Effect of sleep disorders on the risks of cancers and site-specific cancers

Whether preexisting sleep disorder is an independent risk factor for cancer remains unclear. Therefore, we performed this propensity score–matched population-based cohort study to compare the incidence rate ratios (IRRs) of specific cancers between patients with and without sleep disorders. Patients were categorized into two groups on the basis of the presence or absence of sleep disorders and matched at a 1:1 ratio. Propensity score matching yielded a final cohort of 289,162 patients (i.e., 144,581 and 144,581 in the sleep disorder and nonsleep disorder groups, respectively) who were eligible for further analysis. In multivariate Cox regression analysis, the adjusted hazard ratio (aHR; 95% confidence interval [CI]) of cancer risk in the sleep disorder group compared with the nonsleep disorder group was 1.07 (1.04–1.12; P = 0.0001). Furthermore, the adjusted IRRs (95% CIs) for all cancers, breast cancer, and ovarian cancer in the patients with sleep disorders were 1.08 (1.02–1.18), 1.20 (1.08–1.32), and 1.30 (1.10–1.52), respectively. The results suggested that sleep disorders are a significant risk factor for all cancers, breast cancer, and ovarian cancer. •Whether preexisting sleep disorder is an independent risk factor for cancer remains unclear. This study investigated the effect of sleep disorders on cancer incidence.•We determined the significant adjusted incidence rate ratios of the risks of all cancers, breast cancer, and ovarian cancer in patients with or without a diagnosis of sleep disorder before cancer.