Comparison of Underlying Risk of Developing and Dying From Lung Cancer in Screened Populations.

[BACKGROUND] Trial participants typically are healthier than the general population. Differences in underlying characteristics between the population undergoing lung cancer screening (LCS) and LCS trial participants may alter the benefits of LCS.

[RESEARCH QUESTION] Does the risk of lung cancer developing and death resulting differ between trial participants and the general population?

[STUDY DESIGN AND METHODS] Using data from the (1) the North Carolina Lung Screening Registry (NCLSR), (2) the 2022 Centers for Disease Control and Prevention's Behavioral Risk Factor Surveillance System (BRFSS) Lung Cancer Screening Module, and (3) the National Lung Screening Trial (NLST), we estimated the 5-year probability of lung cancer developing and death resulting if patients were not screened using publicly available macros. Using Cohen's D, we compared these metrics in NCLSR and BRFSS populations with those in NLST participants.

[RESULTS] BRFSS and NCLSR populations were older, had higher rates of COPD and prior history of cancer, and higher risk of lung cancer developing and death resulting compared with NLST participants. Although NCLSR populations were more likely to be currently smoking, median smoking exposure was similar among all groups. Median 5-year lung cancer risk was 21.2 per 1,000 NLST participants (interquartile range,13.0-35.2 per 1,000 NLST participants) compared with 46.1 per 1,000 2013 BRFSS participants (Cohen's D = 0.67515), 34.5 per 1,000 2021 BRFSS participants (Cohen's D = 0.47813), 36.5 per 1,000 2013 NCLSR participants (Cohen's D = 0.07748), and 32.3 per 1000 2021 NCLSR participants (Cohen's D = 0.48289). Median 5-year probability of dying of lung cancer if not screened showed similar patterns, with lowest rates among NLST participants at 12.5 deaths per 1,000 participants vs BRFSS and NCLSR populations.

[INTERPRETATION] Our results showed that NCLSR and BRFSS populations have similar smoking exposure as NLST participants, but higher prevalence of lung cancer risk factors, lung cancer risk scores, and risk of death resulting from lung cancer if not screened. Monitoring LCS in the general population is crucial because compared with trial participants, individuals in the general population are older and have more comorbidities, raising concerns about potential LCS harms. However, they have a higher risk of dying of lung cancer if not screened.