The location of deep-vein thrombosis as a predictive factor for recurrence and cancer discovery after proximal deep-vein thrombosis.

Few studies have investigated the possible influence of the anatomic location of deep-vein thrombosis (DVT) on the evolution of the disease. Using a database of a randomized trial involving 400 patients with proximal DVT, we performed multivariate analyses to identify independent predictors of DVT recurrence and cancer discovery within two years. Besides known cancer at inclusion, the upper limit of DVT and its lateralization were independent risk factors for DVT recurrence with a hazard ratio (HR) of 1.75 [95% CI=1.00-3.07] for iliocaval DVT compared to femoro-popliteal DVT, and a HR of 1.88 [1.07-3.30] for right DVT compared to the left one. Among patients without known cancer at baseline (344 patients), bilateral DVT was an independent predictive factor of cancer discovery with a HR of 6.28 [2.06-19.15] compared with unilateral one. This study demonstrates that the location of DVT is an independent risk factor of DVT recurrence and cancer discovery.