Table 1.
Clinicopathological characteristics of training group and validation group
| Characteristics | Training group
|
Validation group
|
P-value |
|---|---|---|---|
| (n=1,193) | (n=499) | ||
| Age, years | 47.9±10.9 | 47.4±10.2 | |
| Tumor | 0.072 | ||
| Left | 631 (52.9%) | 240 (48.1%) | |
| Right | 562 (47.1%) | 259 (50.9%) | |
| Preoperative size | 0.001 | ||
| ≤2 cm | 595 (49.9%) | 271 (54.3%) | |
| 2–5 cm | 432 (36.2%) | 191 (38.3%) | |
| Unknown | 166 (13.9%) | 37 (7.4%) | |
| Histology type | 0.058 | ||
| Ductal | 1,029 (86.3%) | 409 (82.0%) | |
| Lobular | 42 (3.5%) | 27 (5.4%) | |
| Specified | 122 (10.2%) | 63 (12.6%) | |
| CN stage | 0.007 | ||
| Positive | 201 (16.8%) | 112 (22.4%) | |
| Negative | 992 (83.2%) | 387 (77.6%) | |
| HR | 0.124 | ||
| Positive | 1,026 (86.0%) | 443 (88.8%) | |
| Negative | 167 (14.0%) | 56 (11.2%) | |
| HER2 status | 0.376 | ||
| Positive | 277 (23.2%) | 106 (21.2%) | |
| Negative | 916 (78.8%) | 393 (78.8%) | |
| Initial margin status | 0.008 | ||
| Positive | 232 (19.4%) | 126 (25.2%) | |
| Negative | 961 (80.6%) | 373 (74.8%) | |
| Suspicion of multifocality | 0.436 | ||
| Presence | 79 (6.6%) | 28 (5.6%) | |
| Absence | 1,114 (93.4%) | 471 (94.4%) | |
| Neoadjuvant chemotherapy | 0.016 | ||
| Yes | 123 (10.3%) | 72 (14.4%) | |
| No | 1,070 (89.7%) | 427 (85.6%) | |
| Presence of DCIS | |||
| Yes | 231 (19.5%) | 53 (10.6%) | <0.001 |
| No | 962 (80.6%) | 446 (89.4%) |
Abbreviations: DCIS, ductal carcinoma in situ; CN, clinical node; HR, hormone receptor; HER2, human epidermal growth receptor 2.