Volume-based low-dose CT screening reduces lung cancer–specific mortality (NELSON)

Reference

de Koning HJ, van der Aalst CM, de Jong PA, et al. Reduced lung cancer mortality with volume CT screening in a randomized trial. N Engl J Med 2020;382(6):503-513.

Synopsis

To date, the National Lung Screening Trial is the only individual study (out of several to date) to demonstrate reduced lung cancer–specific (and all-cause) mortality by screening high-risk persons with low-dose computed tomography (CT). This Dutch study used a protocol based on the volume of nodules and doubling time to identify which patients needed additional imaging or referral for biopsy. They identified 13,195 men and 2594 women, aged 50 to 74 years, who had smoked 15 cigarettes a day for at least 25 years or 10 cigarettes a day for at least 30 years, and were either current smokers or had quit within the last 10 years. Participants were randomized to receive screening with low-dose CT at baseline, 1 year later, 3 years later, and 5.5 years later, or usual care. The cause of death was determined from national registries and, if necessary, by review of a cause of death committee. The mean age of participants was 58 years, the median pack-years of smoking was 38 years, and 55% were current smokers. After a mean 8.8 years of follow-up, the primary outcome of lung cancer mortality for men and women (based on data from the Appendix) was significantly lower in the screened group (relative risk [RR] 0.75; 0.62 - 0.90). For men, the cumulative rate ratio was 0.76 (0.61 - 0.95); for women, it was 0.67 (0.38 - 1.14). The absolute risk reduction was 0.8% over the study period, for a number needed to screen to prevent 1 lung cancer death of 127. There was no difference in all-cause mortality, but the study was not powered for this outcome. Overall, only 2.1% of test results were classified as positive and required evaluation for biopsy.