Patient classification according to mutation carrier status and type of breast cancer
| Mutation carrier status | Multifocal unilateral | Synchronous bilateral | Metachronous bilateral |
| Non-carriers | 50 (53%) | 8 (6%) | 37 (41%) |
| BRCA1 mutation positive | 4 (31%) | 1 (8%) | 8 (61%) |
| BRCA2 mutation positive | 7 (64%) | 3 (27%) | 1 (9%) |
| Total | 61 (51%) | 12 (10%) | 46 (39%) |