Table 1.
Clinicopathologic and molecular characteristics by HER2 IHC group.
| Clinical values | HER2 IHC 0 (n = 89) No. (%) |
HER2 IHC 1+ (n = 71) No. (%) |
HER2 IHC 2+ (n = 54) No. (%) |
Chi-square test (Fisher’s Exact test) P-value |
|---|---|---|---|---|
| Age (years) | ||||
| <50 | 9 (10) | 12 (17) | 7 (13) | .45 |
| ≥50 | 80 (90) | 59 (83) | 47 (87) | |
| Tumor grade | ||||
| 1 | 31 (35) | 31 (44) | 12 (22) | .16 |
| 2 | 47 (53) | 32 (45) | 32 (59) | |
| 3 | 11 (12) | 8 (11) | 10 (19) | |
| Ki-67 percent positivitya | ||||
| Low (<20%) | 36 (97) | 31 (89) | 12 (75) | .03 |
| High (≥20%) | 1 (3) | 4 (11) | 4 (25) | |
| HER2 RT-PCR | ||||
| Positive (≥11.5) | 0 | 0 | 1 (2) | .06 |
| Equivocal (10.7-11.5) | 0 | 0 | 1 (2) | |
| Negative (<10.5) | 89 (100) | 71 (100) | 52 (96) | |
| Recurrence score | ||||
| Low (≤25) | 77 (87) | 61 (86) | 36 (67) | .006 |
| High (>25) | 12 (13) | 10 (14) | 18 (33) |
a88 out of 214 patients had Ki-67 IHC performed.