic, reproductive, hormonal, hereditary, breast related, and lifestyle contribute to the incidence of breast cancer.

CONCLUSION

The results of this study indicated that incidence and mortality rates of breast cancer is rising, so design and implementation of screening programs and the control of risk factors seem essential.

Habitual Meat Consumption and Changes in Sleep Duration and Quality in Older Adults

Dietary proteins are sources of some amino acid precursors of two neurotransmitters relevant for biological rhythms, serotonin and melatonin, which are involved in sleep and alertness. Meat is the main source of proteins in many countries. Furthermore, meat consumption is of special interest because it provides high-quality protein as well as saturated and trans fatty acids. However, its effect on sleep patterns is unclear. Thereby, the aim was to examine the association of habitual meat consumption with changes in sleep duration and with sleep quality in older adults. We used data from 1,341 participants in the Seniors-ENRICA cohort aged ≥60 years, followed from 2012 through 2015. Habitual meat consumption was assessed at baseline with a validated diet history. Sleep duration and quality were ascertained both in 2012 and 2015. Analyses were performed with logistic regression and adjusted for socio-demographic variables, lifestyle, morbidity, sleep duration and poor sleep indicators at baseline. During follow-up, 9.0% of individuals increased and 7.9% decreased their sleep duration by ≥2 hours/night. Compared with individuals in the lowest tertile of meat consumption (<87 g/d), those in the highest tertile (≥128 g/d) showed increased incidence of a large decrease (≥2 h) in sleep duration (OR: 1.93; 95% CI:1.01-3.72; p-trend:0.04). Higher consumption of meat was also associated with incidence of snoring (OR:2.06; 95% CI:1.17-3.60; p-trend:0.01) and poor general sleep quality (OR:1.71; 95% CI:1.04-2.82; p-trend:0.03). Each 100 g/d increment in meat intake was associated with a 60% higher risk of both large sleep duration changes and poor sleep quality (OR:1.60; 95% CI:1.07-2.40). Results were in the same direction for red and processed meat and for white meat separately, and among individuals with physical impairment. Higher meat consumption (≥128 g/d) was associated with changes in sleep duration and with poor sleep in older adults.

The association between sleep duration and cancer-specific mortality: a systematic review and meta-analysis

PURPOSE

In this systematic review and meta-analysis, we aimed to estimate cancer-specific mortality and all-cause mortality among cancer survivors associated with both short (typically 5 or 6 h/night) and long (typically 9 or 10 h/night) sleep duration (versus recommendations), separately by sex, cancer site, and sampling frame.

METHODS

We completed a systematic literature search in five databases and captured relevant literature published through December 2018. Two reviewers independently screened 9,823 records and 32 studies were included representing over 73,000 deaths in cancer survivors. Estimates for short and long sleep duration compared to 'recommended' were pooled using random-effects models.

RESULTS

Pooled hazards ratios for short and long sleep duration for all-cancer-specific mortality were 1.03 (95% CI 1.00-1.06) and 1.09 (95% CI 1.04-1.13), respectively. In subgroup analyses by cancer site, statistically significant increased risks were found for both short and long sleep durations for lung cancer-specific mortality. These associations were maintained when stratified by sex and sampling frame. There were no statistically significant associations found between either short or long sleep duration and breast, colorectal, ovarian, or prostate cancer-specific mortality. Statistically significant increases in all-cause mortality were observed with long sleep duration in breast cancer survivors (1.38; 95% CI 1.16-1.64) with no significant associations found for colorectal or liver/pancreatic cancers.

CONCLUSIONS

We observed that long sleep duration increases cancer-specific mortality for all-cancers and lung cancers, while all-cause mortality is increased for breast cancer survivors. Limitations were found within the existing literature that need to be addressed in future studies in order to improve the understanding regarding the exact magnitude of the effect between sleep duration and site-specific mortality.

Joint effects of multiple sleep characteristics on breast cancer progression by menopausal status

OBJECTIVES

Sleep has been closely linked to breast cancer risk. However, the association between sleep and breast cancer prognosis remains unclear. The aim of this study was to evaluate the separate and joint effects of multiple sleep characteristics on breast cancer prognosis among Chinese women.

METHODS

A total of 1580 breast cancer patients were recruited between October 2008 and December 2014 and followed up until December 31, 2017 in Guangzhou. Multivariate Cox models were conducted to estimate the hazard ratios (HR) and 95% confidence intervals (95%CI) for breast cancer prognosis in association with sleep characteristics.

RESULTS

Long sleep duration at night (>9 h) (HR = 2.33, 95%CI: 1.01-5.42), poor sleep quality (HR = 3.08, 95%CI: 1.74-5.47), and impaired daytime function (HR = 2.49, 95%CI: 1.65-3.79) after diagnosis were associated with an increased risk of breast cancer progression. Both short sleep duration (<6 h) (HR = 2.00, 95%CI: 1.06-3.77, P_interaction = 0.011) and long sleep duration (>9 h) (HR = 4.69, 95%CI: 1.31-16.78, P_interaction = 0.187) increased the progression risk only among patients with impaired but not normal daytime function. In addition, daytime napping significantly modified the effect of short sleep duration on the progression (HR = 3.55, 0.59, 95%CI: 1.55-7.97, 0.23-1.53 for patients without and with daytime napping, respectively, P_interaction = 0.005). Stratification results suggested that the associations were more evident among pre-menopausal patients, although no significant interaction was observed.

CONCLUSION

Our findings suggested that inadequate sleep duration to feel one's best and poor sleep quality after diagnosis were associated with an increased risk of breast cancer progression, particularly for pre-menopausal women.

Internet-Delivered Cognitive-Behavioral Therapy for Insomnia in Breast Cancer Survivors: A Randomized Controlled Trial

Background

Insomnia is two to three times more prevalent in cancer survivors than in the general population, where it is estimated to be 10% to 20%. Cognitive-behavioral therapy for insomnia (CBT-I) is the recommended treatment for chronic insomnia, but meeting survivor needs remains a challenge. Internet-delivered CBT-I (iCBT-I) has been shown efficacious in otherwise healthy adults. We tested the efficacy of iCBT-I in breast cancer survivors with clinically significant sleep disturbance.

Methods

Women from a national sample of Danish breast cancer survivors who experienced clinically significant sleep disturbance were randomly allocated to iCBT-I or waitlist control (55:45). The fully automated iCBT-I program consisted of six cores. Online measures of insomnia severity, sleep quality, and fatigue were collected at baseline, postintervention (nine weeks), and follow-up (15 weeks). Online sleep diaries were completed over two-week periods pre- and postintervention. Intention-to-treat analyses (time × group interactions) were conducted with mixed linear models and corrected for multiple outcomes. All statistical tests were two-sided.

Results

A total of 255 women were randomly allocated to iCBT-I (n = 133) or waitlist control (n = 122). Statistically significant (P ≤ .02) time × group interactions were found for all sleep-related outcomes from pre- to postintervention. Effect sizes (Cohen's d) ranged from 0.33 (95% confidence interval [CI] = 0.06 to 0.61) for wake after sleep onset to 1.17 (95% CI = 0.87 to 1.47) for insomnia severity. Improvements were maintained for outcomes measured at follow-up (d = 0.66-1.10).

Conclusions

iCBT-I appears to be effective in breast cancer survivors, with additional benefit in terms of reduced fatigue. This low-cost treatment could be incorporated in cancer rehabilitation programs.