Incidence and risk factors of venous and arterial thromboembolic events among patients with ovarian cancer- data from a large Canadian database.

Objectives: To determine the incidence of thromboembolic events (TEEs) in ovarian cancer patients and to identify risk factors that are significantly associated with the development of venous thromboembolism (VTE), arterial thromboembolism (ATE), or overall TEEs in this population.

Methods: This is a retrospective cohort study of 4491 patients with epithelial ovarian cancer identified in the British Columbia cancer registry between 1996 and 2017. The presence of TEEs and risk factors were identified in administrative health records from fee-for-service provider visits and hospital data using ICD-9-CM and ICD-10-CM billing codes. Statistical analysis was performed using Chi-squared test and Fischer's exact test.

Results: Of 4491 patients with epithelial ovarian cancer included in this study, 1.74% experienced ATE and (9.44%) experienced VTE. There was a significant association found between the occurrence of TEEs and all-cause mortality. Sepsis was significantly associated with both venous and arterial thromboembolism. The top three risk factors for arterial thromboembolism included peripheral vascular disease (PVD), open wound, and aneurysm.

Conclusions: Risk factors predictive of thrombosis in ovarian cancer patients are not consistent between ATE and VTE, thus thrombotic events should not be combined for analysis. Differential thrombosis risk assessment is needed to improve prevention strategies and guide thromboprophylaxis for these patients.