This article is more than 5 years old. Information may no longer be current.
USPSTF issues finalized lung cancer screening recommendations
The US Preventive Services Task Force today recommended annual lung cancer screening with low-dose CT scans in adults aged 55 to 80 years who are at high risk for lung cancer.
The recommendation is based on a review of randomized controlled trials and modeling studies which demonstrated that high-risk adults — defined as those with a 30 pack-year smoking history who currently smoke or who have quit within the past 15 years — experience more benefit than harm with yearly screening programs.
The recommendation also stipulates that annual screening can discontinue once the adult has reached 15 years without smoking, or if they develop a comorbidity that limits life expectancy or the ability to undergo surgery for lung cancer.
The USPSTF reviewed data from the National Lung Screening Trial, which included more than 50,000 participants aged 55 to 74 years with a history of tobacco use of at least 30 pack-years, and who were current smokers or who had quit smoking within the past 15 years. Participants were assigned to low-dose CT or chest radiography and followed for a median of 6.5 years.
During this time, death from lung cancer occurred in 2.06% of participants in the chest radiography arm compared with 1.75% of those in the low-dose CT arm (absolute difference, 0.31%).
Low-dose CT was associated with a 16% (95% CI, 5%-25%) reduction in lung cancer mortality and a 6.7% (95% CI, 1.2%-13.6%) reduction in all-cause mortality.
Modeling studies conducted by Cancer Intervention and Surveillance Modeling Network investigators indicated that annual screening resulted in the detection of 50% of early-stage lung cancers. Screening was associated with a 14% reduction in lung cancer mortality, which equated to the prevention of 521 deaths per 100,000 adults.
False–negative or false–positive results, overdiagnosis and radiation exposure are harms associated with annual CT screening, according to the statement.
Data from the National Lung Screening Trial showed that among screening tests, 24.2% were positive. Of these, 96.4% were false–positive.
Additional invasive diagnostic procedures were conducted in 2.5% of positive test results and were associated with 61 complications and 6 deaths.
Modeling study researchers estimated that overdiagnosis occurs in 9.5% to 11.9% of lung cancers detected through low-dose CT. The risk for radiation-induced lung cancer death was less than 1%.
The current recommendation — which was updated to reflect the public comment period from July to August of this year — is an update to the 2004 statement which concluded more evidence was necessary.
“Although lung cancer screening is not an alternative to smoking cessation, the USPSTF found adequate evidence that annual screening for lung cancer with low-dose CT in a defined population of high-risk persons can prevent a substantial number of lung cancer-related deaths,” the task force wrote. “The magnitude of benefit to the person depends on that person’s risk for lung cancer because those who are at highest risk are most likely to benefit.”
In an invited commentary, Frank C. Detterbeck, MD, of the Yale University School of Medicine, and Michael Unger, MD, of the Fox Chase Cancer Center, wrote the recommendation neglects to comment on the patient selection process, adherence and who will conduct the evaluations.
“Is the health care system willing to support what the USPSTF is recommending?” Detterbeck and Unger wrote. “Are we willing to provide the resources to make the process of patient selection and counseling achievable and to make contribution to a registry and tracking of quality metrics actually happen? The USPSTF recommendation involves more than performing a scan and having a radiologist interpret it.”
Perspective
Back to TopThe recent USPSTF Grade B recommendation marks a monumental event in the efforts to battle lung cancer. The recommendation means that lung cancer screening will be funded as required by the Affordable Care Act. Although smoking cessation is the most effective measure to prevent lung cancer, there are many people whose smoking history cannot be undone. Unfortunately, despite the best efforts, nothing has been successful to reduce lung cancer in this group until now. The results of the NLST give us hope for reducing lung cancer deaths.
A low-dose CT scan can reduce lung cancer-specific mortality by 20%. However, lung cancer screening with CT is not a simple test. There remain issues: high false-positive rates (96% in the NLST), detection of nonsignificant or incidental findings, unnecessary follow-up testing, overdiagnosis of cancer (18.5% in the NLST), and costs. Although the cost-effective analysis of the NLST is pending, all indications are that screening is cost-effective despite these issues. However, to improve the screening process and to have success compatible to the NLST, it is paramount that screening be performed with a team dedicated to lung cancer screening. Only then will improved selection of patients, decreased false-positive rates and lower costs be accomplished in lung cancer screening.