Proposed national recommendations would nearly double the number of smokers and former smokers in the U.S. who are eligible for annual low-dose CT (LDCT) lung cancer screening.
The U.S. Preventive Services Task Force (USPSTF) issued a Tuesday that annual LDCT screening be extended to current smokers between the ages of 50 and 80, who have a 20-pack-year smoking history, and former smokers with the same pack-year history who have quit within the past 15 years (Grade "B" evidence).
LDCT screening is not recommended for people who have not smoked for the past 15 years and those with health problems that limit life expectancy or their eligibility for curative lung cancer surgery.
The proposed recommendation lowers the age at first screening from 55 years to 50 years, and it also reduces smoking pack-year eligibility from 30 years to 20 years.
Close to are projected to be diagnosed this year in the U.S. Roughly one in 10 lung cancer cases in the U.S. occur in smokers or former smokers, and smokers have an estimated 20-fold higher risk for lung cancer than lifetime nonsmokers.
"New evidence provides as proof that there are real benefits to starting to screen at a younger age and among people with a lighter smoking history," USPSTF member Michael Barry, MD, of Massachusetts General Hospital and Harvard Medical School, said in a press statement.
Albert Rizzo, MD, chief medical officer of the American Lung Association (ALA), said the USPSTF draft recommendations, if adopted, would extend screening to more African Americans and more women.
"We are very supportive of this recommendation, which will greatly increase the number of people eligible for screening" Rizzo told ѻý.
He added that the next big hurdle is making sure that Medicare, Medicaid, and private insurers extend screening reimbursement eligibility to reflect the recommended changes once they are finalized.
The draft recommendations will be posted for on the USPSTF website until August 3.
The ALA, along with other patient advocacy groups, have long called for additional lung cancer risk factors -- such as family history and occupational exposure -- to be included in the LDCT screening guidelines.
"We know that genetics play a role in cancer risk, and certainly family history of lung cancer is an indication that a smoker has a greater risk," Rizzo said, adding that occupational exposures to radon, asbestos, coal smoke, and other toxic agents are also risk significant risk factors for developing lung cancer.
USPSTF members reviewed seven randomized clinical trials evaluating LDCT screening to finalize the new recommendations. Just two of those trials -- the (NLST) and the from the Netherlands -- were adequately powered to detect a lung cancer mortality benefit with screening.
NLST enrolled 53,454 current or former heavy smokers (mean pack year history of 56 years) between the ages of 55 and 74, and showed a relative risk reduction in lung cancer mortality of 16% (95% CI 0.61-0.90) associated with screening at 10-years follow-up.
The NELSON trial showed screening to be associated with clear lung cancer mortality benefits among smokers and former smokers with a lighter lifetime smoking history than NLST participants.
The USPSTF draft recommendation noted that reducing smoking history requirements to 20 pack-years, and lowering the age at recommended first screening, may reduce long-recognized racial disparities in lung cancer screening.
"African Americans have a higher risk of lung cancer compared with whites, and this risk difference is more apparent at lower levels of smoking intensity," the report noted.
found just 17% of African-American smokers to be eligible for screening based on the versus 31% of white smokers. Among people with a lung cancer diagnosis in the same study, 32% of African-American smokers were eligible for screening versus 56% of white smokers.
Primary Source
U.S. Preventive Services Task Force
USPSTF "Draft Recommendation Statement: Lung Cancer Screening 2020."