False-positive screenings expose healthy persons to potential harms
To examine the cumulative risk of a person who received a false-positive result for a lung cancer screening, a research team, led by Jennifer Croswell, MD, MPH, conducted a randomized controlled trial to compare low-dose CT with chest radiography.
Involved in the study were 3,190 current or former smokers, aged 55 to 74 years old, who had a smoking history of ≥30 pack-years and no history of lung cancer. Patients were randomly assigned to receive low-dose CT or chest radiography and 1 repeated annual screening for lung cancer.
The study revealed that the risks for false-positive results on a lung cancer screening test were substantial after only two annual examinations, particularly for low-dose CT. Researchers reported that a patient's cumulative probability of one or more false-positive low-dose CT examinations was 21% after one screening and 33% after the second screening. The rates for chest radiography were 9% and 15%, respectively. Furthermore, a total of 7% of participants with a false-positive low-dose CT examination and 4% with false-positive chest radiography had a resulting invasive procedure.
“Given the relatively high probability of a false-positive low-dose CT lung cancer screening examination, it is important that providers have careful discussions with patients who request this technology to help them weigh known harms against currently theoretical benefits,” the authors concluded. “Further investigation into the physical, psychological, and economic ramifications of false-positive low-dose CT screening test results is warranted.”