Results of the Randomized Danish Lung Cancer Screening Trial with Focus on High-risk Profiling

RATIONALE: As of April 2015, participants of the Danish Lung Cancer Screening Trial have been followed for at least 5 years since the last screen. Objectives Mortality, causes of death, and lung cancer findings are reported.

METHODS: 4,104 participants aged 50-70 years at time of inclusion and with minimum 20 packyears were randomized to five annual low-dose CT scans or no screening.

MEASUREMENTS: Follow-up information regarding date and cause of death, lung cancer diagnosis, stage, and histology was obtained from national registries.

MAIN RESULTS: No differences in lung cancer mortality (Hazard Ratio (HR): 1.03, p=0.888, 95% CI: 0.66-1.6) or all-cause mortality (HR: 1.02, p=0.867, 95% CI: 0.82-1.27) were observed between the two groups. More cancers (100 vs. 53, p<0.001) were found in the screening group, in particular adenocarcinomas (58 vs. 18, p<0.001). More early-staged cancers (stage I+II: 54 vs. 10, p<0.001) and stage IIIa cancers (15 vs. 3, p=0.009) were found in the screening group. Stage IV cancers were non-significantly more frequent in the control group (23 vs. 32, p=0.278). For the highest-stage cancers (T4N3M1: 8 vs. 21, p=0.025) this was statistically significant, indicating an absolute stage-shift. Participants with higher age, COPD, and more than 35 pack-years had significantly increased risk of death from lung cancer with non-significantly fewer deaths in the screening group.

CONCLUSIONS: No statistically significant effects of CT screening on lung cancer mortality were found, but results of post hoc high-risk sub-group analyses show non-significant trends that seem in good agreement with results of the American NLST. Clinical trial registration available at www.clinicaltrials.gov, ID NCT00496977.