The association between sleep duration and prostate cancer: A systematic review and meta-analysis

Prostate Cancer: Emerging Modifiable Risk Factors and Therapeutic Strategies in the Management of Advanced Cancer

Prostate cancer (PCa) is the third highest cause of cancer death in men. PCa is a very heterogeneous tumor form in terms of grade, phenotypes, and genetics, often accompanied by complex networks. PCa is characterized by slow growth that does not compromise the patient's quality of life, unlike more aggressive forms showing rapid growth and progression. Early diagnosis, even for the most aggressive forms, increases the possibilities of cure with less aggressive treatments and fewer side effects. However, it is important to know how to decrease the exposure to modifiable risk factors, including diet, sedentary life, smoking and alcohol, can represent an effective tool to reduce the incidence of PCa. In addition, the chronic exposure to environmental factors, most of which act as endocrine disruptors, is the focus of recent studies for their potential role in promoting the onset and progression of PCa. Although molecular therapies and clinical trials for biomarker identification have been introduced into the management of PCa, these still lag behind research performed in other solid tumors. This review provides an overview of the modifiable factors of PCa, linked to lifestyle and environmental pollutants, which together with the development of new therapeutic targets, can reduce the incidence of PCa and improve the quality of life of patients.

Actigraphy-derived measures of sleep and risk of prostate cancer in the UK Biobank

BACKGROUND

Studies of sleep and prostate cancer are almost entirely based on self-report, with limited research using actigraphy. Our goal was to evaluate actigraphy-measured sleep and prostate cancer and to expand on findings from prior studies of self-reported sleep.

METHODS

We prospectively examined 34 260 men without a history of prostate cancer in the UK Biobank. Sleep characteristics were measured over 7 days using actigraphy. We calculated sleep duration, onset, midpoint, wake-up time, social jetlag (difference in weekend-weekday sleep midpoints), sleep efficiency (percentage of time spent asleep between onset and wake-up time), and wakefulness after sleep onset. Cox proportional hazards models were used to estimate covariate-adjusted hazards ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

Over 7.6 years, 1152 men were diagnosed with prostate cancer. Sleep duration was not associated with prostate cancer risk. Sleep midpoint earlier than 4:00 am was not associated with prostate cancer risk, though sleep midpoint of 5:00 am or later was suggestively associated with lower prostate cancer risk but had limited precision (earlier than 4:00 am vs 4:00-4:59 am HR = 1.00, 95% CI = 0.87 to 1.16; 5:00 am or later vs 4:00-4:59 am HR = 0.79, 95% CI = 0.57 to 1.10). Social jetlag was not associated with greater prostate cancer risk (1 to <2 hours vs <1 hour HR = 1.06, 95% CI = 0.89 to 1.25; ≥2 hours vs <1 hour HR = 0.90, 95% CI = 0.65 to 1.26). Compared with men who averaged less than 30 minutes of wakefulness after sleep onset per day, men with 60 minutes or more had a higher risk of prostate cancer (HR = 1.20, 95% CI = 1.00 to 1.43).

CONCLUSIONS

Of the sleep characteristics studied, higher wakefulness after sleep onset-a measure of poor sleep quality-was associated with greater prostate cancer risk. Replication of our findings between wakefulness after sleep onset and prostate cancer are warranted.

Risk factors for prostate cancer: An umbrella review of prospective observational studies and mendelian randomization analyses

BACKGROUND

The incidence of prostate cancer is increasing in older males globally. Age, ethnicity, and family history are identified as the well-known risk factors for prostate cancer, but few modifiable factors have been firmly established. The objective of this study was to identify and evaluate various factors modifying the risk of prostate cancer reported in meta-analyses of prospective observational studies and mendelian randomization (MR) analyses.

METHODS AND FINDINGS

We searched PubMed, Embase, and Web of Science from the inception to January 10, 2022, updated on September 9, 2023, to identify meta-analyses and MR studies on prostate cancer. Eligibility criteria for meta-analyses were (1) meta-analyses including prospective observational studies or studies that declared outcome-free at baseline; (2) evaluating the factors of any category associated with prostate cancer incidence; and (3) providing effect estimates for further data synthesis. Similar criteria were applied to MR studies. Meta-analysis was repeated using the random-effects inverse-variance model with DerSimonian-Laird method. Quality assessment was then conducted for included meta-analyses using AMSTAR-2 tool and for MR studies using STROBE-MR and assumption evaluation. Subsequent evidence grading criteria for significant associations in meta-analyses contained sample size, P values and 95% confidence intervals, 95% prediction intervals, heterogeneity, and publication bias, assigning 4 evidence grades (convincing, highly suggestive, suggestive, or weak). Significant associations in MR studies were graded as robust, probable, suggestive, or insufficient considering P values and concordance of effect directions. Finally, 92 selected from 411 meta-analyses and 64 selected from 118 MR studies were included after excluding the overlapping and outdated studies which were published earlier and contained fewer participants or fewer instrument variables for the same exposure. In total, 123 observational associations (45 significant and 78 null) and 145 causal associations (55 significant and 90 null) were categorized into lifestyle; diet and nutrition; anthropometric indices; biomarkers; clinical variables, diseases, and treatments; and environmental factors. Concerning evidence grading on significant associations, there were 5 highly suggestive, 36 suggestive, and 4 weak associations in meta-analyses, and 10 robust, 24 probable, 4 suggestive, and 17 insufficient causal associations in MR studies. Twenty-six overlapping factors between meta-analyses and MR studies were identified, with consistent significant effects found for physical activity (PA) (occupational PA in meta: OR = 0.87, 95% CI: 0.80, 0.94; accelerator-measured PA in MR: OR = 0.49, 95% CI: 0.33, 0.72), height (meta: OR = 1.09, 95% CI: 1.06, 1.12; MR: OR = 1.07, 95% CI: 1.01, 1.15, for aggressive prostate cancer), and smoking (current smoking in meta: OR = 0.74, 95% CI: 0.68, 0.80; smoking initiation in MR: OR = 0.91, 95% CI: 0.86, 0.97). Methodological limitation is that the evidence grading criteria could be expanded by considering more indices.

CONCLUSIONS

In this large-scale study, we summarized the associations of various factors with prostate cancer risk and provided comparisons between observational associations by meta-analysis and genetically estimated causality by MR analyses. In the absence of convincing overlapping evidence based on the existing literature, no robust associations were identified, but some effects were observed for height, physical activity, and smoking.

Sleep disorders and cancer incidence: examining duration and severity of diagnosis among veterans

Introduction

Sleep disruption affects biological processes that facilitate carcinogenesis. This retrospective cohort study used de-identified data from the Veterans Administration (VA) electronic medical record system to test the hypothesis that patients with diagnosed sleep disorders had an increased risk of prostate, breast, colorectal, or other cancers (1999-2010, N=663,869). This study builds upon existing evidence by examining whether patients with more severe or longer-duration diagnoses were at a greater risk of these cancers relative to those with a less severe or shorter duration sleep disorder.

Methods

Incident cancer cases were identified in the VA Tumor Registry and sleep disorders were defined by International Classification of Sleep Disorder codes. Analyses were performed using extended Cox regression with sleep disorder diagnosis as a time-varying covariate.

Results

Sleep disorders were present among 56,055 eligible patients (8% of the study population); sleep apnea (46%) and insomnia (40%) were the most common diagnoses. There were 18,181 cancer diagnoses (41% prostate, 12% colorectal, 1% female breast, 46% other). The hazard ratio (HR) for a cancer diagnosis was 1.45 (95% confidence interval [CI]: 1.37, 1.54) among those with any sleep disorder, after adjustment for age, sex, state of residence, and marital status. Risks increased with increasing sleep disorder duration (short [<1-2 years] HR: 1.04 [CI: 1.03-1.06], medium [>2-5 years] 1.23 [1.16-1.32]; long [>5-12 years] 1.52 [1.34-1.73]). Risks also increased with increasing sleep disorder severity using cumulative sleep disorder treatments as a surrogate exposure; African Americans with more severe disorders had greater risks relative to those with fewer treatments and other race groups. Results among patients with only sleep apnea, insomnia, or another sleep disorder were similar to those for all sleep disorders combined.

Discussion

The findings are consistent with other studies indicating that sleep disruption is a cancer risk factor. Optimal sleep and appropriate sleep disorder management are modifiable risk factors that may facilitate cancer prevention.

2022 Update on Prostate Cancer Epidemiology and Risk Factors-A Systematic Review

CONTEXT

Prostate cancer (PCa) is one of the most common cancers worldwide. Understanding the epidemiology and risk factors of the disease is paramount to improve primary and secondary prevention strategies.

OBJECTIVE

To systematically review and summarize the current evidence on the descriptive epidemiology, large screening studies, diagnostic techniques, and risk factors of PCa.

EVIDENCE ACQUISITION

PCa incidence and mortality rates for 2020 were obtained from the GLOBOCAN database of the International Agency for Research on Cancer. A systematic search was performed in July 2022 using PubMed/MEDLINE and EMBASE biomedical databases. The review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines and was registered in PROSPERO (CRD42022359728).

EVIDENCE SYNTHESIS

Globally, PCa is the second most common cancer, with the highest incidence in North and South America, Europe, Australia, and the Caribbean. Risk factors include age, family history, and genetic predisposition. Additional factors may include smoking, diet, physical activity, specific medications, and occupational factors. As PCa screening has become more accepted, newer approaches such as magnetic resonance imaging (MRI) and biomarkers have been implemented to identify patients who are likely to harbor significant tumors. Limitations of this review include the evidence being derived from meta-analyses of mostly retrospective studies.

CONCLUSIONS

PCa remains the second most common cancer among men worldwide. PCa screening is gaining acceptance and will likely reduce PCa mortality at the cost of overdiagnosis and overtreatment. Increasing use of MRI and biomarkers for the detection of PCa may mitigate some of the negative consequences of screening.

PATIENT SUMMARY

Prostate cancer (PCa) remains the second most common cancer among men, and screening for PCa is likely to increase in the future. Improved diagnostic techniques can help reduce the number of men who need to be diagnosed and treated to save one life. Avoidable risk factors for PCa may include factors such as smoking, diet, physical activity, specific medications, and certain occupations.

Sleep and breast and prostate cancer risk in the MCC-Spain study

Breast and prostate cancers have been associated with circadian disruption. Some previous studies examined associations of sleep duration and breast or prostate cancer risk though findings remain inconsistent. This study examines associations of a range of detailed sleep characteristics and breast and prostate cancer risk in a large-scale population-based case-control study, MCC-Spain. A total of 1738 incident breast cancer cases, 1112 prostate cancer cases and frequency matched controls (n = 1910, and 1493 respectively) were recruited. Detailed data on habitual sleep duration, quality, timing, and daytime napping ("siesta") were collected at recruitment. Additional data on sleep habits during both the previous year and at age 40 years were also subsequently captured. Adjusted odds ratios (ORs) and 95% confidence intervals (CI) were estimated. There were no associations of habitual sleep duration (h), timing of sleep, or any or specific sleep problems, and either breast and prostate cancer risk. There was a significant positive association of ever taking habitual siestas at recruitment and breast cancer risk (OR = 1.22, 95% CI 1.06-1.42), which strengthened with increased frequency or duration. There were also significant positive associations observed for both breast and prostate cancer, among those reporting recent sleep problems, but not sleep problems at age 40 years, in a subsequent circadian questionnaire. Adverse associations with siesta and disturbed sleep during the previous year likely reflect symptoms of developing/diagnosed cancer and comorbidities. Overall, there was no clear association between various sleep characteristics and breast or prostate cancer risk observed.

Sleep Characteristics and Cancer-Related Outcomes: An Umbrella Review of Systematic Reviews and Meta-Analyses of Observational Studies

BACKGROUND

Sleep is closely related to various diseases. Several meta-analyses have provided evidence of sleep and cancer, and yet the credibility of this evidence has not been comprehensively quantified. Thus, we conducted an umbrella review to quantify the evidence for systematic reviews and meta-analyses of observational studies on sleep characteristics (sleep duration, sleep quality, napping, bedtime, and wake-up time) and cancer-related outcomes.

METHODS

PubMed, Web of Science (Core Collection), and Embase databases were searched from inception until 29 July 2022. Assessment of Multiple Systematic Reviews, version 1, was used to evaluate the methodological quality of each eligible systematic review or meta-analysis. For each association, the summary effect with a 95% confidence interval was evaluated by fixed and random effects models. The 95% prediction interval, heterogeneity, small-study effects, and excess significance bias were also evaluated. Evidence of the associations from systematic reviews and meta-analyses was ranked based on the established criteria of published literature as convincing, highly suggestive, suggestive, weak, or non-significant.

RESULTS

The umbrella review identified thirty meta-analyses on the aforementioned associations from six articles. The methodological quality of five articles was high or moderate. Suggestive evidence was found for associations between long sleep duration and a 21% increased risk of colorectal cancer, a 9% increased all-cancer mortality and a 65% increased mortality of lung cancer, and associations between short sleep duration and a 21% increased mortality of lung cancer. Additionally, the evidence of associations between short sleep duration and lung cancer mortality was upgraded to convincing, and between long sleep duration and lung cancer mortality was upgraded to highly suggestive, among the population reporting 24 h sleep duration.

CONCLUSION

Abnormal sleep duration might be linked to several adverse cancer-related outcomes.

Systematic review of sleep and sleep disorders among prostate cancer patients and caregivers: a call to action for using validated sleep assessments during prostate cancer care

OBJECTIVE/BACKGROUND

To examine the impact of prostate cancer (PCa) on sleep health for patients and caregivers. We hypothesized that sleep disturbances and poor sleep quality would be prevalent among patients with PCa and their caregivers.

PATIENTS/METHODS

A systematic literature search was conducted according to the Preferred Reporting Items for a Systematic Review and Meta-analysis guidelines. To be eligible for this systematic review, studies had to include: (1) patients diagnosed with PCa and/or their caregivers; and (2) objective or subjective data on sleep. 2431 articles were identified from the search. After duplicates were removed, 1577 abstracts were screened for eligibility, and 315 underwent full-text review.

RESULTS AND CONCLUSIONS

Overall, 83 articles met inclusion criteria and were included in the qualitative synthesis. The majority of papers included patients with PCa (98%), who varied widely in their treatment stage. Only 3 studies reported on sleep among caregivers of patients with PCa. Most studies were designed to address a different issue and examined sleep as a secondary endpoint. Commonly used instruments included the Insomnia Severity Index and European Organization for Research and Treatment of Cancer Core Quality of Life Questionnaires (EORTC-QLQ). Overall, patients with PCa reported a variety of sleep issues, including insomnia and general sleep difficulties. Both physical and psychological barriers to sleep are reported in this population. There was common use of hypnotic medications, yet few studies of behavioral interventions to improve sleep for patients with PCa or their caregivers. Many different sleep issues are reported by patients with PCa and caregivers with diverse sleep measurement methods and surveys. Future research may develop consensus on validated sleep assessment tools for use in PCa clinical care and research to promote facilitate comparison of sleep across PCa treatment stages. Also, future research is needed on behavioral interventions to improve sleep among this population.

Relationships of sleep traits with prostate cancer risk: A prospective study of 213,999 UK Biobank participants

BACKGROUND

The effect of sleep on the occurrence of prostate cancer (PCa) remains unclear. This study explored the influence of sleep traits on the incidence of PCa using a UK Biobank cohort study.

METHODS

In this prospective cohort study, 213,999 individuals free of PCa at recruitment from UK Biobank were included. Missing data were imputed using multiple imputation by chained equations. Cox proportional hazards models were used to calculate the adjusted hazard ratios and 95% confidence intervals for PCa (6747 incident cases) across seven sleep traits (sleep duration, chronotype, insomnia, snoring, nap, difficulty to get up in the morning, and daytime sleepiness). In addition, we newly created a healthy sleep quality score according to sleep traits to assess the impact of the overall status of night and daytime sleep on PCa development. E values were used to assess unmeasured confounding.

RESULTS

We identified 6747 incident cases, of which 344 died from PCa. Participants who usually suffered from insomnia had a higher risk of PCa (hazard ratio [HR]: 1.11; 95% confidence interval [CI]: 1.04-1.19, E value: 1.46). Finding it fairly easy to get up in the morning was also positively associated with PCa (HR: 1.09; 95% CI: 1.04-1.15, E value: 1.40). Usually having a nap was associated with a lower risk of PCa (HR: 0.91; 95% CI: 0.83-0.99, E value: 1.42).

CONCLUSIONS

Fairly easy to get up in the morning and usually experiencing insomnia were associated with an increased incidence of PCa. Moreover, usually having a nap was associated with a lower risk of PCa. Therefore, sleep behaviors are modifiable risk factors that may have a potential impact on PCa risk.

Sleep Duration/Quality With Health Outcomes: An Umbrella Review of Meta-Analyses of Prospective Studies

Background

To quantitatively evaluate the evidence of duration and quality of sleep as measured by multiple health outcomes.

Methods

This review is registered with PROSPERO, number CRD42021235587. We systematically searched three databases from inception until November 15, 2020. For each meta-analysis, the summary effect size using fixed and random effects models, the 95% confidence interval, and the 95% prediction interval were assessed; heterogeneity, evidence of small-study effects, and excess significance bias were also estimated. According to the above metrics, we evaluated the credibility of each association.

Results

A total of 85 meta-analyses with 36 health outcomes were included in the study. We observed highly suggestive evidence for an association between long sleep and an increased risk of all-cause mortality. Moreover, suggestive evidence supported the associations between long sleep and 5 increased risk of health outcomes (stroke, dyslipidaemia, mortality of coronary heart disease, stroke mortality, and the development or death of stroke); short sleep and increased risk of overweight and/or obesity; poor sleep quality and increased risk of diabetes mellitus and gestational diabetes mellitus.

Conclusions

Only the evidence of the association of long sleep with an increased risk of all-cause mortality was graded as highly suggestive. Additional studies are needed to be conducted.

Systematic Review Registration:https://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42021235587

Distinct Sleep Disturbance Profiles in Patients With Gastrointestinal Cancers Receiving Chemotherapy

BACKGROUND

Patients with gastrointestinal cancers experience moderate to high levels of sleep disturbance during chemotherapy that decreases their functional status and quality of life (QOL).

OBJECTIVE

The objectives of this study were to identify subgroups of patients with gastrointestinal cancers with distinct sleep disturbance profiles and evaluate for differences among these subgroups in demographic, clinical, and sleep characteristics, as well as co-occurring symptoms and QOL outcomes.

METHODS

Patients (n = 405) completed questionnaires 6 times over 2 cycles of chemotherapy. Latent profile analysis was used to identify subgroups of patients with distinct sleep disturbance profiles.

RESULTS

Three distinct sleep disturbance profiles (ie, low, high, very high) were identified. Compared with the low class, patients in the other 2 classes were significantly younger and less likely to be married and to exercise on a regular basis and received a higher number of previous treatments. Compared with the low class, patients in the other 2 classes reported higher levels of anxiety, depressive symptoms, morning and evening fatigue, and pain and lower levels of attentional function and QOL scores at enrollment.

CONCLUSIONS

This study is the first to use latent profile analysis to identify subgroups of patients with gastrointestinal cancers with distinct sleep disturbance profiles. Findings provide new insights on the associations between sleep disturbance and multiple co-occurring symptoms in these patients.

IMPLICATIONS FOR PRACTICE

Clinicians can identify patients who are at the highest risk for sleep disturbance and recommend a variety of sleep hygiene interventions (eg, establishment of a bedtime routine), as well as initiate interventions for other co-occurring symptoms.

Sleep Quality and Cancer-Related Fatigue in Patients with Cancer

Introduction: Sleep problems and fatigue are common symptoms reported by cancer patients. In this study, the researchers used a specialized tool to measure fatigue in cancer patients and its relationship with sleep quality in Yazd, Iran.

Methods: This descriptive correlational study included 149 cancer patients (age range: over 18 years) referred to Shahid Sadoughi Hospital in Yazd, Iran. Data were collected by the Pittsburgh Sleep Quality Index (PSQI) and Cancer-Related Fatigue Questionnaire. A PSQI score of ≥5 indicated a poor sleep. Data were analyzed using SPSS Statistics for Windows, version 13.0 (SPSS Inc., Chicago, IL, USA), Pearson’s correlation, t test, analysis of variance (ANOVA), and linear regression.

Results: The mean (SD) PSQI score of patients was 13 (4.85) out of 21. About 69.3% of patients had a poor sleep quality. While the mean (SD) of sleep duration was 5.57 (0.54) hours, it was 69.44 (46.58) minutes for sleep latency. Also, with increasing the mean of sleep quality, the mean of fatigue significantly increased (P < 0.001, R=0.63).

Conclusion: According to the results, there was a relationship between the sleep quality and fatigue in cancer patients, so that patients with better sleep quality had less fatigue.

Sleep duration and health outcomes: an umbrella review

PURPOSE

To collect existing evidence on the relationship between sleep duration and health outcomes.

METHODS

A thorough search was conducted in PubMed, Web of Science, Embase, and the Cochrane Database of Systematic Reviews from inception to January, 2021. Meta-analyses of observational and interventional studies were eligible if they examined the associations between sleep duration and human health.

RESULTS

In total, this umbrella review identified 69 meta-analyses with 11 outcomes for cancers and 30 outcomes for non-cancer conditions. Inappropriate sleep durations may significantly elevate the risk for cardiovascular disease (CVD), cognitive decline, coronary heart disease (CHD), depression, falls, frailty, lung cancer, metabolic syndrome (MS), and stroke. Dose-response analysis revealed that a 1-h reduction per 24 hours is associated with an increased risk by 3-11% of all-cause mortality, CHD, osteoporosis, stroke, and T2DM among short sleepers. Conversely, a 1-h increment in long sleepers is associated with a 7-17% higher risk of stroke mortality, CHD, stroke, and T2DM in adults.

CONCLUSION

Inappropriate sleep duration is a risk factor for developing non-cancer conditions. Decreasing and increasing sleep hours towards extreme sleep durations are associated with poor health outcomes.

A Longitudinal Study of the Relationship between Shift Work and Prostate-Specific Antigen in Healthy Male Workers

As shift work has become prevalent globally, it is important to evaluate the health effects of shift work on employees. Several studies have demonstrated a positive association between shift work and prostate cancer. Therefore, we aimed to further examine the relationship between shift work and elevated prostate-specific antigen (PSA). Our study collected data from 66,817 male participants at baseline and followed up for about 6 years. We categorized shift worker status and shift schedule types. To evaluate the risk of elevated PSA on shift workers, we estimated hazard ratios using the Cox proportional hazards regression analyses. During a median follow-up of 4.1 years, 1030 participants developed elevated PSA. The multivariable-adjusted hazard ratio (HR) of elevated PSA for shift workers compared with daytime workers was 1.37 (1.04-1.80). Among shift workers, rotating shift workers (HR = 1.47, 95% CI 1.06-2.03) showed a significantly increased risk of elevated PSA compared with daytime workers. Our longitudinal study provides evidence for an association between shift work, especially rotating shift work, and elevations of PSA.