Back in 2013, the U.S. Preventive Task Forces recommended annual lung cancer screening in adults ages 55 to 80 who had a 30 pack-year smoking history and currently smoke, or have quit within the past 15 years. This was determined after a 2011 study called the National Lung Screening Trial (NLST) found that screening could prevent lung cancer deaths in high-risk people. Now, a new study just published in JAMA Internal Medicine finds that implementing such a lung cancer-screening program may be challenging and complex—and even unreliable in offering insights about whether someone actually has cancer or not.