Identification of Homer1 as a Potential Prognostic Marker for Intrahepatic Cholangiocarcinoma

Background: The aim of the present study was to analyze whether Homer1 is a potential prognostic markerfor intrahepatic cholangiocarcinoma (ICC). Materials and
Methods: The expression of Homer1 in ICC tissuewas detected with immunohistochemistry and levels of protein in ICC and paratumor tissues were evaluated byWestern blotting. Survival analysis by the Kaplan-Meier method was performed to assess prognostic significance.
Results: Homer1 expression was high in 67.4% (58/86) of ICC samples, and there was significant differencebetween ICC and adjacent noncancerous tissues (p<0.001); high expression was associated with poor histologicdifferentiation (p=0.019), TNM stage (p=0.014), lymph node metastasis (p=0.040), and lymphatic invasion(p=0.025). On Kaplan-Meier analysis, a comparison of survival curves of low versus high expressors of Homer1revealed a highly significant difference in OS (p=0.001) and DFS (p=0.006), indicating that high expressionof Homer1 was linked with a worse prognosis. Multivariate analyses showed that Homer1 expression was anindependent risk factor predicting overall survival[Hazard ratio(HR), 7.52; 95% confidence interval (CI), 2.63-21.47; p=0.002] and disease-free survival (HR, 11.56; 95%CI, 5.17-25.96; p<0.001) in ICC.
Conclusions: Homer1promotes lymphatic invasion and associates with lymph node metastasis and poor prognosis of ICC. The currentstudy shows that Homer1 may be an independent prognostic factor for ICC patients after curative resection,and it provides an important basis for screening/treating high-risk patients.