LDCT for Lung Cancer Screening: The Effect of False-Positives

August 1, 2014

Patients who underwent low-dose CT for lung cancer screening and received false-positives benefited from counseling.

Patients who underwent low-dose computed tomography (LDCT) to screen for lung cancer and had a false-positive diagnosis had no significant decrease in health-related quality of life or increase in anxiety compared with patients who had a negative screening result, according to data from the National Lung Screening Trial published in Cancer.

“These results provide evidence that in a screening program that includes counseling and advises participants of the high likelihood of a false-positive screen and additional testing, there may be no impact on health-related quality of life or anxiety for participants who are free of lung cancer,” wrote Ilana F. Gareen, PhD, of Brown University School of Public Health, and colleagues.

The National Lung Screening Trial was a collaboration between the American College of Radiology Imaging Network (ACRIN) and the National Cancer Institute Division of Cancer Prevention Lung Screening Study. The trial compared chest X-ray screening and LDCT screening for the detection of lung cancers in patients at high risk. Results of the study indicated that LDCT screening was associated with a 20 percent reduced risk for lung cancer death; however, concerns exist about the negative effect of false-positive screening results.

“During the informed consent process, ACRIN advised participants that up to 50 percent of those screened might receive a screen result suspicious for lung cancer, even though the participants did not have lung cancer, and that as many as 20 percent to 50 percent of those participants would require additional imaging or other testing to confirm that findings initially thought to be of concern were not cancer.”

To examine the effect of false-positive screens, Gareen and colleagues examined abnormal findings from health-related quality of life and anxiety screens in 2,812 patients. Quality of life and anxiety were assessed at baseline and at one month and six months using the complete Short-Form-36 and the State Trait Anxiety Inventory questionnaires; 82.4 percent of participants completed the forms at one month and 70.8 percent completed it at six months.

Of the screened participants, 36.4 percent had a false-positive diagnosis and 12.2 percent had significant incidental findings; 2.2 percent of patients had true positive screens.

The researchers did not identify any difference in health-related quality of life or state anxiety between patients with a false-positive, positive for significant incidental findings or negative findings. However, higher rates of anxiety and lower rates of health-related quality of life were found in patients with true positive screening results.

“These findings are relevant to the anticipated adoption of LDCT screening in the United States,” the researchers wrote. “They provide evidence that in a large screening program in which participants received extensive counseling as part of the consent process, screening was not associated with high psychological costs for participants who screen positive but were free of lung cancer.”

The researchers did point out several limitations of the study including the fact that participants found out the results of their lung cancer status at different time points and that it was an unmatched analysis.