Table 2.
BRCA1 promoter hypermethylation and BRCA1-null frequency in TNBC.
| BRCA1 hypermethylated (n = 57) | BRCA1-null (n = 25)a | BRCA1 non-altered (n = 155) | |
|---|---|---|---|
| Total SCAN-B cohort (n = 237)b | 24.1% | 10.5% | 65.4% |
| Primary disease only (n = 231) | 24.2% | 10.4% | 65.4% |
| Age | |||
| <50 years (n = 52) | 46.2% | 19.2% | 34.6% |
| 50–70 years (n = 108) | 25.0% | 12.0% | 63.0% |
| ≥70 years (n = 77) | 7.8% | 2.6% | 89.6% |
| Tumor size | |||
| ≤20 mm (n = 120) | 27.5% | 10.8% | 61.7% |
| >20 mm (n = 117) | 20.5% | 10.3% | 69.2% |
| Nodal status | |||
| Node negative (n = 153) | 26.1% | 7.8% | 66.0% |
| Node positive (n = 81) | 19.8% | 14.8% | 65.4% |
| Tumor grade | |||
| Grade 2 (n = 28) | 0% | 0% | 100% |
| Grade 3 (n = 204) | 27.5% | 11.8% | 60.8% |
| ER-staining positivity | |||
| <1% (n = 206) | 24.8% | 10.2% | 65.0% |
| 1–10% (n = 29) | 20.7% | 13.8% | 65.5% |
| Adjuvant therapyc | |||
| Chemotherapy (n = 149, IDFS) | 28.9% | 12.8% | 58.4% |
| Untreated (n = 50) | 12.0% | 2.0% | 86.0% |
| PAM50 subtypes61 | |||
| Basal-like (n = 183) | 30.1% | 13.1% | 56.8% |
| HER2-enriched (n = 31) | 3.2% | 3.2% | 93.5% |
| Luminal A (n = 0) | 0% | 0% | 0% |
| Luminal B (n = 1) | 0% | 0% | 100% |
| Normal-like (n = 22) | 4.5% | 0% | 95.5% |
| TNBC molecular subtypes63 | |||
| Basal-like 1 (BL1, n = 46) | 39.1% | 13.0% | 47.8% |
| Basal-like 2 (BL2, n = 23) | 17.4% | 8.7% | 73.9% |
| Immunomodulatory (IM, n = 46) | 19.6% | 13.0% | 67.4% |
| Luminal androgen receptor (LAR, n = 30) | 0% | 0% | 100% |
| Mesenchymal (M, n = 41) | 26.8% | 12.2% | 61.0% |
| Mesenchymal stem-like (MSL, n = 14) | 28.6% | 7.1% | 64.3% |
| IntClust 10 molecular subgroups62 | |||
| 10 (n = 148) | 33.8% | 12.2% | 54.1% |
| 9 (n = 13) | 15.4% | 15.4% | 69.2% |
| 4 (n = 57) | 7.0% | 5.3% | 87.7% |
| 1 (n = 2) | 0% | 0% | 100% |
| 3 (n = 5) | 0% | 0% | 100% |
| 5 (n = 2) | 0% | 0% | 100% |
| 8 (n = 1) | 0% | 0% | 100% |
| CIT molecular subtypes29 | |||
| Basal-like (basL, n = 175) | 31.4% | 12.0% | 56.6% |
| Molecular apocrine (mApo, n = 46) | 2.2% | 4.3% | 93.5% |
| Luminal B (n = 1) | 0% | 0% | 100% |
| Luminal C (n = 2) | 0% | 0% | 100% |
| Normal-like (n = 4) | 0% | 0% | 100% |
Proportions calculated excluding missing data. Clinical data obtained from the Swedish national breast cancer quality registry.
aBRCA1-null includes both germline and somatic cases.
bNumbers for each reported group are provided for reference.
cOnly includes cases eligible for outcome analysis by invasive disease-free survival (IDFS).