Table 1.
Histoclinical features of basal-like tumors (IPC and validation series)
| Characteristics (N) | Basal |
|---|---|
| N = 591 | |
| N (% of evaluated cases) | |
| Age (445) | |
| ≤ 50 years | 215 (57%) |
| > 50 years | 162 (43%) |
| Histological type (256) | |
| ductal | 234 (91%) |
| lobular | 7 (3%) |
| other* | 15 (6%) |
| Pathological tumor size, pT (466) | |
| pT1 | 115 (25%) |
| pT2-4 | 351 (75%) |
| Pathological lymph node status, pN (493) | |
| negative | 314 (64%) |
| positive | 179 (36%) |
| Tumor grade (493) | |
| SBR 1 | 14 (3%) |
| SBR 2-3 | 479 (97%) |
| IHC ER status (507) | |
| negative | 411 (81%) |
| positive | 96 (19%) |
| IHC PR status (223) | |
| negative | 199 (89%) |
| positive | 24 (11%) |
| IHC ERBB2 status (105) | |
| negative | 86 (84%) |
| positive | 19 (16%) |
| Adjuvant chemotherapy (309) | |
| no | 203 (66%) |
| yes | 106 (34%) |
| Adjuvant hormone therapy (322) | |
| no | 237 (95%) |
| yes | 13 (5%) |
| Events (453)** | 183 (40%) |
| 5-year DFS (453)** | 61% |
*4 metaplastic carcinomas, 4 mixed adenocarcnomas, 1 mucinous carcinoma, and 5 adenocarcinomas non otherwise specified. **out of these 453 patients with available follow-up, 193 did not received any systemic adjuvant treatment, 115 received adjuvant systemic therapy, no patient received adjuvant Trastuzumab, and data were unavailable for 145 patients.