Risk of ischemic stroke in patients with ovarian cancer: a nationwide population-based study

Background: Cancer patients are at risk of thromboembolism. However, studies investigating the relationship between ovarian cancer and ischemic stroke are lacking. The objectives of this study were to assess the association between ovarian cancer and ischemic stroke, and to determine the predictive risk factors. Methods: Ovarian cancer patients aged 20 years and older without antecedent cerebrovascular events and who were followed up for more than 1 year between 1 January 2003 and 31 December 2011 were recruited from the Taiwan National Health Insurance database. Hazard ratios (HRs) of stroke risk for ovarian cancer patients compared with an age-and comorbidity-matched cohort were calculated by Cox proportional regression analysis. The difference in cumulative ischemic stroke incidence between ovarian cancer patients and the matched cohort was analyzed with the Kaplan-Meier method and tested with the log-rank test. Results: Each cohort (ovarian cancer and matched cohort) consisted of 8,810 individuals, with a median age of 49 years. After a median follow-up of 2.68 and 3.85 years, respectively, the ischemic stroke incidence was 1.38-fold higher in the ovarian cancer cohort than in the comparison cohort (9.4 versus 6.8 per 1,000 person-years), with an age-and comorbidity-adjusted HR of 1.49 (P < 0.001). The ischemic stroke risk imposed by ovarian cancer was more prominent in patients under 50 years old (HR 2.28; P < 0.001) compared with patients 50 years and older (HR 1.33; P = 0.005). Significant risk factors predicting stroke development were age 50 years and older (HR 2.21; P < 0.001), hypertension (HR 1.84; P < 0.001), diabetes mellitus (HR 1.71; P < 0.001), and treatment with chemotherapy (HR 1.45; P = 0.017), especially platinum-based regimens. Conclusions: Ovarian cancer patients were at an increased risk of developing ischemic stroke. Age, hypertension, diabetes, and chemotherapy treatment were independent risk factors.