Published online Dec 28, 2013. doi: 10.3748/wjg.v19.i48.9334
Revised: September 15, 2013
Accepted: September 29, 2013
Published online: December 28, 2013
Processing time: 257 Days and 18.7 Hours
AIM: To investigate the expression and clinical relevance of inhibitor of differentiation (ID) proteins in biliary tract cancer.
METHODS: ID protein expression was analyzed in 129 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 stage I vs 0.6 years in stage IV, 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.
Core tip: Cholangiocarcinoma present as heterogeneous tumors with generally poor prognosis. Molecular changes that drive tumor development are poorly understood, and no valid prognostic markers other than stage and performance status have been identified. Here we analyzed the protein expression of the four inhibitor of differentiation (ID)-proteins by immunohistochemistry in 129 patients with advanced biliary tract cancer, which showed a deregulated ID protein expression in cancer cells and this protein expression partly correlated with the overall survival of patients. Therefore the ID-proteins maybe useful prognostic markers.