After surgical resection of pancreatic cancer, the tissue is immunostained by hENT1 antibody. The grades of immunostaining are categorized as 0 (0%), 1 (\<50%), and 2 (\>=50%). According to the grade, patients with grade 0 or 1 will be treated with 5-FU and those with grade 2 will be treated with gemcitabine. After the study, investigators will calculate the overall survival and recurrence free survival of the patients and investigate the role of hENT1 as a predictive biomarker for adjuvant gemcitabine chemotherapy.
