TABLE 1.
Patients’ demographics and clinicopathological characteristics.
| Variables | All patients (n = 1,044) N (%) | SEER training set (n = 732) N (%) | SEER validation set (n = 312) N (%) | Chinese multicenter validation set (n = 40) N (%) |
|---|---|---|---|---|
| Age | ||||
| ≤72 | 788 (75.5) | 554 (75.7) | 234 (75.0) | 39 (97.5) |
| ≥73 | 256 (24.5) | 178 (24.3) | 78 (25.0) | 1 (2.5) |
| Race | ||||
| Black | 170 (16.3) | 119 (16.3) | 51 (16.3) | -- |
| White | 796 (76.2) | 566 (77.3) | 230 (73.7) | -- |
| Other | 78 (7.5) | 47 (6.4) | 31 (9.9) | -- |
| Marital status | ||||
| Married | 575 (55.1) | 409 (55.9) | 166 (53.2) | -- |
| Single | 169 (16.2) | 113 (15.4) | 56 (17.9) | -- |
| Other | 300 (28.7) | 210 (28.7) | 90 (28.8) | -- |
| Laterality | ||||
| Left | 533 (51.1) | 378 (51.6) | 155 (49.7) | -- |
| Right | 511 (48.9) | 354 (48.4) | 157 (50.3) | -- |
| Grade | ||||
| I | 24 (2.3) | 18 (2.5) | 6 (1.9) | -- |
| II | 120 (11.5) | 79 (10.8) | 41 (13.1) | -- |
| III | 863 (82.7) | 609 (83.2) | 254 (81.4) | -- |
| IV | 37 (3.5) | 26 (3.6) | 11 (3.5) | -- |
| 8th AJCC T stage | ||||
| T1 | 254 (24.3) | 183 (25.0) | 71 (22.8) | 7 (17.5) |
| T2 | 514 (49.2) | 347 (47.4) | 167 (53.5) | 19 (47.5) |
| T3 | 187 (17.9) | 134 (18.3) | 53 (17.0) | 11 (27.5) |
| T4 | 89 (8.5) | 68 (9.3) | 21 (6.7) | 3 (7.5) |
| 8th AJCC N stage | ||||
| negative | 800 (76.6) | 563 (76.9) | 237 (76.0) | 34 (85) |
| positive | 244 (23.4) | 169 (23.1) | 75 (24.0) | 6 (15) |
| 8th AJCC M stage | ||||
| M0 | 1,001 (95.9) | 700 (95.6) | 301 (96.5) | 38 (95) |
| M1 | 43 (4.1) | 32 (4.4) | 11 (3.5) | 2 (5) |
| Tumor size | ||||
| ≤4.2 | 700 (67.0) | 486 (66.4) | 214 (68.6) | 25 (62.5) |
| 4.3–6.7 | 215 (20.6) | 148 (20.2) | 67 (21.5) | 4 (10.0) |
| ≥6.8 | 129 (12.4) | 98 (13.4) | 31 (9.9) | 11 (27.5) |
| Subtype | ||||
| Luminal A | 252 (24.1) | 175 (23.9) | 77 (24.7) | -- |
| Luminal B | 24 (2.3) | 17 (2.3) | 7 (2.2) | -- |
| HER2 enriched | 41 (3.9) | 33 (4.5) | 8 (2.6) | -- |
| Triple negative | 727 (69.6) | 507 (69.3) | 220 (70.5) | -- |
| ER | ||||
| Positive | 212 (20.3) | 144 (19.7) | 68 (21.8) | -- |
| Negative | 832 (79.7) | 588 (80.3) | 244 (78.2) | -- |
| PR | ||||
| Positive | 139 (13.3) | 98 (13.4) | 41 (13.1) | -- |
| Negative | 905 (86.7) | 634 (86.6) | 271 (86.9) | -- |
| HER2 | ||||
| Positive | 65 (6.2) | 50 (6.8) | 15 (4.8) | -- |
| Negative | 979 (93.8) | 682 (93.2) | 297 (95.2) | -- |
| Radiation | ||||
| No/unknown | 540 (51.7) | 378 (51.6) | 162 (51.9) | 30 (75) |
| Yes | 504 (48.3) | 354 (48.4) | 150 (48.1) | 10 (25) |
| Chemotherapy | ||||
| No/unknown | 324 (31.0) | 231 (31.6) | 93 (29.8) | 9 (22.5) |
| Yes | 720 (69.0) | 501 (68.4) | 219 (70.2) | 31 (77.5) |
| Surgery type | ||||
| Lumpectomy | 423 (40.5) | 291 (39.8) | 132 (42.3) | 8 (20) |
| Mastectomy | 621 (59.5) | 441 (60.2) | 180 (57.7) | 32 (80) |