Abstract
PURPOSE: In vitro and animal models suggest that the physiological effects of sleep apnea could contribute to cancer risk, yet epidemiologic studies have been inconsistent. METHODS: We identified a cohort of adults diagnosed with sleep apnea between 2005 and 2014 using regional administrative databases. Linking this cohort to a population-based cancer registry, we identified first incident cancers diagnosed after sleep apnea diagnosis through 2015. We calculated age-sex standardized cancer incidence ratios (SIRs) to compare the observed number of cancers among those with sleep apnea with expected population estimates over a comparable period. RESULTS: Among 34,402 individuals with sleep apnea, 1,575 first incident cancers were diagnosed during follow-up (mean ± SD; 5.3 ± 2.0 years). Compared to the general population, cancer incidence (SIR 1.26, 95% CI 1.20-1.32) was elevated among sleep apnea patients. We observed significantly elevated incidence for kidney (SIR 2.24, 95% CI 1.82-2.72), melanoma (SIR 1.71, 95% CI 1.42-2.03), breast (SIR 1.43, 95% CI 1.76-2.00), and corpus uteri (SIR 2.80, 95% CI 2.24-2.47) while risk for lung (SIR 0.66, 95% CI 0.54-0.79) and colorectal cancer (SIR 0.71, 95% CI 0.56-0.89) was lower. CONCLUSION: These findings suggest an elevated cancer burden, particularly at certain sites, among individuals with diagnosed sleep apnea. Results should be interpreted with caution due to unmeasured confounders (e.g., BMI, diabetes).