USPSTF: CT screening could prevent lung cancer deaths

The United States Preventive Services Task Force has issued a draft recommendation supporting the use of lung cancer screening with low-dose computed tomography (LDCT) for persons at high risk of developing the disease due to age and a history of smoking.

According to the recommendation, the USPSTF has determined that adequate evidence exists that annual screening with LDCT for at-risk individuals can prevent a "substantial number of lung cancer deaths." At-risk individuals are specifically described as current and former smokers, ages 55 to 79, who have a history of 30 pack-years of smoking, or who have smoked in the last 15 years.

"Lung cancer is the leading cause of cancer death in the United States and a devastating diagnosis for more than 200,000 people each year," USPSTF Chair Virginia Moyer said in an announcement. "Sadly, nearly 90 percent of people who develop lung cancer die from the disease, in part because it often is not found until it is at an advanced stage. By screening those at high risk, we can find lung cancer at earlier stages when it is more likely to be treatable."

The public now has until Aug. 26 to submit comments on the USPSTF recommendation before the task force issues its final recommendation.

The draft recommendations are based on a review published online June 30 in the Annals of Internal Medicine, and are primarily driven by results from the National Lung Screen Trial (NLST). The NLST enrolled more than 50,000 current or heavy smokers from across the U.S. in a trial comparing LDCT lung cancer screening with standard chest X-ray. The results of the trial showed that participants who received LDCT scans had a 20 percent lower risk of dying from lung cancer than those participants who received chest X-rays.

The USPSTF draft recommendation is classified as one that is Grade B, meaning that there is a "high certainty that the net benefit is moderate, or a moderate certainty that the net benefit is moderate to substantial."

The net benefit of the proposed LDCT screening protocol, according to the USPSTF, would be a 14 percent reduction in lung cancer mortality--or 521 lung cancer deaths prevented per 100,000 persons in the population.

The USPSTF also found that there are potential harms associated with screening, such as overdiagnosis, radiation exposure and false-negative and false-positive results. It determined that following the suggested screening protocol will result in an overdiagnosis rate of 4 percent and radiation-induced lung cancer deaths of less than 1 percent.

Claudia Henschke, M.D., Ph.D., of the Mount Sinai Medical Center in New York who led the Early Lung Cancer Action Project, found in an earlier studier that low-dose CT screening could detect lung cancer at an earlier, more curable stage. She told NBC News that she is "thrilled" with the USPSTF action.

"It is going to make a big difference to how many people die of lung cancer," Henschke said. "Back in 1999 when we published our results, we were very confident that it was going to make a big difference. Now, finally, it will be made available to those people who are at highest risk."

To learn more:
- read the USPSTF draft recommendation
- see the announcement from the USPSTF (.pdf)
- read the review in the Annals of Internal Medicine
- check out the story in NBC News