Abstract 711: The expression of human equilibrative nucleoside transporter 1 (hENT1) is associated with overall survival in advanced biliary tract carcinoma (BTC) treated with gemcitabine

[Introduction] The outcome of patients with unresectable and postoperative recurrent biliary tract carcinoma (BTC) is mostly miserable and most patients are possible candidates for palliative chemotherapy. Gemcitabine is a pyrimidine nucleoside analogue that is commonly used chemotherapeutic agent for advanced BTC. Gemcitabine is transported into the cell mostly by human equilibrative nucleoside transporter 1(hENT1). The hENT1 expression has been demonstrated to play an important role in predicting clinical outcome after gemcitabine chemotherapy for several types of cancer. The aim of the present study was to investigate a predictive marker for good prognosis of gemcitabine chemotherapy for unresectable and postoperative recurrent BTC. [Materials and methods] The analysis was performed on samples from 25 patients with unresectable (6 patients) and postoperative recurrent (19 patients) BTC treated with gemcitabine at the host institute between January 1997 and January 2011. The hENT1 expression levels in tumors were evaluated by immunohistochemistry. The clinical and histopathological variables were analyzed to evaluate predictive values for survival. [Results] Of the 25 tumor specimens, 18 (72%) specimens had positive hNET1 immunostaing, while 7 (28%) specimens were classified as negative. No statistical significant differences were found between the expression of hENT1 and patient characteristics (gender, age, tumor stage, lymph node stage, lymph duct invasion, vascular invasion, perineural invasion). In the univariate analysis, hENT1 expression was significantly correlated with overall survival (OS). The median OS was 15.3 versus 4.2 months, respectively in patients with positive versus negative hENT1 staining (p=0.006). As a result of multivariate analysis, hENT1 expression was useful as a predictive marker for good prognosis with significant difference (p Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 711. doi:1538-7445.AM2012-711