Variable | No cancer diagnosed as a result of T1 scan (n=24 368) | Lung cancer diagnosed as a result of T1 scan (n=174) | P values* | Total (n=24 542) |
Positive T1 screen (%) | 6680 (27.4) | 165 (94.8) | <0.001 | 6845 (27.9) |
Patient characteristics | ||||
Age, mean (SD), years | 61.4 (5.0) | 63.9 (5.1) | <0.001 | 61.4 (5.0) |
Sex, female (%) | 9952 (40.8) | 70 (40.2) | 0.870 | 10 022 (40.8) |
Lung cancer in family (%) | 5283 (21.7) | 44 (25.3) | 0.250 | 5327 (21.7) |
History of cancer (%) | 969/24311 (4.0) | 12/174 (6.9) | 0.051 | 981/24485 (4.0) |
Smoking status, active (%) | 11 486 (47.1) | 100 (57.5) | 0.007 | 11 586 (47.2) |
Pack-years, mean (SD), pack-years | 55.7 (23.8) | 66.6 (26.9) | <0.001 | 55.8 (23.8) |
Smoking duration, mean (SD), years | 39.7 (7.3) | 44.1 (7.4) | <0.001 | 39.7 (7.3) |
Quit duration, mean (SD), years | 3.8 (5.0) | 2.7 (4.3) | 0.004 | 3.8 (5.0) |
History of COPD (%) | 1203 (4.9) | 17 (9.8) | 0.003 | 1220 (5.0) |
Prior diagnosis of pneumonia (%) | 5391 (22.1) | 44 (25.6) | 0.317 | 5435 (22.1) |
Occupational exposure to asbestos (%) | 1110 (4.6) | 13 (7.5) | 0.067 | 1123 (4.6) |
T0 scan findings | ||||
Emphysema on scan (%) | 7450 (30.6) | 75 (43.1) | 0.002 | 7525 (30.7) |
Longest nodule diameter, mean (SD), mm | 7.7 (5.7) | 12.2 (12.0) | <0.001 | 7.8 (5.9) |
Longest perpendicular diameter, mean (SD), mm | 5.8 (3.8) | 9.5 (10.8) | <0.001 | 5.9 (4.0) |
Presence of a non-solid nodule (%) | 975 (4.0) | 18 (10.3) | <0.001 | 993 (4.0) |
Presence of a part solid nodule (%) | 326 (1.3) | 15 (8.6) | <0.001 | 341 (1.4) |
Presence of a nodule in upper lobe (%) | 2344 (9.6) | 58 (33.3) | <0.001 | 2402 (9.8) |
Presence of a spiculated nodule (%) | 614 (2.5) | 24 (13.8) | <0.001 | 638 (2.6) |
Number of additional nodules, mean (SD), nodules | 0.14 (0.59) | 0.41 (0.79) | <0.001 | 0.14 (0.59) |
Slashes are used to show the total number of participants when there are missing data, with the total on the right.
*Unpaired t-test for continuous variables; N-1 χ2 test for binary variables.
NLST, National Lung Screening Trial; T0, baseline screening round; T1, first 1-year follow-up screening round.