Table 1. Clinicopathological characteristics of enrolled patients stratified by SII.
| Variables | All patients (n=3,984) | Low SII (SII ≤479, n=2,341) | High SII (SII >479, n=1,643) | P values |
|---|---|---|---|---|
| Age (years) | 0.011 | |||
| Median [IQR] | 60 [53, 66] | 60 [53, 66] | 60 [54, 67] | |
| Mean ± SD | 59.1±10.2 | 58.8±10.3 | 59.6±10.0 | |
| Sex, n (%) | <0.001 | |||
| Female | 1,845 (46.3) | 1,232 (52.6) | 613 (37.3) | |
| Male | 2,139 (53.7) | 1,109 (47.4) | 1,030 (62.7) | |
| Smoking history, n (%) | <0.001 | |||
| Never | 2,411 (60.5) | 1,582 (67.6) | 819 (50.5) | |
| Ever | 1,573 (39.5) | 759 (32.4) | 814 (49.5) | |
| CT appearance, n (%) | <0.001 | |||
| Pure GGO | 637 (16.0) | 462 (19.7) | 175 (10.7) | |
| Mixed GGO | 961 (24.1) | 671 (28.7) | 290 (17.7) | |
| Solid nodules | 2,386 (59.9) | 1,208 (51.6) | 1,178 (71.7) | |
| Operative procedure, n (%) | <0.001 | |||
| Wedge resection | 503 (12.6) | 359 (15.3) | 144 (8.8) | |
| Segmentectomy | 164 (4.1) | 118 (5.0) | 46 (2.8) | |
| Lobectomy | 2,870 (72.0) | 1,683 (71.9) | 1,187 (72.2) | |
| Bi-lobectomy | 191 (4.8) | 86 (3.7) | 105 (6.4) | |
| Sleeve resection | 102 (2.6) | 43 (1.8) | 59 (3.6) | |
| Pneumonectomy | 154 (3.9) | 52 (2.2) | 102 (6.2) | |
| Pathologic size, cm | <0.001 | |||
| Median ± SD | 2.66±1.88 | 2.21±1.48 | 3.29±2.18 | |
| p-TNM stage, n (%) | <0.001 | |||
| 0 | 212 (5.3) | 156 (6.7) | 56 (3.4) | |
| IA | 1,825 (45.9) | 1,253 (53.5) | 572 (34.8) | |
| IB | 645 (16.2) | 349 (14.9) | 296 (18.0) | |
| II | 563 (14.1) | 225 (9.6) | 338 (20.6) | |
| III | 739 (18.5) | 358 (15.3) | 381 (23.2) | |
| Histology, n (%) | <0.001 | |||
| AIS | 212 (5.3) | 156 (6.7) | 56 (3.4) | |
| MIA | 467 (11.7) | 335 (14.3) | 132 (8.0) | |
| LPA | 264 (6.6) | 187 (8.0) | 77 (4.7) | |
| APA | 1,297 (32.6) | 830 (35.5) | 467 (28.4) | |
| PPA | 264 (6.6) | 172 (7.3) | 92 (5.6) | |
| IMA | 97 (2.4) | 69 (2.9) | 28 (1.7) | |
| Histology, n (%) | <0.001 | |||
| MPA | 39 (1.0) | 21 (0.9) | 18 (1.1) | |
| SPA | 322 (8.1) | 158 (6.7) | 164 (10.0) | |
| SQCC | 784 (19.7) | 313 (13.4) | 471 (28.7) | |
| Others | 238 (6.0) | 100 (4.3) | 138 (8.4) | |
| LVI, n (%) | <0.001 | |||
| Yes | 461 (11.6) | 233 (10.0) | 228 (13.9) | |
| No | 3,523 (88.4) | 2,108 (90.0) | 1,415 (86.1) | |
| VPI, n (%) | 0.009 | |||
| Yes | 682 (17.1) | 370 (15.8) | 312 (19.0) | |
| No | 3,302 (82.9) | 1,971 (84.2) | 1,331 (81.0) | |
| Adjuvant chemotherapy, n (%) | <0.001 | |||
| Yes | 1,294 (32.5) | 599 (25.6) | 695 (42.3) | |
| No | 2,690 (67.5) | 1,742 (74.4) | 948 (57.7) | |
| Adjuvant radiotherapy, n (%) | 0.001 | |||
| Yes | 156 (3.9) | 71 (3.0) | 85 (5.2) | |
| No | 3,828 (96.1) | 2,270 (97.0) | 1,558 (94.8) |
SII, systemic immune-inflammation index; IQR, interquartile range; SD, standard deviation; CT, computed tomography; GGO, ground-glass opacity; AIS, adenocarcinoma in situ; MIA, minimally invasive adenocarcinoma; LPA, lepidic pattern-predominant adenocarcinoma; APA, acinar pattern-predominant adenocarcinoma; PPA, papillary pattern-predominant adenocarcinoma; IMA, invasive mucinous adenocarcinoma; MPA, micropapillary pattern-predominant adenocarcinoma; SPA, solid pattern-predominant adenocarcinoma; SQCC, squamous cell carcinoma; LVI, lymphovascular invasion; VPI, visceral pleural invasion.