Won et al. BMC Cancer 2010, 10:564 http://www.biomedcentral.com/1471-2407/10/564 R E S E A R C H A R T I C L E Open Access Comparison of thymidine phosphorylase expression and prognostic factors in gallbladder and bile duct cancer Hye Sung Won1, Myung Ah Lee2*, Eun-Seon Chung3, Dong-Goo Kim4, Young Kyoung You4, Tae Ho Hong4, In-Seok Lee5 Abstract Background: Biliary tract cancers have limitations in information about different location-related pathogenesis and clinico-pathological characteristics. The goal of this study was to investigate anatomical site-related similarities and differences in biliary tract cancers and to assess the expression and clinical significance of functional proteins such as p53, cyclin D1, survivin, thymidine phosphorylase, and ERCC1. Methods: One hundred and sixty-one patients with biliary tract adenocarcinomas, who underwent curative or palliative surgery in a single institution between October 1994 and December 2003 were evaluated, retrospectively. The level of protein expression of p53, cyclin D1, survivin, thymidine phosphorylase, and ERCC1 was assessed by immunohistochemistry. Results: With respect to clinico-pathological characteristics, gallbladder cancer was more frequent in women, and bile duct cancer was more common in men. Perineural invasion was more common in bile duct cancer. Recurrence as a distant metastasis was more common in gallbladder cancer. Immunohistochemical analysis revealed that thymidine phosphorylase expression was significantly higher in gallbladder cancer than in bile duct cancer. Positive thymidine phosphorylase and p53 staining were associated with an advanced stage. Differentiation, vascular invasion, perineural invasion, lymphatic invasion, lymph node metastasis, and TNM stage independently predicted poor prognosis in biliary tract cancer. These correlations were seen more clearly in gallbladder cancer. The immunohistochemical staining patterns of p53, cyclin D1, survivin, thymidine phosphorylase, and ERCC1 showed no prognostic significance in biliary tract cancers. Conclusions: We concluded that gallbladder and bile duct cancers are considered to be separate diseases with different clinico-pathological characteristics and prognostic factors. In addition, we hypothesize that high expression of thymidine phosphorylase by gallbladder cancer results in a higher response rate to capecitabine by gallbladder cancer than bile duct cancer. Background Biliary tract cancers are relatively uncommon cancers in the western countries accounting for approximately 4% of gastrointestinal malignancies, but they are more com- mon in Asia [1]. Based on the data of the National Can- cer Registry in 2007, it is the eighth most common cancer in Korea, with an annual incidence of 4,419 cases * Correspondence: angelamd@catholic.ac.kr 2Division of Medical Oncology, Department of Internal Medicine, Seoul St. Mary’s Hospital, Seoul, Korea Full list of author information is available at the end of the article per 100,000. Although surgical resection remains the only potentially curative treatment, many patients are not eligible for surgery because of the advanced stage at the time of diagnosis. The prognosis for patients with advanced disease is dismal, and the median survival is less than 6 months [1]. Characteristics such as general rarity, difficulty in diagnosis, and overall poor prognosis lead to a paucity of data from which the natural history and optimal treatment regimens can be defined. Additionally, the molecular basis of these tumors and biomarkers related to prognosis or response to © 2010 Won et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.