Table 1 Clinical and pathological characteristics of training set and validation set.
Characteristics | Total (n = 852) | Training set (n = 724) | Validation set (n = 128) | P value |
|---|---|---|---|---|
Age (years) | 51 ± 10 | 51 ± 10 | 52 ± 10 | 0.483 |
Tumor size on pre-NAC MRI (cm) | 4.1 ± 2.1 | 4.2 ± 2.1 | 3.7 ± 1.8 | 0.014 |
Clinical T stage | 0.194 | |||
T1 | 48 (5.6) | 39 (5.4) | 9 (7.0) | |
T2 | 575 (67.5) | 481 (66.4) | 94 (73.4) | |
T3 | 141 (16.5) | 124 (17.1) | 17 (13.3) | |
T4 | 88 (10.3) | 80 (11.0) | 8 (6.3) | |
Clinical N stage | 0.003 | |||
N0 | 124 (14.6) | 94 (13.0) | 30 (23.4) | |
N1 | 358 (42.0) | 303 (41.9) | 55 (43.0) | |
N2 | 240 (28.2) | 217 (30.0) | 23 (18.0) | |
N3 | 130 (15.3) | 110 (15.2) | 20 (15.6) | |
Estrogen receptor status Negative Positive | 583 (68.4) 269 (31.6) | 494 (68.2) 230 (31.8) | 89 (69.5) 39 (30.5) | 0.771 |
Progesterone receptor status Negative Positive | 693 (81.3) 159 (18.7) | 586 (80.9) 138 (19.1) | 107 (83.6) 21 (16.4) | 0.477 |
HER2 status Negative Positive | 326 (38.3) 526 (61.7) | 271 (37.4) 453 (62.6) | 55 (43.0) 73 (57.0) | 0.235 |
Ki-67 index (%) | 22 ± 20 | 22 ± 20 | 22 ± 22 | 0.919 |
Histologic grade | 0.091 | |||
Low or intermediate | 381 (44.7) | 315 (43.5) | 66 (51.6) | |
High | 471 (55.3) | 409 (56.5) | 62 (48.4) | |
Histologic type | 0.475 | |||
Ductal | 831 (97.5) | 705 (97.4) | 126 (98.4) | |
Others | 21 (2.5) | 19 (2.6) | 2 (1.6) | |
Pathologic complete response | 0.495 | |||
No | 542 (63.6) | 464 (64.1) | 78 (60.9) | |
Yes | 310 (36.4) | 260 (35.9) | 50 (39.1) |
