Introduction
Materials and methods
Patients
Data collection
Statistical analyses
Results
Patient characteristics
Without PSM | With PSM | |||||
---|---|---|---|---|---|---|
Groups | NLNs ≤ 5 | NLNs > 5 | p value | NLNs ≤ 5 | NLNs > 5 | p value |
Total | 3850 | 3443 | 2350 | 2350 | ||
Sex (%) | 0.437* | 0.423* | ||||
Male | 1588 (41.2%) | 1452 (42.2%) | 968 (41.2%) | 940 (40.0%) | ||
Female | 2262 (58.8%) | 1991 (57.8%) | 1382 (58.8%) | 1410 (60.0%) | ||
Age (%) | < 0.001* | 0.906* | ||||
≤ 65 | 1468 (38.1%) | 1517 (44.1%) | 990 (42.1%) | 985 (41.9%) | ||
> 65 | 2382 (61.9%) | 1926 (55.9%) | 1360 (57.9%) | 1365 (58.1%) | ||
TNM stage (%) | 0.004* | 1* | ||||
IA1 | 703 (18.3%) | 541 (15.7%) | 349 (14.9%) | 350 (14.9) | ||
IA2 | 3147 (81.7%) | 2902 (84.3%) | 2001 (85.1%) | 2000 (85.1%) | ||
Grade (%) | < 0.001* | 0.707* | ||||
I | 841 (21.8%) | 774 (22.5%) | 525 (22.3%) | 530 (22.6%) | ||
II | 1622 (42.1%) | 1569 (45.6%) | 1045 (44.5%) | 999 (42.5%) | ||
III | 992 (25.8%) | 847 (24.6%) | 578 (24.6%) | 609 (25.9%) | ||
IV | 55 (1.4%) | 37 (1.1%) | 32 (1.4%) | 32 (1.4%) | ||
Unknown | 340 (8.8%) | 216 (6.3%) | 170 (7.2%) | 180 (7.7%) | ||
Tumor location (%) | < 0.001** | 1** | ||||
Upper lobe | 2258 (58.6%) | 2289 (66.5%) | 1388 (59.1%) | 1395 (59.4%) | ||
Middle lobe` | 311 (8.1%) | 148 (4.3%) | 148 (6.3%) | 146 (6.2%) | ||
Lower lobe | 1216 (31.6%) | 965 (28.0%) | 783 (33.3%) | 777 (33.1%) | ||
Main bronchus | 5 (0.1%) | 4 (0.1%) | 1 (0.0%) | 1 (0.0%) | ||
Overlapping | 16 (0.4%) | 12 (0.3%) | 10 (0.4%) | 10 (0.4%) | ||
Lung NOS | 44 (1.1%) | 25 (0.7%) | 20 (0.9%) | 21 (0.9%) | ||
Tumor size (mean (SD) (mm)) | 14.72 (4.03) | 15.05 (3.86) | < 0.001*** | 15.12 (3.88) | 15.08 (3.81) | 0.690*** |
Race (%) | 0.059** | 0.972** | ||||
American Indian | 15 (0.4%) | 14 (0.4%) | 10 (0.4%) | 12 (0.5%) | ||
Asian | 194 (5.0%) | 203 (5.9%) | 141 (6.0%) | 148 (6.3%) | ||
Black | 324 (8.4%) | 239 (6.9%) | 197 (8.4%) | 196 (8.3%) | ||
White | 3308 (85.9%) | 2983 (86.6%) | 3 (0.1%) | 4 (0.2%) | ||
Unknown | 9 (0.2%) | 4 (0.1%) | 1999 (85.1%) | 1990 (84.7%) | ||
Surgical methods (%) | < 0.001** | 1** | ||||
Wedge resection | 1417 (36.8%) | 230 (6.7%) | 230 (9.8%) | 230 (9.8%) | ||
Segmental resection | 284 (7.4%) | 80 (2.3%) | 79 (3.4%) | 79 (3.4%) | ||
Lobectomy | 2126 (55.2%) | 3102 (90.1%) | 2030 (86.4%) | 2030 (86.4%) | ||
Pneumonectomy | 17 (0.4%) | 28 (0.8%) | 11 (0.5%) | 11 (0.5%) | ||
Unknown | 6 (0.2%) | 3 (0.1%) | 0 (0.0%) | 0 (0.0%) | ||
Histological types (%) | 0.157** | 0.866** | ||||
Adeno | 2503 (65.0%) | 2297 (66.7%) | 1592 (67.7%) | 1565 (66.6%) | ||
SCC | 861 (22.4%) | 745 (21.6%) | 494 (21.0%) | 510 (21.7%) | ||
LCC | 117 (3.0%) | 74 (2.1%) | 56 (2.4%) | 60 (2.6%) | ||
PSC | 3 (0.1%) | 2 (0.1%) | 1 (0.0%) | 0 (0.0%) | ||
Other | 222 (5.8%) | 210 (6.1%) | 134 (5.7%) | 136 (5.8%) | ||
Unknown | 144 (3.7%) | 115 (3.3%) | 73 (3.1%) | 79 (3.4%) |
Effect of NLNs on survival outcomes
CSS | OS | ||||||
---|---|---|---|---|---|---|---|
Variable | Number | Univariate analysis | Multivariate analysis | Univariate analysis | Multivariate analysis | ||
p value | HR (95%CIs) | p value | p value | HR (95%CIs) | p value | ||
NLNs | |||||||
≤ 5 | 3850 | 1 (reference) | 1 (reference) | ||||
> 5 | 3443 | < 0.001 | 0.791 (0.710–0.882) | < 0.001 | < 0.001 | 0.821 (0.763–0.884) | < 0.001 |
Sex | |||||||
Male | 3040 | 1 (reference) | 1 (reference) | ||||
Female | 4253 | < 0.001 | 0.757 (0.686–0.835) | < 0.001 | < 0.001 | 0.723 (0.676–0.773) | < 0.001 |
Age | |||||||
≤ 65 | 2985 | 1 (reference) | 1 (reference) | ||||
> 65 | 4308 | < 0.001 | 1.548 (1.393–1.720) | < 0.001 | < 0.001 | 1.946 (1.806–2.096) | < 0.001 |
TNM stage | |||||||
IA1 | 1244 | 1 (Reference) | 1 (Reference) | ||||
IA2 | 6049 | 0.003 | 1.023 (0.843–1.243) | 0.815 | < 0.001 | 1.038 (0.911–1.182) | 0.578 |
Grade | |||||||
I | 1615 | 1 (reference) | 1 (reference) | ||||
II | 3191 | < 0.001 | 2.109 (1.794–2.479) | < 0.001 | < 0.001 | 1.631 (1.471–1.807) | < 0.001 |
III | 1839 | < 0.001 | 2.810 (2.364–3.341) | < 0.001 | < 0.001 | 2.004 (1.792–2.242) | < 0.001 |
IV | 92 | < 0.001 | 1.476 (0.911–2.392) | 0.113 | < 0.001 | 1.303 (0.944–1.797) | 0.107 |
Unknown | 556 | < 0.001 | 1.785 (1.414–2.253) | < 0.001 | < 0.001 | 1.407 (1.207–1.640) | < 0.001 |
Tumor location (%) | |||||||
Upper lobe | 4547 | 1 (Reference) | |||||
Middle lobe | 459 | 0.597 | 0.017 | 0.895 (0.773–1.036) | 0.138 | ||
Lower lobe | 2181 | 0.794 | 0.712 | 1.038 (0.964–1.119) | 0.320 | ||
Main bronchus | 9 | 0.427 | 0.351 | 0.800 (0.257–2.485) | 0.699 | ||
Overlapping | 28 | 0.821 | 0.431 | 1.429 (0.859–2.378) | 0.169 | ||
Lung NOS | 69 | 0.176 | 0.148 | 1.114 (0.811–1.530) | 0.506 | ||
Tumor size (mm) | – | < 0.001 | 1.022 (1.004–1.041) | 0.015 | < 0.001 | 1.018 (1.005–1.030) | 0.005 |
Race | |||||||
American Indian | 29 | 1 (Reference) | |||||
Asian | 397 | 0.725 | 0.160 | 0.613 (0.346–1.083) | 0.092 | ||
Black | 563 | 0.410 | 0.742 | 0.962 (0.551–1.679) | 0.890 | ||
White | 6291 | 0.548 | 0.747 | 0.920 (0.533–1.587) | 0.764 | ||
Unknown | 13 | 0.981 | 0.049 | 0.150 (0.020–1.150) | 0.068 | ||
Surgical methods | |||||||
Wedge resection | 1647 | 1 (reference) | 1 (reference) | ||||
Segmental resection | 364 | 0.397 | 0.944 (0.757–1.178) | 0.610 | 0.009 | 0.841 (0.721–0.981) | 0.027 |
Lobectomy | 5228 | < 0.001 | 0.719 (0.637–0.812) | < 0.001 | < 0.001 | 0.696 (0.641–0.756) | < 0.001 |
Pneumonectomy | 45 | 0.033 | 1.957 (1.183–3.238) | 0.009 | 0.030 | 1.623 (1.137–2.315) | 0.008 |
Unknown | 6 | 0.426 | 0.430 (0.060–3.061) | 0.399 | 0.284 | 0.567 (0.182–1.763) | 0.327 |
Histological types | |||||||
Adeno | 4800 | 1 (reference) | 1 (reference) | ||||
SCC | 1606 | < 0.001 | 1.046 (0.926–1.182) | 0.470 | < 0.001 | 1.376 (1.271–1.490) | < 0.001 |
LCC | 191 | < 0.001 | 1.666 (1.276–2.175) | < 0.001 | < 0.001 | 1.533 (1.257–1.869) | < 0.001 |
PSC | 5 | 0.012 | 2.516 (0.808–7.832) | 0.111 | 0.036 | 1.691 (0.633–4.517) | 0.294 |
Other | 432 | 0.011 | 1.241 (1.014–1.518) | 0.036 | 0.020 | 1.140 (0.984–1.321) | 0.080 |
Unknown | 259 | 0.008 | 0.971 (0.755–1.247) | 0.815 | < 0.001 | 1.135 (0.961–1.339) | 0.136 |
CSS | OS | ||||||
---|---|---|---|---|---|---|---|
Variable | Number | Univariate analysis | Multivariate analysis | Univariate analysis | Multivariate analysis | ||
p value | HR (95%CIs) | p value | p value | HR (95%CIs) | p value | ||
NLNs | |||||||
≤ 5 | 2350 | 1 (reference) | 1 (reference) | ||||
> 5 | 2350 | < 0.001 | 0.631 (0.557–0.714) | < 0.001 | < 0.001 | 0.650 (0.597–0.708) | < 0.001 |
Sex | |||||||
Male | 1908 | 1 (reference) | 1 (reference) | ||||
Female | 2790 | < 0.001 | 0.631 (0.557–0.714) | < 0.001 | < 0.001 | 0.714 (0.657–0.777) | < 0.001 |
Age | |||||||
≤ 65 | 1975 | 1 (reference) | 1 (reference) | ||||
> 65 | 2725 | < 0.001 | 1.410 (1.244–1.599) | < 0.001 | < 0.001 | 1.829 (1.671–2.002) | < 0.001 |
TNM stage | |||||||
IA1 | 699 | 1 (reference) | 1 (reference) | ||||
IA2 | 4001 | 0.005 | 1.153 (0.900–1.478) | 0.261 | 0.003 | 1.117 (0.944–1.322) | 0.197 |
Grade | |||||||
I | 1055 | 1 (reference) | 1 (reference) | ||||
II | 2044 | < 0.001 | 2.094 (1.724–2.543) | < 0.001 | < 0.001 | 1.642 (1.446–1.864) | < 0.001 |
III | 1187 | < 0.001 | 2.762 (2.242–3.402) | < 0.001 | < 0.001 | 2.055 (1.791–2.360) | < 0.001 |
IV | 64 | 0.007 | 1.574 (0.901–2.748) | 0.111 | 0.007 | 1.248 (0.843–1.847) | 0.268 |
Unknown | 350 | 0.005 | 1.643 (1.222–2.210) | 0.001 | 0.037 | 1.277 (1.045–1.560) | 0.017 |
Tumor location (%) | |||||||
Upper lobe | 2783 | ||||||
Middle lobe | 294 | 0.640 | 0.158 | ||||
Lower lobe | 1560 | 0.627 | 0.443 | ||||
Main bronchus | 2 | 0.982 | 0.973 | ||||
Overlapping | 20 | 0.891 | 0.977 | ||||
Lung NOS | 41 | 0.079 | 0.230 | ||||
Tumor size (mm) | – | < 0.001 | 1.019 (0.997–1.042) | 0.094 | < 0.001 | 1.014 (0.999–1.030) | 0.066 |
Race | |||||||
American Indian | 22 | ||||||
Asian | 289 | 0.820 | 0.225 | ||||
Black | 393 | 0.455 | 0.865 | ||||
White | 3989 | 0.667 | 0.924 | ||||
Unknown | 7 | 0.978 | 0.967 | ||||
Surgical methods | |||||||
Wedge resection | 460 | 1 (reference) | 1 (reference) | ||||
Segmental resection | 158 | 0.025 | 0.546 (0.392–0.761) | < 0.001 | < 0.001 | 0.503 (0.396–0.638) | < 0.001 |
Lobectomy | 4060 | < 0.001 | 0.339 (0.283–0.405) | < 0.001 | < 0.001 | 0.353 (0.312–0.400) | < 0.001 |
Pneumonectomy | 22 | 0.533 | 0.581 (0.256–1.318) | 0.194 | 0.225 | 0.537 (0.301–0.958) | 0.035 |
Unknown | 0 | NA | NA | NA | |||
Histological types | |||||||
Adeno | 3157 | 1 (reference) | 1 (reference) | ||||
SCC | 1004 | < 0.001 | 1.064 (0.915–1.237) | 0.424 | < 0.001 | 1.371 (1.240–1.516) | < 0.001 |
LCC | 116 | < 0.001 | 1.640 (1.163–2.314 | 0.005 | < 0.001 | 1.585 (1.228–2.045) | < 0.001 |
PSC | 1 | 0.981 | 0.000 (0.000–Inf) | 0.981 | 0.981 | 0.000 (0.000–Inf) | 0.972 |
Other | 270 | 0.140 | 1.140 (0.883–1.472) | 0.314 | 0.082 | 1.117 (0.929–1.342) | 0.240 |
Unknown | 152 | 0.575 | 0.867 (0.612–1.228) | 0.422 | 0.008 | 1.086 (0.867–1.361) | 0.472 |