By Jeffrey Norris, UCSF Science Cafe | November 9, 2010
CT scans to detect lung cancer early can save lives, according to a study of 53,456 current and former smokers ages 55 to 74.
The study findings were announced by the National Institutes of Health (NIH) -- which funded the massive study -- on Novembers 4.
The study, called the National Lung Screening Trial (NLST), marks the first time a screening test for lung cancer has been shown to improve the odds of survival. The study demonstrated that a low-dose, helical computed tomography (CT) exam -- lasting from seven to 15 seconds -- is significantly better than an X-ray for detecting life-threatening lung cancers at an earlier stage when treatment often is more successful.
During the course of the study there were 442 deaths in the group that received X-rays, compared to 354 deaths among those who received CT exams. So far, participants' health has been tracked for up to seven years.
"The results were pretty striking," says Rebecca Smith-Bindman, MD, a UCSF radiologist and epidemiologist. "They showed a decrease in lung cancer mortality of 20 percent and a decrease in overall mortality of 7 percent. I think that's really exciting."
Just as they are used to detect breast cancer through X-ray mammograms, X-rays also can be used to detect many lung tumors. However, earlier studies on the costs and benefits of X-ray screening for smokers led to the rejection of X-rays for use in routine diagnostic screening for this group.
According to the trial design, the study was ended by an independent monitoring panel, because the life-saving benefit of CT screening already had become significant despite the fact that the trial was not yet completed.
"This is an enormous step forward for improving outcomes for lung cancer patients and for preventing thousands of deaths that would occur without screening," says UCSF thoracic surgeon and lung cancer specialist David Jablons, MD. "CT screening of the appropriate population of patients saves lives in real time today."