Table 1.
Phenotypic characterization of breast tumors derived from BRCA2 germline mutation carriers
| Biomarkers for definition of phenotypes | 0 | I-II | III |
|---|---|---|---|
| ER | 8 (25%) | 7 (22%) | 17 (53%) |
| PR | 12 (37%) | 14 (44%) | 6 (19%) |
| HER2 | 22 (69%) | 10 (31%) | 0 (0) |
| Cellular proliferation; The proportion of cells positive for Ki-67 | |||
| Ki-67 | 0-14% (1st Qu.) | > 14%-35% (IQR) | > 35% (3rd Qu.) |
| Luminal | 8 (33%) | 14 (58%) | 2 (8%) |
| Triple-negative | 0 (0) | 3 (37%) | 5 (63%) |
| Χ2 test; P = 0.004 | |||
| Expression of basal features | |||
| EGFR | 0 | I | ≥ II |
| Luminal | 22 (96%) | 1 (4%) | 0 (0) |
| Triple-negative | 4 (50%) | 1 (13%) | 3 (37%) |
| Χ2 test; P = 0.004 | |||
| CK5/6 | Negative | Positive | |
| Luminal | 24 (100%) | 0 | |
| Triple-negative | 3 (37%) | 5 (63%) | |
| Χ2 test; P = 0.0003 | |||
| pRb/p16 pathway | |||
| p16 (CDKN2A) | 0 | I-II | III |
| Luminal A | 3 (38%) | 4 (50%) | 1 (12%) |
| Luminal B | 9 (60%) | 5 (33%) | 1 (7%) |
| Triple-negative | 0 | 1 (12%) | 7 (88%) |
| Χ2 test; P = 0.0007 | |||
| Cyclin-D1 (CCND1) | 0-15% (1st Qu.) | > 15%-75% (IQR) | > 75% (3rd Qu.) |
| Luminal A | 1 (12%) | 4 (50%) | 3 (38%) |
| Luminal B | 1 (6%) | 8 (50%) | 7 (44%) |
| Triple-negative | 6 (75%) | 2 (25%) | 0 |
| Χ2 test; P = 0.005 | |||
| pRb (RB1) | 0 (Negative) | I (Positive) | |
| Luminal A | 1 (13%) | 7 (87%) | |
| Luminal B | 2 (13%) | 14 (87%) | |
| Triple-negative | 4 (50%) | 4 (50%) | |
| Χ2 test; P = 0.085 | |||
| Morphologic features | |||
| Histologic grade | I | II | III |
| Luminal | 2 (8%) | 11 (44%) | 12 (48%) |
| Triple-negative | 1 (12%) | 1 (12%) | 6 (75%) |
| Χ2 test, P = 0.27 | |||