Scientists with the Ottawa Health Research Institute, who studied data from almost 10,000 patients in 34 studies, found that the basic cancer screening strategy regularly used on these patients only detects 49 percent of cancers. However, following a more extensive protocol that includes a CT scan of the abdomen and pelvis detected 70 percent of cancers.

The study, published in the Sept. 2 issue of the Annals of Internal Medicine, noted that blood clots in the legs, arms and lungs (called venous thromboembolism) can be an early sign of an underlying cancer, as up to 10 percent of these patients are diagnosed with cancer within a year of the venous thromboembolism.

"To treat cancer effectively, it is essential that we detect it as early as possible, and our analysis shows that CT scanning may help us do this in this high-risk group of patients," Marc Carrier, an associate scientist at the Ottawa Health Research Institute, said in a news release from the group.

Carrier and his team are testing a modified CT scanning procedure that may further increase the rate of cancer detection.

More information

The National Heart, Lung, and Blood Institute has more about blood clots.