Angiogenesis index CD105 (endoglin)/CD31 (PECAM-1) as a predictive factor for invasion and proliferation in intraductal papillary mucinous neoplasm (IPMN) of the pancreas.

BACKGROUND Intraductal papillary-mucinous neoplasm (IPMN) of the pancreas is an increasingly diagnosed entity since its definition by the World Health Organization in 1996. It has a broad clinical spectrum ranging from benign to malignant tumors. Optimum treatment is controversial and a better understanding of the development of IPMN of the pancreas and identification of potential prognostic factors will help to address this. Angiogenesis plays an elementary role in the development of malignant tumors and may well also be important in the development of IPMN of the pancreas. Therefore we investigated endothelial cell marker CD31 (PECAM-1) and angiogenesis associated marker CD105 (endoglin) by immunohistochemistry. METHODS Thirty-two cases of surgically resected IPMN were chosen retrospectively and clinical data were obtained. Specimens were stained for proliferation marker (Ki-67), CD31 and CD105 by immunohistochemistry. A CD105/CD31 Angiogenesis ratio (AR) was established to determine the proliferating fraction of endothelial cells. RESULTS The AR is significantly elevated in invasive IPMN of the pancreas (Mann-Whitney-U Test, p<0.05) and is associated with the Ki-67-labelling-index, demonstrating synergy between tumor-growth and neovascularisation. Invasive IPMN of the pancreas is associated with significantly lower recurrence-free and overall survival. CONCLUSIONS Neovascularisation plays an important role in the tumorigenesis of invasive IPMN of the pancreas, and therefore angiogenesis-associated molecules like CD105 and CD31 might be useful tools as prognostic markers. Furthermore, the results indicate a potential role for adjuvant anti-angiogenic therapies in selected patients with recurring and/or invasive IPMN of the pancreas.