Table 1.
Baseline characteristics (N = 4,260).
| Total | Non-metastasis | Metastasis | p-value | ||
|---|---|---|---|---|---|
| Number | 4,260 | 4,133 | 127 | ||
| Follow-up duration | Median (IQR) | 43.9 (19.0–76.1) | 43.1 (18.6–74.3) | 91.4 (39.4–122.3) | |
| Age at operation | Mean ± STD | 55.5 ± 12.4 | 55.5 ± 12.5 | 57.6 ± 10.7 | 0.032 |
| Gender | Male | 3,020 (70.9) | 2,929 (70.9) | 91 (71.7) | 0.848 |
| Female | 1,240 (29.1) | 1,204 (29.1) | 36 (28.3) | ||
| Body mass index (kg/cm2) | Mean ± STD | 24.5 ± 3.4 | 24.5 ± 3.4 | 24.2 ± 2.9 | 0.232 |
| Diabetes | Yes | 602 (14.1) | 581 (14.1) | 21 (16.5) | 0.432 |
| Hypertension | Yes | 1,602 (37.6) | 1,545 (37.6) | 57 (44.9) | 0.095 |
| ASA | 1 | 1,419 (33.3) | 1,385 (42.9) | 34 (34.0) | 0.301 |
| 2 | 1,727 (40.5) | 1,667 (51.6) | 60 (60.0) | ||
| 3 | 177 (4.3) | 171 (5.3) | 6 (6.0) | ||
| 4 | 5 (0.1) | 5 (0.2) | 0 (0.0) | ||
| Hb | Median (IQR) | 13.9 (12.7–15.0) | 13.9 (12.7–15.0) | 13.8 (12.2–14.9) | 0.131 |
| Platelet | Median (IQR) | 229 (193–271) | 229 (192.5–270) | 244 (194–292) | 0.048 |
| Creatinine | Median (IQR) | 1.0 (0.8–1.1) | 1.0 (0.8–1.1) | 1 (0.9–1.2) | 0.025 |
| Albumin | Median (IQR) | 4.4 (4.1–4.6) | 4.4 (4.1–4.6) | 4.2 (3.9–4.5) | <0.001 |
| Nephrectomy | Open surgery | 1,940 (45.5) | 1,848 (45.3) | 92 (76.0) | <0.001 |
| Laparoscopic | 2,261 (53.1) | 2,232 (54.7) | 29 (24.0) | ||
| Operative Extent | Partial | 1,854 (43.5) | 1,839 (57.6) | 15 (26.3) | <0.001 |
| Radical | 1,394 (32.7) | 1,352 (42.4) | 42 (73.7) | ||
| pT | T1 | 3,397 (79.7) | 3,353 (81.2) | 44 (35.8) | <0.001 |
| T2 | 338 (7.9) | 310 (7.5) | 28 (22.8) | ||
| T3 | 490 (11.5) | 442 (10.7) | 48 (39.0) | ||
| T4 | 25 (0.6) | 22 (0.5) | 3 (2.4) | ||
| Tx | 3 (0.1) | 3 (0.1) | 0 (0.0) | ||
| pN | N0 | 1,784 (41.9) | 1,696 (41.1) | 88 (71.5) | <0.001 |
| N1 | 55 (1.3) | 53 (1.3) | 2 (1.6) | ||
| Nx | 2,407 (56.5) | 2,374 (57.6) | 33 (26.8) | ||
| Histology | Clear cell | 3,589 (84.3) | 3,476 (84.5) | 113 (91.9) | 0.077 |
| Non-clear cell | 604 (14.2) | 595 (14.5) | 9 (7.3) | ||
| Mixed | 45 (1.1) | 44 (1.1) | 1 (0.8) | ||
| Nuclear grade | Grade 1–2 | 2,198 (51.6) | 2,171 (55.2) | 27 (25.7) | <0.001 |
| Grade 3–4 | 1,843 (43.3) | 1,765 (44.8) | 78 (74.3) | ||
| Sarcomatoid differentiation | Yes | 79 (1.9) | 70 (1.7) | 9 (7.1) | 0.001 |
| Necrosis | Yes | 314 (7.4) | 287 (6.9) | 27 (21.3) | <0.001 |
| Lymphovascular invasion | Yes | 161 (3.8) | 150 (3.6) | 11 (8.7) | 0.008 |
| Capsular invasion | Yes | 723 (17.0) | 693 (16.8) | 30 (23.6) | 0.043 |
| Cause of death (n = 361) | RCC related | 222 (61.5) | 184 (57.3) | 38 (95.0) | <0.001 |
| Non-RCC-related | 139 (38.5) | 137 (42.7) | 2 (5.0) |