Routine Lung CT Scans for Older, Heavy Smokers
Yearly testing will prevent some lung cancer deaths, experts conclude
The USPSTF is an independent volunteer panel of national health experts who issue evidence-based recommendations on clinical services intended to detect and prevent illness.
The task force has previously ruled on mammography, PSA testing and other types of screening. It reports to the U.S. Congress every year and its recommendations often serve as a basis for federal health care policy. Insurance companies often follow USPSTF recommendations as well.
Weighing heavily in the task force's latest decision were the results from the National Cancer Institute's 2011 National Lung Screening Trial. That study, which involved more than 53,000 smokers across the United States, found that annual low-dose CT screenings could prevent one of five lung cancer deaths.
The guidelines revolve around who is at highest risk for lung cancer and who would be able to benefit most from early detection.
Smoking is the biggest risk factor for lung cancer, and causes about 85 percent of lung cancers in the United States. The risk for developing lung cancer increases with age, with most lung cancers occurring in people aged 55 and older.
However, the task force decided to limit CT screenings just to people who either still smoke or quit smoking within the past 15 years. "If you quit more than 15 years ago, because the risk of lung cancer goes down every year from the time you quit smoking, we would take you out of that high-risk category," LeFevre said.
The task force also had to weigh the benefits of early cancer detection against the potential harm caused by regular exposure to radiation from the CT scans, said recommendation co-author Dr. Linda Humphrey, a professor of medicine and clinical epidemiology at Oregon Health & Science University and associate chief of medicine at the Portland VA Medical Center.
"The radiation associated with low-dose CT is on the order of the radiation associated with mammography," Humphrey said. "It's not a short-term risk, it's a long-term risk."
She added that there are a fair number of false positives involved in CT scans for lung cancer. These can be resolved through screening, but that adds to the number of radiation exposures a patient will receive.