Pancreatic cancer has a dismal prognosis, with a 5-year survival of less than 9%. Consequently, pancreatic cancer is projected to surpass colorectal cancer to become the second leading cause of cancer-related death in the Western World by 2030. Complete surgical resection offers the only hope for long-term survival in these patients. However, even among the fortunate to undergo curative-intent resection, recurrence rates remains high, indicating that there is a subgroup of patient who already harbor microscopic metastases at diagnosis. At present, the majority of radiographically resectable pancreatic cancer patients undergo immediate pancreatic cancer surgery followed by chemotherapy instead of receiving chemoradiation before the surgery (also known as preoperative or neoadjuvant therapy), as is standard of care for many other gastrointestinal malignancies. The results of this thesis demonstrate that neoadjuvant therapy was association with increased overall survival and quality-adjusted life expectancy compared to surgery without neoadjuvant therapy in pancreatic cancer patients. In addition, the results of this thesis demonstrate that molecular marker, including integrin αvβ6, CEA, EGFR, and uPAR, may be used to identify patients who are at high risk of early recurrence after pancreatic surgery and may benefit most from neoadjuvant therapy. Advisors/Committee Members: Velde, C.J.H. van de, Vahrmeijer, A.L., Kuppen, P.J.K., Hage, J.A. van der, Besselink, M.G.H., Marijnen, C.A.M., Smit, V.T.H.B.M., Bonsing, B.A., Groot Koerkamp, B., Leiden University.