Table 1. Summary of previously published randomized clinical trials on low-dose computed tomography screening for lung cancer.

Trial name	Group (LDCT vs. control)	Recruitment years	N (LDCT vs. control)	Sex (F/M)	Eligibility criteria	Tomogram thickness (mm)	Screening intervals	Screening duration	Follow-up	Outcomes	Citations
NLST	LDCT vs. CXR	2002-2004	26,722 vs. 26,732	41/59	Age: 55-74 y; current or former (<15 years since quitting) smokers (≥30 pack-years)	1-2.5	0, 1, 2	3 y	6.5 y	Lung cancer specific mortality: reduction of 20.0% (95% CI, 6.8-26.7; P=0.004); all-cause mortality: reduction of 6.7% (95% CI, 1.2-13.6; P=0.02)	(7,25)
DANTE	LDCT vs. no screening	2001-2006	1,276 vs. 1,196	0/100	Age: 60-74 y; current or former smokers (≥20 pack-years)	5	0, 1, 2, 3, 4	5 y	2.8 y	LDCT vs. control number (%); lung cancer specific mortality: 20 (1.6) vs. 20 (1.7); all-cause mortality: 46 (3.6) vs. 45 (3.8)	(26,27)
DLCST	LDCT vs. no screening	2004-2006	2,052 vs. 2,052	44/56	Age: 50-70 y; current or former smokers (≥20 pack-years)	3 or 1	0, 1, 2, 3, 4	5 y	4.8 y	LDCT vs. control number (%); lung cancer specific mortality: 15 (0.7) vs. 11 (0.5); all-cause mortality: 61 (3.0) vs. 42 (2.1)	(28,29)
MILD	LDCT (annual or biennial) vs. observation	2005-2011	2,376 (1,190 annual, 1,186 biennial) vs. 1,723	34/66	Age: ≥49 y; current or former (quit <10 years ago) smokers (≥20 pack-years)	1-5	0, 1, 2, 3, 4	5 y	4.4 y	LDCT vs. control lung cancer specific mortality: HR =1.64 (95% CI, 0.67-4.01; P=0.21); all-cause mortality: HR =1.40 (95% CI, 0.82-2.38; P=0.13).	(30)

LDCT, low-dose computed tomography; F, female; M, male; y, years; CI, confidence interval; HR, hazard ratio; NLST, National Lung Screening Trial; DANTE, Detection and Screening of Early Lung Cancer by Novel Imaging Technology and Molecular Essays; DLCST, Danish Lung Cancer Screening Trial; MILD, Multicentric Italian Lung Detection.