EGFR and HER2 expression in advanced biliary tract cancer

AIM: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%. CONCLUSION: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.

Inhibitor of differentiation proteins do not influence prognosis of biliary tract cancer

AIM:To investigate the expression and clinical relevance of inhibitor of differentiation(ID)proteins in biliary tract cancer.METHODS:ID protein expression was analyzed in129 samples from patients with advanced biliary tract cancer(BTC)(45 extrahepatic,50 intrahepatic,and 34 gallbladder cancers),compared to normal controls and correlated with clinical an pathological parameters.RESULTS:ID1-3 proteins are frequently overexpressed in all BTC subtypes analyzed.No correlation between increased ID protein expression and tumor grading,tumor subtype or treatment response was detected.Survival was influenced primary tumor localization(extrahepatic vs intrahepatic and gall bladder cancer,OS 1.5 years vs 0.9 years vs 0.7 years,P=0.002),by stage at diagnosis(OS 2.7 years in stageⅠv s 0.6 years in stageⅣ,P<0.001),resection status and response to systemic chemotherapy.In a multivariate model,ID protein expression did not correlate with clinical prognosis.Nevertheless,there was a trend of shorter OS in patients with loss of cytoplasmic ID4 protein expression(P=0.076).CONCLUSION:ID protein expression is frequently deregulated in BTC but does not influence clinical prognosis.Their usefulness as prognostic biomarkers in BTC is very limited.