Table 1.
Characteristics of the Combined Dataset.
| Training (~2/3) | Testing (~1/3) | |||||
|---|---|---|---|---|---|---|
| Characteristics | Total N | % | N | N | P-value* | |
| Subjects | 550 | 359 | 191 | - | ||
| ER | + | 395 | 71.8% | 259 | 136 | 0.89 |
| - | 155 | 28.2% | 100 | 55 | ||
| Size | < 2 cm | 309 | 56.2% | 198 | 111 | 0.56 |
| ≥ 2 cm | 241 | 43.8% | 161 | 80 | ||
| HER2* | + | 110 | 20.0% | 73 | 37 | 0.88 |
| - | 440 | 80.0% | 286 | 154 | ||
| Grade | 1 | 98 | 17.8% | 63 | 35 | 0.45 |
| 2 | 182 | 33.1% | 113 | 69 | ||
| 3 | 270 | 49.1% | 183 | 87 | ||
| Published Dataset^ | Ivshina | 137 | 24.9% | 89 | 48 | 1 |
| Loi | 42 | 7.6% | 28 | 14 | ||
| NKI | 141 | 25.6% | 92 | 49 | ||
| UNC | 33 | 6.0% | 22 | 11 | ||
| Wang | 197 | 35.8% | 128 | 69 | ||
| Platform | Affymetrix | 376 | 68.4% | 245 | 131 | 0.99 |
| Agilent | 174 | 31.6% | 114 | 60 | ||
| Subtype (PAM50) | Luminal A | 156 | 28.4% | 98 | 58 | 0.92 |
| Luminal B | 131 | 23.8% | 85 | 46 | ||
| HER2-enriched | 83 | 15.1% | 56 | 27 | ||
| Basal-like | 106 | 19.3% | 72 | 34 | ||
| Normal Breast-like | 74 | 13.5% | 48 | 26 | ||
*HER2 status is based on ERBB2 mRNA levels. P-values have been calculated based on a Chi-square test.
^compiled from Ivshina et al., 2006; Loi et al., 2007; van de Vijver et al., 2002; Wang et al., 2005; http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE15393.