Patients with cancer are more than twice as likely to suffer arterial thromboembolism within six months of diagnosis as cancer-free patients, according to a new study published in the Journal of the American College of Cardiology.

The retrospective, matched-cohort study linked Surveillance, Epidemiology and End Results (SEER) data with Medicare claims from 2002 to 2012.

A total of 279,719 patients age 66 or older diagnosed with primary breast, lung, prostate, colorectal, bladder, pancreatic or gastric cancer were matched with cancer-free individuals in the Medicare database. Patients were paired based on year of birth, sex, race, geographic region and Charlson Comorbidity Index, which predicts the 10-year mortality of a patient based on various risk factors. The cohort was 52 percent women and the median age was 74.

At six months post-diagnosis, cancer patients’ cumulative incidence of arterial thromboembolism was 4.7 percent compared to 2.2 percent for those without cancer. The six-month cumulative incidences for myocardial infarction (2 percent to 0.7 percent) and ischemic stroke (3 percent to 1.6 percent) were also higher in the cancer group.

Lead researcher Babak B. Navi, MD, MS, of the department of neurology at Brain and Mind Research Institute, Weill Cornell Medicine in New York, and colleagues noted more advanced stages of cancer were associated with higher risk. They also observed “excess risks attenuated in patients with cancer over time and generally had resolved by one year,” although the risk of myocardial infarction was higher and lasted longer than for ischemic stroke.

“Our findings raise the question of whether patients with newly diagnosed malignant cancer, particularly those with advanced disease, should be considered for antithrombotic and statin medicines for primary prevention of cardiovascular disease,” Navi and colleagues wrote. “Given that patients with cancer are also prone to bleeding due to frequent coagulopathy and invasive procedures, carefully designed clinical trials are needed to answer these questions.”

The researchers found lung, gastric and pancreatic cancers carried the highest excess risk of arterial thromboembolism when compared to the control group.

“Our results suggest that malignant cancer may be an underappreciated, yet common risk factor for arterial thromboembolism,” Navi and colleagues wrote. “Future research should aim to investigate the mechanistic basis for these findings, the utility of including cancer in cardiovascular risk prediction instruments, and optimal strategies to prevent arterial thromboembolism in patients with cancer.”