Uniformed Services University of the Health Sciences, Bethesda, MD (Drs. Covey and Cagle); David Grant Medical Center, Travis Air Force Base, Fairfield, CA (Dr. Covey); Ehrling Burquist Clinic, Offutt Air Force Base, Bellevue, NE (Dr. Cagle) carlcovey24@gmail.com
The authors reported no potential conflict of interest relevant to this article.
The views expressed in this article are those of the authors and do not necessarily reflect the official policy or position of the Uniformed Services University, Department of the Air Force, Department of Defense, nor the US government.
Potential harms: False-positives and related complications
Screening for lung cancer is not without its risks. Harms from screening typically result from false-positive test results leading to overdiagnosis, anxiety and distress, unnecessary invasive tests or procedures, and increased costs.19TABLE 26,19-23 lists specific complications from lung cancer screening with LDCT.
The false-positive rate is not trivial. For every 1000 patients screened, 250 people will have a positive LDCT finding but will not have lung cancer.19 Furthermore, about 1 in every 2000 individuals who screen positive, but who do not have lung cancer, die as a result of complications from the ensuing work-up.6
Annual LDCT screening increases the risk of radiation-induced cancer by approximately 0.05% over 10 years.21The absolute risk is generally low but not insignificant. However, the mortality benefits previously outlined are significantly more robust in both absolute and relative terms vs the 10-year risk of radiation-induced cancer.
The trial was discontinued prematurely when investigators noted a 20% reduction in lung cancer mortality in the lowdose computed tomography group vs the chest x-ray group.
Lastly, it is important to note that the NELSON trial and NLST included a limited number of LDCT scans. Current guidelines for lung cancer screening with LDCT, including those from the USPSTF, recommend screening annually. We do not know the cumulative harm of annual LDCT over a 20- or 30-year period for those who would qualify (ie, current smokers).
If you screen, you must be able to act on the results
Effective screening programs should extend beyond the LDCT scan itself. The studies that have shown a benefit of LDCT were done at large academic centers that had the appropriate radiologic, pathologic, and surgical infrastructure to interpret and act on results and offer further diagnostic or treatment procedures.