title: Association between sleep-disordered breathing, obstructive sleep apnea, and cancer incidence: a systematic review and meta-analysis.
abstract: OBJECTIVE
  Via this systematic review and meta-analysis, we assessed the associatio between sleep-disordered breathing (SDB)/obstructive sleep apnea (OSA) and cancer incidence.
  
  
  METHODS
  Medline, Embase, Cochrane Central, and electronic databases were searched for relevant studies in any language. Studies were included based on the following criteria: (1) those on patients with SDB/OSA, (2) those reporting cancer incidence rates specific to patients with SDB/OSA, and (3) those defining SDB/OSA using sleep-study-based objective measures. The quality of the included studies was assessed using the Newcastle-Ottawa Quality Assessment Scale (NOQA).
  
  
  RESULTS
  Of the 8766 retrieved citations, five studies that defined SDB/OSA using the apnea-hypopnea index (AHI) or the respiratory disturbance index (RDI) totaling 34,848 patients with SDB and 77,380 patients without SDB were pooled into a meta-analysis. All five studies were of good quality (NOQA ≥ 6). A total of 574 (1.6%) and 290 (0.37%) incident cancers were reported in patients with and without SDB, respectively. In the unadjusted analysis, patients with SDB/OSA were at an increased risk of incident cancer (relative risk [RR]: 1.53, 95% confidence interval [CI]: 1.31-1.79, P <0.001, I(2): 0, five included studies). When adjusted for traditional cancer risk factors, the association between SDB/OSA and cancer incidence, although attenuated (RR: 1.40, 95% CI: 1.01-1.95, P = 0.04, I(2): 60%, five included studies), remains significant.
  
  
  CONCLUSIONS
  SDB/OSA may increase the risk of incident cancer. Inferring an independent association is not possible from our analysis considering the retrospective cohort design of the included studies and high inter-study heterogeneity. An individual patient data meta-analysis would help validate our findings.
authors.affiliation: Department of Cardiovascular Medicine, The Wright Center for Graduate Medical Education, 501 Madison Avenue, Scranton, PA 18510, USA.
authors.forename: Ghanshyam
authors.initials: G
authors.lastname: Palamaner Subash Shantha
authors.affiliation: Department of Epidemiology, The Johns Hopkins Bloomberg School of Public Health, 550 N. Broadway Suite 1001, Baltimore, MD 21205, USA.
authors.forename: Anita Ashok
authors.initials: AA
authors.lastname: Kumar
authors.affiliation: Johns Hopkins Weight Management Center, Johns Hopkins University, 550 N. Broadway Suite 1001, Baltimore, MD 21205, USA; Department of International Health, Center for Human Nutrition, Johns Hopkins Bloomberg School of Public Health, 550 N. Broadway Suite 1001, Baltimore, MD 21205, USA; Department of Health, Behavior and Society, Johns Hopkins Bloomberg School of Public Health, 550 N. Broadway Suite 1001, Baltimore, MD 21205, USA.
authors.forename: Lawrence J
authors.initials: LJ
authors.lastname: Cheskin
authors.affiliation: Department of Cardiovascular Medicine, The Wright Center for Graduate Medical Education, 501 Madison Avenue, Scranton, PA 18510, USA; Department of Medicine, The Commonwealth Medical College, 501 Madison Avenue, Scranton, PA 18510, USA. Electronic address: pancholys@gmail.com.
authors.forename: Samir Bipin
authors.initials: SB
authors.lastname: Pancholy
mesh_terms: D006801:Humans; D015994:Incidence; D009369:Neoplasms / Q000453:epidemiology / Q000209:etiology*; D012307:Risk Factors; D012891:Sleep Apnea Syndromes / Q000150:complications*; D020181:Sleep Apnea, Obstructive / Q000150:complications*
keywords: Cancer; Meta-analysis; Obstructive sleep apnea; Sleep-disordered breathing