Low-dose CT screening yields high detection of lung nodules in never smokers

Low-dose chest CT screening resulted in “notable detection” of lung nodules among never smokers, researchers reported in the European Respiratory Journal.

“Although lung cancer screening using low-dose computed tomography is now widely used in clinical practice, the characteristics and outcomes of diagnostic procedures related to screen-detected nodules in never smokers remains unclear,” Yeon Wook Kim, MD, of the division of pulmonary and critical care medicine in the department of internal medicine at Seoul National University College of Medicine and Seoul National University Bundang Hospital in Seongnam, South Korea, and colleagues wrote.

The researchers conducted a study to determine the incidence of lung nodules considered for invasive therapy and also to evaluate final diagnoses and complications in never smokers compared with ever smokers after low-dose CT screening.

The retrospective, hospital-based cohort study included 37,436 asymptomatic adults (17,968 never smokers and 19,468 ever smokers) who underwent low-dose chest CT screening for lung cancer in South Korea from 2009 to 2018.

Positive lung nodules were detected in 16.2% of never smokers. In total, 0.77% of never smokers and 1% of ever smokers underwent invasive biopsy (P = .022), the researchers reported.

A lung cancer diagnosis was made in 0.47% of never smokers and 0.63% of ever smokers (P = .032).

After invasive biopsy, 0.28% of 17,968 never smokers and 0.35% of 19,468 ever smokers were diagnosed with benign disease (P = .191), according to the study.

Researchers observed no significant association between smoking and risk for a false-positive lung cancer diagnosis (OR = 0.98; 95% CI, 0.62-1.57) and related complications (OR = 1.33; 95% CI, 0.65-3.73) after biopsy.

Of 84 never smokers diagnosed with lung cancer, 97.6% had adenocarcinoma and 89.3% were in stage I with a favorable prognosis, the researchers wrote.

“Our results indicate that nodules detected in never smokers should not be underestimated and emphasize the need for careful follow-up and relevant decision-making process regarding the need for invasive diagnosis,” the researchers wrote.

According to the researchers, although the lung cancer detection rate was lower among never smokers, the related complication rates and false-positive rates were comparable to ever smokers.

“Our results indicate the need for a specifically tailored strategy for the management of screen-detected nodules in Asian never smokers,” the researchers wrote.