Alison Rustagi

M.D., Ph.D

University of California, San Francisco

Assistant Professor

NLST (Learn more about this study)

NLST-1236

Apr 18, 2024

From clinical trials to real world practice: health status of community-dwelling veterans receiving lung cancer screening compared to randomized trial participants

Lung cancer screening (LCS) via low-dose computed tomography (LDCT) prevents death from lung cancer. Two randomized trials, the National Lung Screening Trial (NLST) and Dutch-Belgian Randomized Lung Cancer Screening Trial (Dutch: NELSON), were powered to detect a mortality benefit of LCS among healthy smokers. Because poor health increases potential harms and decreases potential benefits, all national guidelines recommend against screening those in poor health. However, little is known how these guidelines are being applied in real world healthcare settings. This study seeks to compare the health of screen-eligible and screened patients in the community relative to participants in the NLST trial.
We will use two data sources: 1) individual-level, deidentified data from the NLST and 2) individual-level data from a national cohort of community-dwelling patients ages 65-80 in VA primary care (5R01AG058678, PI Keyhani). To ascertain LCS eligibility for cohort members, individual interviews were conducted at baseline to obtain a detailed lifetime cigarette smoking history. As the NLST restricted to those 55-74 years, and the cohort restricted to those 65-80 years, this analysis will restrict to those ages 65-74 at enrollment to promote comparability.
Our primary exposure is study (NLST control participants vs. prospective cohort participants). Our primary outcome is all-cause mortality in the 12 months after study enrollment. We will compare all-cause mortality between studies using Kaplan Meier survival curves and Cox proportional hazards regressions among those eligible for LCS and those who received LCS.
This analysis will yield important insights into the overall health of LCS-eligible individuals, and how LCS is currently being used in the community. If LCS is commonly used among those who are substantially less healthy than NLST participants, then LCS may expose screened individuals to the harms of screening while offering relatively less benefit.