Stroke and cancer: the importance of cancer-associated hypercoagulation as a possible stroke etiology

Abstract

Background and purpose: The importance of cancer-associated hypercoagulability as a possible stroke etiology in patients with cancer has received relatively little attention to date. A recent study has suggested that cancer-associated hypercoagulation may be of special importance in the absence of conventional stroke mechanisms.

Methods: We identified patients with ischemic stroke sequentially admitted to our stroke center with the additional diagnosis of active and malignant cancer from 2002 to 2011. By using our prospectively collected stroke, MRI, and laboratory data banks, the etiology and risk factors of stroke, types of cancer, deep vein thrombosis/pulmonary embolism, d-dimer levels, and diffusion-weighted imaging lesion patterns were compared to an age- and sex-matched control group. Patients with cancer with a conventional stroke etiology and patients with an unidentified and/or cancer-associated stroke etiology were analyzed separately.

Results: One hundred forty patients with cancer and 140 control subjects were included. Unidentified stroke (P<0.001) and infarction in multiple vascular territories (P<0.001) were significantly more frequent and d-dimer levels significantly higher (P<0.05) in patients with cancer. Vice versa, risk factors such as hypertension (P<0.05) and hyperlipidemia (P<0.01) were more prevalent in control subjects. Deep vein thrombosis and pulmonary embolism were more frequent (P<0.01) and d-dimer levels higher (P<0.01) in the patients with unidentified and/or cancer-associated stroke etiology compared to the patients with cancer with a conventional stroke etiology. Lung and pancreatic cancer were significantly overrepresented and d-dimer levels higher in these patients compared with other patients with cancer (P<0.01).

Conclusions: Our data confirm the concept of cancer-associated hypercoagulation as a widely underestimated important stroke risk factor in patients with cancer, especially in those with severely elevated d-dimer levels and in the absence of conventional risk factors.