Table 1 Clinical characteristics of the patients
| Â | 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 |