Table 1 Characteristics between the training set and the validation set
Characteristics | All Patients n = 2205 (%) | Training n = 1543 (%) | Validation n = 662 (%) | P value |
|---|---|---|---|---|
Age (years) | ||||
 Median | 60 | 59 | 61 |  |
 ≤ 60 | 1135 (51.5) | 814 (52.8) | 321 (48.5) | 0.066 |
 > 60 | 1070 (48.5) | 729 (47.2) | 341 (51.5) |  |
Race | ||||
 White | 1691 (76.7) | 1165 (75.5) | 526 (79.5) | 0.103 |
 Black | 364 (16.5) | 271 (17.6) | 93 (14.0) |  |
 Othersa | 150 (6.8) | 107 (6.9) | 43 (6.5) |  |
Marital status | ||||
 Unmarried | 959 (43.5) | 670 (43.4) | 289 (43.6) | 0.750 |
 Married | 1173 (53.2) | 819 (53.1) | 354 (53.5) |  |
 Unknown | 73 (3.3) | 54 (3.5) | 19 (2.9) |  |
Grade | ||||
 I | 103 (4.7) | 67 (4.4) | 36 (5.4) | 0.666 |
 II | 299 (13.6) | 207 (13.4) | 92 (13.9) |  |
 III | 1701 (77.1) | 1199 (77.7) | 502 (75.8) |  |
 IV | 102 (4.6) | 70 (4.5) | 32 (4.9) |  |
Laterality | ||||
 Right | 1129 (51.2) | 777 (50.4) | 352 (53.2) | 0.225 |
 Left | 1076 (48.8) | 766 (49.6) | 310 (46.8) |  |
ER status | ||||
 Negative | 1803 (81.8) | 1265 (82.0) | 538 (81.3) | 0.691 |
 Positive | 402 (18.2) | 278 (18.0) | 124 (18.7) |  |
PR status | ||||
 Negative | 1919 (87.0) | 1342 (87.0) | 577 (87.2) | 0.905 |
 Positive | 286 (13.0) | 201 (13.0) | 85 (12.8) |  |
HER-2 status | ||||
 Negative | 1091 (49.5) | 751 (48.7) | 340 (51.4) | 0.155 |
 Positive | 76 (3.4) | 60 (3.9) | 16 (2.4) |  |
 Unknown | 1038 (47.1) | 732 (47.4) | 306 (46.2) |  |
Tumor size | ||||
 ≤ 2 cm | 572 (25.9) | 399 (25.9) | 173 (26.1) | 0.976 |
 > 2 cm and ≤ 5 cm | 1157 (52.5) | 812 (52.6) | 345 (52.1) |  |
 > 5 cm | 476 (21.6) | 332 (21.5) | 144 (21.8) |  |
Regional lymph nodes | ||||
 Negative | 1659 (75.2) | 1164 (75.4) | 495 (74.8) | 0.741 |
 Positive | 546 (24.8) | 379 (24.6) | 167 (25.2) |  |