Table 1. Patient characteristics.
| Characteristics | Training set | Validation set |
|---|---|---|
| No. of patients | 82 | 89 |
| Age (median) |
60 |
58 |
|
Histologic type | ||
| Ductal (IDC) | 68 | 76 |
| Lobular (ILC) | 10 | 10 |
| Other |
4 |
3 |
|
Histologic grade | ||
| Grade 1 | 7 | 11 |
| Grade 2 | 32 | 27 |
| Grade 3 | 43 | 49 |
| Missing |
|
2 |
|
Tumour size | ||
| ⩽2 cm | 29 | 28 |
| ⩾2 cm | 53 | 59 |
| Missing |
|
2 |
|
Oestrogen receptor | ||
| Positive | 56 | 64 |
| Negative | 25 | 23 |
| Missing |
1 |
2 |
|
Progesterone receptor | ||
| Positive | 44 | 54 |
| Negative | 38 | 33 |
| Missing |
0 |
2 |
|
HER2 overexpression | ||
| Positive | 15 | 16 |
| Negative | 57 | 63 |
| Missing |
10 |
10 |
|
Lymphovascular invasion | ||
| Present | 34 | 35 |
| Absent |
48 |
54 |
|
Lymph node involvement | ||
| Positive | 42 | 43 |
| Negative | 40 | 44 |
| Missing | 2 | |
Abbreviations: HER2=human epidermal growth factor receptor 2; IDC=invasive ductal carcinoma; ILC=invasive lobular carcinoma.