Table 1.
Comparison of patient and lesion characteristics between the training and validation cohorts
| Variables | Training cohort (n = 160) | Validation cohort (n = 82) | P-value |
|---|---|---|---|
| Age (years) | 56 ± 14 | 60 ± 13 | 0.0080* |
| Diameter of breast cancer (mm) | 15.9 ± 10.5 | 18.9 ± 14.9 | 0.1777 |
| Histological types of breast cancer (n (%)) | 0.2985 | ||
| No specific type | 137 (85.6) | 74 (90.2) | |
| Invasive lobular carcinoma | 10 (6.3) | 4 (4.9) | |
| Mucinous carcinoma | 12 (7.5) | 2 (2.4) | |
| Apocrine carcinoma | 1 (0.6) | 1 (1.2) | |
| Microinvasive carcinoma | 0 (0) | 1 (1.2) | |
| Receptor status of breast cancer (n (%)) | |||
| ER positive | 147 (92) | 72 (88) | 0.3560 |
| negative | 13 (8) | 10 (12) | |
| PR positive | 129 (81) | 66 (80) | 1.0000 |
| negative | 31 (19) | 16 (20) | |
| HER2 positive | 15 (9) | 12 (15) | 0.2804 |
| negative | 145 (85) | 70 (85) | |
| Ki-67 labelling index | 19.4 ± 16.3 | 17.6 ± 13.6 | 0.4468 |
| Nottingham’s histologic grade (n (%)) | 1.0000 | ||
| 1 | 64 (44) | 33 (40) | |
| 2 | 85 (53) | 44 (54) | |
| 3 | 11 (7) | 5 (6) | |
| Pathological diagnosis of LN metastasis (n (%)) | 0.5086 | ||
| Positive | 32 (20) | 20 (24) | |
| Negative | 128 (80) | 62 (76) |
Data are expressed as mean ± standard deviation. *indicates statistical significance. ER, oestrogen receptor; HER2, human epidermal growth factor 2; LN, lymph node; PR, progesterone receptor.