CT Scans Catch Lung Cancer Earlier Than X-Rays: NCI

Nov. 4, 2010— -- Low-dose computerized tomography -- or CT -- scans better detect earlier stages of lung cancer than a standard chest X-ray, significantly cutting deaths from the disease, the National Cancer Institute announced today.

The NCI's study enrolled 53,000 current and past smokers who were screened annually for three years by either CT scan or conventional chest X-rays and found those who were screened CT were 20 percent less likely to die from lung cancer.

In a teleconference today, trial investigators said they presumed CT scans were able to detect smaller tumors, which led to an earlier diagnosis and subsequently earlier intervention.

"This has the potential to save many lives among those at risk for lung cancer," said Dr. Harold E. Varmus, director of the National Cancer Institute, at the teleconference.

The trial, which began in 2002, ended earlier than expected after the Data Safety Monitoring Board, an independent panel of reviewers, found there was sufficient data collected to show a significant decrease in lung cancer death in participants who underwent CT screening.

Lung cancer is the major cause of death from all cancers in United States, said Varmus. It will cause 157,000 deaths in U.S. this year, he said.

A CT scan uses multiple X-ray views to assemble cross-sectional images of structures inside the body. Because its use involves several X-ray scans, it generally exposes patients to nearly three times the degree of radiation than a single X-ray.

Still, investigators said the amount of radiation in a low-dose scan such as the one used is almost equivalent to a standard mammography, which is used to detect breast cancer.