Table 1 Summary of molecular features of MBCs
From: Genomic and transcriptomic heterogeneity in metaplastic carcinomas of the breast
Metaplastic breast cancer | Triple-negative breast cancer of no special type | |||
|---|---|---|---|---|
Histologic subtype | Chondroid | Spindle | Squamous | |
Intrinsic subtype | Predominantly basal-like | Claudin-low | Basal-like, claudin-low and normal breast-like | Predominantly basal-like |
Triple-negative breast cancer subtypes | Mesenchymal | Predominantly mesenchymal stem-like and unstable | Various, except luminal androgen receptor and immunomodulatory | All types |
Integrative clusters | Preferentially 9 | Predominantly 4 | Various | Predominantly 10, 4, 9 |
BRCAness | Preferentially non-BRCAness | Preferentially non-BRCAness | Preferentially BRCAness | Roughly equal |
TP53 mutations | 75% | 50% | 78% | 81% |
Mutations in PI3K/AKT/mTOR pathway | 44% | 70% | 67% | 22% |
Mutations in canonical Wnt pathway | 56% | 50% | 44% | 28% |
Chromosomal instability | + | + | ++ | ++ |
Copy number alterations | Frequent gains of 1q and 8q, losses of 5q and 12q | |||
Frequent high-level gain of 8q21.11-24.3a | Infrequent copy number gain of CLDN3/4a | Infrequent amplification of 8q24, frequent losses of 7q and 12qa | ||
Gene expression | Up-regulation of genes involved in chondrocyte differentiationa | Down-regulation of claudins, E-cadherin and EpCAMa | Up-regulation of cell cycle-related genesa | |
Pathognomonic fusion gene | Lack of pathognomonic fusion gene | |||
