EGFR and HER2 expression in advanced biliary tract cancer.
OBJECTIVE
To analyze the pathogenetic role and potential clinical usefulness of the epidermal growth factor receptor (EGFR) and the human epidermal growth factor receptor 2 (HER2) in patients with advanced biliary tract cancer (BTC).


METHODS
EGFR and HER2 expression was studied in biopsy samples from 124 patients (51% women; median age 64.8 years), with advanced BTC diagnosed between 1997 and 2004. Five micrometers sections of paraffin embedded tissue were examined by standard, FDA approved immunohistochemistry. Tumors with scores of 2+ or 3+ for HER2 expression on immunochemistry were additionally tested for HER2 gene amplification by fluorescence in situ hybridisation (FISH).


RESULTS
34/124 patients (27.4%) had gallbladder cancer, 47 (37.9%) had intrahepatic BTC and 43 (34.7%) had extrahepatic or perihilar BTC. EGFR expression was examined in a subset of 56 samples. EGFR expression was absent in 22/56 tumors (39.3%). Of the remaining samples expression was scored as 1+ in 12 (21.5%), 2+ in 13 (23.2%) and 3+ in 9 (16%), respectively. HER2 expression was as follows: score 0 73/124 (58.8%), score 1+ 27/124 (21.8%), score 2+ 21/124 (17%) and score 3+ 4/124 (3.2%). HER2 gene amplification was present in 6/124, resulting in an overall amplification rate of 5%.


CONCLUSIONS
Our data suggest that routine testing and therapeutic targeting of HER2 does not seem to be useful in patients with BTC, while targeting EGFR may be promising.
Harder
Jan
J
Department of Medicine II, University Medical Center, D-79106 Freiburg, Germany. jan.harder@uniklinik-freiburg.de
Waiz
Oliver
O
Otto
Florian
F
Geissler
Michael
M
Olschewski
Manfred
M
Weinhold
Brigitte
B
Blum
Hubert E
HE
Schmitt-Graeff
Annette
A
Opitz
Oliver G
OG
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001653:Bile Ducts, Intrahepatic / Q000378:metabolism; D001661:Biliary Tract Neoplasms / Q000378:metabolism* / Q000473:pathology / Q000628:therapy; D018281:Cholangiocarcinoma / Q000378:metabolism; D066246:ErbB Receptors / Q000378:metabolism*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*
D066246:ErbB Receptors; D018719:Erb-b2 Receptor Tyrosine Kinases; C512478:EGFR protein, human; C508053:ERBB2 protein, human