Table 2.
Rates of pathogenic variants by age group, pathology and Manchester Scoring System
| Total cases | Total PVs | % | BRCA1 | % | BRCA2 | % | TP53 | % |
BRCA1/BRCA2/
TP53 combined |
Other genes | Genes | |
| Age <26 | 61 | 18 | 29.5% | 6 | 9.8% | 3 | 4.9% | 7 | 11.5% | 26.2% | 2 | ATM; PALB2 |
| 26–30* | 318 | 127 | 39.9% | 69 | 21.7% | 32 | 10.1% | 15 | 4.7% | 36.5% | 11 | ATM; BRIP1; CHEK2 (3); PALB2 (3); PTEN; RAD50; RECQL |
| Total | 379 | 145 | 38.3% | 75 | 19.8% | 35 | 9.2% | 22 | 5.8% | 34.8% | 13 | |
| Receptor status | ||||||||||||
| TNBC | 125 | 61 | 48.8% | 51 | 40.8% | 6 | 4.8% | 3 | 2.4% | 48.0% | 1 | PALB2 |
| HER2+ | 43 | 12 | 27.9% | 1 | 2.3% | 2 | 4.7% | 8 | 18.6% | 25.6% | 1 | RECQL |
| ER+/HER2- | 79 | 30 | 38.0% | 14 | 17.7% | 8 | 10.1% | 2 | 2.5% | 30.4% | 6 | ATM; CHEK2; PALB2 (2); PTEN; RAD50 |
| DCIS | 26 | 11 | 42.3% | 2 | 7.7% | 2 | 7.7% | 6 | 23.1% | 38.5% | 1 | PALB2 |
| ER+/no HER2 test | 25 | 15 | 60.0% | 2 | 8.0% | 10 | 40.0% | 1 | 4.0% | 52.0% | 2 | ATM; BRIP1 |
| No receptors | 81 | 16 | 19.8% | 5 | 6.2% | 7 | 8.6% | 2 | 2.5% | 17.3% | 2 | CHEK2 (2) |
| Total | 379 | 145 | 38.3% | 75 | 19.8% | 35 | 9.2% | 22 | 5.8% | 34.8% | 13 | |
| Grade/type | ||||||||||||
| Grade 1 | 12 | 1 | 8.3% | 0 | 0.0% | 1 | 8.3% | 0 | 0.0% | 8.3% | ||
| Grade 2 | 48 | 15 | 31.3% | 4 | 8.3% | 8 | 16.7% | 0 | 0.0% | 25.0% | 3 | ATM; BRIP1; PTEN |
| Grade 3* | 242 | 106 | 43.8% | 65 | 26.9% | 19 | 7.9% | 14 | 5.8% | 40.5% | 8 | ATM; CHEK2 (2); PALB2 (3); RAD50; RECQL |
| Lobular | 8 | 3 | 37.5% | 1 | 12.5% | 1 | 12.5% | 1 | 12.5% | 37.5% | ||
| DCIS | 26 | 11 | 42.3% | 2 | 7.7% | 2 | 7.7% | 6 | 23.1% | 38.5% | 1 | PALB2 |
| Unknown | 43 | 9 | 20.9% | 3 | 7.0% | 4 | 9.3% | 1 | 2.3% | 18.6% | 1 | CHEK2 |
| Total | 379 | 145 | 38.3% | 75 | 19.8% | 35 | 9.2% | 22 | 5.8% | 34.8% | 13 | |
| Manchester Scoring System | ||||||||||||
| <15 | 106 | 14 | 13.2% | 1 | 0.9% | 2 | 1.9% | 5 | 4.7% | 7.5% | 6 | CHEK2 (2); PALB2 (2); PTEN; RECQL |
| 15–19 | 119 | 28 | 23.5% | 9 | 7.6% | 7 | 5.9% | 10 | 8.4% | 21.8% | 2 | BRIP1; PALB2 |
| 20–24 | 64 | 29 | 45.3% | 13 | 20.3% | 10 | 15.6% | 3 | 4.7% | 40.6% | 3 | ATM; CHEK2; PALB2 |
| 25–39* | 59 | 43 | 72.9% | 29 | 49.2% | 9 | 15.3% | 3 | 5.1% | 69.5% | 2 | ATM; RAD50 |
| 40> | 31 | 31 | 100.0% | 23 | 74.2% | 7 | 22.6% | 1 | 3.2% | 100.0% | ||
| Total | 379 | 145 | 38.3% | 75 | 19.8% | 35 | 9.2% | 22 | 5.8% | 34.8% | 13 | |
| Bilateral breast cancer | ||||||||||||
| Bilateral | 63 | 36 | 57.1% | 18 | 28.6% | 8 | 12.7% | 10 | 15.9% | 57.1% | 1 | BRIP1 |
*One case is BRCA1 and BRCA2 positive.
†Two cases are ER-/ HER2-, but PR+.
TNBC, triple-negative breast cancer.