Not All High-Risk Lung Cancer Patients Need Annual Screening

Annual low-dose CT screening for lung cancer may not be necessary for all patients, according to a study published in The Lancet Oncology.

Researchers from Duke University in Durham, NC, Brown University School of Public Health in Providence, RI, the University of California in Los Angeles, and the National Health Institute in Bethesda, MD, performed a retrospective cohort analysis to determine the utility and efficacy of annual low-dose CT (LDCT) assessments for the detection of lung cancer in high-risk eligible individuals. These are people aged 55 to 74 who have at least a 30 pack-year smoking history or who are former smokers who quit within the previous 15 years.

The new policy of annual screening has significant public policy implications, lead author Edward F. Patz, Jr., MD, the James and Alice Chen Professor of Radiology, said in a release. "Not screening patients annually could save millions in health care costs and spare patients the radiation exposure and the downstream effects of false positive screenings."

The researchers compared three annual LDCTs from the participants, who were followed up for up to five years after their last screening examination. The researchers assessed the frequency, stage, histology, study year of diagnosis, and incidence of lung cancer, as well as overall and lung cancer-specific mortality, and whether lung cancers were detected as a result of screening or within one year of a negative screen.[[{"type":"media","view_mode":"media_crop","fid":"47372","attributes":{"alt":"Edward F. Patz, Jr., MD","class":"media-image media-image-right","id":"media_crop_2854697557660","media_crop_h":"0","media_crop_image_style":"-1","media_crop_instance":"5566","media_crop_rotate":"0","media_crop_scale_h":"0","media_crop_scale_w":"0","media_crop_w":"0","media_crop_x":"0","media_crop_y":"0","style":"height: 177px; width: 180px; border-width: 0px; border-style: solid; margin: 1px; float: right;","title":"Edward F. Patz, Jr., MD","typeof":"foaf:Image"}}]]

The findings showed that the 19,066 participants who had a negative T0 screen had a lower incidence of lung cancer than did all 26,231 T0-screened participants. A total of 444 (2%) of the initial 19,066 participants with a negative initial LDCT scan were diagnosed with lung cancer at last available follow-up. In the first year after a negative screen and before the scheduled first annual screen, 17 patients (0.09% of all initial negative LDCT participants) were diagnosed with lung cancer. Additionally, 75 patients (0.4%) were diagnosed with lung cancer between the first and second annual screening. The incidence of lung cancer at the first screen among those who were initially negative was 0.34%, compared to 1% of patients who were diagnosed during the baseline screening.

“We estimated that if the T1 screen had not been done in the T0 negative group, at most, an additional 28 participants in the T0 negative group would have died from lung cancer (a rise in mortality from 185.82 per 100 000 person-years to 212.14 over the course of the trial,” the authors wrote.

"Our analysis suggests that annual screens may not be warranted for patients who have had an initial negative scan, and future risk prediction and cost-effectiveness models could incorporate these data to improve screening guidelines," Patz added in the release.