Incidental respiratory findings on low-dose CT lung cancer screening common

Incidental respiratory disease-related findings, including emphysema and reticular opacities, observed on low-dose CT lung cancer screenings were common and associated with increased mortality, researchers reported.

“There has been relatively little research on ancillary findings noted on low-dose CT screenings. It is unclear how much, if any, benefit there is in noting ancillary findings,” Paul F. Pinsky, PhD, chief of the Early Detection Research Group in the division of cancer prevention at the National Cancer Institute, told Healio. “While noting these could be beneficial in terms of detecting conditions early, they could also increase health care costs due to unnecessary workups and possibly lead to complications in some cases.”

Participants in the National Lung Screening Trial (n = 25,002; 41% women) underwent three annual low-dose CT lung cancer screens. Trial radiologists identified findings related to possible lung cancer and respiratory-related findings and, using these data, researchers assessed cumulative respiratory disease mortality and risk factors in addition to incidental CT findings, respiratory disease history, smoking history and demographic factors. All patients completed a baseline questionnaire to collect demographics, smoking history and medical history.

Overall, 26.5% of adults were aged 65 years or older at baseline, 47% were current smokers and 10.6% reported COPD/emphysema history.

At baseline, 30.7% of adults had emphysema on low-dose CT compared with 44.2% of adults at any screen. Of those with emphysema at baseline, 18% reported COPD/emphysema history.

During a median follow-up of 10.3 years, 3,639 participants died; 708 deaths were caused by respiratory disease.

The 10-year cumulative respiratory disease mortality was lower among those with no COPD/emphysema history, ranging from 3.9% for adults with emphysema and reticular opacities to 1.1% for those without compared with adults with COPD/emphysema history with 17.3% for those with emphysema and reticular opacities and 3.7% for those without.

Emphysema on low-dose CT was associated with significantly elevated respiratory disease mortality in the multivariate model (HR = 2.27; 95% CI, 1.92-2.7) and presence of reticular opacities was also associated with elevated respiratory disease mortality (HR = 1.39; 95% CI, 1.19-1.62).

According to Pinsky, regarding early emphysema detection, potential benefits include providing additional motivation for smoking cessation and encouraging increased physical activity and use of respiratory severity to reduce respiratory symptom severity.

“The next step is research on whether interventions in [people] with emphysema noted on low-dose CT screening improve outcomes in these patients,” Pinsky said. “Interventions to study include smoking cessation interventions and interventions to encourage physical activity.”

For more information:

Paul F. Pinsky, PhD, can be reached at pinskyp@mail.nih.gov.