The progression of a
tumor from benign to malign and localized to invasive and metastatic growth is the major cause of poor outcome of
therapy in
cancer patients. The deposition of
fibrin along with other pro-
coagulant molecules into the extracellular matrix obviously serves as a scaffold to support proliferation, migration and
tumor cell growth as well as protection against the immune system. The use of
antibodies as agents for the immunodetection of
fibrin deposits in vivo has been hampered by anti-
fibrin cross-reactivities with
fibrinogen. For the immunohistochemical detection of
fibrin we used highly specific
monoclonal antibodies to a synthetic fibrinunique
peptide, because the
fibrin molecule shares many
epitopes with
fibrinogen. The
monoclonal antibody was applied to
adenocarcinoma of colon, mamma, pancreas,
sarcoma and acute myeloic
leukemia. In all tissue sections and cytospin preparations
fibrin was identified in a direct apposition to the surface membranes of
carcinoma and
sarcoma cells, predominantly at the host-
tumor interface and also in regions directly adjacent to zones of angiogenesis, whereas normal cells and tissue showed no deposits of
fibrin. The findings will be supported by investigations that factors and components of the coagulation system could be detected in the
tumor stroma and
tumor cells. These factors are obviously produced and secreted by the malignant cells and deposited together with
fibrinogen into the extracellular matrix. Our results show that basically all malignant cells examined, independently of ectodermal or mesenchymal derivation, themselves are the origin of
hypercoagulability and fibrinolytic system inhibition.