TABLE 2.
Clinical cancer characteristics of ever-smokers and never-smokers before and after matching
| Before matching | After matching | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
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| Characteristic | Never-smokers (n = 172) | Ever-smokers (n = 1376) | Standardized difference, % | Never-smokers (n = 169) | Ever-smokers (n = 165) | Standardized difference, % | ||||
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| n* | No. (%) | n* | No. (%) | n* | No. (%) | n* | No. (%) | |||
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| Tumor location | 172 | 1376 | 168 | 165 | ||||||
| Right upper | 51 (30) | 498 (36) | −14 | 50 (30) | 58 (35) | −11 | ||||
| Right middle | 5 (2.9) | 71 (5.1) | −11 | 5 (3.0) | 11 (6.4) | −16 | ||||
| Right lower | 45 (26) | 255 (19) | 18 | 45 (27) | 35 (21) | 13 | ||||
| Left upper | 40 (23) | 357 (26) | −6.2 | 38 (23) | 42 (26) | −6.3 | ||||
| Left lower | 28 (16) | 184 (13) | 8.2 | 27 (16) | 20 (12) | 11 | ||||
| Right central | 2 (1.2) | 14 (1.0) | 1.4 | 2 (1.2) | 0.95 (0.57) | 6.5 | ||||
| Left central | 2 (1.2) | 19 (1.4) | −1.9 | 2 (1.2) | 0.73 (0.44) | 8.3 | ||||
| Focality | 170 | 1373 | 0.55 | 167 | 165 | −4.0 | ||||
| Unifocal | 156 (92) | 1262 (92) | 154 (92) | 150 (91) | ||||||
| Multifocal | 14 (8.2) | 111 (8.1) | 13 (7.9) | 15 (9.0) | ||||||
| Histopathological type | 172 | 1373 | 169 | 165 | ||||||
| Adenocarcinoma | 151 (88) | 845 (62) | 63 | 148 (88) | 146 (89) | −3.0 | ||||
| Large cell | 2 (1.2) | 60 (4.4) | −20 | 2 (1.2) | 4.5 (2.8) | −11 | ||||
| Not otherwise specified | 0(0) | 18 (1.3) | −16 | 0(0) | 1.3 (0.76) | −12 | ||||
| Other | 9 (5.2) | 31 (2.3) | 16 | 9 (5.1) | 3.0 (1.8) | 18 | ||||
| Squamous | 10 (5.8) | 419 (31) | −68 | 10 (6.0) | 9.8 (6.0) | −0.15 | ||||
| Invasion and involved margins | ||||||||||
| Visceral pleural invasion | 167 | 55 (33) | 1360 | 386 (28) | −9.9 | 164 | 54 (33) | 163 | 44 (27) | 13 |
| Lymphovascular invasion | 128 | 54 (42) | 1049 | 426 (41) | 3.2 | 124 | 52 (42) | 126 | 53 (42) | −0.75 |
| Soft tissue margin involved | 120 | 7 (5.8) | 1040 | 35 (3.4) | 12 | 118 | 7 (5.9) | 123 | 4.0 (3.2) | 13 |
| Bronchial margin involved | 158 | 6 (3.8) | 1230 | 13(1.1) | 18 | 155 | 5.8 (3.8) | 151 | 0.69 (0.46) | 23 |
| Vascular margin involved | 161 | 3 (1.9) | 1222 | 15 (1.2) | 5.0 | 158 | 3 (1.9) | 150 | 0.75 (0.5) | 13 |
| Parenchymal margin involved | 103 | 1 (0.97) | 902 | 9 (1.0) | −0.27 | 101 | 1 (0.99) | 108 | 0.57 (0.53) | 5.3 |
| Pathological T category | 172 | 1376 | 169 | 165 | ||||||
| 1a | 7 (4.1) | 104 (7.6) | −15 | 7 (4.1) | 12 (7.1) | −13 | ||||
| 1b | 45 (26) | 379 (28) | −3.1 | 44 (26) | 47 (28) | −4.6 | ||||
| 1c | 47 (27) | 341 (25) | 5.8 | 46 (27) | 42 (26) | 3.3 | ||||
| 2a | 35 (20) | 212(15) | 13 | 34 (20) | 25 (15) | 13 | ||||
| 2b | 13 (7.6) | 116 (8.4) | −3.2 | 13 (7.7) | 14 (8.6) | −3.4 | ||||
| 3 | 13 (7.6) | 129 (9.4) | −6.5 | 13 (7.5) | 17 (10) | −9.0 | ||||
| 4 | 12 (7.0) | 95 (6.9) | 0.29 | 12 (7.1) | 8.3 (5.0) | 8.7 | ||||
| Pathological N category | 172 | 1376 | 169 | 165 | ||||||
| 0 | 116 (67) | 1007 (73) | −13 | 113 (67) | 116 (70) | −6.1 | ||||
| 1 | 35 (20) | 241 (18) | 7.2 | 35 (21) | 30 (18) | 5.8 | ||||
| 2 | 21 (12) | 126 (9.2) | 9.9 | 20 (12) | 19(11) | 1.95 | ||||
| 3 | 0(0) | 2 (0.15) | −5.4 | 0(0) | 0.13 (0.08) | −3.99 | ||||
| Pathological M category | 172 | 170 (99) | 1376 | 1353 (98) | −4.3 | 169 | 167 (99) | 165 | 163 (99) | −0.74 |
| Pathological stage group | 172 | 1376 | 11 | 169 | 165 | 7.3 | ||||
| IA1 | 4 (2.3) | 95 (6.9) | 4 (2.3) | 11 (6.5) | ||||||
| IA2 | 40 (23) | 317 (23) | 39 (23) | 36 (22) | ||||||
| IA3 | 29 (17) | 255 (19) | 28 (16) | 28 (17) | ||||||
| IB | 19(11) | 133 (9.7) | 19(11) | 14 (8.8) | ||||||
| IIA | 6 (3.5) | 63 (4.6) | 6 (3.6) | 8.2 (5.0) | ||||||
| IIB | 41 (24) | 252(18) | 41 (24) | 36 (22) | ||||||
| IIIA | 27 (16) | 203 (15) | 26 (16) | 25 (15) | ||||||
| IIIB | 4 (2.3) | 34 (2.5) | 4 (2.3) | 3.8 (2.3) | ||||||
| IIIC | 0(0) | 1 (0.07) | 0(0) | 0.03 (0.02) | ||||||
| IV | 2 (1.2) | 23 (1.7) | 2 (1.2) | 2.1 (1.3) | ||||||
*
Patients with data available.