Association between sleep-disordered breathing and breast cancer aggressiveness

PSGL-1: a novel immune checkpoint driving T-cell dysfunction in obstructive sleep apnea

Introduction

Although higher incidence of cancer represents a major burden for obstructive sleep apnea (OSA) patients, the molecular pathways driving this association are not completely understood. Recently, the adhesion receptor P-selectin glycoprotein-1 (PSGL 1) has been identified as a novel immune checkpoint, which are recognized major hallmarks in several types of cancer and have revolutionized cancer therapy.

Methods

The expression of PSGL-1 and its ligands VISTA and SIGLEC-5 was assessed in the leucocytes of OSA patients and control subjects exploring the role of intermittent hypoxia (IH) using in vitro models. In addition, PSGL-1 impact on T-cells function was evaluated by ex vivo models.

Results

Data showed PSGL-1 expression is upregulated in the T-lymphocytes from patients with severe OSA, indicating a relevant role of hypoxemia mediated by intermittent hypoxia. Besides, results suggest an inhibitory role of PSGL-1 on T-cell proliferation capacity. Finally, the expression of SIGLEC-5 but not VISTA was increased in monocytes from OSA patients, suggesting a regulatory role of intermittent hypoxia.

Discussion

In conclusion, PSGL-1 might constitute an additional immune checkpoint leading to T-cell dysfunction in OSA patients, contributing to the disruption of immune surveillance, which might provide biological plausibility to the higher incidence and aggressiveness of several tumors in these patients.

Screening for obstructive sleep apnoea in post-treatment cancer patients

BACKGROUND AND AIMS

For cancer patients, comorbid obstructive sleep apnea (OSA) poses additional risk to their surgical/anaesthetic outcomes, quality of life, and survival. However, OSA screening is not well-established in oncology settings. We tested two screening tools (STOP-Bang questionnaire [SBQ] and the at-home monitoring device, ApneaLink™Air), for predicting polysomnography (PSG) confirmed OSA in post-treatment cancer patients.

METHODS

Breast (n = 56), endometrial (n = 37) and melanoma patients (n = 50) were recruited from follow-up clinics at Westmead Hospital (Sydney, Australia). All underwent overnight PSG, 137 completed SBQ, and 99 completed ApneaLink™Air. Positive (PPV) and negative (NPV) predictive values for PSG-determined moderate-to-severe OSA and severe OSA, were calculated using an SBQ threshold ≥3 au and ApneaLink™Air apnoea-hypopnea index thresholds of ≥10, ≥15 and ≥30 events/h.

RESULTS

Both SBQ and ApneaLink™Air had high NPVs (92.7% and 85.2%-95.6% respectively) for severe OSA, but NPVs were lower for moderate-to-severe OSA (69.1% and 59.1%-75.5%, respectively). PPV for both tools were relatively low (all <73%). Combining both tools did not improve screening performance.

CONCLUSIONS

These screening tools may help identify cancer patients without severe OSA, but both are limited in identifying those with moderate-to-severe or severe OSA. PSG remains optimal for adequately identifying and managing comorbid OSA in cancer patients.

Cancer sleep symptom-related phenotypic clustering differs across three cancer specific patient cohorts

Specific sleep disorders have been linked to disease progression in different cancers. We hypothesised sleep symptom clusters would differ between cancer types. The aim of this study was to compare sleep symptom clusters in post-treatment melanoma, breast and endometrial cancer patients. Data were collected from 124 breast cancer patients (1 male, 60 ± 15 years, 28.1 ± 6.6 kg/m² ), 82 endometrial cancer patients (64.0 ± 12.5 years, 33.5 ± 10.4 kg/m² ) and 112 melanoma patients (59 male, 65.0 ± 18.0 years, 29.1 ± 6.6 kg/m² ). All patients completed validated questionnaires to assess sleep symptoms, including the Epworth Sleepiness Scale (ESS), Pittsburgh Sleep Quality Index (PSQI), Insomnia Severity Index (ISI), and Functional Outcomes of Sleep Questionnaire-10 (FOSQ-10). Snoring, tiredness, observed apneas, age, BMI, and gender data were also collected. Binary values (PSQI, ISI, FOSQ), or continuous variables for sleepiness (ESS) and perceived sleep quality (PSQI), were created and sleep symptom clusters were identified and compared across cancer cohorts. Four distinct sleep symptom clusters were identified: minimally symptomatic (n = 152, 47.7%); insomnia-predominant (n = 87, 24.9%); very sleepy with upper airway symptoms (n = 51, 16.3%), and severely symptomatic with severe dysfunction (n = 34, 11.1%). Breast cancer patients were significantly more likely to be in the insomnia predominant or severely symptomatic with severe dysfunction clusters, whereas melanoma patients were more likely to be minimally symptomatic or sleepy with upper airway symptoms (p <0.0001). Endometrial cancer patients were equally distributed across symptom clusters. Sleep symptom clusters vary across cancer patients. A more personalised approach to the management of sleep-related symptoms in these patients may improve the long term quality of life and survival.

Association of obstructive sleep apnea and nocturnal hypoxemia with all-cancer incidence and mortality: a systematic review and meta-analysis

STUDY OBJECTIVES

Biological models suggest that obstructive sleep apnea (OSA) is potentially carcinogenic. We aimed to clarify the inconsistent epidemiological literature by considering various traditional and novel OSA severity indices.

METHODS

We systematically searched PubMed, Embase, Scopus, and the Cochrane Library for observational or randomized studies of associations of OSA, measured by diagnostic codes or any index, each with all-cancer incidence or mortality in adults, compared with participants with no/mild OSA. Two reviewers independently selected studies, extracted data, and evaluated study bias using the Newcastle-Ottawa scale and quality of evidence using GRADE (Grading of Recommendations Assessment, Development, and Evaluation). We performed inverse variance-weighted, random-effects meta-analyses and sensitivity analyses.

RESULTS

We included 20 observational studies (5,340,965 participants), all with moderate/low bias, from 1,698 records. Based on T90 (sleep duration with oxygen saturation < 90%), patients with OSA who had moderate (T90 > 1.2%, hazard ratio [HR] = 1.28, 95% confidence interval [CI] = 1.07-1.54) and severe nocturnal hypoxemia (T90 > 12%, HR = 1.43, 95% CI = 1.16-1.76) experienced 30%-40% higher pooled all-cancer risk than normoxemic patients, after multiple adjustment for covariates including obesity. Furthermore, severe nocturnal hypoxemia nearly tripled all-cancer mortality (HR = 2.66, 95% CI = 1.21-5.85). Patients with apnea-hypopnea index-defined severe OSA, but not moderate OSA, had higher all-cancer risk (HR = 1.18, 95% CI = 1.03-1.35) but similar all-cancer mortality as patients without OSA. An OSA diagnosis was not associated with all-cancer risk. Evidence quality ranged from low to moderate. Insufficient evidence was available on the oxygen desaturation index, lowest/median saturation, and arousal index.

CONCLUSIONS

In patients with OSA, nocturnal hypoxemia is independently associated with all-cancer risk and mortality. Future studies should explore if risk differs by cancer type, and whether cancer screening and OSA treatment are beneficial.

SYSTEMATIC REVIEW REGISTRATION

Registry: PROSPERO; URL: https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=220836; Identifier: CRD42021220836.

CITATION

Tan BKJ, Teo YH, Tan NKW, et al. Association of obstructive sleep apnea and nocturnal hypoxemia with all-cancer incidence and mortality: a systematic review and meta-analysis. J Clin Sleep Med. 2022;18(5):1427-1440.

Cancer and obstructive sleep apnea: An updated meta-analysis

OBJECTIVE

The relationship between cancers and obstructive sleep apnea (OSA) has been discussed for decades. However, the previous meta-analysis led to opposite conclusions. To further investigate this controversial issue, we performed this systematic review and meta-analysis update.

METHODS

PubMed, Embase, and the Cochrane Library were systematically searched and studies on "cancer and OSA" were all included. Two reviewers independently searched articles, extracted data, and assessed the quality of included studies. Moreover, the overall incidence of cancer and OSA in corresponding populations was calculated.

RESULTS

Of the 1434 titles identified, 22 articles involving more than 32.1 million patients were included in this meta-analysis. An overall incidence of OSA positive individuals in cancer was 46 (95%CI, 27-67)%, and the prevalence of cancers in OSA patients reached 1.53 (95%CI, 1.01-2.31) times higher than non-OSA individuals.

CONCLUSION

This meta-analysis indicated that there was a high prevalence of OSA in cancer patients, and individuals with OSA were more likely to develop tumors, and the incidence was related to the severity of OSA.

The Association of Obstructive Sleep Apnea With Breast Cancer Incidence and Mortality: A Systematic Review and Meta-analysis

Purpose

Emerging evidence from animal models suggests that intermittent hypoxia due to obstructive sleep apnea (OSA) is a risk factor for breast cancer. Despite their biological plausibility, human epidemiological studies have reported conflicting results. Therefore, we conducted a meta-analysis to delineate this relationship.

Methods

We searched the PubMed, Embase, Scopus, and Cochrane Library databases for eligible studies from inception until June 6, 2021. Two reviewers selected randomized trials or observational studies reporting the association between OSA and breast cancer incidence compared with those without OSA. Two reviewers extracted relevant data and assessed the quality of evidence using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework and Newcastle-Ottawa Scale (NOS). We pooled the maximally covariate-adjusted hazard ratios (HRs) using a random-effects inverse variance-weighted meta-analysis and performed pre-specified subgroup analyses.

Results

We included six studies out of 1,707 records, comprising a combined cohort of 5,165,200 patients. All studies used the International Classification of Diseases codes to classify OSA and breast cancer. OSA patients had a 36% increased breast cancer risk (HR, 1.36; 95% confidence interval [CI], 1.03–1.80; N = 6, I² = 96%) compared to those without OSA. Most studies adjusted for confounders, such as age, sex, obesity, diabetes mellitus, alcohol use, and hypertension. Subgroup analyses for studies with (1) multivariate adjustment and (2) at least five years of follow-up yielded HRs of 1.35 (95% CI, 0.98–1.87; N = 5, I² = 96%) and 1.57 (95% CI, 1.14–2.18; N = 4; I² = 90%), respectively. One Mendelian randomization study suggested a causal relationship, with a two-fold increase in the odds of breast cancer in patients with OSA.

Conclusion

This meta-analysis suggested that OSA is a risk factor for breast cancer. Future studies should explore the dose-response relationship between OSA and breast cancer, and whether treatment may mitigate breast cancer risk or progression.

Increased prevalence of obstructive sleep apnea in women diagnosed with endometrial or breast cancer

Background

Epidemiological studies demonstrate associations between obstructive sleep apnea (OSA) and cancer incidence and mortality. The aim of this study was to measure OSA in women with breast (BC) or endometrial cancer (EC) and associations with clinico-pathological tumor variables.

Methods and findings

In a cross sectional study, women with BC (12 months) or EC (3 months) post-diagnosis were recruited from cancer clinics. We collected demographic, anthropometric data, cancer stage, grade, histopathology and history of cancer treatment and all subjects had in-laboratory polysomnography. Sleepiness was assessed with the Epworth Sleepiness Scale (ESS). We compared anthropometric and polysomnographic data between cancer groups (unpaired t-tests), and assessed relationships between cancer characteristics and OSA variables (Fishers exact test). There were no significant differences between average age (BC:59.6±8.7 years(n = 50); EC:60.3±7.7 years(n = 37)), or ESS score (BC:6.4±4.4; EC 6.8±4.7; mean±SD; all p>0.2), however, BMI was higher in EC (BC: 29.7±7.9kgm^-2; EC: 34.2±8.0 kgm^-2; p<0.05). BC had longer sleep latency (BC:31.8±32minutes; EC:19.3±17.9 minutes), less Stage 3 sleep (BC:20.0±5.2%; EC:23.6±8.2%) and more REM sleep (BC:21.1±6.9%; EC: 16.6±5.7%), all p<0.05. EC had lower average awake and asleep oxygen saturation levels (BC: 95.6±1.3%; EC: 94.6±1.9% [awake]: BC: 94.8±2.1%; EC: 93.3±2.4% [asleep]; both p<0.05). Apnea-Hypopnea Index (AHI) (BC: 21.2(7.3–36.9) events/hr; EC: 15.7 (10–33.5) events/hour (median (interquartile range)) was not different p = 0.7), however, 58% and 57% of women with BC and EC respectively, had an AHI>15 events/hour. In this small sample size group, no significant associations (all p>0.1) were detected between OSA metrics and clinico-pathological tumor variables.

Conclusion

In postmenopausal women with breast or endometrial cancer there is high prevalence of OSA, with no association with specific tumor characteristics detected. Recognition of the high prevalence of OSA in women with cancer is important to recognise as it may impact on surgical risk and quality of life.

Atractylon treatment prevents sleep-disordered breathing-induced cognitive dysfunction by suppression of chronic intermittent hypoxia-induced M1 microglial activation

Chronic intermittent hypoxia (CIH) induced by sleep-disordered breathing (SDB) is a key factor involved in cognitive dysfunction (CD). Increasing evidence has shown that atractylon (ATR) has anti-inflammatory effects. However, it remains unclear if ATR has a protective effect against SDB-induced nerve cell injury and CD. So, in the present study, CIH-exposed mice and CIH-induced BV2 cells were used to mimic SDB. The results showed that ATR treatment decreased CIH-induced CD and the expression of inflammatory factors in the hippocampal region by suppression of M1 microglial activation and promotion of M2 microglial activation. Also, ATR treatment promoted sirtuin 3 (SIRT3) expression. Down-regulation of SIRT3 decreased the protective effect of ATR against CIH-induced microglial cell injury. Furthermore, in vitro detection found that SIRT3 silencing suppressed ATR-induced M2 microglial activation after exposure to CIH conditions. Taken together, these results indicate that ATR treatment prevents SDB-induced CD by inhibiting CIH-induced M1 microglial activation, which is mediated by SIRT3 activation.

Sleep Apnoea Adverse Effects on Cancer: True, False, or Too Many Confounders?

Obstructive sleep apnoea (OSA) is a prevalent disorder associated with increased cardiovascular, metabolic and neurocognitive morbidity. Recently, an increasing number of basic, clinical and epidemiological reports have suggested that OSA may also increase the risk of cancer, and adversely impact cancer progression and outcomes. This hypothesis is convincingly supported by biological evidence linking certain solid tumours and hypoxia, as well as by experimental studies involving cell and animal models testing the effects of intermittent hypoxia and sleep fragmentation that characterize OSA. However, the clinical and epidemiological studies do not conclusively confirm that OSA adversely affects cancer, even if they hold true for specific cancers such as melanoma. It is likely that the inconclusive studies reflect that they were not specifically designed to test the hypothesis or because of the heterogeneity of the relationship of OSA with different cancer types or even sub-types. This review critically focusses on the extant basic, clinical, and epidemiological evidence while formulating proposed directions on how the field may move forward.

Obstructive sleep apnea and cancer: a complex relationship

PURPOSE OF REVIEW

Obstructive sleep apnea (OSA) has been recognized as a risk factor for cancer mainly through hypoxia, based on studies that did not distinguish among cancer types. The purpose of this review is to discuss the most recent data on epidemiology and pathophysiology of the OSA-cancer association.

RECENT FINDINGS

According to epidemiological studies, OSA may have different influences on each type of cancer, either increasing or decreasing its incidence and aggressiveness. Time spent with oxygen saturation below 90% appears the polysomnographic variable most strongly associated with unfavorable effects on cancer. Experimental studies support the role of hypoxia as an important risk factor for cancer growth and aggressiveness, especially when it shows an intermittent pattern. These effects are largely mediated by the hypoxia-inducible factor, which controls the synthesis of molecules with effects on inflammation, immune surveillance and cell proliferation. Sleep fragmentation participates in increasing cancer risk. Modulating effects of age remain controversial.

SUMMARY

Effects of OSA on cancer may largely vary among neoplastic diseases, both in their magnitude and direction. The worse risk associated with intermittent rather than persistent hypoxia, and the effects of OSA therapy on cancer natural history are still poorly known, and deserve new careful studies.

Impact of sleep apnoea-hypopnoea syndrome on diabetic neuropathy. A systematic review

INTRODUCTION

Diabetes mellitus and sleep apnoea-hypopnoea syndrome appear to be related, but it is not well defined whether there is an increased risk of peripheral neuropathy in patients with both diseases. For this reason, we conducted a systematic review.

METHODS

Bibliographic search in 3 electronic databases using a predefined strategy and the PRISMA methodology. Only original studies (any type of design) published from 2000 onwards in English, French, Portuguese or Spanish were included. A study quality scale was established.

RESULTS

Twelve articles were selected, of which six studied type 2 diabetic patients. The overall prevalence of sleep apnoea-hypopnoea syndrome was 43.7% (1,559/3,564 patients). Diabetic neuropathy was more frequent in patients with sleep apnoea-hypopnoea syndrome in nine studies, although significantly only in four (60% vs 27%, P<.001; 64.5% vs 36%, P=.03; 37% vs 23.4%, P<.02; 66.6% vs 0%, P=.007). In one study, diabetic neuropathy was more frequent in patients without sleep apnoea-hypopnoea syndrome (although not statistically significant) and in 2 no comparison was made between patients with/without sleep apnoea/hypopnoea syndrome.

CONCLUSIONS

The observed results suggest a relationship between diabetes mellitus and sleep apnoea-hypopnoea syndrome in the occurrence of diabetic neuropathy.

Association between obstructive sleep apnoea and breast cancer: The Korean National Health Insurance Service Data 2007-2014

Some studies have argued that obstructive sleep apnoea (OSA) increases the risk of breast cancer. However, the results are often conflicting. This study aimed to investigate associations between OSA and breast cancer incidence using the Korea National Health Insurance Service (KNHIS) database. This retrospective cohort study analyzed data from the KNHIS database. A total of 45,699 women (≥20 years of age) newly diagnosed with OSA between 2007 and 2014 were included. The control groups were a 5-fold, age-matched women who had not been diagnosed with OSA. Mean follow-up duration was 3.7 ± 2.3 years. The primary endpoint was newly diagnosed breast cancer. The breast cancer hazard ratio (95% confidence interval) was calculated for patients with OSA and compared with that of the control group. The incidence of breast cancer among patients with OSA was significantly higher than that among the controls (1.20 [1.04–1.39]). In particular, the incidence of breast cancer was higher among patients aged ≥65 years (1.72 [1.10–2.71]). The result suggests that OSA may be a risk factor for breast cancer in women.