Age-standardized incidence rates for pancreatic cancer (PC) in men have increased by 25% from 1957 to 2011 in Finland. The average age of diagnosis for PC is 69 years in Nordic males, whereas the average age of diagnosis of chronic pancreatitis (CP) is 40-50 years, but the cases overlap in age. By radiology the evaluation of a pancreatic mass, i.e. the differential diagnosis between CP and PC is often difficult. Preoperative needle biopsies are difficult to obtain and are demanding to interpret. New blood based biomarkers are needed. The accuracy of the only established biomarker for PC, CA 19-9 is rather poor in differentiating between benign and malignant mass of the pancreas. In this study, we have performed mass spectrometry HDMSE analysis of serum samples from patients with chronic pancreatitis and pancreatic cancer. We have quantified 652 proteins and performed detailed statistical analysis such as principal component analysis, orthogonal partial least square discriminant analysis and receiver operating curve analysis.