As reported in The New England Journal of Medicine by Harry J. de Koning, MD, PhD, and colleagues, the Dutch/Belgian NELSON trial has shown a significant reduction in 10-year lung cancer mortality with volume-based low-dose computed tomography (CT) screening vs no screening in high-risk men.
Harry J. de Koning, MD, PhD
Male patients were the primary patient group analyzed in the trial; outcomes in a smaller population of women were also reported. As stated by the investigators, “At the time of initiation (2000 through 2004), only a small number of women were eligible, because smoking was much less prevalent and much less intensive among women than among men. Because of the importance of the inclusion of women, a sample of high-risk women was approached for participation.”
Study Details
In the trial, a total of 13,195 men aged 50 to 74 were randomly assigned to undergo CT screening at T0 (baseline), year 1, year 3, and year 5.5 (n = 6,583) or no screening (6,612). Participants were current or former smokers (those who had quit ≤ 10 years ago) who had smoked more than 15 cigarettes a day for more than 25 years or more than 10 cigarettes a day for more than 30 years. A minimum follow-up of 10 years through December 31, 2015, was completed for all participants.
Screening Outcomes and Mortality in Men
Among men, the average adherence to CT screening was 90.0%. An average of 9.2% of screened participants underwent at least one additional CT scan due to initially indeterminate findings. The overall referral rate for suspicious nodules was 2.1%.
At 10-year follow-up among men, the cumulative incidence of lung cancer was 5.58 cases per 1,000 person-years (341 lung cancers with known date of diagnosis) among participants in the screening group vs 4.91 cases per 1,000 person-years (304 lung cancers with a known date of diagnosis) among those in the control group (rate ratio = 1.14, 95% confidence interval [CI] = 0.97–1.33).
KEY POINTS
- The rate ratio for lung cancer death among men at 10 years for the screened vs control groups was 0.76.
- The rate ratio at 10 years in the smaller population of women was 0.67.
At 10 years of follow-up among men, the cumulative incidence of death among participants with a known date of lung cancer diagnosis was 2.50 deaths per 1,000 person-years (156 participants) in the screening group vs 3.30 deaths per 1,000 person-years (206 participants) in the control group (rate ratio = 0.76, 95% CI = 0.61–0.94, P = .01). Similar significantly different rate ratios were observed at years 8, 9, and 11.
Analysis in Women
Among the smaller population of 2,594 women randomly assigned to screening vs no screening, the 10-year rate ratio of death from lung cancer among those with a known date of lung cancer diagnosis was 0.67 (95% CI = 0.38–1.14). Rate ratios were 0.46 (95% CI = 0.21–0.96) at 7 years, 0.41 (95% CI = 0.19–0.84) at 8 years, and 0.52 (95% CI = 0.28–0.94) at 9 years.
The investigators concluded, “In this trial involving high-risk persons, lung cancer mortality was significantly lower among those who underwent volume CT screening than among those who underwent no screening. There were low rates of follow-up procedures for results suggestive of lung cancer.”
Disclosure: The study was funded by the Netherlands Organization of Health Research and Development and others. For full disclosures of the study authors, visit nejm.org.
