Table 3 Overlap of HER2 mRNA level, PI3K mutation status, and HER2 IHC staining pattern biomarker subgroups
Biomarker subgroup | Patients n (%a) | ||
|---|---|---|---|
HER2 mRNA and PI3K status available (N = 951) | HER2 mRNA level | PI3K mutation status | |
≤median (n = 484) | Mutated | 171 (35.3) | |
Non-mutated | 313 (64.7) | ||
>median (n = 467) | Mutated | 86 (18.4) | |
Non-mutated | 381 (81.6) | ||
HER2 mRNA and HER2 IHC expression available (N = 989) | HER2 mRNA level | HER2 IHC expression | |
≤median (n = 495) | Focal/heterogeneous | 114 (23.0) | |
Homogeneous | 381 (77.0) | ||
>median (n = 494) | Focal/heterogeneous | 19 (3.8) | |
Homogeneous | 475 (86.6) | ||
PI3K mutation status and HER2 IHC expression available (N = 976) | HER2 IHC expression | PI3K mutation status | |
Focal/heterogeneous (n = 136) | Mutated | 57 (41.9) | |
Non-mutated | 79 (58.1) | ||
Homogeneous (n = 840) | Mutated | 202 (24.0) | |
Non-mutated | 638 (76.0) | ||