The Graves lecture, 1966. Host factors in neoplasia

Procoagulant and fibrinolytic activities of gastric and colorectal cancer

Procoagulant activity (PA) and fibrinolytic activity (FA) were investigated in 14 specimens of gastric cancer (GC) and in 26 specimens of colorectal cancer (CC) and simultaneously, in samples of the normal mucosa obtained from the same organs. Histochemical localization of plasminogen activator was performed at the tumor borderline. The PA of the tumor extracts was in most cases lower than in the corresponding normal mucosa from GC as well as CC patients. The FA of the extracts of CC was also lower than that of normal mucosa. On the other hand, 11 of 14 cases with GC showed a significantly higher FA in the tumor extracts than that in the corresponding normal mucosa. The histochemical localization of plasminogen activator revealed that its activity is connected with small and medium-sized blood vessels, but not with the cells of the two kinds of cancer investigated. Morphological and histochemical findings from both kinds of cancer demonstrate that the FA of their extracts depends on the vascularity of specimens of the respective tumors.

[The significance of fibrin/fibrinogen for growth and metastasis of malignant tumors (author's transl)]

It seems evident that fibrinogen and fibrin representing the final substrate und product of clotting system act as pathogenetic connecting links for development and spread of malignant tumors. The results reported demonstrate the influence of fibrin on the initial phase of haematogenic metastasis particularly. Several tumor-specific mechanisms are shown to cause frequently an accumulation of fibrin in malignant tumors. The results discussed here stress the importance of fibrin in tumors for tumor cells and tumor cell units. In the literature a large number of indications to fibrin depositions in experimental tumors is found, an attempt is made to compare these findings semiquantitatively. The last part of this article discusses the therapeutic and diagnostic consequences based on the possible key position of fibrin-(ogen) in the tumor pathology.