Table 1.
Patient and tumor characteristics
| Characteristic | Stiftung Tumorbank Basel data set | The Netherlands Cancer Institute data set |
| Method | Quantitative RT-PCR | Agilent Microarray |
| n | 317 | 295 |
| Age | ||
| Mean/median (years) | 60/59 | 44/44 |
| ≤ 40 years | 20 (6%) | 75 (25%) |
| 41–55 years | 110 (35%) | 220 (75%) |
| ≥ 56 years | 187 (59%) | 0 (0%) |
| pT stage | ||
| pT1 | 100 (32%) | 155 (53%) |
| pT2 | 183 (58%) | 140 (47%) |
| pT3/4 | 33 (10%) | 0 |
| pN status | ||
| Negative | 161 (54%) | 151 (51%) |
| Positive | 136 (46%) | 144 (49%) |
| Unknown | 20 | 0 |
| Histological grade | ||
| 1 (good) | 28 (9%) | 75 (25%) |
| 2 (intermediate) | 137 (46%) | 101 (34%) |
| 3 (poor) | 133 (45%) | 119 (41%) |
| Unknown | 19 | 0 |
| Estrogen receptor statusa | ||
| Positive | 231 (73%) | 226 (77%) |
| Negative | 86 (27%) | 69 (23%) |
| ErbB2 status | ||
| Positive | 70 (22%) | 52 (18%) |
| Negative | 247 (78%) | 243 (82%) |
| Adjuvant therapy | ||
| None | 60 (20%) | 165 (56%) |
| Hormone | 135 (44%) | 20 (7%) |
| Chemotherapy | 72 (24%) | 90 (30%) |
| Combination | 38 (12%) | 20 (7%) |
| Total | 245 (80%) | 130 (44%) |
| Unknown | 12 | 0 |
| Follow-up | ||
| Events (metastases) | 57 (18%) | 101 (34%) |
| Mean/median metastasis-free survival (years) | 3.7/3.6 | 7.3/6.8 |
Data presented as n (%) unless stated otherwise. aEstrogen receptor positive, ≥ 20 fmol/mg protein (enzyme immunoassay) for the Stiftung Tumorbank Basel data set; for The Netherlands Cancer Institute study, see [5,6]