Table 1.
Clinical characteristics of the patients
| Total | Before PSM | After PSM | |||||
|---|---|---|---|---|---|---|---|
| SII | SII | ||||||
| < 529 | > 529 | P-value | < 529 | > 529 | P-value | ||
| No. of patients | 646 | 483 | 163 | 163 | 163 | ||
| Age (years) | 54.77 ± 12.61 | 54.03 ± 12.52 | 56.95 ± 12.68 | 0.014 | 54.93 ± 12.84 | 56.95 ± 12.68 | 0.214 |
| Gender | 0.159 | 0.816 | |||||
| Male | 394 (60.99%) | 287 (59.42%) | 107 (65.64%) | 105 (64.42%) | 107 (65.64%) | ||
| Female | 252 (39.01%) | 196 (40.58%) | 56 (34.36%) | 58 (35.58%) | 56 (34.36%) | ||
| Hypertension | 169 (26.16%) | 114 (23.60%) | 55 (33.74%) | 0.011 | 44 (26.99%) | 55 (33.74%) | 0.185 |
| Diabetes mellitus | 77 (11.92%) | 51 (10.56%) | 26 (15.95%) | 0.066 | 18 (11.04%) | 26 (15.95%) | 0.195 |
| Laterality | 0.203 | 0.506 | |||||
| Left | 313 (48.45%) | 227 (47.00%) | 86 (52.76%) | 80 (49.08%) | 86 (52.76%) | ||
| Right | 333 (51.55%) | 256 (53.00%) | 77 (47.24%) | 83 (50.92%) | 77 (47.24%) | ||
| Tumor size (cm) | 4.97±2.53 | 4.57±2.13 | 6.16±3.16 | < 0.001 | 5.85±2.71 | 6.16±3.16 | 0.641 |
| Operative approach | 0.305 | 0.705 | |||||
| Open | 451 (69.81%) | 332 (68.74%) | 119 (73.01%) | 122 (74.85%) | 119 (73.01%) | ||
| Laparoscopic | 195 (30.19%) | 151 (31.26%) | 44 (26.99%) | 41 (25.15%) | 44 (26.99%) | ||
| Nephrectomy | < 0.001 | 0.597 | |||||
| Radical | 436 (67.49%) | 308 (63.77%) | 128 (78.53%) | 124 (76.07%) | 128 (78.53%) | ||
| Partial | 210 (32.51%) | 175 (36.23%) | 35 (21.47%) | 39 (23.93%) | 35 (21.47%) | ||
| Pathological T stage | < 0.001 | 0.486 | |||||
| T1 | 522 (80.80%) | 413 (85.51%) | 109 (66.87%) | 111 (68.10%) | 109 (66.87%) | ||
| T2 | 53 (8.20%) | 32 (6.63%) | 21 (12.88%) | 28 (17.18%) | 21 (12.88%) | ||
| T3 | 63 (9.75%) | 34 (7.04%) | 29 (17.79%) | 21 (12.88%) | 29 (17.79%) | ||
| T4 | 8 (1.24%) | 4 (0.83%) | 4 (2.45%) | 3 (1.84%) | 4 (2.45%) | ||
| Histologic subtype | 0.807 | 0.636 | |||||
| Clear cell | 543 (84.06%) | 405 (83.85%) | 138 (84.66%) | 141 (86.50%) | 138 (84.66%) | ||
| Non-clear cell | 103 (15.94%) | 78 (16.15%) | 25 (15.34%) | 22 (13.50%) | 25 (15.34%) | ||
| Tumor grade | < 0.001 | 0.145 | |||||
| G1 | 24 (3.72%) | 20 (4.14%) | 4 (2.45%) | 3 (1.84%) | 4 (2.45%) | ||
| G2 | 340 (52.63%) | 276 (57.14%) | 64 (39.26%) | 72 (44.17%) | 64 (39.26%) | ||
| G3 | 263 (40.71%) | 181 (37.47%) | 82 (50.31%) | 84 (51.53%) | 82 (50.31%) | ||
| G4 | 19 (2.94%) | 6 (1.24%) | 13 (7.98%) | 4 (2.45%) | 13 (7.98%) | ||
| Tumor necrosis | 71 (10.99%) | 38 (7.87%) | 33 (20.25%) | < 0.001 | 32 (19.63%) | 33 (20.25%) | 0.890 |
| Sarcomatoid differentiations | 7 (1.08%) | 3 (0.62%) | 4 (2.45%) | 0.072 | 2 (1.23%) | 4 (2.45%) | 0.685 |