Immunohistochemical staining for type IV collagen and laminin in the stroma of human pancreatic cancer.

Fourteen human pancreatic cancer, six normal pancreatic, and four alcoholic chronic pancreatitis tissue samples were examined by immunohistochemistry with antitype IV collagen and antilaminin monoclonal antibodies (MAb). The basement membranes of acinar, ductal, and endothelial cells from all of the normal pancreatic and alcoholic chronic pancreatitis tissue samples were continuously immunostained, but the stroma was negatively immunostained by both antibodies. On the other hand, all 14 pancreatic cancer tissues showed irregular immunostaining on the basement membranes surrounding cancer cells, and positive fibrillar immunostaining for type IV collagen in the stroma of the carcinomatous parenchyma. Six of the 14 pancreatic cancer tissue samples also showed positive immunostaining for laminin in the stroma. The stromal type IV collagen with or without laminin in human pancreatic cancer tissues may have originated from basement membranes degraded through cancer invasion and proliferation.