Spontaneous hematogenous and lymphatic metastasis, but not primary tumor growth or angiogenesis, is diminished in fibrinogen-deficient mice.

Previous studies of tumor cell-associated procoagulants and fibrinolytic factors have strongly suggested that local thrombin and plasmin generation may be important in tumor growth and dissemination. Given that one central target of both of these serine proteases is fibrin(ogen), a logical extension of this hypothesis is that local fibrin deposition and dissolution may be key determinants of tumor progression. In this paper, the role of fibrin(ogen) and its degradation products in the growth and spontaneous metastasis of Lewis lung carcinoma was directly examined by comparative studies of control and fibrinogen-deficient mice.