INFREQUENT STROMAL EXPRESSION OF GELATINASE-A AND INTACT BASEMENT-MEMBRANE IN INTRADUCTAL NEOPLASMS OF THE PANCREAS

Background/Aims: Basement membrane disruption is a characteristic of invasive carcinoma. Gelatinases (also called type IV collagenases) that degrade type IV collagen are believed to play an important role in tumor invasion and metastasis. Intraductal neoplasm (IDN) of the pancreas is a unique tumor that grows intraductally with an infrequent stromal invasion. However, in IDN, basement membrane anomaly and gelatinase expression have not been clarified. The aim of this study was to examine the relationships between basement membrane disruption and the expression of gelatinase A in relation to the biological behavior of IDN or pancreatic duct cell carcinoma (DCC). Methods: Disruption of basement membrane and expression of gelatinase A were immunohistochemically investigated in 14 cases of IDN and 16 cases of DCC. Results: Basement membrane was intact in all cases of IDN, whereas focal to severe disruption was observed in DCC. Stromal expression of gelatinase A was higher in DCC than in IDN, and the intensity of expression was related to the degree of disruption of the basement membrane in DCC. Conclusions: Stromal expression of gelatinase A and disruption of basement membrane, common characteristics of invasive cancer, were not prominent in IDN. This may be related to the benign biological behavior of IDN.