The association between new onset atrial fibrillation and incident cancer-A nationwide cohort study.

A recent analysis showed an association with new onset atrial fibrillation (NOAF) and incident cancer among women. We aimed to examine the risk of cancer among patients with NOAF in general population. A retrospective cohort of 5130 patients with NOAF was identified from a random sample of one million subjects between 2005 and 2010 from Taiwan National Health Insurance Research Database. The standard incidence ratio of incident cancer and hazard ratios were calculated by modeling cumulative incidence with competing risk of death. During a mean follow-up duration of 3.4 years, 330 patients developed cancer. The standard incidence ratio of all malignancies was 1.41 (95% confidence interval 1.26-1.57), suggesting a 41% increase in cancer risk compared with the general population. The risk of cancer was higher among men or the elderly with NOAF after adjusting for confounding factors and after considering the competing risk of death. The risk of cancer was not associated with CHA2DS2-VASc score (p = 0.32) among patients with NOAF. In conclusion, patients with NOAF were associated with a higher risk of cancer. Within this group, the risk of ischemic stroke (in terms of CHADS2-VASc score) did not reflect the risk of incident cancer.