Table 4.
HER2 expression and amplification results in biliary tract carcinomas
| HER2 status | No. of studies | Expression rate mean (95 % CI, %) | p value | |
|---|---|---|---|---|
| Overall expression by IHC | All | 38 | 26.5 % (18.9–34.1 %) | |
| By ethnicity | Asian | 17 | 28.4 % (14.5–42.3 %) | Ref |
| Western | 16 | 19.7 % (10.1–29.2 %) | 0.4936 | |
| By IHC assessment (quality) | Low quality (LQ) | 11 | 41.7 % (22.9–60.5 %) | Ref |
| High quality (HQ) | 27 | 20.3 % (13.2–27.5 %) | 0.0336 | |
| By site of primary (HQ studies only) | IHCC | 8 | 4.8 % (0–14.5 %) | Ref |
| EH-BTC | 28 | 19.9 % (12.8–27.1 %) | 0.0049 | |
| EHCC | 11 | 17.4 % (3.4–31.4 %) | 0.0134 | |
| GBC | 12 | 19.1 % (11.2–26.8 %) | 0.0123 | |
| AC | 5 | 27.9 % (0–60.7 %) | 0.0642 | |
| Overall amplification by ISH | All | 16 | 30.1 % (11.7–48.5 %) | |
| By site of primary | IHCC | 6 | 17.6 % (0–60.1 %) | Ref |
| EH-BTC | 14 | 22.5 % (7.9 %–37.2 %) | 0.0468 | |
| By patient selection | Unselected | 12 | 17.9 % (0.1–35.4 %) | Ref |
| Selected | 5 | 57.6 % (16.2–99 %) | 0.0072 |
LQ low quality, HQ high quality, ISH in situ hybridization, IHCC intrahepatic cholangiocarcinoma, EHCC extrahepatic cholangiocarcinoma, EH-BTCs extrahepatic biliary tract cancers, GBC gallbladder carcinoma, AC ampulla of Vater carcinoma, Ref category used as reference for comparisons
Bold-italics represent statistically significant results