Lung Cancer and Incidence of Stroke

BACKGROUND AND PURPOSE: Stroke is a known cerebrovascular complication in lung cancer patients; however, whether lung cancer patients are at elevated risk of developing stroke relative to the noncancer population remains unclear. METHODS: The present study used population-based claims data from the Taiwan National Health Insurance, which identified 52,089 patients with an initial diagnosis of lung cancer between 1999 and 2007, and 104,178 matched noncancer subjects from all insured subjects age 20 years and older. Subsequent occurrence of stroke was measured until 2008, and the association between lung cancer and the hazard of developing stroke was estimated using Cox proportional hazard models. RESULTS: The incidence of stroke was 1.5 times higher (25.9 versus 17.4 per 1000 person-years) in the lung cancer group compared with the comparison group. The multivariate-adjusted hazard ratio (HR) comparing lung cancer patients with the noncancer group was 1.47 (95% CI, 1.39-1.56) for stroke, 1.78 (95% CI, 1.54-2.05) for hemorrhagic stroke, and 1.43 (95% CI, 1.34-1.51) for ischemic stroke. The risk of stroke fell over time, decreasing after 1 year of follow-up for men and after 2 years of follow-up for women. Within the first year of follow-up, the risk of stroke peaked during the first 3 months for men and within 4 to 6 months for women. CONCLUSIONS: Lung cancer is associated with increased risk of subsequent stroke within 1 year after diagnosis for men and 2 years after diagnosis for women.