Table 2.
The baseline characteristics between the training and validation datasets.
| Characteristics | Training set (N = 920) | Validation set (N = 392) |
|---|---|---|
| Age (years), median (IQR) | 48 (42–57) | 47 (44–55) |
| Tumor stage | ||
| T1 | 330 (35.9%) | 137 (35.0%) |
| T2 | 508 (55.2%) | 211 (53.8%) |
| T3 | 39 (4.2%) | 26 (6.6%) |
| T4 | 43 (4.7%) | 18 (4.6%) |
| Node stage | ||
| N0 | 470 (51.0%) | 217 (55.4%) |
| N1 | 254 (27.6%) | 91 (23.2%) |
| N2 | 123 (13.4%) | 40 (10.2%) |
| N3 | 73 (8.0%) | 44 (11.2%) |
| Clinical stage | ||
| I | 222 (24.2%) | 95 (24.2%) |
| II | 476 (51.7%) | 203 (51.8%) |
| III | 222 (24.1%) | 94 (24.0%) |
| Histological type | ||
| Invasive ductal carcinoma | 781 (84.9%) | 328 (83.7%) |
| Others | 139 (15.1%) | 64 (16.3%) |
| ER status | ||
| Positive | 661 (71.8%) | 281 (71.7%) |
| Negative | 259 (28.2%) | 111 (28.3%) |
| PR status | ||
| Positive | 591 (64.2%) | 251 (64.0%) |
| Negative | 329 (35.8%) | 141 (36.0%) |
| HER-2 status | ||
| Positive | 202 (22.0%) | 82 (20.9%) |
| Negative | 718 (78.0%) | 310 (79.1%) |
| Ki-67 | ||
| >14% | 403 (43.8%) | 172 (43.9%) |
| ≤14% | 517 (56.2%) | 220 (56.1%) |
| PIV | ||
| >310.2 | 101 (11.0%) | 51 (13.0%) |
| ≤31.02 | 819 (89.0%) | 341 (87.0%) |
IQR, interquartile range; ER, estrogen receptor; PR, progesterone receptor; HER-2, human epidermal growth factor receptor-2.