1.
Baseline demographics and clinical characteristics of study population
| Characteristics | All
(N=717) |
Development cohort
(n=423) |
Validation cohort
(n=294) |
P** | |||||||
| All | LN-positive | LN-negative | P* | All | LN-positive | LN-negative | P* | ||||
| IQR, inter-quartile range; CT, computed tomography; LN, lymph node; *, P value was derived from univariable association analyses between each of clinicopahologic variables and LN status; **, P value was derived from comparison of patient characteristics between development cohort and validation cohort. | |||||||||||
| Age (year) | |||||||||||
| Median (IQR) | 61
(53, 67) |
61
(54, 67) |
59
(50, 65) |
62
(55, 68) |
0.002 | 61
(52, 67) |
58
(52, 64) |
62
(53, 69) |
0.023 | 0.829 | |
| >60 [n (%)] | 365
(50.9) |
214
(50.6) |
51
(38.9) |
163
(55.8) |
0.001 | 151
(51.4) |
38
(40.4) |
113
(56.5) |
0.010 | 0.839 | |
| Gender [n (%)] | |||||||||||
| Male | 425
(59.3) |
258
(61.0) |
79
(60.3) |
179
(61.3) |
0.846 | 167
(56.8) |
59
(62.8) |
108
(54.0) |
0.157 | 0.261 | |
| Female | 292
(40.7) |
165
(39.0) |
52
(39.7) |
113
(38.7) |
127
(43.2) |
35
(37.2) |
92
(46.0) |
||||
| Smoking history [n (%)] | |||||||||||
| Yes | 246
(34.3) |
152
(35.9) |
43
(32.8) |
109
(37.3) |
0.372 | 94
(32.0) |
36
(38.3) |
58
(29.0) |
0.111 | 0.272 | |
| No | 471
(65.7) |
271
(64.1) |
88
(67.2) |
183
(62.7) |
200
(68.0) |
58
(61.7) |
142
(71.0) |
||||
| Tumor diameter (cm) | |||||||||||
| Median (IQR) | 25
(18, 38) |
26
(19, 37) |
35
(26, 48) |
23
(17, 32) |
<0.0001 | 24
(17, 38) |
34
(22, 44) |
23
(14, 32) |
<0.0001 | 0.146 | |
| >3 [n (%)] | 265
(37.0) |
160
(37.8) |
78
(59.5) |
82
(28.1) |
<0.0001 | 105
(35.7) |
51
(54.3) |
54
(27.0) |
<0.0001 | 0.565 | |
| Tumor location [n (%)] | |||||||||||
| Peripheral | 575
(80.2) |
340
(80.4) |
73
(55.7) |
267
(91.4) |
<0.0001 | 235
(79.9) |
63
(67.0) |
172
(86.0) |
<0.0001 | 0.883 | |
| Central | 142
(19.8) |
83
(19.6) |
58
(44.3) |
25
(8.6) |
59
(20.1) |
31
(33.0) |
28
(14.0) |
||||
| CT-based LN status [n (%)] | |||||||||||
| Negative | 392
(54.7) |
231
(54.6) |
44
(33.6) |
187
(64.0) |
<0.0001 | 161
(54.8) |
21
(22.3) |
140
(70.0) |
<0.0001 | 0.968 | |
| Positive | 325
(45.3) |
192
(45.4) |
87
(66.4) |
105
(36.0) |
133
(45.2) |
73
(77.7) |
60
(30.0) |
||||