Overview of the screening-detected lung cancers and interval cancers across the four rounds. Overview of the screening-detected lung cancers and interval cancers across the four rounds. The numbers of lung cancers presented are not equal to the number of participants with lung cancer: as 12 participants with screening-detected lung cancer (round 1, n=4; round 2, n=3; round 3, n=2; and round 4, n=3), and 1 participant with an interval lung cancer (2nd year round 3) were diagnosed with synchronous double tumours. Uraujh Yousaf-Khan et al. Thorax 2017;72:48-56 Copyright © BMJ Publishing Group Ltd & British Thoracic Society. All rights reserved.