Table 1. Expression of EGFR, HER2 and HER3, and amplification status for HER2 in pancreatobiliary and intestinal type periampullary adenocarcinoma.
| PB-type | I-type | All | ||
|---|---|---|---|---|
| n = 110 | n = 65 | n = 175 | ||
| Excluded due to neoadjuvant treatment | 2 | 0 | 2 | |
| EGFR IHC score | ||||
| 0 | 2 (2%) | 2 (3%) | 4 (2%) | |
| 1 | 18 (17%) | 16 (25%) | 34 (20%) | |
| 2 | 39 (36%) | 22 (35%) | 61 (36%) | |
| 3 | 48 (45%) | 23 (37%) | 71 (42%) | |
| Unassessable | 1 | 2 | 3 | |
| HER2 IHC score | ||||
| 0 | 48 (44%) | 27 (43%) | 75 (44%) | |
| 1 | 45 (42%) | 23 (37%) | 68 (40%) | |
| 2 | 15 (14%) | 9 (14%) | 24 (14%) | |
| 3 | 0 (0%) | 4 (6%) | 4 (2%) | |
| Unassessable | 0 | 2 | 2 | |
| HER2 SISH (for IHC 2/3+) | ||||
| Not amplified | 8 (53%) | 4 (31%) | 12 (43%) | |
| Amplified | 1 (7%) | 2 (15%) | 3 (11%) | |
| Failed SISH | 6 (40%) | 7 (54%) | 13 (46%) | |
| Not assessed | 93 | 52 | 145 | |
| HER3 IHC score | ||||
| 0 | 67 (63%) | 18 (29%) | 85 (50%) | |
| 1 | 18 (17%) | 12 (19%) | 30 (18%) | |
| 2 | 4 (4%) | 1 (2%) | 5 (3%) | |
| 3 | 18 (17%) | 32 (51%) | 50 (29%) | |
| Unassessable | 1 | 2 | 3 | |
IHC: immunohistochemistry. SISH: silver in situ hybridization. Due to rounding effects, percentages may not add up to 100.