BACKGROUND AND PURPOSE:

• Low-dose computed tomography (LDCT) lung screening reduces lung cancer mortality, but may reveal significant abnormalities that are not associated with lung cancer
• Gareen et al. (JAMA Intern Med, 2023) describe significant incidental findings (SIFs) reported in the LDCT arm of the National Lung Screening Trial

METHODS:

• Retrospective case series study
• Population
  • Participants in the National Lung Screening Trial who underwent at least 1 screening examination with LDCT
• Study design
  • Data were collected from 2002 to 2009 at 33 US medical centers
  • Participants were scheduled to undergo 3 screenings during the course of the trial
• Primary outcomes
  • SIFs, defined as either a
    • Final diagnosis of a negative screen result with significant abnormalities that were not suspicious for lung cancer
    • Positive screen result with emphysema, significant cardiovascular abnormality, or significant abnormality above or below the diaphragm

RESULTS:

• 26,455 participants | 75,126 LDCT screening examinations
  • Mean age: 61.4 (SD, 5.0) years
  • Women: 41.0%
  • Black: 4.5% | Hispanic/Latino: 1.8% | White: 91.2%
• Incidence of SIFs: 33.8% of participants
  • Incidence of SIFs considered reportable: 89.1%
• There was a higher incidence of reportable SIFs among those with a positive screen result for lung cancer, compared to those with a negative screen result
  • Positive screen result: 94.1% | Negative screen result: 81.8%
• The most common SIFs reported
  • Emphysema: 43.0% of SIFs reported
  • Coronary artery calcium: 12.2% of SIFs reported
  • Masses or suspicious lesions: 7.4% of SIFs reported
• Masses reported occurred in the
  • Kidney: 3.2%
  • Liver: 2.1%
  • Adrenal: 1.3%
  • Breast: 0.8%

CONCLUSION:

• SIFs were common with LDCT screening
  • Most SIFs were considered reportable and would likely require follow-up
• The authors state

In this case series study, slightly more than one-third of all NLST LDCT screening participants had a SIF detected

… the discovery of these SIFs can potentially present an opportunity for early detection of non–lung cancer conditions in a high-risk population

Learn More – Primary Sources:

Significant Incidental Findings in the National Lung Screening Trial