Introduction
Pancreatic cancer is highly malignant with poor prognosis [1]. Despite advances in diagnosis and treatment, the mortality rates are almost equal to the incidence rates and the 5-year survival rate is below 5 % [1]. Since effective markers of early diagnosis are not available, over 80 % patients lose opportunity for surgical resection [1, 2]. For unresectable patients, median survival is 8–12 months for locally advanced pancreatic cancer and 3–6 months for metastatic disease [2]. Up to now, limited progress has been made in the chemotherapy and biotherapy of pan- creatic cancer, and gemcitabine remains to be the standard therapy of pancreatic cancer. Recently, accumulating evi- dence has shown that target therapy may be promising to this cancer. For instance, erlotinib (a HER-1/EGFR tyro- sine kinase inhibitor) in combination with gemcitabine has been approved by the FDA as the first-line treatment for advanced pancreatic cancer although the survival benefit is modest (the median survival time is 6.24 vs 5.9 months) [3]. The future of the treatment for pancreatic cancer may depend on finding effective biomarkers with better response to targeted therapies, thus providing individuali- zation of the patient treatment.