TABLE 1.
Patient characteristics
| Characteristics | No. of patients (%) |
|---|---|
| Gender | |
| Male | 8997 (73.0) |
| Female | 3323 (27.0) |
| Age | |
| Median (range) | 70 (22‐102) |
| Mean (standard deviation) | 69.3 (±10.2) |
| Smoking status | |
| Never smoker | 2489 (20.2) |
| Former smoker | 4808 (39.0) |
| Current smoker | 5023 (40.8) |
| TNM stage | |
| T‐factor | |
| TX | 353 (2.9) |
| T0 | 31 (0.3) |
| Tis | 16 (0.3) |
| T1a | 856 (6.9) |
| T1b | 1246 (10.1) |
| T2a | 2678 (21.7) |
| T2b | 1084 (8.8) |
| T3 | 2243 (18.2) |
| T4 | 3813 (30.9) |
| N‐factor | |
| NX | 165 (1.3) |
| N0 | 2056 (16.7) |
| N1 | 1274 (10.3) |
| N2 | 4058 (32.9) |
| N3 | 4767 (38.7) |
| M‐factor | |
| M0 | 4155 (33.7) |
| M1a | 2450 (19.9) |
| M1b | 5715 (46.4) |
| Stage | |
| IA | 261 (2.1) |
| IB | 207 (1.7) |
| IIA | 253 (2.1) |
| IIB | 168 (1.4) |
| IIIA | 1535 (12.5) |
| IIIB | 1725 (14.0) |
| IV | 8171 (66.3) |
| Histology | |
| Non–small cell lung cancer | 9872 (80.1) |
| Adenocarcinoma | 6276 (50.9) |
| Squamous cell carcinoma | 2602 (21.1) |
| Large cell | 165 (1.3) |
| Adenosquamous | 60 (0.5) |
| Not otherwise specified | 632 (5.1) |
| Others | 137 (1.1) |
| Small cell lung cancer | 2353 (19.1) |
| Others | 19 (0.2) |
| Unknown | 76 (0.6) |
| Performance status | |
| 0 | 3783 (30.7) |
| 1 | 5701 (46.3) |
| 2 | 1515 (12.3) |
| 3 | 921 (7.5) |
| 4 | 400 (3.2) |