An easily derived score can indicate whether persons with cancer-associated thrombosis are at high or low risk of recurrent venous thromboembolism (VTE). Such information may help improve VTE-protective treatment for this at-risk population.
Physicians and other collaborators in Ottawa, Canada, reviewed the charts of patients with both cancer and VTE who came through the thrombosis unit of Ottawa Hospital from 2002 to 2004 and from 2007 to 2008. Of 543 patients, 55 (10.1%) presented with a recurrent VTE within the first 6 months of anticoagulation therapy. Of these persons, 36 were using low-molecular-weight heparin (LMWH) therapy at the time of recurrence and 19 were using vitamin K antagonist (VKA).
No significant difference in relative risk for recurrence existed between the two groups. However, researchers Martha L. Louzada, BSc, MD, and colleagues did learn that gender, primary tumor site, tumor stage, and prior VTE were significant variables to include in the clinical prediction rule. In the final model, female gender, lung cancer, and prior VTE were considered to increase risk of VTE recurrence; breast cancer and stage I disease were considered to lower risk. Ultimately, 48% of the subjects had a prediction-risk score of 0 or lower, making them low-risk for recurrent VTE. Persons with a score of 1 or higher are deemed to be at high risk.
“We were able to derive a simple and easy scoring system that stratifies patients with cancer-associated thrombosis into low or high risk of recurrent VTE,” wrote the authors in an abstract made available at the annual meeting of the American Society of Hematology, held December 4-7, 2010 (http://ash.confex.com/ash/2010/webprogram/Paper30752.html). “Future prospective validation of the model is warranted and may be very relevant to better tailor anticoagulation treatment in this heterogenous population.”