Mechanisms of disease: chronic inflammation and cancer in the pancreas--a potential role for pancreatic stellate cells?

Late diagnosis and ineffective therapeutic options mean that pancreatic ductal adenocarcinoma (PDA) is one of the most lethal forms of human cancer. The identification of genetic alterations facilitated the launch of the Pancreatic Intraepithelial Neoplasm nomenclature, a standardized classification system for pancreatic duct lesions, but the factors that contribute to the development of such lesions and their progression to high-grade neoplasia remain obscure. Age, smoking, obesity and diabetes confer increased risk of PDA, and the presence of chronic pancreatitis is a consistent risk factor for pancreatic cancer. It is hypothesized that chronic inflammation generates a microenvironment that contributes to malignant transformation in the pancreas, as is known to occur in other organs. Pancreatic stellate cells (PSCs) are the main mediator of fibrogenesis during chronic pancreatitis, but their contribution to the development of PDA has not been elucidated. Data now suggest that PSCs might assume a linking role in inflammation-associated carcinogenesis through their ability to communicate with inflammatory cells, acinar cells, and pancreatic cancer cells in a complicated network of interactions. In this Review, the role of PSCs in the process of inflammation-associated carcinogenesis is discussed and new potential treatment options evaluated.