Table 1. Baseline characteristics of 7,311 enrolled lung cancer patients by pathological stage.
| Characteristic | Total† | Pathological stage | P value§ | ||||
|---|---|---|---|---|---|---|---|
| Stage I | Stage II | Stage III | Stage IV | Unknown‡ | |||
| Age | <0.01 | ||||||
| <60 years | 3,401 (46.5) | 459 (43.0) | 166 (44.4) | 680 (47.5) | 1,346 (50.3) | 750 (42.5) | |
| ≥60 years | 3,910 (53.5) | 608 (57.0) | 208 (55.6) | 751 (52.5) | 1,328 (49.7) | 1,015 (57.5) | |
| Sex | <0.01 | ||||||
| Male | 4,912 (67.2) | 582 (54.5) | 256 (68.4) | 1,052 (73.5) | 1,751 (65.5) | 1,271 (72.0) | |
| Female | 2,399 (32.8) | 485 (45.5) | 118 (31.6) | 379 (26.5) | 923 (34.5) | 494 (28.0) | |
| Smoking | <0.01 | ||||||
| Never-smoker | 3,283 (44.9) | 624 (58.5) | 150 (40.1) | 554 (38.7) | 1,249 (46.7) | 706 (40.0) | |
| Current-smoker | 3,148 (43.1) | 330 (30.9) | 166 (44.4) | 696 (48.6) | 1,118 (41.8) | 838 (47.5) | |
| Former-smoker | 812 (11.1) | 108 (10.1) | 54 (14.4) | 175 (12.2) | 275 (10.3) | 200 (11.3) | |
| Unknown‡ | 68 (0.9) | 5 (0.5) | 4 (1.1) | 6 (0.4) | 32 (1.2) | 21 (1.2) | |
| Alcohol assumption | <0.01 | ||||||
| No | 4,968 (68.0) | 797 (74.7) | 241 (64.4) | 891 (62.3) | 1,861 (69.6) | 1,178 (66.7) | |
| Yes | 2,281 (31.2) | 259 (24.3) | 127 (34.0) | 533 (37.2) | 790 (29.5) | 572 (32.4) | |
| Unknown‡ | 62 (0.8) | 11 (1.0) | 6 (1.6) | 7 (0.5) | 23 (0.9) | 15 (0.8) | |
| Disease history | <0.01 | ||||||
| No | 5,547 (75.9) | 648 (60.7) | 278 (74.3) | 1,115 (77.9) | 2,169 (81.1) | 1,337 (75.8) | |
| Yes¶ | 1,654 (22.6) | 411 (38.5) | 93 (24.9) | 301 (21.0) | 470 (17.6) | 379 (21.5) | |
| Unknown‡ | 110 (1.5) | 8 (0.7) | 3 (0.8) | 15 (1.0) | 35 (1.3) | 49 (2.8) | |
| Family history | <0.01 | ||||||
| No | 6,553 (89.6) | 916 (85.8) | 325 (86.9) | 1,222 (85.4) | 2,432 (90.9) | 1,658 (93.9) | |
| Yes†† | 283 (3.9) | 77 (7.2) | 13 (3.5) | 52 (3.6) | 87 (3.3) | 54 (3.1) | |
| Unknown‡ | 475 (6.5) | 74 (6.9) | 36 (9.6) | 157 (11.0) | 155 (5.8) | 53 (3.0) | |
| Body mass index‡‡ | <0.01 | ||||||
| Underweight | 342 (4.7) | 28 (2.6) | 15 (4.0) | 75 (5.2) | 136 (5.1) | 88 (5.0) | |
| Normal | 3,372 (46.1) | 398 (37.3) | 163 (43.6) | 602 (42.1) | 1,242 (46.4) | 967 (54.8) | |
| Overweight | 1,508 (20.6) | 280 (26.2) | 94 (25.1) | 289 (20.2) | 440 (16.5) | 405 (22.9) | |
| Unknown‡ | 2,089 (28.6) | 361 (33.8) | 102 (27.3) | 465 (32.5) | 856 (32.0) | 305 (17.3) | |
| Histological classification | <0.01 | ||||||
| Squamous cell carcinoma | 1,579 (21.6) | 201 (18.8) | 130 (34.8) | 430 (30.0) | 388 (14.5) | 430 (24.4) | |
| Adenocarcinoma | 3,335 (45.6) | 704 (66.0) | 183 (48.9) | 558 (39.0) | 1,344 (50.3) | 546 (30.9) | |
| Small cell carcinoma | 938 (12.8) | 51 (4.8) | 20 (5.3) | 212 (14.8) | 310 (11.6) | 345 (19.5) | |
| Others§§ | 518 (7.1) | 71 (6.7) | 32 (8.6) | 115 (8.0) | 178 (6.7) | 122 (6.9) | |
| Unknown‡ | 941 (12.9) | 40 (3.7) | 9 (2.4) | 116 (8.1) | 454 (17.0) | 322 (18.2) | |
| Lesion site | <0.01 | ||||||
| Right | 3,971 (54.3) | 636 (59.6) | 200 (53.5) | 800 (55.9) | 1,414 (52.9) | 921 (52.2) | |
| Left | 3,184 (43.6) | 428 (40.1) | 168 (44.9) | 625 (43.7) | 1,192 (44.6) | 771 (43.7) | |
| Both | 49 (0.7) | 1 (0.1) | 5 (1.3) | 5 (0.3) | 26 (1.0) | 12 (0.7) | |
| Unknown‡ | 107 (1.5) | 2 (0.2) | 1 (0.3) | 1 (0.1) | 42 (1.6) | 61 (3.5) | |
| Treatment | <0.01 | ||||||
| No | 954 (13.0) | 42 (3.9) | 18 (4.8) | 158 (11.0) | 365 (13.6) | 371 (21.0) | |
| Yes¶¶ | 6,307 (86.3) | 1,023 (95.9) | 356 (95.2) | 1,268 (88.6) | 2,289 (85.6) | 1,371 (77.7) | |
| Unknown‡ | 50 (0.7) | 2 (0.2) | 0 (0.0) | 5 (0.3) | 20 (0.7) | 23 (1.3) | |
| Sample size | 7,311 | 1,067 | 374 | 1,431 | 2,674 | 1,765 | |
Categorical data are shown as n (%). †, the total proportion may not be 100 due to the rounding; ‡, unknown data were not included in the statistical tests; §, P values were calculated by Chi square/Fisher exact test; ¶, referring to lung diseases, such as tuberculosis, chronic bronchitis, emphysema, asthma, and silicosis/pneumoconiosis; ††, referring to participants with first-degree or second-degree relatives diagnosed with any type of lung cancer; ‡‡, body mass index was calculated based on the height and weight values, and was categorized in to 3 groups according to the WHO standard, which were underweight (<18.5 kg/m2), normal (18.5–24.9 kg/m2), and overweight (≥25 kg/m2); §§, including large cell carcinoma, carcinoid, sarcomatoid carcinoma, and adenosquamous carcinoma; ¶¶, Including surgery, chemotherapy, radiotherapy and targeted therapy.