Table 2.
Baseline characteristics by HER2 positivity.
| Characteristics | HER2-Positive N = 7 |
HER2-Negative N = 34 |
p Value |
|---|---|---|---|
| Age | 0.031 | ||
| Median (range) | 69 (60–75) | 59.5 (39–75) | |
| Sex | 0.188 | ||
| Male | 1 (14.3%) | 17 (50.0%) | |
| ECOG PS at diagnosis | 1.000 | ||
| 0 | 1 (14.3%) | 5 (14.7%) | |
| 1 | 6 (85.7%) | 29 (85.3%) | |
| Primary tumour location | 0.445 | ||
| Gallbladder | 3 (42.9%) | 14 (41.2%) | |
| Intrahepatic | 1 (14.3%) | 12 (35.3%) | |
| Extrahepatic | 3 (42.9%) | 8 (23.5%) | |
| Aetiology | 0.208 | ||
| Hepatitis B | 0 (0.0%) | 2 (5.9%) | |
| Hepatitis C | 0 (0.0%) | 1 (2.9%) | |
| Clonorchis infection | 1 (14.3%) | 0 (0.0%) | |
| APBDU/Choledochal cyst | 0 (0.0%) | 2 (5.9%) | |
| Unknown | 6 (85.7%) | 29 (85.3%) | |
| Histologic grade | 0.614 | ||
| Well differentiated | 0 (0.0%) | 4 (11.8%) | |
| Moderately differentiated | 5 (71.4%) | 18 (52.9%) | |
| Poorly differentiated | 2 (28.6%) | 9 (26.5%) | |
| Not specified | 0 (0.0%) | 3 (8.8%) | |
| Disease status at palliative first-line chemotherapy | 0.606 | ||
| Initially metastatic | 5 (71.4%) | 18 (52.9%) | |
| Locally advanced | 0 (0.0%) | 2 (5.9%) | |
| Recurrent after curative surgery | 2 (28.6%) | 14 (41.2%) | |
| No of metastatic sites | 0.756 | ||
| 0 | 1 (14.3%) | 5 (15.2%) | |
| 1 | 2 (28.6%) | 15 (44.1%) | |
| ≥2 | 4 (57.1%) | 14 (42.4%) | |
| Sites of metastasis | |||
| Liver | 3 (42.9%) | 17 (50.0%) | 1 |
| Distant lymph node | 4 (57.1%) | 19 (55.9%) | 1 |
| Peritoneum | 1 (14.3%) | 12 (35.3%) | 0.521 |
| Lung | 3 (42.9%) | 3 (8.8%) | 0.083 |
| HER2 status | < 0.001 | ||
| Positive, IHC 3+ | 2 (28.6%) | 0 (0.0%) | |
| Positive, IHC 2+ SISH+ | 5 (71.4%) | 0 (0.0%) | |
| Negative, IHC 2+ SISH- | 0 (0.0%) | 4 (11.8%) | |
| Negative, IHC 0-1+ | 0 (0.0%) | 30 (88.2%) | |
| Level of CA19-9 at palliative first-line chemotherapy | 0.135 | ||
| Normal | 0 (0.0%) | 12 (35.3%) | |
| Elevated | 7 (100.0%) | 20 (58.8%) | |
| Not assessed | 0 (0.0%) | 2 (5.9%) |
Abbreviations: GemCis, gemcitabine and cisplatin; ECOG PS, Eastern Cooperative Oncology Group performance status; APBDU, anomalous pancreaticobiliary ductal union; SISH; silver in situ hybridisation; IHC, immunohistochemistry; CA19-9; carbohydrate antigen 19-9.