Table 1.
Patient characteristics in the training and validation set.
| Characteristics | Training set (n = 169) | Validation set (n = 59) | p value |
|---|---|---|---|
| Age, years* | 52.2 ± 12.5 | 53.7 ± 11.5 | 0.426 |
| Tumor size on MRI, mm* | 27.5 ± 16.0 | 28.1 ± 16.1 | 0.789 |
| Pathological T category | 0.120 | ||
| pT1 | 114 (67.5) | 37 (62.7) | |
| pT2 | 47 (27.8) | 22 (37.3) | |
| pT3 | 8 (4.7) | 0 (0) | |
| Pathological N category | 0.708 | ||
| pN0 | 134 (79.3) | 44 (74.6) | |
| pN1 | 25 (14.8) | 10 (16.9) | |
| pN2 | 10 (5.9) | 5 (8.5) | |
| Type of surgery | 0.896 | ||
| Breast-conserving surgery | 113 (66.9) | 40 (67.8) | |
| Mastectomy | 56 (33.1) | 19 (32.2) | |
| Adjuvant radiation therapy | 0.878 | ||
| No | 30 (17.8) | 11(18.6) | |
| Yes | 139 (82.2) | 48 (81.4) | |
| Neoadjuvant chemotherapy | 0.871 | ||
| No | 125 (74.0) | 43 (72.9) | |
| Yes | 44 (26.0) | 16 (27.1) | |
| Adjuvant chemotherapy | 0.706 | ||
| No | 59 (34.9) | 19 (32.2) | |
| Yes | 110 (65.1) | 40 (67.8) | |
| Histological grade | 0.531 | ||
| 1 or 2 | 61 (36.1) | 24 (40.7) | |
| 3 | 108 (63.9) | 35 (59.3) | |
| Lymphovascular invasion | 0.818 | ||
| No | 156 (92.3) | 55 (93.2) | |
| Yes | 13 (7.7) | 4 (6.8) |
Note.—Unless otherwise noted, data are numbers of patients, with percentages in parentheses.
*Data are means ± standard deviations.