A. See (Singapore, Singapore)
Singapore General HospitalAuthor Of 1 Presentation
158P - Obstructive sleep apnea and breast cancer incidence: a systematic review and meta-analysis
Abstract
Background
Obstructive sleep apnea (OSA) is a prevalent form of sleep-disordered breathing. Emerging evidence from animal models suggests that intermittent nocturnal hypoxia in OSA may induce carcinogenesis. However, epidemiological studies have reported conflicting findings on this relationship. We conducted this systematic review and meta-analysis to evaluate the association between OSA and breast cancer - the most common cancer in women worldwide.
Methods
PubMed, Embase, Scopus and Cochrane Library were systematically searched for observational studies published until 15 November 2020, in adults aged ≥18 years, reporting objective measurements or clinical diagnosis of sleep apnea and the association with incident breast cancer. Maximally covariate-adjusted hazard ratios (HR) were pooled using the generic inverse variance method and random effects model on RevMan. Pre-specified subgroup analysis was performed for studies with median follow-up duration ≥5 years. Two reviewers independently assessed risk of bias using the Newcastle-Ottawa Scale.
Results
7 studies totalling 5,370,466 participants were included from 1,707 search results. All studies used International Classification of Diseases codes to classify OSA and breast cancer. Compared to controls, those with OSA had 43% higher pooled hazards of breast cancer (HR=1.42; 95%CI 1.09-1.85, I2=96%, P=<0.00001). Out of 7 studies, 5 adjusted for type 2 diabetes mellitus, 4 adjusted for age and obesity, and 3 adjusted for sex and hypertension. In a subgroup analysis of studies with median follow-up duration ≥5 years, the pooled HR increased to 1.74 (95%CI 1.10-2.77, I2=90%). There were insufficient studies to assess publication bias.
Conclusions
This meta-analysis suggests that OSA is a risk factor for breast cancer. However, animal models and prospective studies adjusting for additional confounders specific to breast cancer should be done to strengthen the evidence base. Further studies are needed to determine if a dose-response relationship exists with rising OSA severity, and if OSA increases the aggressiveness and progression of breast cancer. Importantly, clinical trials are needed to assess the potential impact of timely OSA treatment in mitigating breast cancer risk and progression.
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.