Plasma Proteomic Study Of Pancreatic Cancer And Assessment Of Candidate Tumor Biomarkers

BackgroundThe incidence and mortality of pancreatic cancer have increased steadily during the last decade in China. At present the 5-year survival rate of pancreatic cancer is less than 5%, which is the lowest of any cancer. Late diagnosis and the subsequently low resection rate is the major reason for this. Therefore early diagnosis of pancreatic cancer is critical for improvement of the prognosis. Besides, in clinical practice it is very difficult to differentiate pancreatic cancer and chronic pancreatitis in some cases. But the treatment and prognosis of these two diseases are very different.Serum CA19-9 is the most widely used biomarker of pancreatic cancer. However, it is of limited value as a screening marker because approximately 10%-15% of individuals do not secrete CA19-9 due to their Lewis antigen status. Also, CA19-9 levels may be within the normal range while the cancer is still small. Therefore it is of great importance to develop new biomarkers that is helpful for early diagnosis and differentiation.Proteomics is a new and emerging technology that can identify protein molecules in a high-throughput discovery approach in patient's serum, biofluids and tissues. It has been used widely in researches of a variety of tumors in recent years. A large number of disease-associated candidate biomarkers have been identified. With regard to pancreatic cancer, Lu ZH et al identified 110 differently expressed proteins in cancerous pancreatic tissue using comparative proteomic analysis. Besides, surface-enhanced laser desorption ionization (SELDI) approach had been used to search for biomarkers in serum and pancreatic juice. To date plasma proteomic analysis of pancreatic cancer with 2-dimenssional gel electrophoresis (2-DE) approach has not been reported.