June 16 (Bloomberg) -- Medical imaging scans may be an appropriate alternative to colonoscopies for some people who have a high risk of colon cancer, researchers said.

The computed tomography, or CT, scans identified 85 percent of advanced abnormal-growth spots and colorectal cancers in the Italian study, and correctly ruled them out in 88 percent of cancer-free patients. The report in the Journal of the American Medical Association involved 937 patients with signs of the cancerous lesions or a family or personal history of the disease.

The scans are already one of the methods recommended for screening people with an average risk of cancer. For those who are most prone to the disease, however, doctors recommend colonoscopies that have higher cancer detection rates. These procedures require a tube with a tiny camera to be threaded through the rectum, and many people are reluctant to undergo the process.

A CT scan is “better accepted than colonoscopy,” said the researchers, led by Daniele Regge from the radiology unit at the Institute for Cancer Research and Treatment in Turin, Italy. “Thus, it may help increase the low adherence reported for individuals who are candidates for screening.”

About 210,000 Europeans and 50,000 Americans die each year from colorectal cancer, making it one of the most deadly tumor types, according to the American Cancer Society. Most cases arise when benign-growth polyps turn malignant, a process that can be circumvented by finding and treating the spots before they become cancerous.

Cost, Availability

The scans costs $600 to $1,200 and can be done using standard computed tomography equipment and software made by companies including General Electric Co.’s GE Healthcare unit, Royal Philips Electronics NV, Siemens AG and Vital Images Inc.

The CT images didn’t pick up all the polyps subsequently detected with colonoscopies in the study. About 5 percent to 15 percent of those who were told they were cancer-free actually had lesions, the researchers said. There were no serious side effects or complications from the scans.

It’s important for doctors and patients to understand the trade-offs when comparing colonoscopy and CT scans, wrote Emily Finlayson, from the University of Michigan’s Surgical Collaborative for Outcomes Research and Evaluation in Ann Arbor, in an editorial. While there is a lower risk of complications and a greater acceptance of CT scans, doctors must be trained to interpret them and have the right equipment, she said.

“With the majority of individuals in the United States who meet criteria for colorectal cancer screening and surveillance not undergoing recommended procedures,” Finlayson wrote, “an imperfect test that has a lower risk profile and greater acceptance among patients seems to be an appealing solution.”

The study was funded by the Italian Association for Cancer Research and other Italian organizations.

To contact the reporter on this story: Michelle Fay Cortez in London at mcortez@bloomberg.net

Last Updated: June 16, 2009 16:00 EDT