Table 4.
Findings among MBC patients tested for 16 breast cancer genes (n = 512)
| Result category | No prior BRCA testing (n = 354) | Prior BRCA testing (n = 158) | ||
|---|---|---|---|---|
| N | % | N | % | |
| Pathogenic/likely pathogenic variant | 64 | 18.1 | 12 | 7.6 |
| Pathogenic/likely pathogenic variant(s) in a single gene | 60a | 16.9 | 11 | 7.0 |
| BRCA1/2 | 39 | 11.0 | 2 | 1.3 |
| Non-BRCA1/2 | 21 | 5.9 | 9 | 5.7 |
| Pathogenic/likely pathogenic variant(s) in multiple genes | 4 | 1.1 | 1 | 0.6 |
| Combination of BRCA1/2 and non-BRCA1/2 genes | 3 | 0.8 | 0 | 0.0 |
| Multiple non-BRCA1/2 genes | 1 | 0.3 | 1 | 0.6 |
| Pathogenic/likely pathogenic variant + VUS | 16 | 4.5 | 5 | 3.2 |
| VUS only | 59 | 16.7 | 34 | 21.5 |
| Negative | 231 | 65.3 | 112 | 70.9 |
a59 had a single pathogenic/likely pathogenic variant and 1 had biallelic ATM mutations