Abstract 3503: Ovarian Cancer Increases the Risk of Stroke, but Not in Patients with Hypertension, Diabetes or Both
Background and Purpose: Cancer and stroke are the first and third leading cause of death in Taiwan respectively. Cancer has been considered to be a stroke risk factor. Ovarian cancer as a cause of stroke has appeared in the literature as case reports featuring increase in systemic thromboembolic tendency, frequently associated with non-bacterial endocarditis. To the best of our knowledge, no systemic assessment of ovarian cancer as a stroke risk factor has been made. Based on the Taiwan National Health Insurance claim files covering 1997 - 2008, we explored ovarian cancer as a stroke risk factor.
Methods: There were a total of 8,728 patients with diagnosis of ovarian cancer from 1997 to 2007. A cohort of 34,912 age- and gender-matched patients without cancer served as the control group. Both groups were followed until the end of 2008. The ovarian cancer and control cohorts were further divided into 2 subgroups with and without key stroke risk factors (hypertension, diabetes, or both). Cox proportional hazard regression analysis was used to estimate the stroke risk in patients with ovarian cancer to derive hazard ratios (HRs) and 95% confidence intervals (CIs)
Results: In the ovarian cancer cohort without hypertension or diabetes, the incidence rate was 4.89 per 1000 person-years in comparison with 4.70 in the control group without comorbidity. The hazard ratio (HR) is 1.44 (95% CI 1.22-1.77). For the ovarian cancer cohort with hypertension, diabetes or both, the incidence rate of stroke was 12.05 per 1000 person-years as compared to 30.67 in the control cohort with hypertension, diabetes or both. The HR is 0.44 (95% CI 0.29-0.68).
Conclusion: Ovarian cancer increased the risk of stroke by 44% in patients without hypertension, diabetes or both in comparison with the age- and gender-matched control without the same comorbidity. However, patients with ovarian cancer who had hypertension, diabetes or both had signnificantly lower stroke risk than the control group with the same comorbidity. The mechanism for the apparent paradox associated with comorbidity (hypertension, diabetes or both) known to increase the stroke risk in patients with ovarian cancer remains to be determined.
- © 2012 by American Heart Association, Inc.