Table 2.
Clinicopathological information for patients in the METABRIC data set
| Training set | Validation set | |||
|---|---|---|---|---|
| Basal I | Basal II | Basal I | Basal II | |
| Age [years] | ||||
| ≤ 40 | 7 | 18 | 4 | 17 |
| 41 to 50 | 11 | 18 | 10 | 21 |
| 51 to 60 | 8 | 20 | 9 | 16 |
| > 60 | 9 | 24 | 13 | 35 |
| mean | 50.6 | 52.5 | 54.7 | 54.1 |
| p-value | 0.46 | 0.8 | ||
| MS | ||||
| Pre/post | 18/17 | 36/43 | 15/21 | 37/52 |
| Pre/post (%) | 51.4% | 45.6% | 41.7% | 41.6% |
| p-value | 0.31 | 1 | ||
| Size [cm] | ||||
| ≤ 2 cm | 15 | 30 | 17 | 32 |
| > 2 cm | 20 | 50 | 19 | 55 |
| Mean | 23.5 | 30.6 | 22.1 | 29.6 |
| p-value | 0.01 | 0.005 | ||
| Grade | ||||
| Grade 2 | 2 | 8 | 5 | 3 |
| Grade 3 | 33 | 71 | 30 | 85 |
| Na | 0 | 1 | 1 | 1 |
| Mean | 2.9 | 2.9 | 2.9 | 3 |
| p-value | 0.4 | 0.092 | ||
| NPI | ||||
| ≤2.4 | 0 | 1 | 1 | 1 |
| 2.4 to 3.4 | 1 | 6 | 3 | 2 |
| 3.4 to 5.4 | 28 | 62 | 27 | 77 |
| >5.4 | 6 | 11 | 5 | 9 |
| Mean | 4.7 | 4.6 | 4.5 | 4.6 |
| p-value | 0.43 | 0.7 | ||
| Lymph Node | ||||
| Neg/pos | 16/19 | 37/43 | 17/19 | 47/42 |
| Neg/pos (%) | 45.7% | 46.2% | 47.2% | 52.8% |
| p-value | 1 | 0.34 | ||
| Histology | ||||
| ILC | 0 | 2 | 0 | 1 |
| IDC | 28 | 70 | 23 | 83 |
| IDC-med | 7 | 5 | 9 | 3 |
| Others | 0 | 3 | 4 | 2 |
| p-value | 0.001 | 5.4·10−8 | ||
| p53 | ||||
| Mut/wild | 1/15 | 11/14 | 2/11 | 12/17 |
| Mut/wild (%) | 6.25% | 44% | 15.4% | 41.4% |
| p-value | 1.1·10−7 | 7·10−4 | ||
| Population size | ||||
| 35 | 80 | 36 | 89 | |
The clinicopathological features described are: Age in years, menopausal status (MS), tumour Size in cm, tumour Grade [1–3], Nottingham Prognostic Index (NPI), Lymph Node invasion, histopathological classification (Histology) and p53 status, for Basal I and II subgroups in the METABRIC discovery and validation sets. In all cases, the p-value indicates the significance of the difference between Basal I and II subgroups. For numerical variables (Age, Size, Grade, and NPI) it was calculated using the ANOVA on ranks; for the categorical (MS, Lymph Node, Histology, p53), a binomial test was used. Population sizes for each group are indicated in the last row. Tumour histology is as follows: IDC=Invasive Ductal Carcinoma, ILC=Invasive Lobular Carcinoma, IDC-med=Medullary Carcinoma, and others include tubular, mucinous and phyllodes tumours