Clinical Outcomes of Venous Thromboembolism in Patients with and without Cancer: The SWIss Venous ThromboEmbolism Registry (SWIVTER).

Background  The association between cancer and venous thromboembolism (VTE) in producing adverse clinical outcomes requires further investigation. Methods  In the Swiss Venous ThromboEmbolism Registry (SWIVTER), we compared adverse clinical outcomes between 493 patients with cancer-associated VTE and 1,569 VTE patients without cancer, and identified independent predictors of 90-day mortality. Results  Among cancer patients, 351 (71%) had active disease at the time of VTE diagnosis and 232 (47%) had metastatic disease. Cancer patients more frequently had asymptomatic VTE (13 vs. 4%; p p  = 0.017), and upper extremity deep vein thrombosis (16 vs. 7%; p p p  = 0.007), and bleeding requiring medical attention (5.7 vs. 3.3%; HR, 1.80; 95% CI, 1.13–2.86; p  = 0.013). Among cancer patients, the strongest factor associated with mortality was metastatic disease (HR, 4.86; 95% CI, 2.68–8.81; p p  = 0.009). Symptomatic as compared with asymptomatic VTE predicted neither mortality (12.6 vs. 15.9%; HR, 0.76; 95% CI, 0.39–1.49; p  = 0.42) nor recurrent VTE (4.7 vs. 4.8%; HR, 0.98; 95% CI, 0.29–3.31; p  = 0.98) in cancer patients. Conclusion  In SWIVTER, early mortality of cancer-associated VTE was mainly driven by the extent of cancer disease and not by VTE symptoms or severity.