Training cohort (n = 287) | Internal validation cohort (n = 122) | External validation cohort (n = 65) | |
---|---|---|---|
Age, median (IQR) | 60 (54–67) | 60 (51–66.3) | 61 (52–69) |
Gender (%) | |||
Male | 127 (44.3) | 60 (49.2) | 27 (41.5) |
Female | 160 (55.7) | 62 (50.8) | 38 (58.5) |
Smoking history (%) | |||
Never | 254 (88.5) | 110 (90.2) | 40 (61.5) |
Ever | 33 (11.5) | 12 (9.8) | 25 (38.5) |
Tumor location (%) | |||
Upper left | 58 (20.2) | 23 (18.9) | 15 (23.1) |
Lower left | 40 (13.9) | 20 (16.4) | 11 (16.9) |
Upper right | 102 (35.5) | 47 (38.5) | 19 (29.2) |
Right middle | 32 (11.1) | 5 (4.1) | 8 (12.3) |
Lower right | 55 (19.2) | 27 (22.1) | 12 (18.5) |
Pathological subtype (%) | |||
Lepidic | 36 (12.5) | 12 (9.8) | 19 (29.2) |
Acinar/papillary | 236 (82.2) | 106 (86.9) | 40 (61.5) |
Solid/micropapillary | 15 (5.2) | 4 (3.3) | 6 (9.2) |
Tumor size (cm) | |||
0–1 | 47 (16.4) | 23 (18.9) | 22 (33.8) |
1–2 | 146 (50.9) | 53 (43.4) | 17 (26.2) |
2–3 | 73 (25.3) | 36 (29.5) | 18 (27.7) |
3–4 | 21 (7.3) | 10 (8.2) | 8 (12.3) |
TNM stage (%) | |||
IA1 | 45 (15.7) | 20 (16.4) | 22 (33.8) |
IA2 | 130 (45.3) | 45 (36.9) | 10 (15.4) |
IA3 | 62 (21.6) | 31 (25.4) | 7 (10.8) |
IB | 50 (17.4) | 26 (21.3) | 26 (40.0) |
Visceral pleural invasion (VPI, %) | |||
Absent | 247 (86.1) | 101 (82.8) | 45 (69.2) |
Present | 40 (13.9) | 21 (17.2) | 20 (30.8) |
Lymphovascular invasion (LVI, %) | |||
Absent | 278 (96.9) | 119 (97.5) | 64 (98.5) |
Present | 9 (3.1) | 3 (2.5) | 1 (1.5) |
Duration of follow-up, median (month) | 92.3 | 92.4 | 26.6 |
Adjuvant chemotherapy (%) | 32 (11.1) | 11 (9.0) | NA |