Background: This study attempted to determine if there is a pattern of matrix/matrix-degrading-enzyme immunoreactivity related to the morphologic types of gastric carcinoma or to their invasiveness.
Methods: The authors performed an immunohistochemical study of the basement membrane antigens laminin and collagen IV, fibronectin, and Type IV collagenase in a series of 87 gastric carcinomas and their respective nodal metastases (n = 329).
Results: Laminin expression was observed almost exclusively in carcinomas of the intestinal type. The expression of collagen IV was significantly higher in intestinal (52%) and atypical (44%) carcinomas than in diffuse (10%) carcinomas; collagen IV expression also was significantly correlated with lymphatic invasion and aneuploidy. Ninety percent of the carcinomas expressed fibronectin, mostly in the connective tissue at the invading edge of the tumors; fibronectin expression was significantly related to the expanding growth pattern of the neoplasms. Eighty-six percent of the tumors expressed Type IV collagenase, regardless of the histologic type or invasive properties. No relationship was observed between the expression of any of the antigens and the S-phase fraction of the tumors. No significant differences were found between the immunohistochemical profile of the primary tumors and their metastases.
Conclusions: The authors conclude that the expression of basement membrane antigens is related to the type of gastric carcinomas, rather than the cell differentiation or proliferative activity of the tumors. The putative prognostic meaning of the relationship between collagen IV immunoreactivity and aneuploidy and lymphatic invasiveness of the carcinomas remains to be clarified.